Pesticides in Environmental Samples

Advanced Chromatographic and Electromigration Methods in Biosciences Z. Deyl, I.MikSik, F. Tagliaro and E. TesdovA, editors 01998 Elsevier Science B.V. All rights reserved

CHAPTER 18

Pesticides in Environmental Samples Katalin FODOR-CSORBA

Research Institute for Solid State Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525Budapest, Hungary

CONTENTS 18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2 Analytical procedures for the determination of pesticides in the environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2.1 Sample preparation . . . . . . . . . . . . . . . . . . . . . 18.2.2 Determination of pesticides by TLC, GC, HPLC and MS methods. . . . . . . . . . . . . . . . . . . . . . . . . . 18.2.3 Separation of pesticides by capillary electrophoresis . . . . 18.3 Analysis of pesticide residues in soil . . . . . . . . . . . . . . . . . 18.3.1 Analysis, persistence and fate ofherbicide residues in soils 18.3.2 Analysis, persistence and fate of insecticide-, nematicide-, and miticide residues in soils . . . . . . . . . . . . . . . 18.3.3 Analysis, persistence and fate ofacaricides in soils . . . . . 18.3.4 Analysis, persistence and fate of growth regulators in soils 18.3.5 Adsorption of hngicides in soils . . . . . . . . . . . . . . 18.4 Determination ofpesticides residues in water samples . . . . . . . 18.4.1 Extraction of water samples . . . . . . . . . . . . . . . . . 18.4.2 Analysis and fate of herbicides in water samples . . . . . . 18.4.3 Analysis and fate of insecticides, acaricides and miticides in water samples . . . . . . . . . . . . . . . . . . . . . . . 18.5 Pesticides in air . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.6 Pesticides, chemical names . . . . . . . . . . . . . . . . . . . . . . 18.7 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. .

.

780

.. . .

. .

780 780

. . . 782 . . . 783 . . . 786 . . . 786 . . . 799 . . . 809 . . . 809 . . . 8 10 . . . 810 . . . 8 10 . . . 819 . . . . .

. . . . .

. . . . .

820 822 824 826 827

780

Chapter I8

18.1 INTRODUCTION

Modern agricultural production needs new, effective, biodegradable pesticides that will not cause such serious problems in the environment as DDT and related compounds did. There is an ever-increasing demand for the improvement of analytical procedures for detection and determination of the well-known and recently developed pesticides. In environmental analysis, these methods should give information about the adsorption, desorption, and accumulation of pesticides in soils of high and low organic-matter contents, under different pH, moisture, and temperature circumstances. Their leaching in deeper soils, and their appearance in groundwater-, river-, and sea water samples, or even in drinking- or tap water, or in the air, need different individual or multiresidue procedures. These should have high recoveries, low detection limits, high selectivity and sensitivity, and good reproducibility. The persistence of a pesticide is also strongly influenced by the climatic circumstances. Quite different degradation or alteration processes are observed in tropical and temperate zones. This can be explained by different degradation pathways, in which either photochemical or microbial processes become predominant, and where different biologically active degradation products are formed. The term "pesticide residue" means not only the originally applied pesticide in the environment, but the active metabolites and degradation products also. The European Community Directive on Quality of Water Intended for Human Consumption sets a maximum admissible concentration (MAC) of 0.1 pgll individual pesticides [ 11: included in this value are the active metabolites and degradation products. Methods have to be developed in order to allow the determination of pesticide residues together with their alteration products at levels one or two orders of magnitude more sensitive than this value. In this review some individual and multiresidue methods and reviews published in the past several years will be summarized. The papers have been selected to show the main problems in the environmental analysis of pesticides as well as the trends in development. 18.2 ANALYTICAL PROCEDURES FOR DETERMINATION OF PESTICIDES IN THE ENVIRONMENT 18.2.1 Sample preparation

The analytical procedures for the determination of pesticide residues consist of sampling, sample preparation (extraction, clean-up), detection, and determination. The sample preparation process for a sample of environmental-, food-, or feed origin needs

Pesticides

781

an extraction step with organic solvents, and liquid-liquid partitioning (LLP) followed by column clean-up - mainly on a Florisil, alumina or silica gel column [2-41. The soil samples should be ground and dried prior to analysis. This sample preparation procedure usually takes one or two days [4]. The Drinking Water Inspectorate for England and Wales reported 1,006,458 as the total number of individual pesticide determinations carried out in 1993 [ S ] . This value only demonstrates clearly that there is a great demand for finding procedures that considerably reduce the solvent consumption and the time required for the analytical procedures. One can see a trend to reducing the extraction time and solvent consumption of the older solvent-, labour-, and time-consuming procedures. Minimization of the solvent consumption in pesticide residue analysis has been summarized [6] recently. The extraction methods for individual pesticides and multiresidue methods’ applying Soxhlet, liquid-liquid extraction (LLE), and large scale sample extraction, used either in environmental or food analysis, are collected in the Manual of Pesticide Residue Analysis [7]. The extraction of triazines, phenylureas, organophosphates (OPs), phenoxy acid herbicides, carbamates, and other classes of herbicides have also been summarized [8]. There are mentioned not only the LLE method for water samples, using dichloromethane, diethyl ether or ethyl acetate, and clean-up by Florisil column, but also the preconcentration of these pesticides on polymer sorbents or their liquidsolid extraction (LSE) on C 18 cartridges or on C8- or C 18-membrane extraction disks. Further information on the use of cation exchangers is mentioned, as well. Solid-phase extraction (SPE), and off- and on-line methods on a variety of silica-bonded, polymeric- or carbon-type phases are also listed [8]. The methods are discussed in comparisons. Individual- and numerous multiresidue methods for the extraction of phenoxy acids, benzonitriles, ureas, triazines, dinitroanilines, chloroacetamides, and thiocarbamates have been summarized [9]. Liquid-liquid partitioning (LLP), LLE- and Soxhlet-extraction carried out using organic solvents, followed by Florisil-column clean-up, are described there, also. x4D resins and reversed-phase columns have been applied for the extraction of dinitroaniline herbicides from water samples. Numerous multiresidue methods for analysing different types of herbicides in water-, soil-, and air samples have been published. The clean-up of water samples is usually not necessary, but may be for the extracts of soils of high organic-matter content [9]. The methods for determination of N-methylcarbamate (NMC) residues have also been reviewed [ 101. Water-, soil-, and plant materials were extracted by water-immiscible solvents, then enriched using SPE cartridges on C 18 silica or XAD resins, and eluted by organic solvents. A derivatization method has been developed for chlo-

References pp. 82 7-831

782

Chapter 18

rophenols, using pentafluorobenzyl bromide during their SFE: this gives a higher rate of reaction and more sensitive detection [113. 18.2.2 Determination of pesticides by TLC, GC, HPLC and MS methods The European Drinking Water Directive demands a limiting value of 0.1 ng/ml for a single pesticide, and 0.5 ng/ml for the sum of all pesticides, owing to their toxicological hazardous potential. In environmental pollution the triazine-type herbicides give the most dangerous residues. Numerous papers deal with their determination in water and soil samples, as summarized recently [4]. The sensitivity of these detections has been enhanced, not only by using more efficient extraction methods, but also by combining detection methods such as gas chromatography (GC) using capillary columns and coupled with mass spectroscopy (MS). These GC-MS detection systems not only have higher selectivity and sensitivity, but are also capable of positively confirming the identity of the analytes in a single determination step. The MS detectors can be used in two modes: total-ion scanning, or selective ion monitoring (SIM) [4]. GC methods for the analysis of cereal herbicides, combined with derivatization methods, have been summarized [9]. In these, halogen-containing derivatives are mainly prepared in order to enhance the sensitivity of the electron capture detector (ECD). An alternative for the detection of halogenated derivatives is the Coulson electrolytic conductivity detector (CCD). Flame photometric detectors are used occasionally for the detection of triazines and thiocarbamate herbicides containing sulfur atoms [9]. The detection of thiocarbamate herbicides by GC does not give a high recovery because of their heat sensitivity. In this case the TLC and OPLC methods are more important [3]. Carbamate and N-rnethylcarbamate insecticides have been analysed by thermospray (TSP), particle beam (PB), and atmospheric pressure ionisation (API) methods. API methods include the electrospray (ESP), ion-spray (SP), and atmospheric-pressure chemical ionization (APCI) methods [9,11]. Capillary GC methods have been used with electron capture- (ECD), flame photometric- (FPD), or nitrogen-phosphorus (NPD) detectors, but these methods have been developed in multidimensional detectors such as GC-MS-SIM, GC-MS-TIC, GC-ion trap MS, and tandem MS-MS determinations. HPLC equipped with a UV-, or diodearray (DAD) detector, fluorescence (FD), etc., are also listed in Tables 18.1-3. GC-FT-IRMS methods, GC-atomic emission, and LC-GC methods must also be mentioned. Detection and determination methods for carbamates, phenylureas, triazines, phenoxyacetic acid derivatives, and chlorinated phenols have been summarized [ 111. Individual and multiresidue GC, LC, and MS methods have been given for the analysis of pesticide residues with relatively high polarities, in aqueous samples. Thermally un-stable pesticides were converted into their more stable derivatives or

Pesticides

783

were coupled with chemical groups to increase the sensitivity of measurements and to reduce the temperature of the detection and the time of analysis. GC-MS, LC-TSPMS, LC-ISP-MS, LC-PB-MS methods have also been discussed [11,121.

18.2.3 Separation of pesticides by capillary electrophoresis Recently, capillary electrophoresis (CE) has become very popular in analytical practice. It permits highly efficient separations in relatively short times, requiring very small samples, and it has cost lower than HPLC. Its importance is growing quickly and it needs only nanolitres of sample. There are different methods for CE: capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MECC), and isotachophoresis [13]. CE is a very effective and useful separation method, not only for vitamins, carbohydrates, inorganic ions, metal chelates, nucleic acids, etc., but its importance is becoming more pronounced in the analysis of pesticides in environmental samples. The separation methods such as CZE, capillary gel eletrophoresis (CGE), MECC, capillary electrochromatography (CEC), capillary isoelectro-focusing (CIET) and capillary isotachophoresis (CITP) [14,15] can also be exploited for pesticide analysis. The separations are characterized by a very high chromatographic efficiency - over 600,000 theoretical plates for low molar mass compounds. The column efficiency is about 10-20 times higher than that of HPLC. When the selectivity is optimized CE resolves closely eluting peaks and separates a large number of compounds in a short time 1161. In free-solution electrophoresis (FSE) electroosmotic flow (EOF) can be used at any pH, for separation of chlorophenols and phenoxy acid herbicides. The theory of this separation method and the practical effects of optimization of the voltage, ionic strength, capillary dimensions, temperature, addition of organic modifiers, and parameters for FSE are also described [17]. The ions separated by CE can be detected by UV if the compounds have chromophoric groups. An indirect detection using a constant flow of a chromophore electrolyte has been used for the detection of analytes which lack chromophore groups. This detection is based on the change of the UV absorption of the chromophore solution if the analyte appears [17]. The most effective and highly successful approach to the suppression of the buffer ions has been adapted from ion chromatography. An ion-exchange membrane positioned between the separator column and the conductivity cell converts the buffer ions into their weakly conductive form [ 171. MECC couples together both the electrophoretic and chromatographic partitioning elements for the simultaneous separation of charged and neutral compounds, thereby providing some of the versatility of reversed-phase ion-pair chromatography along with the efficiency of CZE [ 181. References pp. 827-831

784

Chapter 18

The separation of s-triazine herbicides and their metabolites by CZE has been studied as a function of pH. On a fused-silica CE column the separation was carried out at constant temperature (30°C) and voltage (20 kV), with UV detection. The effect of acetate (pH 3.8-5.6), citrate @H 2.2-7.8), and citrate with HCI buffers @H 1.2-5.0) on the separation of four chloro-herbicides, four chloro-metabolites, four hydroxy-metabolites, and seven thiomethy I-s-triazine derivatives were investigated. The best separation, with a high reproducibility for s-triazine derivatives was achieved at about pH=pKa with the citrate-HC1 buffer system. This CE method did not give a good separation for the chloro-s-triazine derivatives, but MECC gave much better results for the analysis of these compounds [ 191. MECC was first developed in 1984. Its applicability to neutral compounds makes the method very useful in pesticide analysis: PAH [20], phenols [21], and pyrethroids [22] have been separated using it. The low system loadability is the only drawback of this procedure which combines capillary electrophoresis with W detection in the presence of sodium dodecyl sulfate (SDS) as a surfactant which is added to the sample around its critical micelle concentration (CMC) to make the residues of pesticides soluble in the aqueous system. MECC gave satisfactory results in separations of triazines, providing high efficiency in short analysis times. Here, the injection conditions, pH, buffer concentration, surfactant concentration, and applied voltage were investigated more detailed. A Sep-Pak C18 cartridge was used for preconcentration of atrazine, symetrine, cyanazine, prometryn, propazine, simazine, and terbutryn [23]. Triazines, e.g., chlorotriazines and methylthiotriazines exhibit different pKa values. They can be protonated and separated by capillary zone electrophoresis using citric acid, phosphoric acid, and perchloric acid in different concentrations. Chlorotriazines were not separated by the CZE method. Better resolutions were obtained by using MECC. Triazines were resolved in borate buffer (pH 9.2) or 3.5% (vlv) methanol-borate buffer (PH 9.2) using SDS as surfactant. The parameters of injection and separation such as temperature (30"C), pH (8.5-9.7), SDS concentration, and applied voltage (22 kV), were investigated and optimized. The capillaries were conditioned before use, first with hydrochloric acid (0.1 M) and later with sodium hydroxide (0.5 M). The relative standard deviation was about 20% [23]. Another effective procedure for preconcentration, called sample stacking, was developed after SPE extraction and before MECC separation. Here, the direction of the applied voltage is changed, and repeated several times before separation. This method leads to a more concentrated solution at the start and caused a 30-fold more effective preconcentration compared with the SPE afone. A C 18 SPE cartridge was applied for preconcentration and, after it, the sample stacking. The distribution of the pesticides between the micelles and the water zone is shown in Fig. 18.1. The enrichment of 2,4-D was carried out in the presence of HCI and buffered HCI. Propham, carbofuran

Pesticides

785

a

b

0 c

0

0

d

Fig. 18.1. Sample stacking of pesticides with matrix removal using EOF. P. Pesticide. (a) Injection of large pesticide sample; distribution of pesticides between micelles and water zone. (b) Application of high voltage with reverse polarity; movement to the boundary water (samp1e)buffer zone; v>veO, (c) Removal of water zone; compression of the sample-matrix; (d) Switching back the polarity, start of the separation; v-iveo. Reproduced from [24].

