Petroleum hydrocarbons in the surface water of two estuaries in the Southeastern united states

Estuarine Coastal and Shelf Science (1990)

Petroleum Hydrocarbons Water of Two Estuaries United States

T. F. Bidlemana9b~c W. T. Foremana,e,

30,91-109

in the Surface in the Southeastern

, A. A. CastleberryaJd, M. T. Zaransk@ and D. W. Wall”

“Department of Chemistry, bMarine Science Program, and ‘Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208, U.S.A. Received 24 October 1988 and in revised form 31 July 1989

Keywords: petroleum; hydrocarbons; chromatography; water; estuaries

oil

pollution;

fluorescence;

gas

Surface water samples from Charleston Harbor, SC and Winyah Bay, SC were analysed for total hydrocarbons by gas chromatography (GC) and for petroleum residues (expressed as crude oil equivalents) by fluorescence spectrometry. Cleanup by column chromatography and saponification was necessary to reduce the background from extraneous fluorescing materials. Oil concentrations determined by FS ranged from 0525 pg 1-l in Charleston Harbor and < 0.23-9.6 pg 1-l in Winyah Bay. Hydrocarbons determined by GC were significantly correlated (P< 0.01) with crude oil equivalents determined by FS, but the data showed considerable scatter as indicated by r2 = 0.45. Polycyclic aromatic hydrocarbons were determined by gas chromatography-mass spectrometry for one set of Winyah Bay samples. The sum of nonalkylated polycyclic aromatic hydrocarbons having23 rings ranged from 7-64ng 1-l at different stations. Perylene, possibly originating from sediment dredging, was one of the more abundant polycyclic aromatic hydrocarbons. Introduction The pressure of industrial development and rising populations in the coastal zone is likely to result in increased pollutant loadings to estuaries. Pathways of anthropogenic hydrocarbons into water bodies are diverse. In addition to oil inputs from spills, lakes and estuaries receive chronic inputs from a variety of sources including industrial discharge, marinas (Marcus et al., 1988; Voudrias & Smith, 1986), urban runoff (Hoffman et al., 1984, 1985; Hunter et al., 1979), and atmospheric fallout (McVeety & Hites, 1988; Wakeham, 1977). Petroleum contamination of seawater is assessed by several methods. Tows with a neuston net are used to determine the distribution of tar lumps in the water column (Butler Present addresses: TH2M Hill, 2567 Fairlane Drive, P.O. Box 230 Montgomery, Alabama, 36106; ‘National Water Quality Laboratory, U.S. Geological Survey, 5293 Ward Road, Arvada, Colorado, 80002; and ‘Environmental Analytical Research Laboratory, Dow Chemical U.S.A., 734 Building, Midland, Michigan 48667, U.S.A. 0272-7714/90/010091+20$03.00/0

@ 1990 Academic

Press Limited

92

T. F. Bidleman et al.

et al., 1973). Dissolved hydrocarbons and those associated with small particles are

extracted from seawater with an organic solvent and measured by gas chromatography (GC), GC combined with mass spectrometry (GC-MS), infrared, and fluorescence spectrometry (FS) (National Academy of Sciences, 1985). The fluorescence of crude oils and refined petroleum products is due to polycyclic aromatic hydrocarbons (PAH), and FS has frequently been used to determine petroleum in seawater (Keizer et al., 1977; Gordon et al., 1974, 1978; Law, 1981; Fogelqvist et al., 1982, Maher, 1983; Law et al., 1983; El Samra et al., 1986; Knap et al., 1986), sediments (Hargrave & Phillips, 1975; Hoffman et al., 1979; Wakeham, 1977; Keizer et al., 1978; Levy et al., 1981; Law et al., 1983; Douabul et al., 1984; Zarba et al., 1985; Agard et al., 1988), and biological samples (Fong, 1976; Jackson et al., 1981; Litten et al., 1982; Law et al., 1983; Mason et al., 1987; Farrington et al., 1986; Jackson & Bidleman, 1989). A major drawback of FS is that the aromatic content of crude and refined oils varies substantially. If one knows the source of pollution, for example a spill of No. 2 fuel oil, the oil can be chosen as a reference for FS measurements. However, in casesof chronic oil pollution, the sources are varied and the choice of a reference oil is arbitrary. In such situations, FS provides only an estimate of the oil concentration. Advantages of FS are that the technique is faster than GC, allowing the distribution of relative oil concentrations in an areato be carried out in a shorter time. FS alsorespondsto aromatic hydrocarbons, the most toxic fraction of petroleum products. Mutagenicity in Salmonella strains hasbeen correlated to the fluorescence intensity of sediment and sludge extracts (Litten et al., 1982). Farrington et al. (1986) suggestedusing FS in a hierarchical schemeof analysis: samplesjudged to have a substantial petroleum content by FS screening can be selected for more quantitive analysis by GC. The goals of this work were to survey hydrocarbon concentrations in the surface waters of two estuaries in the southeastern United States, Winyah Bay and Charleston Harbor, South Carolina, and to compare FS and GC methods of analysis.

Experimental Locations

During the study, 94 sampleswere taken in Winyah Bay and 37 in Charleston Harbor at the stations shown in Figures 1 and 2. Some stations were sampledonly once, others up to nine times in different months. Replicate sampleswere frequently taken. Winyah Bay (Figure 1) is a relatively clean estuary adjacent to Georgetown, S.C. Main rivers feeding the bay and their mean daily discharges(m3 d-l) are (Clark & Benforado, 1980): the Great and Little Pee Dee Rivers (3.0 x 107), the Waccamaw River (2.8 x 106), and the Black River (2.1 x 106).Most of the likely contamination sourcesare on or near the Sampit River, a stream near Georgetown which contributes lesswater to the bay than the other three rivers (Figure 1). Stations 4 and 5 were located near a paper mill and a steel mill. Commercial fishing trawlers docked near Station 6. Station 10 was outside a small recreational marina. Sampleswere taken in Winyah Bay on ten occasionsin 1981-83, and once in 1988. Charleston Harbor (Figure 2) is formed by the junction of the Cooper, Wando, and Ashley rivers. The harbour is more developed than Winyah Bay. Numerous industries, a naval shipyard, and oil depots are located along the Cooper River between Stations 1 and 4. Stations 5 and 9 were at small boat docking facilities, and Station 7 was inside one of the

Petroleum hydrocarbons in two estuaries in U.S.

