ONEC-MS)

Chemosphere,Vol.27, No.10, pp 1873-1878, 1993 Printed in Great Britain

0045-6535/93 $6.00 + 0.00 Pergamon Press Ltd.

ANALYSIS OF ENVIRONMENTAL SAMPLES FOR TOXAPHENE USING GAS CHROMATOGRAPHY/OXYGEN NEGATIVE ION-ELECTRON CAPTURE MASS SPECTROMETRY (GC/ONEC-MS) GARY W. BRUNS* and DETLEF BIRKHOLZ

ENVIRO-TEST LABORATORIES 9936 - 67 AVENUE, EDMONTON, ALBERTA T6E OP5 ABSTRACT The analysis of fish muscle for polychlorinated camphenes (Toxaphene) at levels down to 2 ng/g(ppb) is presented.

The polychlorinated

camphanes (PCCs) are isolated from

polychlodnated biphenyls (PCBs) using florisil chromatography and analysis is conducted using gas chromatography - oxygen negative ion electron capture mass spectrometer (GC/ONEC-MS). The major PCCs observed in fish obtained from pristine environments were found to be the Cl7 - Gig. The ions selected to monitor for PCCs include: CI7 (341,343 and 345); CI8 (375, 377 and 379); and CIo (411,413 and 415). Three to five components from each of the CI7 - CIo groups were used to quantitate total PCCs.

INTRODUCTION Fish samples were obtained from pristine environments in the Canadian Rocky Mountains and were analyzed for organochlorines (OCs), PCBs and PCCs. Extreme care was taken during sample work.up and analysis to prevent contamination.

Full glassware trains and solvent

proofs were analyzed with each batch of samples to guard against artifacts. Detection limits of 1 - 2 ng/g for PCCs in fish muscle were obtained.

ANALYSIS The analytical flow chart is provided in Figure 1. The florisil clean-up is an adaptation of the method developed by M. Zell and I~ Ballschmiter 1. Gas chromatographic conditions for the 1873

1874

analysis for OCs, PCBs and PCCs are shown in Figure 2. The use of a Townsend discharge tube = coupled with the use of oxygen as an oxidizing gas, resulted in g o o d sensitivity for PCCs. Mass spectrometer conditions for ONEC-MS are shown in Figure 3. The Finnigan 700, 3000 or 4500 series mass spectrometers can a c c o m m o d a t e a Townsend discharge tube for ONEC-MS. 10g HOMOGENIZED RSH TISSUE - PCNB Surrogate Added - Extract 2 X wlth CH~CN

I COMBINED CI-I=CN EXTRACT . Diluted with water and partitioned into Hexane - Dry (N=2SO4) - Con(~'Ltmted by Roto- evaporator

I I

FLORISIL CLEAN.UP 26g, 1.25% Deactivated

I

I FRACTION I (60 mL HEXANE) 1 mL Rnal Volume

I FRACTION II (lS0 mL of 30% DCM/HEXANE) 1 mL Rnal V e l u m

PCB, DDE by GC/ECD OCs by GC/ECD PCC by ONCI GC/MS >95% Toxaphene,< 5% PCB

>95% PCB,<5% Toxaphene

R g u r e 1: A n a l y t i c a l F l o w Diagram

A) PCC (GC/MS)

B) PCBe, ORGANOCHLORINES(GC/ECD)

DB5 Capillary Column 0.S2mm X 25M X 0.25pro Injector Temp. - 280 o C Transfer Une - 800 o C Temperature 1 -120°C Ramp Rate - 10 °/minute Temperature 2 - 800°C (5 min.)

DB1801 Capillary Column 0.25mm X 30M X 0.25pm Injector Temp. - 250 o C Detector Temp. - 300 o C Temperature 1 - 100°C for 0.5 min. Rate - 6 o/minute Temperature 2 - 280°C (4 min.)

Figure 2: GC C o n d i t i o n s

1875

Townsend Discharge @ 800-1000V and O.6ma Oxygen Ionization - Source Pressure - 0.43 torr. Total Scan Time - 1.0 minute Ion Source Temp.- 120 ° C Multiplier- 1250V SELECTED IONS (M/Z) CI7 - Camphene - 8 4 1 , 3 4 8 , 845 CIe - Camphene - 875, 377, 87g Cl o - Camphene - 4 1 1 , 4 1 3 , 415

[M-l] for Cl7 - 339; CI~- 37S; t i p - 411 Figure 3: ONEC/MS Conditions

The components chosen for each chlorine PCC group were free from other organochlorine Interferences such as cis and trans chlordane, nonachlor, and major PCB congeners. Selected ion monitoring of 2 - 3 ions per chlorine group from CI7-CI0 were used since the most intense peaks were found to be in these groups. A Toxaphene standard at 100 ng/g for CIT-cemphene (m/z 343) is shown in Figure 4.

936 100.0

904 970

M/Z

~ 13:20

1 ~ 15:00

i 16:40

Scan Time

Figure 4: Toxaphene Standard at 100 ng/g

18:210

1876

Selected ion chromatograms obtained for fish muscle containing PCCs at 30, 4 and < 2 ng/g are shown in Figures 5 - 7 respectively.

lOO.O

1

936

1

903

1

973

M/Z

l

13:20

15:00

16:40

I

18:20

Scan Time

Figure 5: Fish Muscle at 30 ng/g

100.0

937

1

904

974

|

13:20

|

15:00

16:40

Scan Time

Figure 6: Fish Muscle at 4 ng/g

|

18:20

1877

882 100

343 M/Z

,3:2°

,;:oo

Scan Time

,~,o

,.:~o

Figure 7" Fish Muscle at < 2 ng/g

CI 7 - PCCs can be detected at levels as low as 1 ng/g. Selected ion monitoring chromatograrns for CI 7 - CI O PCCs are shown in Figures 8 and 9.

Figure 8 shows

chromatograms obtained for a 0.5 pg/mL toxaphene reference solution and Figure 9 shows chromatograms obtained for a fish muscle sample containing 20 ng/g of selected PCC congeners.

379

CIg

413

i Ions)]/ (9

' /L

RIC /

,~ '

• .,,-m~ ~ A,

15:00

15:50

14S6

"

' A~'~

N~

/ L , -L/V ' yv' V ~ , - , J 3 •~ . ,

16:40

17:30

18:20

' 19776

--

~

19:10

20':00

Scan Time

Figure 8: Cl 7 - Cl 9 Selected Congeners for a Toxaphene Standard

1878

Cl7

•

J

Cle 379 1

.I

~

I*

,49

,

CI~)413

4400

1 RIC ~

/ 1~00

12256

,5:50

1~':40

1;:30

1;:20

19:10

20':00

Scan Time

Figure 9: CI 7 - CIe Selected Congeners for a Fish Sample at 20 ng/g

DISCUSSION Isolation of PCCs from PCBs is crucial when analyzing environmental sample using ONEC/MS. A single response factor for all the CI7 - CI9 PCC components was used to calculate PCCs. Since the metabolized PCC patterns in environmental samples are different from a Toxaphene standard, the choice of congeners can greatly affect the quantitation of PCC. For this reason, quantitation without individual PCC congeners is an estimation at best.

REFERENCES 1 M. Zell and K Ballschmiter, Anal. Chem., 300, 387-402 (1980). 2 D. F. Hunt et al, Anal. Chem., Vol. 47, No. 11, 1730-1734, (Sept. 1975)