(carbamates), parathionethyl, and chlorfenvinphos (OPs), atrazine, simazine (triazines), desmetryn, diuron (phenylurea), were analysed by this method. The limit of detection obtained by MECC without enrichment is 0.1-0.5 pg/ml, with SPE it is 0.6-2 nglml, and with SPE with sample stacking it is 0.014-0.08 ng/ml [24]. Herbicides have been preconcentrated onto C18 disks from water samples, and seven chlorophenoxy acid herbicides determined, when a- and P-cyclodextrin were used as modifiers in CE analysis. The enantiomers were also resolved by this method. The limit of detection was between 1 and 100 ppm [25]. Quaternary ammonium herbicides such as cholin and chlonnequat were detected by inverse photometry. In this procedure the CE separation was evaluated by electrospray mass spectrometry (CE-ES-MS) [26].

References pp. 82 7-83I

786

Chapter 18

18.3 ANALYSIS OF PESTICIDE RESIDUES IN SOIL 18.3.1 Analysis, persistence and fate of herbicide residues in soils The most powerful tool for the study of the fate of herbicides in the environment is the usage of their labelled derivatives. This allows not only their sorption and desorption to be followed very easily in different types of soils but the labelled metabolites and degradation products formed in the environment can be analysed and quantitated, also. Their degradation processes or even their mineralization to 14C02 can be followed by radiotracer methods. In the same experiments their uptake and translocation in weeds and cultured plants can also be studied. Herbicides applied mainly to the soil have been most studied in recent years using their 14C-labelled derivatives. The most persistent herbicides are the triazines because of their environmental pollution and accumulation. The commercial use of atrazine has been forbidden in Germany since 1991 [19]. Some individual and multiresidue methods are listed here for the extraction and determination of herbicides belonging to the benzamide, carbamate, chloroacetamide, dinitroaniline, pyrimidine, urea, sulfonylurea, and triazine-type herbicides. I4C-Atrazine, a pre-emergence herbicide, is used to control weeds in maize and sugarcane in Brazil. In a maizebean rotation area the persistence of 14C-labelled atrazine was evaluated. Moderate leaching of atrazine in humic soils was observed, with limited movement below 20 cm. Atrazine residues did undergo partial mineralization: its main metabolites are hydroxyatrazine, deisopropylatrazine, and deethylatrazines. The atrazine proved to be more persistent with an increase in the pH of the soil: in more acidic conditions the hydroxyatrazine was accumulated The residues were determined by TLC after methanol extraction (Table 18.1) and the recovery was 80.2-93.8% [27]. Deethylatrazine is an important degradation product of the widely used atrazine, which is more water-soluble, less adsorptive and more desorptive in soil. Its presence in groundwater and surface water has been described [28] earlier. The leaching of ''C-deethylatrazine was studied in undisturbed soil columns under laboratory conditions. Most of the applied 14C-activity remained in the topsoil as bound residue. Some unidentified polar degradation products, and more deethylhydroxyatrazine, didealkylatrazine and deethylatrazine were also analysed. A Bond Elut cyclohexyl SPE cartridge was used for extraction and the residues were determined by TLC. The recovery was about 99% (Table 18.1) [29]. The mobility and dissipation of three types of herbicides have been studied in an undisturbed field lysimeter experiment. The herbicides were atrazine as a representative of triazines, metolachlor as a chloroacetamide derivative, and primisulfuron,

Pesticides

787

as a postemergence sulfonylurea. At 30 days after treatment the atrazine concentration was 43%, and did not decrease significantly 360 days after treatment. 57% of the applied activity was lost by volatilization or metabolism, which was considerably higher than expected. These observations were made after an acetonitrile extraction and TLC determination. The Rf values of the parent compounds and their metabolites are given in Table 18.1 [30]. Metolachlor disappeared in 43% 30 days after treatment 14 because of metabolism and volatilization. The CO evolution, produced from soil, is very low in this case: 38% of primisulhron was recovered 30 days after treatment 1311. 4C-Labelled bentazon, a widely used post-emergence herbicide, was labelled in its benzene ring. Its soil movement, mineralization, and translocation in rice plants grown in fields over four consecutive years, were investigated. The mineralization process was thought to be the principal factor in its loss in the soil. The residues were extracted from the soil and the plant tissues, using ethyl acetate at pH 2. The benzenering labelled metabolites of bentazon, e.g., ‘‘C-6-hydroxy- and 8-hydroxybentazon were also detected on TLC by auto-radiography together with the unchanged bentazon (Table 18.1) [32]. In another experiment 14C-bentazon was studied in two different soils under conventional tillage. Methylbentazon was the main degradation product. The soils not treated with bentazon showed 3-1 1 times higher half-lives than those previously exposed to bentazon. The residues of the parent compound and the main metabolites were desorbed from the soil by methanolic calcium chloride solution and analysed either by LSC or by HPLC with U V or fluorescence detection (Table 18.1). According to these studies the half-life of bentazon was 1-2 weeks. It is a short-lived herbicide in soils [33]. ‘‘C-Flupropacil labelled in its pyrimidine ring was studied in four soils. This uracil-type herbicide had not been studied previously in soil conditions. Only a small amount of the compound was adsorbed by the soils studied, indicating a good potential leacher compound. Flupropacil was proved to be non-volatile and not persistent for a very long time in the environment. Its residues were desorbed from the soil matrix by calcium acetate solution and analysed by TLC or by HPLC (Table 18.1) PI. For 14C-chlorimuron ethyl the sorption and desorption kinetics have been studied for soils, hairy vetch, rye soil, no-cover crop soil, and herbicide desiccated cover-crop residues. Under field conditions, the plant materials intercept and retain chlorimuron ethyl. Its residues were desorbed by a salt-containing methanol solution and analysed by LSC (Table 18.1) [3S]. Alachlor is a soil-applied chloroacetamide herbicide used on soybeans. Its biotransformation and adsorption was studied on soils from two soybean tillage sysReferences pp. 827-831

TABLE 18.1 ANALYSIS OF HERBICIDES IN SOIL

Compounds

Samples

14C-Atrazine

Gley humic, deep red MeOH latosol soil. beans

l4C-Deethylatrazine, ''Cdeethylhydroxyatrazine, ''C-dideakylatrazine

Undisturbed soil, leachate, sandy clay loam, loam

''C-Atrazine deethylatrazine deisopropylatrazine hy droxyatrazine metab. (unidentified) 14~-metolac~or metabolite 1. metabolite 2. l4~-primis~furon metabolite 1. metabolite 2.

Loamy sand

Extraction

Method of analysis

Detection

Comments

Ref.

TLC, silica gel 1: diethyl ether 2: toluene-acetone-acetic acid (7:1:2)

LSC autoradiography

Rec.(%): 80.2-93.8

27

SPE

TLC CHC13-MeOH-HCOOHHzO (100:20:4:2)

LSC

Rec.(%): 99

29

CH3CN

TLC silica gel GF 1: EtOAc-toluene (1:1) 2: CHC13-MeOH-HCOOHHzO (75:20:4:2) 3 : CH2ClrEtOAcCH3COOH (50:50:1)

LSC

M I

Bond Elut MeOH

0.66

0.44 0.34 0.03 0.13

2

0.81 0.30 0.41

3

0.72 0.09 0.41

30

a $-, 2

ag 8

' 5

14C-Bentazon, 6-hydroxybentazon, 8-hydroxybentazon, two other metab.

Soil, rice plant, leachates

pH 2, EtOAc, freeze-drying

TLC silica gel 60 F254 benzenedioxane-IP AHCOOH (60:10:5:1)

AIBA anthranilic acid 14C-bentazon 6-hydroxy bentazon 8-hy droxybentazon methylbentazon ''C-Flupropacil

Silt loam, silty clay loam

MeOH-O.01 M CaC12 (80:20)

TLC benzendioxane-IPAHCOOH (60:10:5:1) HPLC Alltima (H20CH3CN)

LSC UV 250,225 FD 228ex., 433em.

Sand, sandy loam, loamy sand, clay

0.01 M Ca acetate

TLC silica gel 60 F254 I : toluene-tetrahydrofiran (60:5) 2: hexme-EtOAc (60:40) HPLC 0.025 M triethanolamine @H 4)-CH3CN (60:40)

LSC

Rf: 0.75

33

0.44 0.35 0.28 0.94 0.75

34

UV 254

''C-Chlorimuron ethy I

Silt loam, top soil, rye 0.01 M CaC12 LSC MeOH-2 M (NH412c03 (3: 1) .. Silt loam, fine-silty MeOH-O.15% TLC, silicagel Radioscaning ''C-Alachlor, mixed thermic aeric Na2S04 (w/v) (2: 1) 1 : n-hexanecystein, ochraqualf C18-SFE CH3CN 2: butanondH3COOHdes(methoxymethy1) H20 (1O:l:l) alachlor, 3: CH3CN-H20-WOH 2,6-diethylaniline, (44:9:1) hy droxyalachlor, uv HPLC pBondapak RP, oxanilic acid, gradient H20 (1%) in sulfonic acid CH3COOH-CH3CN from hydroxy alachlor (70:30) to (40:60)

35

Rf:1 2 0.82 0.98 0.00 0.33 0.63 0.53 0.98 0.00 0.65 0.00 0.47 0.00 0.98

3 0.95 0.46 -

-

36

TABLE 18.1 (continued)

Compounds

Samples

Extraction

Chromic cambisol

1. quartz sand, 2-5. field soils, 6. high organics, 7. high clay

CaC12 0.01 M

Silty clay loam

Water

''C-Carbonyl diuron, Clay loam ''Ccarbonyl isoproturon Pendimethalin

Vertisol, ferrisol, fluvisol

Method of analysis

Detection

Comments

Ref.

Soil TLC H20

Autoradiography Berthold TLC Trace master 20 linear det.

Rf: 1.0

38

LSC

0.47 0.23 0.38 0.48 0.05 0.35

39

w 220 H2GCH3CN gradient LSC (70:30), (60:40), (0:100), (1OO:O)

40

HF'LC, RP-C 18 H2GCH3CN (diuron) (4:6) H2GCH3CN (isoproturon) (55:45)

41

HPLC

MeOH HF'LC C18-Hypersil acetone- petroleum CH3CN-H2O (80:20) ether GC Florisil

UV 242 LSC

w 244 NPD c

cs

%a

Pendimethalin

Dark brown chemozem, clays

CH3CN-H20CH3COOH (80:20:2.5) n-hexane

GC ECD megabore fussed silica HP-I

M367 metab.. M324 metab. Rimsulfuron

Smectite (hectorite)

CHC13 acetone

HPLC Kromasil5C8 CH3CN-HzO (36:82), (35:65), (62:38) FT-IR

Acifluorfen

Loam, clay loam, silty loam, loamy sand, sandy loam

MeOH

HPLC Supelcosil LC 18 DAD 295 CH3CN-H20 (80:20) pH 3 with orthophosphoric acid

Chloridazon,

Silty clay loamy soil

SPE C18 acetone-H20

HPLC

DAD 288

Glyphosate

Soils

0.01 M CaC12

HPLC Partisil lOSAX

UV 190

Glyphosate

Volcanic soil, peat soil, oxidized coal, leonardite

Humic acid, 1 N NaOH 0.5% V/V HCI-HF dialysis

HPLC Partisil lOSAX UV 190 0.08 N potassium phosphate buffer pH 2.1

I%

2

c

B

.

DAD

Metamitron

6-Chlorobenzoxazo- Montmorillonite, linone, Fe, A1 clay, ethyl 2,4-dihydroxy- Ca, Na clay phenoxypropionate, fenoxaprop acid, Fenoxapropethyl and metab., 2-(4-hydroxyphen0xy)propionic acid

HPLC pBondapakC18 CH~CN-HZO(65135)pH 3 TLC Silicagel F254 CHC134ethyl ether (1:l)

UV 238

44

45

0.025 mgkg, 1.2 pgh, rec.(%): 82 0.034 mgkg, I .3 pgil, rec.(”/.): 93

47 5 PPm

48

Rf: 0.33

49

0.58 FT-IR, N M R

46

0 0.69

0

TABLE 18.1 (continued)

Compounds

Samples

Extraction

Method of analysis

Detection

Tralkoxydim

Soil, crop

CH3CN, partition CH2C12 Bond-Elut diol and amino column hexaneether (1:l)

HPLC Bondapak C18 CH3CN-H20 (7:3) 4% CH3COOH

UV 254

Soil (forest), tree, shrub, herbaceous, grass plant, foliage, twigs, forest litter

H20, EtOH, MeOH GC or hexane fused silica ,DB-17

NPD

Hexazinone metabolite A metabolite B

Hexazinone, 5 metabolites

Soil, vegetation

MeOH-H20 (4:I ) CHC13

CI-MS, SIM

Atrazine, OHA, OHDIA, OHT, Terbuthylazine

Humic, soil

SFE/C02 10% MeOH, Soxhlet

GC fused silica SE-54 HPLC Ultrasphere ODS MeOH-H20 (3:7) 0.05 M CH,COOW, CH3CNH20 (5:85) 0.05 M CH3COOW HPLC RP 18 Super sphere, 1 mM C H 3 C O O w CH3CN (5O:SO)

W 200-245

Comments

Ref. 50

51 Lim. of det.: 7 ng 18 ng 36 ng EX.(%):0-94 micro-column clean-up, Florisil, A1203 neutral, Na2S04, toluene C-18 SPE 52 (Bakerbond), MEOH; CIS-SPE (Bakerbond), MeOH

s h

MS, MS-MS, DLI, rec.(%): 70-104 TSP, TOF, SID-TOF, 30-102 EI

53

s? \

00

Topsoil

Imazapyr

Tropical soil, NH4HC03 temperate soil, sandy clay loam, black clay, loam

Clopyralid, picloram, 14 soils silvex 14C-Atrazine, I4C-2,4-D, ''Cdeltamethrin, 14Cdieldrin, I4C-diuron, ''~-fonofos, ''C-pirimiphos methyl, 14~-prometryn

GC SFE COZ/N20/CHClFz fused silica, DB-1701 toluene, MeOH, pyridine, triethylamine, pyrrolidine, c o z , loooc, 30 MPa, 20 ml, Soxhlet MeOH

Ca(OH)2-H20, CH2C12, MeOHCH2C12 (5:95) Organic soil, mineral SFE/COZfMeOH soil, wheat, beans, SFEMeOH onion, radishes, canola

NPD MS

30 minutes

54

2 9

g ro

18 hours

HPLC MeOH-17 mM H3P04 (30:70)

DAD 200,300,235

GC phenylmethyl polysiloxane fused silica

ECD diazomethane deriv. LSC

Lim. of det. 5 ng/g, 56 rec.(%): 88-103 SPE, Accell QMA tC18-W, Cl8-SPE aromatic sulfonic acid SPE CHzC12 Lim. of det.: 2.5 ng/g 57