93

Atlantic

Ocean

012345

Figure

1.

Sampling

locations

in Winyah

Bay, SC.

many marinas on the harbour. In addition to these point sources, the harbour receives runoff from the city of Charleston. Charleston Harbor hasundergone changesin its recent history due to manipulation of riverine input (Kjerfve, 1976; Kjerfve & Magill, 1989). Prior to 1941, the mean daily flow from the Cooper River was only 1.7 x lo5 m3. In 1941, most of the drainage from the Santee River was diverted to the Cooper River, raising the mean daily flow to 3.6 x lo7 m’. Increased sediment transport to the harbour resulted in extensive shoaling, and constant dredging was needed to keep the shipping channel open. In 1985, about 700,, of the Cooper River flow was rediverted to the Santee River, dropping the mean daily flow to 1.1 x lo7 m3 (Kjerfve & Magill, 1989). This work wasdone on six datesbetween 1982-84, before the rediversion project, when the mean daily flow from the Cooper was sill 3.6 x 10’ m3. By comparison, mean daily flows from the Wando and Ashley Rivers were only 6 x lo5 m3 and 1.7 x lo5 m3 (Kjerfve, 1976). Sample

collection

and preparation

Water sampleswere collected from the bow of a small boat, powered by a gasoline outboard motor. A 4 1glassjug was held approximately 20-50 cm below the surface and filled with 3-l-3.6 1water while the boat wasmoving slowly forward. This volume wassufficient for FS analysis; extracts from two bottles were combined for GC determinations. The bottles had caps lined with polytetrafluoroethylene, and previously contained chromatographic quality solvents. The unfiltered water was extracted by adding 350-400ml chromatographic quality dichloromethane to the collection bottles and rolling the bottles for 3 h or longer on a jar

94

T. F. Bidleman et al.

N32O50’.

Figure

2.

Sampling

locations

in Charleston

Harbor,

SC.

mill. The dichloromethane was drawn off through a plug of glasswool and concentrated to 10-20 ml on a flash evaporator. Approximately 10ml hexane was added, and the extract was reduced to 2-3 ml in a Kuderna-Danish apparatus or by nitrogen blow-down. The extract was transferred to a 2 g column of activity grade III (6% added water) neutral alumina topped with 1 cm anhydrous sodium sulfate, and the column was eluted with 20 ml 20% dichloromethane-petroleum ether. The eluate was then analysed by FS. After alumina chromatography, the sampleswere saponified to provide a futher cleanup for a second examination by FS and for the determination of hydrocarbons by GC. The extract was reduced to < 05 ml, 1.0 ml of 05 M KOH in 90% methanol-water was added, and the sample was refluxed for 15 min. After cooling, 5 ml distilled water was added and the hydrocarbons were extracted with three 3 ml portions of petroleum ether. The combined extracts were diluted to 20ml with 20% dichloromethane-petroleum ether for FS work, and then concentrated to 50-150 ul for GC analysis.

Petroleum hydrocarbons in two estuaries in U.S.

95

Most sampleswere analysed without fractionation. A few extracts were separated on a column of 3 g silicic acid containing 5% added water overlaid by 2 g activity grade III neutral alumina and eluted with 30 ml petroleum ether (Fraction 1) followed by 30 ml 20°b dichloromethane-petroleum ether (Fraction 2). Fraction 1 contained the n-alkanes and most of the unresolved complex mixture (UCM); Fraction 2 contained the PAH (Keller & Bidleman, 1984). Fluorescence

Analysis

FS measurements were made in a 1.0 cm silica cell using a Perkin-Elmer MPF-43A spectrofluorimeter. Spectra of samplesand reference oils were taken in the synchronous mode by scanning the excitation (EX) and emission (EM) monochromators simultaneously with a 10 nm offset and 5 nm bandpasses.Reference oils examined were South Louisiana crude (SLC), No. 2 fuel, and No. 6 fuel oils, obtained from the American Petroleum Institute. Quantitative measurementswere made against SLC and No. 2 fuel oil. Samplesfrom Winyah Bay were only analysed us. SLC; both oils were used in Charleston Harbor work. Wavelengths (5 nm bandpasses)selectedwere: SLC, 320 nm EX, 380 nm EM; No. 2 fuel oil, 280 nm EX, 325 nm EM. After an initial measurement of fluorescence intensity, sampleswere diluted 2-3 fold and the fluorescence was redetermined to ensure that hydrocarbon concentrations were within the linear range. Gas chromatographic