58

Chapter 18

794

tems. The tillage did influence the pattern of alachlor-residue metabolism. In no-tillage fields the mineralization of alachlor was more rapid, leading to the evolution of more 14C02. Greater herbicide retention was observed in un-treated fields. 14CAlachlor sorption was more rapid with no-tillage, accompanied by less CaC12-desorbable parent compound and metabolites. Unextractable 4C was also greater in the no-tillage soils. The residues of the parent compound and its metabolites were extracted with a sodium sulfate solution containing methanol and a C18 SFE matrix using acetonitrile, and determined either by TLC with radioscanning or by HPLC with UV detection (Table 18.1). In conventional treated soil surfaces the polar metabolites might increase and there is a potential danger of their appearance in the groundwater [36]. The mobilities of 14C-labelled samples of the seven major pesticides were studied by soil thin-layer chromatography (STLC) using chromic cambisol soil matrix. The soil sample to be investigated was ground in a mortar and slurried with distilled water,

'

then spread in a 0.5 mm-thick layer on 20 x 5 cm plates, and dried. After application of the pesticide sample, the plates were developed with distilled water. Visualization can be made either by chromogenic reagents [37] or by image analysis of radioactive spots. The pesticide mobility decreased in order acephate>flumeturon>atrazine> ethofumesate>metolachlor>diazinon>glyphosate.The image analysis technique, using a linear analyser, allowed the accurate calculation of radioactivity in the spot which appeared on TLC (Table 18.1) [38]. Five ''C-labelled soil-applied herbicides: carbetamide, a carbarnate-type, isoproturon, a urea-type, propyzamide, a benzamide-type, trifluralin and pendimethalin, both dinitroaniline-type herbicides, were studied from the point of view of their soil partition coefficients (Kd) and half-lifes (EDSO).Their adsorption increased in the The relationorder carbetamide
Pesticides

79s

The influence of soil moisture on the short-term adsorption of the urea-type herbicides, diuron and isoproturon has been studied recently. A new technique using glass microfibre filters was developed for analysis of herbicides in soil solutions. A rapid adsorption for both pesticides was observed in low moisture conditions. The increase of soil moisture had little effect on the sorption capacity. The adsorption was delayed in soil of higher moisture content for a short period of time (about 30 min) for both pesticides. The residues were determined by HPLC, using an RP-C18 column and water-acetonitrile as mobile phase (60:40)for diuron, and (40:60)for isoproturon, with UV detection (Table 18.1) [41]. Pendimethalin, a representative dinitroaniline herbicide, is extensively used for pre-emergence control of most annual grasses and annual broad-leaved weeds in many different cultures. Its residues are adsorbed to soil particles very strongly because of its low water solubility and high hydrogen-bonding potential. Pendimethalin can be characterized as a non-leacher compound, which is why the risk of contamination of the groundwater is very limited. Pendimethalin showed a strong adsorption in all three soils studied and was very difficult to desorb. The soil samples were extracted with methanol or acetone-petroleum, cleaned up using a Florisil column, and determined either by HPLC or GC with NF'D (Table 18.1)[42]. According to another method, its residues were extracted with an acetonitrile-water-acetic acid (80:20:2.5) mixture and determined by GC using a fused-silica column coated with HP-1, and ECD detection. The dissipation of pendimethalin was investigated in the temperate zone in field soils. However, the applied herbicide was present to the extent of 28%, and no leaching of its residues was detected below a depth of 10 cm (Table 18.1) [43]. Rimsulfuron, a representative of the sulfonylurea herbicides, exhibits a low acute and chronic toxicity to mammals and a high biological activity against weeds. It is extremely unstable in water. The decomposition of this herbicide on the smectite surface saturated with A13+ was followed by FT-IR spectroscopy. Metabolite M367 is an N-(4,6-dimethoxypyrimidinyl)-N-(3-ethylsulfony~)-2-pyridinyl) urea. This is bound to the smectic surface by a lone-pair of electrons of its C=O group. The formed M367 is transformed by a nucleophilic attack of solvating water leading to the formation of carbamic acid and metabolite M324. This latter remains adsorbed on the clay by protonation, but carbamic acid itself decomposes, producing C02 and NH3, and it disappears from the environment. Rimsulhron residues and metabolites were analysed by HF'LC using a Kromasil SC8 m column, gradient-elution with an acetonitrile-water system, and DAD detection (Table 18.1) [44]. Acifluorfen is a highly effective post-emergence herbicide for the selective control of broad-leaf weeds in soybeans, peanuts, and rice cultures. Its dissipation in soil is highly dependent on the type of the soil. The adsorption of acifluorfen was studied in eight different soil-humic acids (HAS), whose pH ranged between 1.6 and 6.0.More References pp. 82 7-831

796

Chapter I8

than 70% of acifluorfen was adsorbed in soils at pHC2.5 and less than 10% at pH>4.5. These data indicate that the adsorption is introduced by a protonation both of acifluorfen and HAS. The residues of acifluorfen were extracted with methanol and determined by HPLC on a Supelcosil LC18 column, and eluted with an acetonitrilewater system acidified to pH 3 with orthophosphoric acid (Table 18.1) [45]. Metamitron and chloridazon are selective pre- and post-emergence herbicides, widely used in Italy for weed control in sugarbeets. They are often used together for a more effective action. Low temperatures and a low moisture content can retard the degradation of chloridazon, which may became slightly- to very persistent. It can cause an elevated weed-control ability with the risk of leaching and runoff. The extraction of these herbicides from soil samples was carried out with an acetone and water system and determined by HPLC using a diode-array detector (DAD). Water samples were extracted with an SPE C18 column eluted with methanol (Table 18.1) r461. Glyphosate is extensively used in the control of many annual and perennial weeds. This herbicide was investigated in four typical European soils, with respect to its adsorption and desorption. The isotherms showed a dependence on amorphous ironand aluminium-hydroxide content. The desorption of glyphosate was carried out by 0.01M CaCl2, indicating its high mobility. The residues were determined by HPLC using a Partisil lOSAX column eluted with potassium phosphate buffer at pH2.1 using isocratic flow (Table 18.1) [47]. Adsorption of glyphosate was investigated in four humic substances: in peat (HAl), volcanic soil (HA2), oxidised coal (HA3), and lignite (HA4). The adsorption was found to be very high and followed the order: HAl>HA2>HA3=HA4. The multiple hydrogen-bonding between HAS and glyphosate enhances the latter's adsorptivity. The acidity of the HA was of great importance, but the dependence of adsorptivity from it was not linear. Increasing the aliphatic nature and reducing the molecular size of the HAS adsorbed more of glyphosate. The less adsorptive HAS exhibited higher aromaticity. This was investigated by 13C NMR-spectroscopy and high-performance size-exclusion chromatography. After alkaline and acidic extraction of different soils, dialysis was carried out against distilled water. The HPLC determination was similar to that above (Table 18.I) [48]. The influence of ions on the sorption and desorption of the herbicides glyphosate and fenoxapropethyl has been investigated. Clay surfaces are rather effective in catalysing hydrolysis of organic pollutants. Montmorillonite saturated by different exchangeable cations such as Fe3+, A13+, Ca2', and Na' were examined in the hydrolysis of fenoxapropethyl which is an extensively used herbicide for post-emergence control of a broad spectrum of grass weeds in broadleaf crops. AAer exposing this herbicide to hydrolysis on the surface of montmorillonite, the super-

Pesticides

797

natant was analysed by HPLC on Bondapak C18 analytical column which was eluted with an acetonitrile-water system (Table 18.1). The hydrolysis products were investigated by TLC and IR and Nh4R spectroscopy [49]. Tralkoxidim is a cereal-selective post-emergence herbicide of the cyclohexanedione group, recently developed for the control of grass weeds in wheat and barley. Its persistence in wheat crops and soils was studied in sub-tropical conditions at two application rates. Its dissipation from wheat and soil followed an initial faster rate and a subsequent lower rate, both in the crop and soil. The residues were extracted with acetonitrile, then partitioned between water and dichloromethane. After evaporation of the solvent, the residues were taken up in an n-hexane-diethylether (1 :1 ) mixture and passed through Bond-Elut diol and amino columns. After removal of the solvent the residues were dissolved in acetonitrile-water mixture and determined by HPLC on a Bondapak C 18 column (Table 18.1) eluted with an acetonitrile-water system containing 0.4% acetic acid [SO]. A soil clean-up method using a disposable microcolumn and a modified GC method was developed for the determination of hexazinone and its two main metabolites. After water-methanol extraction, the sample was centrifuged, filtered, concentrated, and cleaned up by the above microcolumn which contained an anhydrous sodium sulfate, neutral aluminium oxide, and Florisil support, and eluted with methanol (Table 18.1) [51]. Thermospray-ionization liquid chromatography-mass spectroscopy (TI-LC-MS) and chemical ionization gas chromatography-mass spectroscopy (GC-CI-MS) were applied for the determination of highly polar metabolites of hexazinone in soils and vegetation extracts. Soil samples were extracted with methanol-water (4:1) mixture and, after the addition of lead(I1) acetate (1 M) solution to the extract, the solution was concentrated on a C18 SPE column, eluting with methanol (Fig. 18.2) (Table 18.1). Different sample preparation methods are described for metabolites A and B, another for G, and a third one for D and E. A selective and sensitive technique, the LC-TI-MS method, was developed for the detection and determination of polar, small, and thermally labile compounds (herbicide metabolites) in the environmental samples [521. Structural elucidation and trace-analysis with combined hyphenated chromatography and mass spectroscopy were used for determination of triazines and their hydroxy metabolites in hurnic soil samples. Recoveries using Soxhlet- and supercritical fluid-extraction (SFE) using C02 with 10% MeOH modifier (Table 18.1) were compared. The yields for atrazine and terbuthylazine were above 90% obtained by both methods. For hydroxy metabolites, the recoveries (80%) obtained by SFE were considerable higher than from Soxhlet extraction, and much cleaner extracts were obtained by SFE, showing a lower background of humic co-extracts. Determination of the residues was carried out both by HPLC-particle-beam MS (LC-PB-MS) and the References pp. 827-83 I

Chapter 18

798

I

A AA

C EA 5

10

15 i0 Time (min)

25

30

Pig. 18.2. Gradient HPLC separation of hexazinone (HX) and its metabolites (A,B,C,D,E,G) with programmed variable-wavelength ultraviolet absorbance detection. Reproduced from [=I.

MS-MS method. This new MS-MS unit was a tandem-sector field-time-of-flight MS (TOF-MS). Hydroxyterbutylatrazine (OHT), hydroxyatrazine ( O m ) , hydroxydeethylatrazine (OHDEA), hydroxydeisopropyl atrazine (OHDIA) and hydroxydeterbuty1 atrazine were examined by these methods. The determination methods were compared, aslo (Table 18.1) [53]. The extraction of pirimicarb from soils was studied by the Soxhlet method and by SFE. A great variety of neat supercritical fluids, such as carbon dioxide, nitrous oxide, chlorofluoromethane,and modifiers such as toluene, methanol, pyridine, triethylamine and pyrrolidone were studied. Instead of the time- and solvent-consuming Soxhlet extraction, SFE using C02 (at IOO'C, 30 MPa, 20 ml) with 5% triethylamine gave much better results, and the whole analytical procedure was improved by a factor of ten (Table 18.1) (541. 14 [Pyridine- C]-imazapyr residues were investigated in tropical and temperate soils. The residues were extracted from soil samples with ammonium hydrogen carbonate and cleaned up by centrifuging, anion-exchange SPE and C18-SPE, and finally determined by HPLC. Recoveries were strongly dependent on the soil type. The procedures described earlier showed 60% or lower recoveries [SS], but this improved method gave about 100% ofthe original radioactivity (Fig. 18.3) (Table 18.1) [56]. Clopyralid, picloram and silvex were determined in fourteen soil samples at low concentrations. According to the procedure, soils were extracted with calcium hydroxide-water, acidified with phosphoric acid, and partitioned with dichloromethane. Derivatization was carried out with diazomethane, and the quantitation was by GLC-

799

Pesticides

0.14

0 I2 0 10

c 00s 2 6

0.06

Havsian Black Spike BlXk B1U.L

OYllO"

0.M

0.02 0.co

0

5

10

I5

20

Time. min

Fig. 18.3. High-performanceliquid chromatogramsof extracts obtained using the ammonium hydrogen carbonate extraction method. The standard tracing is from an injection containing 20 ng imazapyr; the spiked soil samples were fortified to a level of 10 ng g-' soil. Reproduced from [56].

ECD. Recoveries were examined for their dependence on the pH in the LLP. The greatest recoveries were observed at pH 1.5 or 0.5 (Table 18.1). However, clopyralid had a higher recovery (83.3%) but for picloram (68.7%) and silvex (58.0%) [57]only low recoveries were obtained. The SFE of 14C-labelledpesticide residues from soil-, plant-, and wheat samples is described. I4C-Atrazine, 14C-2,4-D, l4C-die1drin, I4C-diuron, ''C-deltamethrin, I4Cfonofos, ''C-pirimiphos-methy1, and 14C-prometryn were investigated when supercritical C02 was applied, with or without methanol as modifier (Fig. 18.4). The extraction conditions were investigated by varying the temperature, pressure, and the amount of modifier. The recoveries obtained by radioassay and GC analysis were compared (Table 18.1) [ 5 8 ] .

18.3.2 Analysis, persistence and fate of insecticide-, nematocide-, and miticide residues in soils Some aspects of the analysis, sorption, desorption, and degradation of organochlorine (OC), organophosphorus (OP), carbarnate, carbamate oxime-type insecticides, and that of nematocides, acaricides and miticides will be mentioned here. The broad-spectrum insecticides, HCHs, (a,p, y), p,p'-DDE, o,p'-DDT, p,p'-DDT and PCBs were analysed in two kinds of soil samples. SFE with C 0 2 gas was used for extraction of the pesticides investigated and the compounds were eluted by isooctane. References pp. 82 7-83I

800

Chapter I8

Fig. 18.4.Recovery of I4C from mineral soil spiked with ['4C]atrazine using supercritical carbon dioxide: (a) influence of extraction temperature on the recovery of I4Cat 350 atm and with 30% methanol modifier; (b) influence of extraction pressure on the recovery of 14C at 125°C and with 30% methanol modifier using a 90 min extraction; (c) influence of methanol modifier on the recovery of I4C at 350 atm and 125°C; and (d) influence of methanol modifier on the recovery of I4Cand atrazine at 350 atm and 125°C using a 90 min extraction.

Reproduced from [58].

This procedure was compared with the conventional one: after extraction of the samples with acetone, the extract was partitioned with n-hexane, evaporated in Kudema-Danish, equipment, and cleaned up if necessary.This procedure combined with LLP was compared with SFE. The extraction parameters were optimized. Even so high recoveries were obtained by both methods, e.g., the conventional extraction and SFE. The change in the pressure had no influence on the extraction efficiency, but the extraction time and modifier (methanol) did (Table 18.2) [59]. OC and OP insecticides and herbicides (Table 18.2) were analysed by near-infrared spectroscopy (near-IR) in reflectance-, GC-ECD-, NPD-and chemometric modes. Twenty samples were fortified with six pesticides, and extraction was performed with SFE or solid-phase microextraction (SPME). The data showed about 76-77% of matrix-analyte interaction by both extraction methods, i.e., SFE and SPME. According to these results the near-IR method seems to be usefid for prediction of the leachability of pesticides [60].

Pesticides

80 1

SPME is an effective method for extracting organic compounds from aqueous systems. The analytes were extracted into a stationary phase placed on a hsed-silica fibre and desorbed thermally in the injector of GC-ECD equipment. In this study a 100 Fm polydimethylsiloxane solid-phase microextraction (SPME) fibre assembly was applied. For GC-MS studies the MS spectrometer worked in the single-ion-monitoring (SIM) mode. a-,p-, and y-HCH isomers were detected at the 5 ngA level with SPME-GC-ECD, and P-HCH at the 80 ng/l level by SPME-GC-MS. These experiments showed the mobility of P-HCH, despite of its low solubility in water and long persistence in soils (Table 18.2) [61]. Another OC insecticide, chlordane, and its cis- and trans-isomers were investigated in sediments. The sorption and desorption profile was established. Water samples were extracted with hexane, dried on sodium sulfate, and analysed by GCECD. Sediments were extracted with n-hexane-isopropanol (2: 1). After filtration, isopropanol was removed by washing with a 2% solution of sodium sulfate. The extract was cleaned up with concentrated sulfuric acid and analysed [62]. The OP insecticides chlorpyrifos and fonophos were examined in four soils and turfgrass thatch using a membrane filter. The batch equilibrium method was used for sorption studies. Two methods are described for extraction. After filtration, the water solution of OP pesticides was extracted with n-hexane and analysed by GC. According to the other method, the water solution of the above mentioned pesticides, obtained from sand equilibrium was extracted with hexane-acetone (9:1). The solutions from sandy loam, blended clay, and thatch were extracted with 20% acetone in hexane. If hexane was used alone it extracted only fonophos. The GC-NF'D determination showed 91.2% recovery (Table 18.2) [63]. Disulfoton is a systemic OP insecticide, toxic to a large number of chewing and sucking pests. The distribution of disulfoton and its insecticide metabolites, sulfoxide and sulfone were studied in various parts of potato plants grown on treated soils. Both the soil and plant samples were extracted with acetone and directly analysed by GC (Table 18.2) [64]. A representative of the carbamate insecticides, aldicarb, ia a broad-spectrum insecticide, which is toxic to a large number of chewing and sucking pests as is the above disulfoton. Its insecticidal metabolites, aldicarb-sulfoxide and -sulfone were investigated in soil, potato seed pieces, potato foliage, and developing new tubers, during 12 weeks in the field. Its residues were analysed. Extraction from soils was made first with sodium sulfate and chloroform, and from foliage and other potato parts with acetonitrile. The residues were determined by HPLC on a Spherisorb CIS reversedphase column, where acetonitrile-water ( 13:87) mixture eluted aldicarb sulfoxide and -sulfone together, and a (25:75) mixture eluted aldicarb. The aldicarb disappeared more slowly from soils containing high organic matter than from sand and clay. Four References pp. 827-831

TABLE 18.2 ANALYTICAL PROCEDURES FOR DETERMINATION OF INSECTICIDE RESIDUES IN SOILS

Compounds

Sample

Extraction

p,p'-DDE, o,p'-DDT, Sand, peat soil, A: LLE: acetone n-hexane p,p'-DDT, HCH-s, PCB-s grassland, agricultural B: SFE30 (C02) land, orchard soil modifier: toluene, CH3CN, MeOH, collection solvent: isooctane p,p'-DDE, dichlobenil, 76 Agricultural soils SFE C02, MeOH, SPME, lindane, linuron, thermal desorption parathion-methy1, terbuthylazine HCH3 a,P,y,G Chlorpyrifos, fonofos

Disulfoton, disulfoton sulfone, disulfoton sulfoxide

Sandy soil, loamy soil SPME polymethyl-siloxane Sand, silt loam, sandy A: acetonewater (1:1) loam, Blended clay n-hexane loam, thatch B: SPE acetonehexane (9: 1) or (8:2) Soil, seed, potato foliage

Acetone

Method of analysis

Detection

Comments

Ref.

GLC Ultra-2, DB-5

ECD

Rec.(%): 81-100.6. Lim. of det. 0.5 nglg

59

GC CP-sil 19CB, CP-sil5CB MS

ECD Near IR reflectance SIM

Rec.(%): 0-95

60

Gc

ECD MS

Lim. of det. ng/l

61

Ultra 1 GC fused silica HP-1

GLC

ECD NPD

63

64

8 w

8 T

4

03

23

$$

8

$

3

2

2

Lv

Aldicarb, aldicarb sulfoxide, aldicarb sulfone Alachlor, atrazine, carbofuran, cyanazin, ethoprop, metolachor, metribuzin, pendimethalin, prometrin I4C-Aldicarb, 14C-aldicarbsulfone, I4C-aldicarb sulfoxide aldicarb sulfon nitrile ''C-Chlorpyrifos

1,3-Dichloropropene (1,3-D)

Soil, potatoes, seed, foliage, tubers

Na2S04 CHC13 CH3CN

HPLC Spherisorb C-18 CH3CN-H20 1, (13:87) 2, (25:75)

uv 200

STLC AutoradioGC 3% OV-17, SPB-5 graphy NPD. ECD

Water saturated subsoil

0

EtOAc

HPLC LiChrosorb-5RP-18 H 2 M H 3 C N (95:5)

UV 205 LSC

Gc

FPD

37 Soils loam, sandy loam, silt loam, clay loam

acetone-H+H3PO4 (98: 1:1)

HPLC Bondapack C 18 A: H20-CH3CNCH3COOH (90:10:0.5) B: CH3CN-H20CH3COOH (90:10:0.5)

UV 300 LSC

Soil gas, soil residue of pineapple field

direct injection, hexane

GC DB-I 70 1

ECD

Rf: 0.52 0.67 0.78 0.66 0.63 0.48 0.75 Rec.(%): 79-103

66

78

79

Rec.(%): cis: 98.3, 80 fruns: 84.6, co-distillation, direct injection 00 W 0

00

0

P

TABLE 18.2 (continued)

Compounds

Samples

Extraction

Method of analysis

Detection

Abamectin

Soil, animal tissues

SFE, 2-methoxyethauol

HPLC, ODS MeOH-H20 (9: 1) HPLC, ODS MeOH-H20 (90:lO) CH3CN-HzO (5050) (60:40), (70:30) SrLC W20)

FD (LDC)

''C-Atrazine, I4c-2,4-~, Emamectin benzoate, [5-3H]MABla benzoate, [3-,7-,11-,13- or 23l 4 c l ~ benzoate, ,, I4~-paatlion, ''~-trifluarin Fenbutatin oxide, metabolites

Sandy loam, sand clay/clay loam, silt loam, l o d s a n d y loam

Comments

Derivatization: 365ex 418em 1-methylimidazole W-VIS245 Rf: sand1 sand2 LSC 0.50 0.96 0.99 1.00 -

-

0.00 0.12 0.00 Soil of orchards, red clay loam, sandy loam, clay, sandfloamy sand, loamy sand

CH2ClyMeOH (2:3) MeOH derivatization CHCl3-conc.HCI (3: 1) acetone-hexane (1:1) partitioning

GC fused silica, OV-17

FPD tin-sensitive mode

SPE

Ref.

82 83

-

0.00 0.29 0.21

rec.(%): 70-100 derivatization: MeLi:LBr

84

%

.3

Azadirachtin

2

Sandy loam, forest soil

2

%

% -4

5

Diflubenzuron (DFB)

Buffer solution pH 4.0 and 7.0 CH2Cl2

Conifer foliage, litter, CH3CN soil partition to n-hexane

4

Orthic luvisol

TLC, silica gel 2-propanol-n-hexane (1 1.9) HPLC GLC Chromosorb W (HP) 3% ov-210

Acetone-O.01M CaC12 Lsc (2:1), acetone or CH2C12, NQP207

Rf: 0.58

85

Clean-up:Florisil, EtOAc EC

(85+6%) Florid 86 (5.5% water) Na2S04 1) n-hexane 2) acetone-n-hexane ( I :9) 3) acetone-n-hexane (1 :4) 4) acetone-n-hexane ( I :4) 87

b

c2. 2.

806

Chapter 18

weeks after application, 45% of the original dose was recovered from sand. The uptake of aldicarb by potato was very quick: aldicarb sulfoxide accumulated slowly, but after 6 weeks the concentration declined by about 90%. A detailed study is presented on the residues of aldicarb and metabolites in different parts of the potato (Table 18.2) [65]. Soil TLC (STLC) provides a useful tool for modelling the relative mobility of pesticides in soils. Seven pesticides can be investigated in one experiment. Alachlor, carbofuran, cyanazine, ethoprop, metolachlor, atrazine, metribuzin, pendimethalin, and prometryn were applied to one STLC plate. After development with water, the plates were dried, and divided into 22 zones, extracted and analysed each by GCECD, NPD. A multiresidue detection and determination was possible for each of the pesticides studied, and the method did not require the expensive radiolabelled compounds. However, this method was checked and the results confirmed using radiolabelled pesticides. The Rf values are summarized in Table 18.2 [66]. STLC was used for investigation of the mobility of avermectins [67] and fluometuron [68] in soils. A detailed review summarizes the TLC and radio-TLC methods used in the analysis of environmental and food samples for studying the pesticides’ residues, metabolism, uptake, translocation, and degradation1 [69]. The Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) co-ordinated a large research project on the behaviour of DDT in tropical environments [70]. The major objective of this program was to study the dissipation and degradation rates of DDT under tropical field conditions to determine its environmental acceptability. The insecticidal properties of DDT were discovered in 1938. Against nearly 200 agricultural pests DDT showed potential activity. The World Health Organization (WHO) used 400,000 tones of DDT over a period of ten years without any harm to large numbers of spraymen or millions of inhabitants of sprayed houses [71]. In this FAODAEA programme, the most typical countries carried out experiments with labelled (I4C)-DDT and its metabolites and degradation products, to gain more information about the persistence of DDT in tropical conditions, its volatility, leaching, binding to the soil, dissipation mechanism, chemical, and microbial breakdown, and the influence of climatic and soil factors, etc. Sunlight and UV light, which are more intense in tropical and subtropical zones, lead to a greater loss before incorporation of the residues into the soil. High temperatures in the tropics favour pesticide loss through volatilization and increased microbial activity. Photodecomposition and chemical decomposition are more rapid on the surface of warm, moist agricultural soil, than if the chemical is incorporated into the soil. Soil flooding can accelerate the breakdown of organochlorine (OC) insecticides, in-

Pesticides

807

cluding DDT, by anaerobic biodegradation. Furthermore, ring cleavage and ring hydroxylation occur more rapidly under aerobic soil conditions. In many tropical areas characterized by intermittent heavy rain and dry seasons, soils are subjected to alternate periods of arid and flooded state, which cause frequent changes in which anaerobic and aerobic micro-organisms predominate. Such alternate oxidation and reduction cycles provide a more favourable environment for even more destruction of the pesticides than either system alone. Most tropical soils have a low organic-matter content because it is mineralized rapidly at the tropical temperature. The adsorption and desorption of DDT were investigated. Within a few days after application, a small percentage of the DDT becomes bound to the soil and can not be removed by Soxhlet extraction. Its concentration in the soil increases with the course of time and after a year it becomes 5-20%. Its dissipation mechanism was also studied. There are patterns of two or more phases of dissipation. The loss departed from a first-order decline and a long term half-life is the second pattern. According to the investigations, DDT dissipates much more rapidly in tropical conditions than in temperate zones. DDT is nearly immobile in soil and, as an extremely hydrophobic material, tends to migrate to the aidwater interface. DDT evaporates with water molecules faster than would be predicted from its extremely low vapour pressure, and this explains the fact that DDT appears in untreated areas throughout the world. Micro-organisms dehydrohalogenate DDT to DDE. This reaction is catalysed by iron present in the soil. DDT is transformed into DDD under anaerobic conditions. The dissipation of I4C-p,p‘-DDT and 14C-p,p‘-DDE in the field has also been extensively investigated in tropical countries. Soil columns were used in these experiments which were carried out over five years. DDE proved to be the most important degradation product. Most studies in tropical countries reported much higher dissipation and degradation rates than those in temperate zones - less than a year in tropical environment vs. 10 years or longer in temperate climates. From the soil, p,p’-DDT dissipated itself faster than the total I4C activity, and p,p’-DDE was the major degradation product. In China, in flooded conditions the anaerobic degradation dominated and p,p’-DDD is the major product, but in aerobic conditions the main degradation products are p,p’-DDE and DDMU. According to earlier studies, in anaerobic conditions Enterobacter aerogenes converts the p,p’-DDT into reduced dechlonnated compounds, or the oxidized derivatives such as p,p’-dichlorobenzophenone [72]. The above study of FAOlIAEA was extended to I4C-ring-labelled parathion, also. Extremely different dissipation rates for parathion were established, depending on the soil type and climatic conditions in the tropical zone. In India and the Philippines the binding to soil showed a maximum after treatment, but the dissipation was gradual