analysis

GC determinations were done on a 180 cm x 0.3 cm id. glasscolumn packed with 3”, Dexsil-300 on 100/120-mesh Supelcoport, mounted in a Packard 7300 serieschromatograph with aflame ionization detector (FID). The carrier gaswasnitrogen at 30 ml/min-‘. Sampleswere injected at a column temperature of 80°C. After a 5-min hold, the column wasprogrammed at 8” min-’ to 270°C. Injector and detector temperatures were 220” and 280”. Quantification was based on FID responsefactors, derived from a seriesof n-alkane external standards in the n-C,, to n-C,, range. An n-alkane internal standard was added after sampleblow-down to allow solution volumes to be determined. Hydrocarbon concentrations were basedon the total area of chromatograms between the retention times of n-C,, and n-C,, (resolved plus unresolved components). The ability of the integrator (Varian CDS 111) to correctly evaluate total areas of complex chromatograms was checked by injecting 4-10 ug of No. 2 fuel oil and quantifying the resulting chromatograms us. n-alkane standards. Ten determinations yielded 117+ 129,) recovery of the fuel oil. Near the end of the project we acquired a Hewlett-Packard 5890 GC-5970 seriesMass Selective Detector, enabling individual PAH in the August, 1988 samplesto be determined by capillary GC-MS. This work was done using a 30m methyl silicone, 6O;, cyanopropylphenyl bonded-phase fused silica column (DB-1301, 0.25 urn film, J & W Scientific, Inc., Folsom, CA, U.S.A.) and He carrier at 30-40 cm s-i. The temperature program was: inject at 90”, hold 1.0 min, program at 20” min’ to 120”, then at 5” min-’ to 270”. Quantitative determinations were done by selected ion monitoring (SIM) of the following ions: fluorene (166), phenanthrene, anthracene (178) methylphenanthrenes and methylanthracenes (192), fluoranthene, pyrene (202), benz(a)anthracene, chrysene (228), benzofluoranthenes, benzopyrenes, perylene (252).

96

T. F. Bidleman et al.

A//

1

1

1

300 290

A

1

I

1

1

No.6fuel

1

400 390

Figure 3. Synchronous February 1983, and three

1

I

I

1

1

500 490

fluorescence oil standards.

fi

EM EX

spectra

of samples

from

Charleston

Harbor,

Results and discussion Spectral

Characteristics

of Water Extracts

EM spectra of petroleum mixtures taken at a constant EX wavelength are broad and featureless. Greater spectral detail is obtained from complex mixtures of aromatic hydrocarbons by simultaneously scanning the EX and EM monochromators with a constant wavelength offset (usually 10-25 nm)(John & Soutar, 1976; Wakeham, 1977; Law, 1981; Vo-Dinh et al., 1981). Such synchronous spectra provide more information about the aromatic content of the sample, since individual PAH show relatively narrow bands at wavelengths that increase with higher ring number (Vo-Dinh et al., 1981). Maximum emissionis observed between 310-330 nm for 2-ring aromatic hydrocarbons, 340-380 nm

97

Petroleum hydrocarbons in two estuaries in U.S.

TABLE

1. PAH

in the Sampit

River

and Winyah

Bay’, August

1988 (ng l--l)

Station 1

Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benz(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(e)pyrene Benzo(a)pyrene Perylene SLUIl

‘Dissolved

plus particulate

1.8 1.2 < 0.04 1.7 1.0 <0.04 0.2 <0.04 < 0.04 0.09 10.04 0.8 6.8

6 10 20 1.6 15 10 0.8 l-4 0.6 0.3 0.4 0.2 3-8 64

7 1.7 1.5 < 0.04 2.0 1-2 0.07 0.3 0.05 <0.04 0.06 < 0.04 6.2 13

10 0.6 1.6 <0.04 2.1 1.5 0.17 0.4 0.2 0.1 0.2 <0.04 13 20

PAH.

for 3- and 4-ring PAH, and above 400nm for 5-ring and higher-ring compounds (Wakeham, 1977). Synchronous spectra of water samplesfrom Charleston Harbor are compared to spectra of SLC and Nos 2 and 6 fuel oils in Figure 3. Strong emission in the 300-330 nm region suggestedthe presenceof two-ring aromatic hydrocarbons in the water samples.Evidence of higher-ring PAH was alsoindicated by the hump near 410 run. Spectra of samplesfrom Winyah Bay were similar to those from Charleston Harbor. A band of varying intensity near 440-450 nm appeared in the spectra of most samples from Charleston Harbor (Figure 3) and Winyah Bay. Wakeham (1977) observed a similar band in synchronous spectra of 14-42 cm deep sedimentsdeposited in Lake Washington (State of Washington) around or before 1900; the band was absent from the O-2 cm sediment layer. The responsible compound was identified by Wakeham as perylene, a PAH. Water sampleswere collected from the Sampit River and the upper portion of Winyah Bay in August, 1988 for the analysis of perylene and other PAH. Synchronous spectra of water extracts after alumina chromatography and saponification showed bands near 440-450 nm which were intense for Stations 6,7, and 10, and weaker for upriver Station 1. The position and shapeof the bands matched those of authentic perylene. The samples were fractionated on an alumina-silicic acid column, and perylene was identified in the Station 10 extract by its massspectrum and coincidence of the analyte retention time with that of authentic perylene. The concentrations of perylene, determined by SIM, ranged from 0.8 ng 1-l at Station 1 to 13 ng 1-i at Station 10 (Table 1). EM spectra of perylene at a constant EX wavelength show maxima at 440nm and 460nm and no fluorescence below 410nm (LaFlamme & Hites, 1978). A standard solution of perylene having the same concentration as the Station 10 extract gave no measureablefluorescence when measured at 320 nm EX, 380 nm EM, the wavelengths used for quantification of oil as SLC equivalents. Thus, perylene at the concentrations found here causedno interference in the FS determination of oil.

98

T. F. Bidleman et al.

Figure 4. Chromatograms of three API reference oils and an outboard ing oil. For reference, even-chain n-alkanes are numbered on the SLC

motor lubricatchromatogram.