References pp. 827-831

808

Chapter 18

and almost complete. In spite of this, in Brazil the highly acidic soil retained the bound residues without further release (30%, 168 days after treatment). The persistence of terbuthiuron was also examined. It showed a half-life in the temperate zone of about 8 months or more, in tropical studies it was found to be 3-6 months, where a faster microbial degradation is supposed [73]. In the past several years, the persistence of the ''C-labelled carbamoyloxime type, aldicarb, the OP insecticide chlorpyrifos, and the OC type of insecticide DDT, and their alteration products and metabolites have been studied in tropical conditions. Aldicarb is extensively used in the Netherlands against harmful nematodes, insects, and mites. In topsoil it is rapidly oxidized to aldicarb sulfoxide and slowly to aldicarb sulfone [74-771. Since all these transition products are biologically active, their persistence in water-saturated subsoil was studied using methylthi~-'~C-labelled aldicarb. The water extract was filtered off and determined by HPLC on a Lichrosorb 5RP-18 column eluted isocratically with a water-acetonitrile ( 9 5 5 ) mobile phase. In higher concentrations, their half-lives ranged between 3.4 and 6.4 years. The behaviours of these two oxidation products were analysed in different subsoils at different temperatures and depths. They are weakly adsorbed by soils, and their residues appear in leaching (Table 18.2) [78]. Chlorpyrifos, an OP insecticide, was studied in abiotic conditions in 37 different soils. Its hydrolysis is accelerated in alkaline conditions. Incubation of chlorpyrifos with sterile and non-sterile soils showed that the degradation of this insecticide follows either a microbial or a hydrolytic mechanism, but the latter is the more decisive. Both in alkaline and acidic soils the hydrolytic transformation was accelerated under moist conditions and was proved to be the main degradation route. The soils were extracted with acidified acetone. After centrihgation the chlorpyrifos and its metabolites were determined by GC or HFLC on a pBondapak-C18 column, eluted with solvent mixtures 100%A to 100% B as given in Table 18.2 [79]. 1,3-dichloropropene,the fumigant nematocide, was investigated in soil when applied by drip irrigation or injection in pineapple culture. Two weeks or one month after application no significant residue was found. In the case of rainfall, considerable leaching was observed in the depth of 150 cm. Its residues in soil gas were analysed, also. The residues in soil were extracted using a standard fumigant co-distillation method. Sub-samples were extracted with n-hexane and determined by GC using direct injection (Table 18.2) [80]. Avermectins are naturally occurring disaccharide derivatives of a pentacyclic, 16-membered lactone ring produced by Streptomyces avermitilis. Abamectin itself is composed of a mixture of avermectin-Bia and avermectin-Bib. These compounds have nematocidal activity as well. An SFE method was developed for extraction of its residues from soil using C02 with 9% of methoxyethanol modifier. Derivatization

Pesticides

809

[81] of the extracts with 1-methylimidazole helped the quantitation: after holding the reaction mixture at 0°C for 5 minutes, trifluoroacetic anhydride and acetonitrile were added and analysis was made by HPLC on an ODS column eluted isocratically with methanol-water (90:10) mobile phase (Table 18.2) [82]. Natural abamectin (avermectin Bla) is a potent miticide, but it has no activity against some insect families. Emamectin benzoate is chemically synthesized from abamectin by modification of the terminal disaccharide part. Its benzoate salt is formulated. Emamectin benzoate is composed of MAE3ia benzoate as the major- (90%), and M A B l b benzoate as the minor constituent (10%). The leaching of emamectin benzoate was investigated by using its isotope-labelled forms. The 3H and 14C radioisotopically labelled [5-3H]MAE31a benzoate and [3-,7-,11-,13-,or 23-14C]MA131a benzoate were applied. Results of batch-equilibrium, STLC, and autoradiography experiments showed that MABla benzoate was tightly bound to the soil and did not move in the environment. MAl3la benzoate and MAE31b benzoate were measured by RP-HPLC using a methanol-water (90:lO) mixture containing 5 mM ammonium acetate as mobile phase (Table 18.2). Four other pesticides, atrazine, 2,4-D, parathion, and trifluralin were measured, also, where the eluents were 50%, 60%, 70% and 70% (v/v) acetonitrile-water, respectively, containing 0.1% phosphoric acid [83]. 18.3.3 Analysis, persistence and fate of acaricides in soils Fenbutatin oxide is a specific acaricide which provides high levels of mite control for an extended period. For the long-term fate of fenbutatin oxide and its two main metabolites, dihydroxy-bis(2-methyl-2-phenylpropyl)stannate and 2-methyl-2-phenylpropylstannoic acid were analysed in soil samples. These samples were extracted with dichloromethane-methanol, or the metabolites with a chloroform-conc. hydrochloric acid (3:l) mixture. A derivatization, e.g., methylation was carried out by methyl-lithiumflithium bromide in dry ether. Partitioning of the methyl derivative of the parent compound was carried out with hexane, and for its metabolites with acetone-hexane ( I : 1). The residues were determined by capillary-GC using FPD detection. The residues of two metabolites and fenbutatin oxide were present on soils. In the lower soil levels, no residues were found 80 days after treatment (Table 18.2) [84]. 18.3.4 Analysis, persistence and fate of growth regulators in soils Analytical procedures are mentioned here for determination of azadirachtin and diflubenzuron, as representatives of growth regulators. Azadirachtin is an isomeric mixture of seven or so tetra-triterpenoids isolated from the seeds of the tropical neem tree. Among the isomers, azadirachtin A (AZ-A) has the highest antifeedant, growth-, and moult-inhibiting effect on larval lepidoptera. The adsorption and desorption of References pp. 82 7-831

810

Chapter 18

AZ-A was studied at pH 4.0 (prepared from 0.05 M potassium hydrogenphthalate) and 7.0 (prepared from potassium hydrogenphthalate and disodium hydrogenphosphate 0.05 M each) in sterilized sandy loam forest soils by the batch equilibrium method. Table 18.2 contains data on the analytical procedure. After equilibrium of the soils at the above-mentioned pHs the sample was centrifuged, the supernatant extracted with dichloromethane, cleaned up by Florisil microcolumn, eluted with ethyl acetate, and determined by HF'LC (Table 18.2) [85]. The insect growth regulator, diflubenzuron's (DFB) residues were investigated in soil, litter and foliage. The samples were extracted with acetonitril, cleaned-up first on a sodium sulfate column, partitioned with n-hexane and cleaned by adsorption chromatography on a Florisil support. It was eluted in sussession with n-hexane, acetone-n-hexane (1 :9), and finally DFB with acetone-n-hexane (1 :4) mixture. For gas chromatographic determination, the residues were converted into their methylated derivatives by methyl iodide and sodium hydride in dimethylsulfoxide (Table 18.2)

[861. 18.3.5 Adsorption of fungicides in soils

Benzene-ring labelled 14C-anilazine (a) and triazine-ring labelled 14C-anilazines ( b ) were used in degradation studies at various soil depths of an orthic luvisol. The organic matter of soils bind anilazine rapidly and very strongly. The oven-dried soil was extracted consecutively with acetone-(0.01 M) calcium chloride (2: 1) mixture, acetone, dichloromethane, and finally with 0.1 M NaqP207 solution. The extracts were combined and acidified with HCI to pH 1.5, and the extracted activity measured by LSC. The extraction results showed that dihydroxy-anilazine is less strongly bound than anilazine, and is mineralized more easily (Table 18.2) [87].

18.4 DETERMINATION OF PESTICIDE RESIDUES IN WATER SAMPLES 18.4.1 Extraction of water samples

Fully automated methods have been developed for routine analysis of water samples. The on-line coupling of an enrichment step, using LLE or SPE, with HPLC is an appropriate method for multiresidue analysis of pesticides in environmental water samples. Effective enrichment techniques coupled with highly selective and sensitive detection methods now represent the main field of the technical development. The "Symposium on Continuous flow liquid-liquid extraction and other methods for isolating organic pollutants in water", organised by the American Chemical Society in 1993 [88] gave an overview of the up-to-date analytical methods.

Pesticides

81 1

The Goulden large sample extraction method (GLSE) was extensively used in pesticide extraction from natural water samples. Numerous multiresidue methods have been described for the analysis of pesticides. For example, 68 miscellaneous pesticides were extracted by this GLSE technique, and surrogate pesticide solutions of six representatives deuterium-labelled pesticides of the OC, organo-nitrogen, and HCH classes were added in order to check the extraction efficiency [89]. Many lectures were devoted to LSE methods using C18 cartridges. The OPs, triazines and thiocarbamates were extracted by using carbon-black SPE according to LLE described in the EPA method. Eleven OP insecticides, ten OC insecticides, seven triazines, four chloroacetanilides, two thiocarbamates and three miscellaneous pesticides were extracted by C18 bound silica cartridge from natural waters [90]. The GLSE and GC-MS method was used for the determination of fourteen OC and twelve OP insecticides and seventeen organo-nitrogen (ON) pesticides. The extract was spiked with a surrogate solution of every pesticide class applied: 6-HCH for OC, methylparathion for OP, and cyanazine for ON pesticides. The continuous liquid-liquid extraction (CLLE) provided a more comprehensive determination of pesticides (Table 18.3) [91]. Instead of large-volume liquid-liquid extraction (LLE), which is time- and solvent consuming, the SPE method was first checked and later developed for analysis of pesticide traces in water samples. One of the multiple pesticide-residue-analysis methods [92] describes the main objectives to be studied for development of a valuable method: 1) determination of the spiked recoveries in distilled and natural waters; 2) determination of analyte collection efficiency on the cartridge; 3) comparison of the extraction performance replication limit of detection achieved in the preconcentration of pesticides using SPE cartridges to get identical extraction using GLSE. In this study, twelve OC and ten OP insecticides, seven triazine herbicides, four chloroacetanilides, two thiocarbamates, and four miscellaneous pesticides were investigated. The mean analyte recovery and cartridge-breakthrough data are given for the abovementioned pesticides. The cartridge collection efficiency was very good except for the polar dimethoate, which is a highly water-soluble compound (Table 18.3) [92]. SPE on a silica cartridge, followed by HPLC with a normal-phase column, was applied in the analysis of the important bipyridylium herbicides diquat, paraquat, and difenzoquat in water samples. A 1 1 sample of drinking water was analysed with a 0.1 @I limit of detection (Fig. 18.5). The effects of seven different surfactants (cetrimide, benzalkonium chloride, sodium tetradecylsulfate, lauryl sulfate, lauryl sulfobetaine, Brij-35, Triton X-100) were investigated. The organic matter content, such as humic acids or surfactants, had a negative effect on the herbicide recoveries. In higher concentration they could dramatically diminish the recoveries from 90-98% to 30% (Table 18.3) [93].

References pp. 827-831

TABLE 18.3 ANALYTICAL PROCEDURES FOR DETERMINATION OF PESTICIDES IN WATER SAMPLES

Compounds

Samples

14 OC, 17 ON, 12 OP

Surface water, drinking GLSE water, irrigation water

12 o c , 10 OP, Water 4 chloroacetanilides, 3 miscellaneous, 2 thiocarbamates, 7 triazines Difenzoquat, diquat, Natural waters ParaqUat

Method of analysis

Detection

Comments

GC, DB-5

MS

GLSE C18 SPE

Gc

MS

Clean-up: CLLE CH2C12 91 Rec.(0/0):30-80 Clean-up: cyclohexane- 92 isopropanol(70:30) rec.(%): 71-102

SPE SepPak, conc. N h O H MeOH (90:70)

HPLC, Spherisorb SW3 1) conc. W O H 2% in water 2) TMA OH (2 9) (NH4)2so4 (30 g) in 1L H20 3) S M H2SO4 HPLC, Lichrosorb FW-I 8 1) 0.01 M TEA-MeOH (80:20) pH 6.9 2) 0.01 M TEA-MeOH (70:30) pH 6.9

W 310,260, 255

Extraction

Acidic herbicides, Drinking water, ground SPE SepPak, benazolin, bentazone, water MeOH 2,4-D, dicamba, MCPA and others

W 230

Lim. of det.: 0.1 pg/l

Ref.

93

94

& b

2

%

Diuron, fenuron, Surface water rnonolinuron, propazine, simazine

2 co Y

L.l

Membrane enrichment supported liquid membrane 1) 0.1 M NaOH 2) 0.5 M H2SO4

HPLC, Lichrosorb W-18

SPME

GC, DB-5, fused silica

22 OC, 2 OP, 7 PCB-s, 2 triazines

RUII-O~~ tile-drainage water Surface, raw, finished drinking water

11 OC, 24 OP

Drinking water

Terbutol, terbutol metabolites

Drainage of golf courses CH2C12, n-hexane deriv.: HCI @H 2), CH2C12, MeOH

Metolachlor

uv

Lim. of det.: 0.1 ppb

95

b

h

5: $L 2

t-CIS LSE-Sep GC, PAS-5, fused silica Pak, CHzC12, t-C 18 LLE-APHA AWWA-WPCF, 15% hexane in CH2C12 XAD-2, XAD-7 GC, Chrornpack OV-1701 C 18-silica, SDB, n-hexane, n-hexaneCH2C12 (75:25), CH2C12

ECD FID

Lirn. of det.: 2 ppt

96

ECD

Lim. of det.: n g L

97

FPD

0-107 Rec. (YO):

98

MS GC, DB-5 uv HPLC, Ultrasphere ODs, CH3CN-H20 (75125) HPLC, TSKgel ODS 120T, FD, 365 ex. 412 em, CH3CN-HzO (70:30) deriv.: 9-antluyldiazornethane

99

TABLE 18.3 (continued)

Compounds

Samples

Extraction

Chloridazon, isoproturon, metamitron, metolachlor, pendimethalin, terbuthylazine

Off target drift, surface, C18 Baker cartridge HPLC, RP-18, gradient UV 220,240 run-off water, drainage elution: H20-CH3CN (1 :I) system, sandy soil, silt to CH3CN loam soil acetone, CH2C12 MOS-Hyped, CH~CN-HZO(2:3)

Amdirachtin

Natural water

Azinphos-methy 1, chlorfenvinphos, diazinon, dimethoate, fensulfothion, malathion, parathion ON, OP

Sediment, soil, water, ditches

Surface water, rivers

CIS BPS, GCB, cyclohexane2-propanol(7:3)

GC, DB-5

MS

Aldrin, chlorpyrifos, dieldrin, lindane, prothiofos

Roof water, galvanized or concrete tanks

n-Hexane

GC, 1.5% SE-30 3.5% ov-210

ECD

Ethyl acetate CH2Cl2

Method of analysis

HF'LC, OC5, CH3CN0.05 M phosphate buffer @H 2.4) (35:65) GC phenyl methyl silicone DB-17

Detection

uv 210 NPD FPD

Comments

Ref.

Clean-up: 1) MeOH 2) hexane silica gel 1) toluene-acetone (2:3) 2) acetone

100

101

Clean-up: GPC, CH2Cl2-cyclohexane (1:l) lim. of det.: 0.01 pgfl, 1.o P g k Lim. of det.: 0.5-3.0 ngfl

102

Rec. (YO): 90-1 12

104

103

h

Tebufenozide

Sterilized, unsterilized water

CH2CH2

Sediment, moss, watercress, fish water (no clean up)

EtOAc

%

2

. Y

Aminocarb

2

CH2C12

HPLC, LiChrosorb RP-8, MOS-Hypersil C8, CH3CN-dioxane-water (50:40:10)

DAD 236 IR

Clean-up: Florisil rec.(%): 95 lim. of det.: 0.05 n g / d

105

GC, 1.5% OV-17, I .%YOOV-210, Chromosorb W

NP-FID

Clean-up: Charcoal+ellulose

106

Fenvalerate

Water, soil, formulations CH2C12

Kelthane (dicofol)

Capay clay, water, sediments

Hexane-acetone (4:l) n-hexane

GC DB-5

2..