Perylene is derived largely from the diagenesis of natural organic material. Once thought to originate from precursor pigments in fungi and insects, and therefore a biomarker of terrestrial organic matter, perylene is now recognized to have aquatic sourcesas well. Reviews of perylene geochemistry (Louda & Baker, 1984; Venkatesan, 1988) concluded that conditions favourable for the formation and preservation of perylene are

Petroleum hydrocarbons in two estuaries in U.S.

99 -

IS

Station

8

18

011 slick Station

6

Figure 5. Chromatograms of Winyah Bay samples (September, 1982, top and middle), and of an oil slick from the Sampit River (November 1982, bottom) showing positions of the even-chain n-alkanes. The internal standard (IS) in Stations 5 and 8 samples is n-C,,; no IS was used in the slick sample. Peakmarked (*) isanartifact.

anoxic marine environments and terrigenous peat deposits. Highest concentrations of perylene were found in diatomaceous sediments deposited from productive waters under conditions where sediment anoxia developed during or shortly after deposition. Sediments deposited under oxic conditions contained little perylene (Louda 81Baker, 1984). Perylene may have anthropogenic sources as well. Relative to other PAH, perylene occurs to only a minor extent in fossil fuels. However perylene is a common PAH in

100

T. F. Bidlemanet

al.

Station

6

I *L Station

4

Figure 6. Chromatograms of samples from the Cooper River in Charleston Harbor, February, 1984. The internal standard (IS) is n-C,,. Peaks marked (*) are artifacts.

ambient air particulate matter, and urban runoff of atmospherically deposited PAH could be a source of perylene to nearshore environments (Venkatesan, 1988). Perylene was abundant in the August, 1988 water samplesrelative to other pyrogenic PAH such as benzopyrenes and benzofluoranthenes (Table l), so the major source in Winyah Bay is unlikely to be anthropogenic. Since perylene is found mainly in reducing sediments,we were surprised to discover it in the upper water column. Both Winyah Bay and Charleston Harbor are continually being dredged to keep shipping channels open, which may result in resuspension of perylene-containing sediment. The water samples were unfiltered, thus the hydrocarbons found were dissolved plus particulate. Gas chromatographic characteristicsof water extracts Packed-column chromatograms of oil standards showed resolved components superimposed on a UCM (Figure 4). In the caseof outboard motor oil, the resolved components were only minor. Dell’Acqua et al. (1975) alsopresented chromatograms of a transmission fluid and three lubricating oils which contained UCMs devoid of resolved components. Prominent features in chromatograms of samples from Winyah Bay (Figure 5) and Charleston Harbor (Figures 6 and 7) were UCMs centered around the retention times of

Petroleum

hydrocarbons

in two estuaries

101

in U.S.

16 IS

Station

Station

4

4

F.2

Figure 7. Chromatograms of the Station 4 sample shown in Figure 6, after fractionation on alumina-silicic acid. Numbers indicate positions of the even-chain n-alkanes. Peaks marked (*) are artifacts.

n-c,, to n-c,,.

These UCMs and fluorescence in the 300-400 nm region (Figure 3) suggested that the water-borne hydrocarbons in the two estuaries were derived from fuel and lubricating oils. Although the presence of two-ring PAH was indicated by FS (Figure 3), these compounds and n-alkanes lighter than n-C,, were not found by GC. The light hydrocarbons were probably lost during the concentration of extracts for GC determinations (see part (i) of next section). Figure 7 shows chromatograms of the Charleston Harbor Station 4 sample in Figure 6 after fractionation on an alumina-silicic acid column. The shape and position of the UCM in the non-polar fraction was similar to one shown by Gordon et al. (1978) for a water sample from Bedford Basin, Nova Scotia. A large peak occurred at retention index 2050, and similar peaks were found in unfractionated samples from Winyah Bay (Figure 5). Gordon et al. (1978) observed a large peak at a retention index of 2052 (OV-101 column in Bedford Basin samples, and suggested that it might be 3,6,9,12,15,18-heneicosahexaene, the dominant hydrocarbon in marine phytoplankton (Blumer et al., 1971).

T. F. Bidleman et al.

102

TABLE

2. Recovery

of hydrocarbons

from

Concentration M/L

Hydrocarbon” SLC SLC No. 2 fuel n-c,, n-c,, - n-c,,

40-200 9-20 25 091.1 0.7-1.1

fortified

estuarine Analytical Methodb FS FS FS GC GC

water

samples % Recovery + S.D. (n) 81& 3(4) 78k 12 (8) 83f l(2) 54k28 (3) 100_+13(4)

‘SLC = South Louisiana crude oil. bFS = fluorescence spectrometry, GC = gas chromatography.

Quantitative Recovery of hydrocarbons

Analysis

from fortified water samples Known quantities of hydrocarbons were added to seawater and carried through the analytical procedures. SLC and No. 2 fuel oils were quantified by FS; GC wasused for the analysisof samplesspiked with n-alkanes. Results (Table 2) indicated 7883% recovery of SLC and No. 2 fuel oils. Loss of n-C,, (and presumably lighter hydrocarbons) was observed, probably by volatilization when blowing the sample down to < 100 ul, but n-C,, through n-C, were recovered in good yield. (ii) EfJect of sample cleanup on fluorescence analysis In many investigations of oil in coastal and open-ocean waters, FS measurementshave been done on solvent extracts of water sampleswithout the benefit of a cleanup step. We found that the fluorescence of Winyah Bay and,Charleston Harbor samplesat the wavelengths used for SLC quantification (320 nm EX, 380 nm EM) was reduced by factors of 5-10 by passingthe extracts through an alumina column. In most casesa further but less dramatic reduction is fluorescence wasachieved upon treatment of the sampleextract with alcoholic KOH. The fluorescence of 65 water samplesfrom Winyah Bay and 19 from Charleston Harbor was measuredafter alumina cleanup and again after the saponification step. The relationship between SLC equivalents (ug 1-l) found in water samplesafter (C,,) and before (C,J saponification was: (i)

C,, = 1.09 C,, - 0.40 ? = 0.89, n = 84

(1)

Since analytical recoveries of SLC and No. 2 fuel oils were approximately 80y0 (Table 2), the fluorescing material removed by the cleanup stepswasnot due to petroleum products. From equation 1, when C,, = 0, C,, = O-37ug 1-t of nonpetroleum fluorescing material that wasremovable by alcoholic KOH treatment. In summary, FS measurements on water extracts before alumina cleanup greatly overestimated their petroleum content, and at low oil concentrations a saponification step was also needed to reduce extraneous fluorescence. Whether saponification alone would provide sufficient cleanup was not investigated. (iii) Hydrocarbon concentrations in the surface waters of Winyah Bay and Charleston

Harbor

FS results were quantified asSLC equivalents for Winyah Bay, and SLC and No. 2 fuel oil equivalents for Charleston Harbor. Although we knew of no crude oil sourcesinto the estuaries, SLC was chosen for two reasons.Several investigators have used crude oils as FS standards to estimate petroleum levels in coastal and open-ocean waters. Also, when

Petroleum

hydrocarbons

TABLE 3. Average Bay and Charleston

1 2 3 4 5 6 7 8 9 10 11 12 13 14 Charleston 1 2

3 4

5 6

7

8

9

concentrations Harbor”

Times’ sampled

Stationb

Winyah

in two estuaries

Methodd

in U.S.

of oil equivalents

Range Ml ‘1

103

and total hydrocarbons

Positive/ total’

in Winyah

Mean of positives i S.D. (ug 1 ‘)

Bay 7 3 2 3 5 4 9 6 5 1 2 7 5 2 2 2 1 1 1 2

FS FS GC FS FS GC FS

(SLC) (SLC) (SLC) (SLC) (SLC)

&LC) GC FS (SLC) FS (SLC) GC FS (SLC) FS (SLC) FS (SLC) FS (SLC) FS (SLC) GC FS (SLC)

Harbor 5 5 5 4 5 1 1 5 4 5 1 5 4 5 4 4 3 5 4 5

&LC) FS W) GC FS (SLC) FS W) GC

1

FS (SLC)

0.26-1.0 0.29-0.33 <0.6 0.59-1.8 0.53-8.3 0.7-30 0.65-9.6 1.1-4.5 0.81-3.1

717 313

0.38-1.1 < 0.23-0.90
2/2

FS (SLC) GC FS (SLC) FS WI GC FS (SLC)

0.82-3.1
&LC)

0.45-25 1.3-14
W#2) GC FS (SLC) FS (SLC) FS W)

0.86-18 0.94-8.8 0.8-5.9 4.2-l 1 1.7-6.9 0.9-3.8 0.62-4.5 0.83-2.3
0.52 k 0.29 O-30*0.02

o/2 313 515 414 919

616 5/5 l/l 617 215

l/2 l/2 o/2

l-3+0,63 3.7 f 3.4 8.7+ 14 3.1 k2.7 1.9k1.3 2.OkO.82 3.1 o-74*051 0.53 i 0.25 1.3kO.60 1.1 1.1

O/l O/l O/l

w

0.63 i 0.33

515 315 5/5 4/4 515 l/l l/l 515 414 415 l/l 5/5 414 515 414 414 313 515 414 315

1.6kO.87 1.3kO.32 2.7k1.7 3,0+ 1.8 2.8k1.9 0.49 1.1 63* 10 4.8f6.1 3.3i3.7 7.2 5317.4 3.0f3.9 2.7k2.1 6.8k2.9 3.322.4 2.2* 1.5 1.9* 1.5 1.4kO.6 1.1 kO.38

l/l

13

“Particulate plus dissolved hydrocarbons; concentrations have been corre’cted for average blank values. bFigures 1 and 2. ‘Number of times (in different months) that a station was occupied. Replicate samples were often taken at a station (see text). dFS =fluorescence spectrometry, results expressed as South Louisiana crude oil (SLC) or No. 2 fuel oil ($2) equivalents. ‘Proportion of sampling periods in which positive results were obtained.

104

T. F. Bidleman

et al.

TABLE 4. Comparison of oil equivalents fluorescence spectrometry Location Winyah Bay Stations l-10 Stations 11-14 Charleston Harbor Bedford Basin, Nova Scotia Gulf of St. Lawrence Nova Scotia Shelf North Atlantic, Nova Scotia to Bermuda Irish Sea Western English Channel Eastern English Channel and Southern North Sea Northern North Sea Arctic Ocean Arabian Gulf Qatar Saudi Arabia Kuwait Southern Baltic Sea

Range,

ug 1~ ’

< 0.23-9.6 <0.23-0.86 0.45-25 0.66-14 16-9.3 06-1.1 0.2-0.8 0.8 (mean, 1 m) 0.4 (mean, 5 m) 2.1-3.5

in coastal and open-ocean

Standard

SLC SLC SLC No. 2 fuel Guanipa

estimated

by

Reference

This This This This crude

waters,

Keizer

work work work work et al., 1977

Guanipa crude Guanipa crude Venezuela crude Venezuela crude Ekofisk crude

Keizer et al., 1977 Keizer et al., 1977 Gordon et al., 1974 Gordon et al., 1974 Law, 1981