(4: 10)

GLC DB608

107

ECD, MS, SIM, TIC, SIE, TD

2.

i-

MeOH-EtOAc 1) Florisil, EtOAc 2) Nuchar SN (AW)cellulose (CF-I 1) (4: 10 w/w) MeOH-EtOAc (1 :4) rec.(%): 84-109 Aldrin, a-benzenehex- Sand (fine to medium C18 Sep Pak Plus (SPE) achloride (BHC), sorted), sand (poorly 0-BHC, I-BHC, 6-BHC, sorted), sediment, water n-hexane dieldnn, endosulfane, heptachlor, heptachlor epoxide

2

VIS

L h . of det.: 1 pglml rec.(%): 95.5% deriv: 4-NPH

108

ECD

Lim. ofdet.: 1.6&

109

TABLE 18.3 (continued)

Method of analysis

Detection

Comments

Ref.

HCI, NaCI, CH2C12 GC,AT-225CC HPLC, Econosphere C 18 MeOH-H20 (3:2)

ECD, MS DAD 240

Rec.(%): 95.1 96.4 85.1 8.5 deriv.: for mecoprop 2,3,4,5,6-pentafluorobenzyl bromide

110

Soil,

a, 1) 1.5% wlv HPLC, Zorbax ODS NaOH-H20 (70:30) MeOH-H20 (58:42) 2) HCI (PH 2-3), CH2C12 b, MeOH-H20 (70:30),(20:80), MeOH-1.5% w/v NaOH-HzO (70:20:lo),

UV 220,245, 265,280

water

a, SPE (C18

Compounds

Samples

Extraction

Fonofos, isoproturon, mecoprop, trifluralin

Surface layer flow, drain flow, sediment

Bromacyl

(NH4)2so4

column), MeOH (C18 disks) b, LLP-CHC13, LLPXH2C12, EtOAc, n-hexane c, SPE, Extract-Clean-C18, Empore C 18

MeOH-H20 (90: 10)

111

h

% Tebufenozide 5 metab. Spruce needles foliage 2 8 2

%

8

s 7

litter, soil, sediment, natural water

0.5 M HCI-MeOH (3:7), Celite CH2C12, 0.5 M HCl @H 1.5), CH2C12

HF'LC DAD 236 ODS -Hypersil Lichrospher 100 RP-18 A) MeOH-H20 (1 :4) PIC A 0.005 M B) MeOH C) A-B (12.5~87.5)

Rec.(%): 69-102 lim. of det.: 0.02 pg/g 1 .o-2.0 pgA clean-up: Florid, 1 ) acetone-n-hexane (1:9) 2) acetone-n-hexane (1:l) 3) acetone 4) MeOH

112

b

E-.

Chapter 18

818

1

I

PO

a

0

4

8

12

16

20

TIme (mi")

Fig. 18.5. Chromatogramsobtained fiom HPLC analyses of tebufenozide and its metabolites in (A) blank natural water, and (B) natural water fortified at 50 pgk Reproduced from 193).

Dicamba, bentazone, benazolin, 2,4-D, and MCPA are representative acidic herbicides, that are potential groundwater pollutants owing to their high soil mobility and long half-lives. HPLC determination using triethylamine as ion-pairing reagent has been developed. The SFE of herbicides and this ion-pairing HPLC determination was optimized and developed for the analysis of drinking- and ground-water samples. Recoveries ranged between 72.9 and 105.8% (Table 18.3) [94]. The triazine-type herbicides, propazine, and simazine, and the phenylurea herbicides, fenuron, monolinuron and diuron were analysed in surface-water samples. The alkalised water sample was placed in contact with the supported liquid membrane (SLM), impregnated with di-hexyl ether. On the other side of the membrane, the pesticides were trapped by dissociation in sulfuric acidic media. Enriched and cleaned-up herbicide solutions were quantitated using HPLC with UV detection. The limit of detection was lppb. Simazine and propazine, as weaker basic compounds, had to be preconcentrated nine or seven times more than the other compounds (Table 18.3) [9S]. Metolachlor, a chloracetanilide herbicide, has been found with increasing frequency in surface waters. A rapid labour- and solvent-saving automated SPME

Pesticides

819

method was developed for determination of its residues: in this, a polydimethylsiloxane-coated fibre was used. FID did not have the good sensitivity for this herbicide that would be necessary in analysis of water samples. Better results were obtained with ECD detection, exhibiting a sensitivity of 0.002 pg/l (2 ppt level) in runoff and drainage water samples (Table 18.3) [96]. The efficiencies of LSE and LLE techniques were compared in the multiresidue analysis of pesticides in raw and finished drinking water samples. Twenty two OC and two OP insecticides, two triazines and seven polychlorinated biphenyls were quantitated by GC with ECD detection. The recoveries obtained by the LLE method were higher than with LSE. The limits of detection were lower (5 ng/l) for the majority of pesticide residues: atrazine and simazine gave higher responses, at 35 ng/l and 95 ng/l, respectively (Table 18.3) [97]. Twenty four OP and eleven OC insecticides were investigated using SPE with Amberlite XAD-2 and XAD-17 resins, reversed-phase C 18 bonded silica, and poly( styrene-divinylbenzene) (SDB) copolymer disks. Macroreticular resins gave unacceptably low recoveries, probable owing to irreversible adsorption. In spite of this, C 18- and SDB-copolymer disks gave very good recoveries, ranging between 80 and 1 10%. Only dichlorvos, monocrotophos and dimethoate gave very low recovery values (Table 18.3) [98].

18.4.2 Analysis and fate of herbicides in water samples Herbicides, insecticides, and fungicides applied to golf courses contaminate drainage- and ground water. Terbutol is a phenylcarbamate herbicide, which was extracted with acidic dichloromethane containing either HCI at pH2 or sodium chloride. After LLP with hexane its residues were analysed by GC-MS, H P L C W and, after derivatization with 9-anthryldiazomethane, by HPLC with fluorescence detection. A possible degradation pathway is the N-demethylation, oxidation of the 4-methyl group and hydrolysis of the carbamate ester linkage (Table 18.3) 1991. Pesticide movement to subsurface drains was investigated in Germany in the crop production areas. Isoproturon, pendimethalin, chloridazon, metamitron, metolachlor and terbuthylazine residues were studied in sandy soil and silt loam over a period of one year. Isoproturon and pendimethalin applied in the autumn were detected in the drain-flow. Isoproturon did not reach the drains until after two months. After a spring application the pesticide movement was of minor importance and showed low concentration in the drain-flow. The filtered drain water was extracted with acetone using Baker cartridges packed with octadecyl-modified silica, then eluted with methanol followed by hexane, and the residues analysed by HPLC with gradient elution (Table 18.3). Soil samples were shaken with acetone, the supernatant treated with sodium chloride and dichlorormethane, evaporated, and separated on a silica column eluted References pp. 827-831

820

Chapter 18

with toluene-acetone (23) and acetone. Finally, the cleaned sample was analysed by HPLC on a MOS-Hypersil column eluting with acetonitrile-water (3:2) (Table 18.3)[1001. The hydrolysis of azadirachtin, a botanical bioactive agent, was studied in buffered solution and in four natural waters at pH 6.2, 7.3, 8.0 and 8.1. Depending on the pH some new, unidentified degradation products were detected. Azadirachtin is more sensitive to hydrolysis than are the OP insecticides such as chlorpyrifos, diazinon, malathion, parathion, or ronnel or even carbamates. At 35°C it hydrolysed quickly and disappeared according to pseudo-first-order kinetics. Its residues were determined by HPlC on an OC5 column, eluted isocratically with acetonitrile-(0.05 M) phosphate buffer of pH 2.4 (Table 18.3). Azadirachtin is not expected to be persistent in water solutions in the environment [loll. 18.4.3

Analysis and fate of insecticides, acaricides, and miticides in water samples

OP insecticides in farm ditches have been investigated. Malathion and azinphosmethyl were not detected in any of the studied samples, showing a rapid degradation in the environmental conditions: diazinon and dimethoate were detected, however. Fensulfothion and parathion were sporadically detected in ditch water samples, and diazinon and fensulfothion were detected in ditch sediments, also. Water samples were extracted with dichloromethane, the solution evaporated, and the residues analysed by GC without further clean-up. Sediments were extracted with ethyl acetate, then after filtration and evaporation the extract was cleaned by gel permeation chromatography with Bio-Beads S-X 12, eluted with a dichloromethane-cyclohexane (1 :1) mixture. GC analysis was performed with dual columns and dual detectors: a H-P cross-linked 5% phenylmethylsilicone capillary column was interfaced with a FPD, and a J&N DB-17 capillary column with NPD (Table 18.3) [102]. Organonitrogen- and OP pesticides were analysed in the fall lines of the Susquehanna, Potomac, and James Rivers, and in Chesapeake Bay, USA. The LSE-GC-MS method was applied for the analysis: 1OL of water sample was passed through an LSE sorbent GCB or C 18-BPS cartridge. These were eluted with cyclohexane-2-propanol (7:3) mixture and analysed by GC-MS. The appearance of their residues was correlated with the field applications (Table 18.3) [ 1031. Dieldrin, aldrin, lindane, chlorpyrifos and prothiofos residues were investigated in stored roof-water. The residues were extracted with hexane and determined by GCECD. Dieldrin and lindane were present during a 36 week period. Aldrin disappeared very quickly, its half-life being 4-5 weeks, and no diedrin formed there. The half-lives of chlorpyrifos and prothiofos ranged between 12-18 weeks, and 11-14 weeks, respectively (Table 18.3) [104].

Pesticides

82 1

Tebufenozide is a narrow-spectrum insecticide affecting the growth and development of insect pests by interfering in their metamorphosis and reproduction. This insecticide was proved to be stable in acidic and neutral conditions. Its hydrolytic degradation was dependent on pH and temperature. Tebufenozide degraded fairly rapidly in unsterilized stream water but was stable in sterilized samples. Photodegradation was also quick, but less rapid than the microbial process. In any case, the photolytic and microbial alterations are dominant in its degradation process. Its residues and degradation products were detected by extraction with dichloromethane, the interfering co-extractives were eliminated by a microcolumn Florisil clean-up, and the residues determined by HPLC on a HP Lichrosorb RP-8 column and HP MOS-Hypersil (C8) guard column. The mobile phase was acetonitrile-dioxane-water (50:40: 10) and the limit of detection was 0.05 ng/ml (Table 18.3) [ 1051. R Matacil 180F, the flowable formulation of aminocarb, was sprayed from aircraft over a mixed-wood boreal forest in Canada. The dissipation of its residues was investigated. At 1-3 hours after spraying the peak concentration was observed in watercress and moss: after that time they degraded gradually. Its residues in fishes were at the 6.1 and 13.8 ppb level, but no mortality was detected. According to this study, aminocarb does not exhibit any aquatic environmental hazard. Its residues were investigated in water, sediment, moss, and fish samples. The water was extracted with dichloromethane, dried and analysed without further clean-up. The sediment was extracted with ethyl acetate, dried over sodium sulfate, and cleaned on a neutral charcoakellulose powder (4: 10) mixture, which was covered with sodium sulfate. This column was eluted with methanol-ethyl acetate (20:80) and analysed by GC. This determination step was carried out on a Chromosorb W column containing 1.5% OV-17 plus 1.95% OV-210, with NP-FID detection (Table 18.3) [ 1061. Some determination methods for representatives of OC, OP, and carbamate-type insecticides, fenvalerate, bromacy 1, and tebufenzide are listed. The persistence of chlorinated insecticides is well known. Newer methods are under development for determination of these residues, not only in food but also in environmental samples. DDT-isomers, PCBs, and PAHs residues have been examined recently in soil/sediment and water samples. A thermal desorption (TD) GC-MS method with selective ion monitoring (SIM) was investigated in comparation with GC-ECD determination. The limit of detection of the TD-GC-MS with SIM was 50 ng/g and 40 mg/l. Totalion-current-selected-ion-extraction (TIC-SIE) and GC-ECD detections were compared: the former gave a higher sensitivity (Table 18.3) [ 1071. Fenvalerate, the non-systemic insecticide and acaricide, was used in the protection of field crops, fruits, vegetables, ornamental plants, and flowers. Its residues were first hydrolysed in alkaline conditions, when 3-phenoxybenzaldehyde was formed. This compound gave a red-purple colour with 4-nitrophenylhydrazine (4-NPH) in the presReferences pp, 827-831

822

Chapter 1%

ence of methanolic potassium hydroxide. The colour formed was stable for 52 hours, allowing the spectrophotometric determination of fenvalerate residues in soil- and water samples after extraction with dichloromethane (Table 18.3) [108]. Kelthane, the miticide is extensively applied in fruit-, vegetable-, and ornamentals production. The appearance of its residues was studied in run-off water fiom polymertreated and untreated soils and in the sediments. The residues from water samples were extracted into hexane by LLP, and from soil samples with hexane-acetone (4:1) mixture by Soxhlet method and analysed by GLC-ECD. The limit of detection was 1.6 pgll. The polymer-treated soils retained more kelthane than the non-treated ones (Table 18.3) [109]. The movement of isoproturon, mecoprop, fonofos and trifluralin from heavy clay soil to surface water has been investigated. The filtered water samples were acidified with HCI and shaken with NaCl before LLE with dichloromethane. Sub-samples of the extract were derivatized with 2,3,4,5,6-pentafluorobenzyIbromide. Isoproturon was determined by HPLC on an Econosphere C18 column, eluted with methanolwater (3:l) mixture. The effect of rainfall, surface-layer flow, and drainage was investigated. Both the sediments and water samples were analysed round the year (Table 18.3) [110]. Bromacyl controls annual and perennial weeds in agricultural and non-agricultural situations. The SPE extraction method was improved by using sodium hydroxide solution for extraction of the residues from soils with high organic-matter content, and water samples. SFE was compared with three different traditional LLE extractions using chloroform, dichloromethane, ethyl acetate, n-hexane, toluene, C 18 columns, and C 18 disks: SFE was found to be more effective in these cases, also (Table 18.3). The final determination was also carried out by HPLC on soil- and water samples as well [ 1 111. Tebufenozide insecticide and five of its metabolites in forestry matrices were analysed by HPLC. Litter, soil, and sediment were extracted with acidic methanol in the presence of Celite. After partitioning to dichloromethane, the solvent was evaporated and cleaned up using a Florisil column. Natural water samples were also extracted with dichloromethane and analysed by HPLC, without column clean-up on an ODS Hypersil column, eluting with a methanol-water mixture containing 0.005 M PIC A as an ion-pairing agent (Fig. 18.6). The limits of detection were in the pgll range (Table 18.3) [ 1121. 18.5 PESTICIDES IN AIR