1.1-1.7

Ekofisk

crude

Law,

1.7-3.1 1.1-1.7 0.05-0.2

Ekofisk Ekofisk Kuwait

crude crude crude

Law, 1981 Law, 1981 Fogelqvist et al., 1982

1.2-428 4.3-546 2.1-3.6

Kuwait Kuwait Kuwait

crude crude crude

El Samra et al., 1986 El Samra et al., 1986 El Samra et al., 1986

2.0-130

Ekofisk

crude

Law and Andrulewicz,

1981

1983

the Winyah Bay study was initiated there were plans (now defunct) to build a refinery on the Sampit River and ship crude oil up the bay. Thus, a knowledge of baseline petroleum levels in the water in terms of crude oil equivalents was desired. A summary of hydrocarbon concentrations determined by FS and GC is given in Table 3. Mean blank values and their standard deviations were: FS, 0.23 f 0.13 ug 1-l (n = 16); GC, O-6+ 0.3 ug 1-l (n=9). A sample was considered positive if its uncorrected hydrocarbon concentration exceeded the average blank by two standard deviations. For FS analysis, 32 replicate sets of samples were taken, 2-6 samples per station. Per cent relative standard deviations (% RSDs) ranged from 3-97%, with an average of 35%. Duplicate samples were collected on six occasions for GC determinations; o/oRSDs ranged from 5113% and averaged 40%. By comparison, samples spiked with SLC, No. 2 fuel oil, or n-C,,-n-C,, alkanes yielded recoveries with average y0 RSDs of 15% or lower (Table 2). The variability in replicate samples from the estuaries probably represents real differences, caused by inhomogeneities in hydrocarbon concentrations within the water column. Winyah Bay was the less contaminated of the two estuaries. The only location where hydrocarbons were consistently above blank values was the Sampit River (Stations 1-7, Figure 1). Hydrocarbons were at or near the detection limit in the middle and lower bay, with the exception of two apparently elevated samples taken at the mouth of the bay (Station 14). On both sampling trips the water was choppy in this region, and the possibility that some contamination from the boat motor occurred cannot be ruled out.

Petroleum

hydrocarbons

in two estuaries

in U.S.

105

MEPH

8000 6000

2000 E G : :

0

10000 8000 6000k

2000 4000

E

E o- F Time

(min)

Figure 8. PAH in samples from Winyah Bay, August 1988 (GC-MS). Abbreviations: anthracene = AN, methylphenanthrenes = fluorene = FLE, phenanthrene = PH, benz(a) MePH, methylanthracenes = MeAN, fluoranthene = FLA, pyrene = PY, benzo(k) anthracene = BAA, chrysene = CHRY, benzo(b)fluoranthene = BBF, fluoranthene = BKF, benzo(e)pyrene = BEP, benzo(a)pyrene = BAP, perylene = PERY.

Petroleum pollution wasmore prevalent in Charleston Harbor, aswould be expected from the greater burdens placed on this estuary. Oil concentrations, expressedasSLC equivalents, are compared to crude oil equivalents reported in other coastaland open oceanwaters in Table 4. In the middle and lower portions of Winyah Bay, concentrations of SLC equivalents were similar to the relatively low levels in the Gulf of St Lawrence, in western North Atlantic waters on the Nova Scotia shelf, and between Nova Scotia and Bermuda. Crude oil equivalents in Charleston Harbor and in the lower Sampit River of Winyah Bay were similar to levels in coastal waters around the U.K., the North Sea, and Bedford Basin, Nova Scotia (Table 4). However, differences in hydrocarbon concentrations among locations are difficult to interpret because various crude oils were used for quantification rather than a standard reference material. PAH having three or more rings were identified at four stations in the Sampit River and upper Winyah Bay in 1988 (Figure 8). Concentrations of unsubstituted PAH were in the Pkt 1-I to ng 1-l range (Table 1); methylated 3-ring compounds were also found, but were not quantified. PAH concentrations were highest in the Sampit River at Station 6, in the vicinity of commercial fishing boats. Perylene wasthe dominant PAH at Stations 7 and 10, and one of the more abundant compounds at Stations 1 and 6 (Table 1). (iv)

Comparison

offluorescence

spectroscopy

andgas

chromatography

Fifty-nine samples,25 from Winyah Bay and 34 from Charleston Harbor, were analysed by both GC and FS. In comparing the two techniques, two sampleswere omitted from the Winyah Bay set because their GC-determined hydrocarbon concentrations greatly exceededthe FS results. One wasan oil slick that showeda lighter hydrocarbon pattern by GC than did the subsurface samples(Figure 5); the other wasa samplefrom Station 4 that appeared to contain relatively high concentrations of nonpetroleum material. Samples with hydrocarbon concentrations below the detection limit by one or both techniques

106

T. F. Bidleman et al.

0

FS (SLC

equlvolentsl

(pq

I-‘) 0

0 0

0

0

0 0 0

0

4 0

“0 0 0

J *O

0

40

00 ox

0 0)O

0 0 0

0

Log FS (SLC

Figure graphy (upper), (lower)

O

equivalents)

0

(+g l-‘1

9. Comparison of hydrocarbon concentrations determined by gas chromato(GC) and fluorescence spectrometry (FS). Parameters for the regression line based on 45 points, are given in Table 5. Data are also plotted on a log scale to better show the distribution of points in the low concentration region.