Only a few papers have been published in recent years dealing with the determination of pesticide residues in air samples. The Symposium on the dissipation of DDT in

Pesticides

823

Q

i

Fig. 18.6. HPLC chromatograms from (A) tap water, (B) tap water spiked with the selected herbicides at 1 pgil, and ( C ) tap water spiked with the selected herbicides at 0.1 pgil. Peak identification: DQ=diquat; PQ=paraquat and DFQ=difenzoquat.Reproduced from [ 1 121.

tropical countries [70] dealt with the air pollution by DDT. The three most likely probabilities for the appearance of the DDT in air were considered to be: 1) gravitational fallout, including adsorption on soil and other surfaces; 2) washout by rain; and 3) photochemical degradation with subsequent rain-out or wash-out of the altered chemicals. Exposure of DDT and reactive compounds to sunlight in the air may result in degradation or modification of the pesticide by photolysis. DDT and many of its degradation products were subjected to photochemical breakdown by UV light. In the presence of air, DDT was converted into DDE, which suffered further degradation by photolysis, to other products such as PCBs. Both pathways lead to the same result either DDT vapours suffered photolysis in the air directly, or DDE vaporized from soil suffered this degradation process in the air [70]. In another study, homes, gardens, yards, and workplaces were subjected to investigation for the presence of chlorpyrifos [ 1131 and carbaryl [114] residues. Americans were exposed in their homes and workplaces to both of these chemicals in all residences tested. Cyflutrin, a pyrethroid, is used to control cockroaches and other pests in dwellings. Its residues are translocated from the application site into the air and onto surfaces. An analytical procedure was developed for determination of its residues, both in the air and on surfaces, using GC-NPD [I IS]. In other investigations 1,3-dichloropropene [ 1 161, endosulfan [ 1 171, and d-trans-allethrin [ 1 181 residues were References p p 827-831

824

Chapter I 8

tested in air samples, However, several pesticide residues were detected in air samples, although they were at very low levels, and EPA studies confirmed that the indoor air is safe, with no chemical danger existing [ 1191. Finally some review articles are worth mention here, which deal with specific and multiresidue analytical methods. TLC, HPTLC, and overpressure-TLC (OPLC) detection methods have been summarized, with mention of derivatization reactions, also [3,120,121]. Sample-preparation and clean-up methods for the analysis of insecticides, herbicides, fungicides and of other different chemical classes of pesticides have also been reviewed there. Automated-multiple-development (AMD)methods applied to the analysis of water samples, and many other techniques, are collected for the detection and determination of pesticides in environmental and food samples [7]. The very efficient SFE methods applied to the pesticide analysis in environmental and food samples have also been discussed [ 122,1231.

18.6 PESTICIDES, CHEMICAL NAMES Aminocarb Abamectin Acephate Acifluorfen Aldrin Alachlor Atrazine Azadirachtin Bentazon BHC Bromacil Carbaryl Carbohan Chlordane Chloridazon Chlorimuron ethyl Chlopyralid Chlorpyrifos Clomazone Cyanazine Cyflutrin 1,3-D 2,4-D p,p’-DDA DDD p,p’-DDE DEA

p,p’-DDMU p,p‘-DDT

4-dimethylamino-3-methylphenyl-(m-tolyl)-N-methylcarbatnate mixture of avermectin B1, and avermectin Bib 0,s-dimethy l-N-acetylphosphoroamidothioate 5-[2-chloro-4-trifluoromethyl)phenoxy]-2-nitrobenzoic acid [1R,4S,5S,8R]-1,2,3,4,1O,lO-hexachloro-l,4,4a,5,8,8a-hexahydro-l,4:5,8dimethanonaphthalene 2-chloro-2’ @-diethy N-(methoxymethy1)acetanilide 6-chloro-N -ethyl- -isopropyl-l,3,5-triazine-2,4-diamine an isomeric mixture of seven or so tetra- or tri-terpenoids 3-isopropyl-2,1,3-benzothiadiazin-4-one-2,2-dioxide a-benzene hexachloride 5-bromo-6-methyI-3-( 1-methy lpropyl)-2,4-(I H,3H)-pyrimidinedione 1-naphthyl-N-methylcarbatnate 2,3-dihydro-2,2-dimethylbenzohan-7-ylmethylcarbamate 1,2,4,5,6,7,8,8-octachloro-4,7-methano-3a,4,7,7a-tetr~ydro~dane 5-amino-4-chloro-2-phenylpyridazin-3-(2H)-one ethyl 2-[ [[[(4-chloro-6-methoxy-2-pyrimidinyl)amino]c~bonyl]a~no] sulfonyl]benzoicacid 3,6-dichloropicolinicacid 0,0-diethyl-0-(3,5,6-trichloro-2-pyridmyl)phosphorothioate 2-(2-chlorophenylmethyl)-4,4-dimethyl-3-isoxazolidinone 2-(4-chloro-6-ethylamino-1,3,5-triazin-2-yl)amino-2-rnethylpropanenitrile cyano(4-fluoro-3-phenoxyphenyl)methyl3-(2,2-dichloroethenyl)-2,2dimethy lcyclopropanecarboxylate 1,3-dichIoropropene 2,4-dichlorophenoxyaceticacid bis@-chloropheny1)acetic acid 1,l-dichloro-2,2-bis~-chlorophenyl)ethane 1,l -dichloro-2,2-bis@-chlorophenyl)ethylene deethylatrazine: 2-chloro-4-amino-6-(isopropylamino)-1,3,5-triazine 1-chloro-2,2-bis@-chlorophenyl)ethylene 1,l , I -trichloro-2,2-bis@-chlorophenyl)ethane

4-

825

Pesticides Diazinon Dieldrin Difenzoquat Diflubenzuron Diquat Diuron Emamectin benzoate Ethofiunesate Ethoprop Fenamiphos Fenbutatin oxide Fenitrothion Fenoxapropethyl Fenvalerate Fluometuron Flupropacil Glyphosate HCH Hexazinone Hexazinone metabolite A Hexazinone metabolite B Hexazinone metabolite C Hexazinone metabolite D Hexazinone metabolite E Hexazinone metabolite G Imazopyr Isoproturon Kelthane Metamitron Metolachlor Metribuzin Paraquat Pendimethalin Picloram Primisulfuron

O,O-diethylO-2-isopropyl-4-methyl-6-pyrimidinyl thiophosphate [ 1R,4S,5S,8R]-1,2,3,4,1O,lO-hexachloro-l,4,4a,5,6,7,8,8a-octahydro-6,7epoxy-l,4:5,8-dimethanonaphthalene 1,2-dimethyl-3,5-diphenyl1 H-pyrazolium ion 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea 1,I'-ethylene-2,2'-bipyridyliumion 3-(3,4-dichlorophenyl)- I , 1-dimethylurea a mixture of 4"-deoxy-4"(epi-methylamino)avermectin B la benzoate and 4"-deoxy-4"-(epi-methylamino)avermectin B l b benzoate

2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofl methanesulfonate 0-ethyl S,S-dipropylphosphorodithioate ethyl 3-methyl-4-(methylthio)phenylisopropylphosphoroamidate bis[tris(2-methyl-2-phenylpropyl)tin] oxide O,O-dimethyl-O-4-nitro-m-tolyl phosphorothioate ethyl 2-[4-(6-chloro-2-benzoxazolyl)oxy]phenoxy propionate

(R,S)-a-cyano-3-phenoxybenzyl(R,S)-2-(4-chlorophenyI)-3-methylbutyrate I , 1-diethyl-3-(a,a,a-trifluoro-rn-tolyI)urea I-methylethyl-2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-trifluoromethyl- 1(2H)-pyrimidinyl]benzoate N-(phosphonomethy1)glycine 1 a,2a,3~,4a,5a,6~-hexachlorocyclohexane 3-cyclohexyl-6-dimethy lamino- 1-methyl- 1,3,5-triazine-2,4-( 1H,3H)-dione

3-(4-hydroxycyclohexyI)-6-dimethylamino-l-methyl-1,3,5-triazine2,4( 1H,3H)-dione 3-cyclohexyl-6-methylamino-l-methyl-l,3,5-triazine-2,4(1H,3H)-dione

3-(4-hydroxycyclohexyl)-6-methylamino-l-methyl-l,3,5-triazine2,4( IH,SH)-dione 3-cyclohexyl-l-methyl-l,3,5-triazine-2,4,6(1H,3H,5H)-trione

3-(4-hydroxycyclohexyI)-l-methyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3-cyclohexyl-6-methy lamino- 1,3,5-triazine-2,4 (1H,3H)-dione

2-(4-isopropyl-4-methyhyl)-5-oxo-2-imidazolin-2-y1 nicotinic acid 3-(4-isopropylphenyl)-l,1-dimethylurea 1,1-bis(p-chlorophenyI)-2,2,2-trichloroethanol 3-methyl-4-amino-6-phenylI ,2,4-triazin-5(4H)-one 2-chloro-6'-ethyl-N-(2-methoxy-l-methylethyl)-acet-~-toluidine 4-amino-6-ter~-butyl-3-(methylthio)-as-triazine-5(4H)-one 1,I'-dimethyl-4,4'-bipyridylium ion N-( I -ethylpropyl)-2,6-dinitro-3,4-xylidine 4-amino-3,5,6-trichloropicolinicacid 2-[[[[[4,6-bis(difluoromethoxy)-2-pyri~dinyl]amino]caronyl]amino]qulfgnyl]benzoic acid Prometryn N ,N -di-isopropyl-6-methyhythio-1,3,5-triazine-2,4-diamine 1H- 1,2,4Propiconazole 1-[[2-(2,4-dichlorophenyl)-4-propy1-1,3-dioxolan-2-yl]methyl]triazole Propoxur 2-isopropoxyphenyl N-methylcarbamate Prothiophos 0-(2,4-dichIorophenyI) 0-ethyl-S-propy I phosphorodithioate Rimsulfuron N-[[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-3-ethylsulfonyl]2-pyridin-sulfonamide Silvex 2-(2,4,5-trichlorophenoxy)propionic acid 2,4,5-T (2,4,5-trichlorophenoxy)acetic acid TDE 2,~-bis(p-chlorophenyl)-~, 1-dichloroethane Terbuthylazine N -tert-butyl-6-chloro-N -ethyl- 1,3,5-triazine-2,4-diamine References pp. 827-831

Chapter 18

826 Terbutol Terbuthiuron Tralkoxydim Triclopyr

2,6-di-tert-butyl-4-rnethylphenyl-N-methyl~arbmate N-5-[( 1,l -dimethylethyl)- 1,3,4-thiadiazol-2-yl]-N,N-dimethylurea 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethylphenyl)-2-cyclohexen- 1-one [(3,5,6-trichloro-2-pyridinyl)oxy]aceticacid

18.7 ABBREVIATIONS AIBA AMD APCI API CE CI CIET CITP CLLE CZE DAD DLI ECD El EOF ESP FA0 FD FID FSE GLSE GPC HA IAEA IPA LLE LLP LSC LSE MAB MAC MCPA MECC NPD NMC 4-NPH

oc

OHA OHDEA OHDIA OHT ON OP PIC A SDB SFE SIE

2-amino-N-isopropy lbenzamide automated multiple development atmospheric pressure chemical ionization atmospheric pressure ionization capillary electrophoresis chemical ionization capillary isoelectro focusing capillary isotachophorsis continuous liquid-liquid extraction capillary zone electrophoresis diode-array detector direct liquid introduction electron capture detector electron impact electro osmotic flow electrospray Food and Agriculture Organization of United Nations fluorescence detection flame ionization detector free solution electrophoresis Goulden large sample extraction gel permeation chromatography humic acid International Atomic Energy Agency iso-propanol liquid-liquid extraction liquid-liquid partitioning liquid scintillation counting liquid-solid extraction 4"-deoxy-4"(epi-methylamino)avermectin B benzoate maximum admissible concentration 4-chloro-2-toly loxy-acetic acid micellar electrokinetic capillary chromatography nitrogen-phosphorus detector N-methy lcarbamate 4-nitropheny lhydrazine organochloro hy droxyatrazine hydroxydeethy latrazine hydroxydeisopropyl atrazine = hydroxydeterbutyl atrazine hy droxyterbutylatrazine organonitrogen organophosphorus tetrabutylammonium hydrogen sulfate poly styrene-diviny lbenzene supercritical fluid extraction selected ion extraction

827

Pesticides SIM SLM SP SPE SPME STLC TEA TD TIC TOF TSP WHO

selective ion monitoring supported liquid membrane ionspray solid-phase extraction solid-phase microextraction soil TLC triethanolamine thermal desorption total ion current time of flight thermospray World Health Organization

18.8 REFERENCES 1 M. Fielding, D. Barcelo, A. Helweg, S. Galassi, L. Torstenson, P. van Zoonen, R. Wolter and G. Angeletti, in Pesticide in Ground and Drinking Water (Water Pollution Research Report, 27), Commission of the European Communities, Brussels, 1992 pp. 1-136. 2 K. Fodor-Csorba, J. Chromatogr., 624 (1992) 353. 3 K. Fodor-Csorba, Pesticides, in J. Sherma and B. Fried (Editors), Handbook of Thin-Layer Chromatography, Marcel Dekker, New York, Basel, Hong Kong, 1996, Ch. 23, pp. 753-817. 4 J.R. Dean, G. Wade and 1.J. Bamabas, J. Chromatogr. A, 733 (1996) 295. 5 Drinking Water Inspectorate, A report by the Chief Inspector, Drinking Water 1993, HMSO, London, 1994. 6 H.B. Wan and M.K. Wong, J. Chromatogr. A, 754 (1996) 43. 7 Manual of Pesticide Residue Analysis Vol. I. and II., Pesticide Commission, Ed. H. P. Thier and J. Kirchhoff, VHC, Weinheim, 1992. 8 3. Hatrik and J. Tekel, J. Chromatogr. A, 733 (1996) 217. 9 J.L. Tadeo, C. Sanchez-Brunete, A.I. Garcia-Valcarcel, L. Martinez and R.A. PCrez, J. Chromatogr. A, 754 (1996) 347. 10 S.S. Yang, A.1. Goldsmith and I. Smetena, J. Chromatogr. A, 754 (1996) 3. 11 I. LiSka and J. Slobodnik, J. Chromatogr. A, 733 (1996) 235. 12 M. Honing, J. Riu, D. Barcelo, B.L.M. van Baar and U.A.Th. Brinkman, J. Chromatogr. A, 733 (1996) 283. 13 V. Pacakova, K. Stulik and J. Jiskra, J. Chromatogr. A, 754 (1 996) 17. 14 L. Kfivinkova, P. BoEek, J. Tekel and J. KovaEiCova, Electrophoresis, I0 (1989) 73 1. 15 Z. Stribsky, J.Chromatogr. A, 320 (1985) 219. 16 G. Dinell, A. Vicari and P. Catizone, J. Chromatogr. A, 733 (1996) 337. 17 G.M. McLaughlin, A. Weston and K.D. Hauffe, J. Chromatogr. A, 744 (1996) 123. 18 D.F. Swaile, D.E. Burton, A.T. Balchunas and M.S. Sepaniak, J. Chromatogr. Sci., 26 (1988) 406. 19 Ph. Schmitt, A.W. Garrison, D. Freitag and A. Kettrup, J. Chromatogr. A, 723 (1996) 169. 20 G.J.M. Bruin, P.P.H. Tock, J.C. Kraak and H. Poppe, J. Chromatogr., 517 (1990) 557. 21 C.P. Ong, C.L. Ng, H.K. Lee and S.F.Y. Li, J. Chromatogr., 542 (1991) 473. 22 V. Dombek and Z. Stransky, Anal. Chim. Acta, 2 (1992) 69.