TABLE 5. Relationships fluorescence spectrometry

Winyah Bay Charleston Harbor Combined

between hydrocarbon concentrations (C,,) and gas chromatography(&)

(ug 1-l) determined Co, = m C,, + b

m

b

rz

n

0.35 0.31 0.31

1.26 1.20 l-25

0.39 0.45 0.45

15 30 45

by

Petroleum

hydrocarbons

in two estuaries

in U.S.

were also not included. Results for the remaining 45 samples were significantly (P < 0.01) through: C,,

=

mC,,

+ b

107

correlated (2)

where Co, and C,, are the total hydrocarbon concentrations determined by GC and SLC equivalents determined by FS (both in ug 1-l). Parameters for equation 2 were similar for Winyah Bay and Charleston Harbor (Table 5); a plot of the combined data set is shown in Figure 9. From Equation 2 and Table 5, the two techniques gave the same results at 1.8 ug 1-l. At lower hydrocarbon levels, GC results were higher. An explanation might be the presence of nonfluorescent biogenic hydrocarbons or polar organic compounds which survived saponification cleanup. Since most samples were analysed without silicic acid fractionation, substances of the latter type could have led to overestimation of hydrocarbons by GC. For Co, > 18 ug l-t, GC determined hydrocarbons were lower than FS estimates. Hoffman et al. (1979) compared GC and FS analysis of hydrocarbons in sediments from the vicinity of the Argo Merchant wreck site off the Massachusetts coast. No significant correlation was found between the two techniques. However, different portions of the sediment samples were taken for GC than FS analysis, and the authors felt that the lack of correlation was primarily due to inhomogeneity in the samples. Mason (1987) compared FS and GC for the analysis of petroleum residues in mussels and found a significant correlation between UCM hydrocarbons and FS values expressed as Qatar crude oil equivalents. Higher results were obtained by GC. Farrington et al. (1986) noted that the presence of octahydrochrysenes in polychaetes led to erroneously high results for petroleum hydrocarbons when analysed by FS. The octahydrochrysenes, which have fluorescence spectra similar to those of substituted naphthalenes, did not originate from petroleum, but from the diagenesis of triterpenoid compounds.

Conclusions Although GC- and FS-determined hydrocarbons in the two estuaries were significantly correlated, the scatter in the data was reflected in the low r2 values (Table 5). Thus, attempts to predict total hydrocarbon levels from FS data should be viewed with caution. In this study, FS analysis required cleanup of water extracts by column chromatography to remove nonpetroleum fluorescing material, and additional cleanup by saponification was necessary when oil levels were low. As a screening method, FS is useful when oil levels are relatively high since the column chromatography step can be done in a short time and the measurement of fluorescence is rapid. However if the saponification step is included, the sample preparation time required for FS analysis is about the same as for GC. Acknowledgements We thank Thomas Sweeney of the South Carolina Sea Grant Consortium for piloting the boat in the Charleston Harbor Study and to Sean Agosta-Bidleman for assistance in Winyah Bay. This work was supported by the National Oceanic and Atmospheric Administration, Coastal Energy Impact Program, through the Division of Natural Resources, Office of the Governor, State of South Carolina, Grant nos. CEIP-82-08 and CEIP-83-04. Contribution 786 of the Belle W. Baruch Institute.

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et al.

References Agard,

J. B. R., Boodoosingh, M. & Gobin, J. 1988 Petroleum residues in surficial sediments from the Gulf of Trinidad. Marine Pollution Bulletin 19,231-233. Blurrier, M., Guillard, R. R. L. & Chase, T. 1971 Hydrocarbons of marine phytoplankton. Marine Biology 8, 183-189. Butler, J. N., Morris, B. F. & Sass, J. 1973 Pelagic Tar from Bermuda and the Sargasso Sea. Special Publication No 10, Bermuda Biological Station for Research, St George’s West, Bermuda, 346 pp. Clark, J. & Benforado, J. 1980 The natural resources of Winyah Bay. In: Winyah Bay Reconnaissance Study, Technical Paper No. 4 Washington, DC: The Conservation Foundation, pp. 21-23. Dell’Acqua, R., Egan, J. A. & Bush, B. 1975 Identification of petroleum products in natural water by gas chromatography. Environmental Science and Technology 9,38-41. Douabul, A. Z., Al-!&ad, H. T. & Darrnoian, S. A. 1984 Distribution of petroleum residues in surficial sediments from Shaat al-Arab River and the northwest region of the Arabian Gulf. Marine Pollution Bulletin 15, 198-200. El Samra, M. I., Emara, H. & Shunbo, F. 1986 Dissolved petroleum hydrocarbons in the northwest Arabian Gulf. Marine Pollution Bulletin 17,65-68. Farrington, J. W., Wakeham, S. G., Livramento, J. B., Tripp, B. W. & Teal, J.M. 1986 Aromatic hydrocarbons in New York Bight polychaetes: ultraviolet fluorescence analysis and gas chromatography-mass spectrometry analyses. Environmental Science and Technology 20,69-72. Fogelqvist, E., Lagerqvist, S. & Lindroth, P. 1982 Petroleum hydrocarbons in the Arctic Ocean surface water. Marine Pollution Bulletin 13,211-213. Fong, W. C. 1976 Uptake and retention of Kuwait crude oil and its effects on oxygen uptake by the soft-shell clam, Mya arenaria. Journal of the Fisheries Research Board of Canada 33,2774-2780. Gordon, D. C., Jr. 1974 Estimates using fluorescence spectroscopy of the present state of petroleum hydrocarbon contamination in the water column of the northwest Atlantic Ocean. Marine Chemistry 2, 251-261. Gordon, D. C., Jr., Keizer, P. D. &Dale, J. 1978 Temporal variations and probable origins of hydrocarbons in the water column of Bedford Basin, Nova Scotia. Estuarine Coastal and Marine Science 7,243-256. Hargrave, B. T. & Phillips, G. A. 1975 Estimates of oil in aquatic sediments by fluorescence spectroscopy. Environmental Pollution 8,192-215. Hoffman, E. J., Latimer, J. S., Hunt, C. D., Mills, G. L. & Quinn, J. G. 1985. Storm runoff from highways. Water, Air, Soil Pollution 25,349-364. Hoffman, E. J., Mills, G. L., Latimer, J. S. & Quinn, J. G. 1984 Urban runoff as a source of polycyclic aromatic hydrocarbons to coastal waters. Environmental Science and Technology l&580-587. Hoffman, E. J., Quinn, J. G., Jadarnec, J. R. & Fortier, S. H. 1979 Comparison of UV fluorescence and gas chromatographic analyses of hydrocarbons in sediments from the vicinity of the Argo Merchant wreck site. Bulletin of Environmental Contamination and Toxicology 23,536-543. Hunter, J. V., Sabatino, T., Gomperts, R. & MacKenzie, M. J. 1979 Contribution of urban runoff to hydrocarbon pollution. Journal of the Water Pollution Control Federation 51,2129-2138. Jackson. L. F. & Bidlernan, T. F. 1989 Fluorescence spectroscopic studies of differential accumulation of aromatic hydrocarbons by Callianassa kraussi. Oil and Chemical Pollution (in press). Jackson, L. F., Bidleman, T. F. & Vemberg. W. B. 1981 Influence of reproductive activity on toxicity of petroleum hydrocarbons to ghost crabs. Marine Pollution Bulletin 12,63-65. John, P. & Soutar, I. 1976 Identification of crude oils by synchronous excitation spectrofluorirnetry. Analytical Chemistry 48520-524. Keizer, P. D., Gordon, D. C., Jr., Dale, J. 1977 Hydrocarbons in eastern Canadian marine waters determined by fluorescence spectroscopy and gas-liquid chromatography Journal of the Fisheries Research Board of Canada 34,347-353. Keizer, P. D., Dale, J. & Gordon, D. C., Jr 1978 Hydrocarbons in surficial sediments from the Scotian Shelf. Geochimica et Cosmochimica Acta 42, 165-172., Keller, C. D. & Bidleman, T. F. 1984 Collection of airborne polycyclic aromatic hydrocarbons and other organics with a glass fiber filter-polyurethane foam system. Atmospheric Environment l&837-845. Kjerfve, B. 1976 The Santee-Cooper: a study of estuarine manipulations. In: Wiley, M. (ed.) Estuarine Processes, Vol. 1, New York: Academic Press, pp. 44-66. Kjerfve, B. & Magill, K. 1989 Salinity changes in Charleston Harbor, 1922-87. Journal of Waterway, Port, Coastal, and Ocean Engineering (in press). Knau. _. A. H.. _Burns, K. A., Dawson. R., Ehrhardt, M., & Palrnork, K. H. 1986 Dissolved-dispersed hydrocarbons, tarballs, and the surface microlayer: experiences from an IOC/UNEP workshop in Bermuda, December, 1984. Marine Pollution Bulletin 17,313-319. LaFlamme, R. E. & Hites, R. A. 1978 The global distribution of polycyclic aromatic hydrocarbons in recent sediments. Geochimica et Cosmochimica Acta 42,289-303. Law, R. J. 1981 Hydrocarbon concentrations in water and sediments from UK marine waters, determined by fluorescence spectroscopy. Marine Pollution Bulletin 12,153-157.