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Chapter 18

23 R. Carabias Martinez, E. Rodriguez Gonzalo, A.I. Muoz Dominguez, J. Dominguez Alvarez and J. Hemhdez Mtndez, J. Chromatogr. A, 733 (1996)349. 24 H. Siisse and H. Miiller, J. Chromatogr. A, 730 (1996)337. 25 Y.Z. Hsieh and H.Y. Huang, J. Chromatogr. A, 745 (1996)217. 26 D. Wycherley, M.E. Rose, K. Giles, T.M. Hutton and D.A. Rimmer, J. Chromatogr. A, 734 (1996)339. 27 L.E. Nakagawa, L.C. Luchini, M.R. Musumeci and M. Matallo, J. Environ. Sci. Health, 831 (1996)203. 28 E.L. Kruger, P.J. Rice, J.C.Anhalt, T.A. Anderson and J.R. Coats, J. Agric. Food Chem., 44 (1996)1144. 29 C.D. Adams and E.M. Thurman, J. Environ. Qual., 20 (1991)540. 30 K.E. Keller and J.B. Weber, J. Agric. Food Chem., 43 (1995)1076. 31 J.J. Anderson and J.J. Dulka, J. Agric. Food. Chem., 33 (1985)596. 32 J.K. Lee, F. Fiihr and K.S. Kyung, J. Environ. Sci. Health, B31 (1 996) 179. 33 S.C. Wagner, R.M. Zablotowicz, L.A. Gaston, M.A. Locke and J. Kinsella, J. Agric. Food Chem., 44 (1996)1593. 34 R.V. Vithala, C.K. White and W.C. Spare, J. Agric. Food Chem. 43 (1995)2981. 35 K.N. Reddy, M.A. Locke, S.C. Wagner, R.M. Zablotowicz, L.A. Gaston and R.J.Smeda, J. Agric. Food Chem., 43 (1995)2752. 36 M.A. Locke, L.A. Gaston and R.M. Zablotowicz, J. Agric. Food Chem., 44 (1996) 1128. 37 S. Khan and M. Khan, Soil Sci., 142(1986)214. 38 M.J. Sanchez-Martin, T. Crisanto, M. Arienzo and M. Sanchez-Camazano, J. Environ. Sci. Health, B29 (1994)473. 39 H.J. Pedersen, P. Kudsk and A. Helweg, PesticSci., 44 (1995)13 1. 40 T.L. Mervosh, G.K. Sims, E.W. Stoller and T.R. Ellsworth, J. Agric. Food Chem., 43 (I 995)2295. 41 P. Gaillardon and J.C. Dur, Pestic. Sci., 45 (1995)297. 42 J.F. Cooper, S.Q. Zheng, L. Palcy and C.M. Coste, J. Environ Sci. Health, B29 (1994) 443. 43 A.E. Smith, A.J. Aubin and T.C. McIntosh, J. Agric. Food Chem., 43 (1 995)2988. 44 0. Pantani, A. Pusino, L. Calamai, C. Gessa and P. Fusi, J. Agric. Food Chem., 44 (1996)617. 45 L. Celi, M. Negre and M. Gennari, J. Agric. Food Chem., 44 (1996)3388. 46 E. Capri, C. Ghebbioni and M. Trevisan, J. Agric. Food Chem., 43 (1995)247. 47 A. Piccolo, G . Celano, M. Arienzo and A. Mirabella, J. Environ Sci. Health, B29 (1994)1105. 48 A. Piccolo, G. Celano and P. Conte, J. Agric. Food Chem., 44 (1996)2442. 49 A. Pusino, S. Petretto and C. Gessa, J. Agric. Food Chem., 44(1996)1150. 50 A. Srivastava, K.C. Gupta and G. Singh, Pestic. Sci., 43 (1995)53. 51 J.C. Feng, Canadian J. Chem., 70 (1992)1087. 52 J.B. Fischer and J.L. Michael, J. Chromatogr. A, 704 (1995)131. 53 S. Schiitz, H.E. Hummel, A. Duhr and H. Wollnik, J. Chromatogr. A, 683 (1994) 141. 54 R. Alzaga, J.M. Bayona and I>. Barcelo, J. Agric. Food Chem., 43 (1995) 395. 55 American Cyanamid, Method M-1713.02-HPLC, method for the determination of CL243,997residues in soil, American Cyanamid Co., Princeton, NJ 1988,11 p. 56 C.S. Helling and M.A. Doherty, Pestic. Sci., 45 (1995)21.

Pesticides

829

57 L.K. Tan, D. Humphries, P.Y.P. Yeung and Z. Florence, J. Agric. Food Chem., 44 (1996) 1135. 58 S.U. Khan, J. Agric. Food Chem., 43 (1995) 1718. 59 E.G. van der Velde, M. Dietvorst, C.P.S Wart, M.R. Ramlal and P.R. Kootstra, J. Chromatogr. A, 683 (1994) 167. 60 S. Bengtsson and T. Berglof and T. Sjoqvist, J. Agric. Food Chem., 44 (1996) 2260. 61 P. Popp, K. Kalbitz and G.P. Oppermann, J. Chromatogr. A, 687 (1994) 133. 62 K.M. Erstfeld, M.S. Simmons and Y.H. Atallah, J. Environ Sci. Health, B3 1 (1996) 43. 63 W.W. Spieszalski, H.D. Niemczyk and D.J. Shetlar, J. Environ. Sci. Health, B29 (1994) 1117. 64 R.A. Chapman, C.R. Harris, J.H. Tolman, D. Dubois and C. Cole, J. Environ. Sci. Health, B29 (1994) 233. 65 R.A. Chapman, C.R. Hanis, J.H. Tolman and D. Dubois, J. Environ. Sci. Health, B29 (1994) 895. 66 M. Mojasevic and C.S. Helling, J. Environ. Sci. Health, B30 (1995) 163. 67 V.F. Gruber, B.A. Halley, S.C. Hwang and C.C. Ku, J. Agric. Food Chem., 38 (1990) 886. 68 H.T. Crisato and L.F. Martin, Toxicol. Environ. Chem., pp.31,63 (1991). 69 J. Sherma, J. Planar Chromatrogr., 7 (1994) 265. 70 Research Cooridination on Meeting Radiotracer Studies on Behaviour of DDT in Tropical Environment, Neuberg, Germany, May 3 1-June 4 (1 993), J. Environ. Health Part. B, Pesticides 29B (1994). 71 J.W. Wright, The future of insecticides, R.L. Metcalf and P. McKelm, Wiley, New York, 1976. 72 G. Wedemayer, Appl. Microbiol., 16. (1968) 661. 73 C.S. Helling, B.F. Engelke and M.A. Doherty, J. Environ. Sci. Health, B29 (1994) 103 74 J.H. Smelt, M. Leistra, N.W.H. Houx and A. Dekker, Pestic. Sci., 9 (1978) 293. 75 R.H. Bromilov, R.J. Baker, M.A. Freeman and K. Gorog, Pestic. Sci., 11 (1980) 371 76 L.T. Ou, K.S.V. Edvardsson and P.S.C. Rao, J. Agric. Food Chem., 33 (1985) 72 77 L.T. Ou, P.S.C. Rao, K.S.V. Edvardsson, R.E. Jessup, A.G. Homsby and R.L. Jones, Pestic. Sci., 23 (1988) 1. 78 J.H. Smelt, A.E. van de Peppel-Groen and M. Leistra, Pestic. Sci., 44 (1995) 323. 79 K.D. Racke, K.P. Steele, R.N. Yoder, W.A. Dick and E. Avidov, J. Agric. Food Chem., 44 (1996) 1582. 80 R.C. Schneider, R.E. Green, J.D. Wolt, R.K.H. Loh, D.P. Schmitt and B.S. Sipes, Pestic. Sci., 43 (1995) 97. 81 T. Wehner, J. Lasota and R. Demchak, in J. Sherma and T. Caims (Editors), Comprehensive Analytical Profiles of Important Pesticides, CRC Press, Boca Raton, Florida, 1993, Ch. 4, p. 73. 82 M.W. Brooks and P.C. Uden, Pestic. Sci., 43 (1995) 141. 83 M. Mushtaq, W.F. Feely, L.R. Syintsakos and P.G. Wislocki, J. Agric. Food Chem., 44 (1 996) 940. 84 A. Gray, A.J. Dutton and Ch.V. Eadsforth, Pestic. Sci., 43 (1995) 295. 85 K.M.S. Sundaram, J. Curry and M. Landmark, J. Environ. Sci. Health, B30 (1995) 827. 86 K.M.S. Sundaram, J. Environ. Sci. Health, B31 (1996) 135. 87 B. Heiltmann-Weber, W. Mittelstaedt and F. Fiihr, J. Environ Sci. Health, B29 (1994) 247.

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Chapter 18

88 Symposium on Continuous Flow Liquid-liquid Extraction and other Methods for Isolating Oraganic Pollutants in Water, 205th ACS National Meeting, Denver, Colorado, March 28-April 2, VO~.33 (1993). 89 W.T. Foreman, P.M. Gates and G.D. Foster, Symposium on Continuous Flow Liquid-liquid Extraction and other Methodsfor Isolating Organic Pollutants in Water, 205th ACS National Meeting, Denver, Colorado, March 28-April 2, Vol. 33 (1993) p. 415. 90 W.T. Foreman, G.D. Foster and P.M. Gates, Symposium on Continuous Flow Liquid-liquid Extraction and other Methods for Isolating Organic Pollutants in Water, 205th ACS National Meeting, Denver, Colorado, March 28-April 2, Vol. 33 (1993) p. 436. 91 G.P. Foster, P.M. Gates, W.T. Foreman, S.W. McKenzie and F.A. Rinella, Environmental Science & Technology, 27 (1 993) 191 1. 92 W.T. Foreman and G.D. Foster, in G.E. Mallard and D.A. Aranson (Editors), US Geological Survey Toxic Substances Hydrology Program - Proceedings of the technical meeting, Monterey, California, March 11-15, 1991, p. 530. 93 M. Ibanez, Y. Pic0 and J, Manes, J. Chromatogr. A, 727 (1996) 245. 94 A. Balinova, J. Chromatogr. A, 728 (1 996) 3 19. 95 J. Trocewicz, J. Chromatogr. A, 725 (1996) 121. 96 K.N. Graham, L.P. Sarna, G.R.B. Webster, J.D. Gaynor and H.Y.F. Ng, J. Chromatogr. A, 725 (1996) 129. 97 M.J. Fernandez, C. Garcia, R.J. Garcia-Villanova and J.A. Gomez, J. Agric. Food Chem., 44 (1996) 1790. 98 I.Tolosa, J.W. Readman and L.D. Mee, J. Chromatogr., A, 725 (1996) 93. 99 T. Suzuki, K. Yaguchi, K. Ohnoshi and T. Suga, J. Agric. Food Chem., 43 (1995) 1712. 100 U. Traub-Eberhard, K.P. Henschel, W. K6rdel and W. Klein, Pestic. Sci., 43 (1995) 121. 101 S.Y. Szeto and M.T. Wan, J. Agric. Food Chem., 44 (1996) 1160. 102 M.T. Wan, S. Szeto and P. Price, J. Environ. Sci. Health, B29 (1994) 917. 103 G.D. Foster and K.A. Lippa, J. Agric. Food Chem., 44 (1996) 1447. 104 K.W. McDougall, H. Wan and C.R. Harris, J. Environ. Sci. Health, B29 (1994) 293. 105 K.M.S. Sundaram, J. Environ. Sci. Health, B29 (1994) 1081. 106 K.M.S. Sundaram, J. Environ. Sci. Health, B31 (1996) 59. 107 A. Robbat, Jr. Ch. Liu and T.-Y. Liu, J. Chromatogr., 625 (1992) 277. 108 R.R. Naidu and R.V.P. Raju, Pestic. Sci., 44 (1995) 163. 109 G. Singh, J. Letey, P. Hanson, P. Osterli and W.F. Spencer, J. Environ. Sci. Health, B31 (1996) 25. 1 10 C.D. Brown, R.A. Hodgkinson, D.A. Rose, J.K. Syers and S.J. Wilcockson, Pestic. Sci., 43 (1995)131. 11 1 T. K. James and D.R. Lauren, J. Agric. Food. Chem., 43 (1995) 684. 1 12 K.M.S. Sundaram and R. Nott, J. Chromatogr. A, 708 (1995) 7 1, 113 C. Cox, J. PesticideReform., 15 (1995) 15. 114 C. Cox, J. Pesticide Reform., 13. (1993) 29. 115 D.M. Stout 11, Ch.G. Wright and R.B. Leidy, J. Environ. Sci. Health, B30 (1995) 765. 116 F.van den Berg, Pestic. Sci., 36 (1992) 195. 117 R. Yasmeen, S.J. Tulasi and J.V.R. Rao, Pestic. Biochem. Physiol., 40 (1991) 205. 118 B.D. Eitzer, Bull. Environ. Contam. Toxicol., 47 (1991) 406.

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119 EPA Study, Pest Control Technology, 18 (1990) 52. 120 K.Fodor-Csorba, Pesticides, in J. Sherma and B. Fried (Editors), Hundbook of Thin-Layer Chromatography, Marcel Dekker, New York, Basel, Hong Kong, 1991, Ch. 22, pp. 663-715. 121 J. Sherma, Anal. Chem., 68 (1996) 1R. 122 T.L.Chester, J.D. Pinkston and D.E. Rayne, Anal. Chem., 68 (1996) 487R. 123 J.R. Dean, J. Chromatogr. A, 754 (1996) 221R.