Petroleum

Law,

hydrocarbons

in two estuaries

in U.S.

109

R. & Andrulewicz, E. 1983 Hydrocarbons in water, sediment, and mussels from the southern Baltic Sea. Marine Pollution Bulletin 14,289-293. Levy, E. M. & Ehrhardt, M. 1981 Natural seepage of petroleum at Buchan Gulf, Bat% Island. Marine Chemistry 10,355-364. Litten, S., Babish, J. G., Jr., Pastel, M., Werner, M. B. & Johnson, B. 1982 Relationship between fluorescence of polycyclic aromatic hydrocarbons in complex environmental mixtures and sample mutagenicity. Bulletin of Environmental Contamination and Toxicology 28,141-148. Louda, J. W. & Baker, E. W. 1984 Perylene occurrence, alkylation, and possible sources in deep sea sediments. Geochimica et Cosmochimica Acta 48,1043-1058. Maher, W. A. 1983 Use of fluorescence spectroscopy for monitoring petroleum hydrocarbon contamination in estuarine and ocean water. Bulletin of Environmental Contamination and Toxicology 30,413-419. Marcus, J. M., Swearingen, G. R., Williams, A. D. & Heizer, D. D. 1988 Polynuclear aromatic hydrocarbon and heavy metal concentrations in sediments at coastal South Carolina marinas. Archives of Environmental Contamination and Toxicology 17,103-l 13. Mason, R. P. 1987 A comparison of fluorescence and CC for the determination of petroleum hydrocarbons in mussels Marine Pollution Bulletin 18,528-533. McVeety, B. D. & Hites, R. A. 1988 Atmospheric deposition of polycyclic aromatic hydrocarbons to water surfaces: a mass balance approach. Atmospheric Environment 22,51 l-536. National Academy of Sciences 1985 Oil in the Sea: Inputs, Fates, and Effects. Washington, D.C.: National Academy Press, 601 pp. Venkatesan, M. I. 1988 Occurrence and possible sources of perylene in marine sediments: a review. Marine Chemistry 25, 1-27. Vo-Dinh, T., Gammage, R. B. & Martinez, P. R. 1981 Analysis of workplace air particulate sample by synchronous luminescence and room temperature phosphorescence. Analytical Chemistry 53,253-258. Voudrias, E. A. & Smith, C. L. 1986 Hydrocarbon pollution from marinas in estuarine sediments. Estuarine Coastal and Shelf Science 22,271-284. Wakeham, S. G. 1977 Synchronous fluorescence spectroscopy and its application to indigenous and petroleum-derived hydrocarbons in lacustrine sediments. Environmental Science and Technology 11, 272-276. Zarba, M. A., Mohammad, 0. S., Anderlini, V. C., Literathy, P. & Shunbo, F. 1985 Petroleum residues in surface sediments of Kuwait. Marine Pollution Bulletin 16,209-211.