Analysis of PCBs in sediments by glass capillary gas chromatography

Chemosphere,Vol.ll,No.2, Printed in G r e a t B r i t a i n

pp

165

- 174,

1982

ANALYSIS OF PCBs IN SEDIMENTS

OO45-6535/82/O20165-iO$O3.OO/O ©1982 Pergamon Press Ltd.

BY GLASS CAPILLARY GAS CHROMATOGRAPHY

M.A.T. KerkhoffT:, A. de Vries Netherlands

Institute

P.O. Box 68,

R.C.C. Wegman, National

for Fishery Investigations

1970 AB Idmuiden, The Netherlands.

A.W.M. Hofstee

Institute of Public Health

P.O. Box I, 3720 BA Bilthoven, The Netherlands.

ABSTRACT The analysis of individual chromatography

was studied.

Decachlorobiphenyl

PCB components

For Aroclor

in river sediments with glass capillary gas

1242 a mean recovery of over 85 % was established.

contents obtained by perchlorination

appear to be 1.1 to 3-7 times higher

than total-PCB contents estimated with capillary GC. Besides reliable PCBs the capillary method provides

information

about the composition

in sediments and may be of use in the identification

contents of individual of the PCB contamination

of PCB sources.

INTRODUCTION Wide-scale PCB contamination partment.

applications

of PCBs have led to their eormnon occurrence

has been observed

in various concentrations

The complex composition of PCBs in environmental

mixtures has always posed problems all PCBs to one single compound, chromatography

for analysts.

tion by mixing different

industrial mixtures

in almost every environmental

com-

samples in relation to industrial

Some of them solved the problems by converting

decachlorobiphenyl

with the best fit industrial

in the environment.

(DCB) (I) or biphenyl

(2). Others used gas

PCB mixture or a standard adapted to the contamina(3). In all these analytical

techniques

total-PCB

contents were determined. High resolution glass capillary in 1974 (4) provided the most complete capillary gas chromatography

columns,

introduced

in PCB analysis by Schulte and Acker

separation of individual polychlorobiphenyls

detailed data of individual PCB components

will give a better understanding

various polychlorinated

biphenyls

also found (6). Furthermore requ[r~ detailed

(5), while differences

the differences

Laboratory

on the microbial

in bioaccumulation

in toxicity of individual

analysis

is known for industrial

mixtures

degradation

chlorobiphenyls

of

(7)

in the environ-

(8), human adipose tissue (4),

fish, bird's eggs (9) and milk fat (10). In this investigation

165

experi-

and metabolism were

information on the occurrence of the individual PCB components

merit. PCB capillary human milk,

can be obtained which

of the behaviour of PCBs in the environment.

ments have already shown the effects of chlorine substitution

and with

the use of glass

166

capillary gas chromatography

in PCB component analysis of sediment was studied and compared

with the DCB determination of perchlorination.

EXPERIMENTAL Materials.

In 1980 sediment samples were taken at 6 sampling sites in the River

Rhine and its tributaries.

The samples were collected by means of a dredger. The dry weight

was determined by heating a sub-sample of the sediment samples at 105 °C for 4 h.

Procedures.

6 ml of water were added to 30 g of wet sediment and shaken with

100 ml

of acetone for 30 min. After keeping overnight the acetone phase was decanted and the extraction procedure was repeated with 50 nul of acetone. After keeping for 4 h. the acetone extracts were combined and concentrated to about 20 ml in a Kuderna-Danish evaporator. With 50 ml of water the acetone extract was transferred in a separatory funnel and after addition of another

150 ml of water the water/acetone mixture was successively extracted with 40, 20 and

20 ml of petroleum ether for 5 min. The combined petroleum ether extracts were dried over anhydrous sodium sulfate and concentrated to about 5 ml in a Kuderna-Danish evaporator. Elemental sulfur, which may be present in sediment, pass through the clean-up procedures and interferes the gas chromatographic detection of PCBs. In order to avoid this problem elemental sulfur~as removed according to the method of Jensen

(11): 2 nd of propanol-2

2 ml of tetrabutylamonium hydrogen sulfate (0.01 M) and 0.5 g of sodium sulfite were added to 5 ml of the concentrated extract and sha/~en for at least

I min. Next,

]0 ml of

water were added and the mixture was shaken again for I min. The organic phase was used for both the capillary GC analysis and the perchlorination method.

Capillary GC.

For the capillary gas chromatography an aliquot of the petroleum

ether extract corresponding to 10 g of sediment was cleaned-up using a column (20 mm ID) of anhydrous

sodium sulfate over

15 g of alumina (basic, activity I, Merck no.

with 5 % H20). The organochlorine

1076, deactivated

compounds were eluted with 230 ml of pentane. The eluate was

concentrated on a rotary evaporator to 2 n~ and transferred to a 6 mm ID silica column (2 g Lichrosorb SI 60-30 wm, activated for 16 h at 210 °C before use) to separate the PCBs from several organochlorine pesticides. chlorobutadiene,

polyehlorobenzenes

PCBs were eluted with

10 ml of hexane. Besides PCBs hexa-

and certain percentages of p, p'-DDE and o , p'-DDE may

be present in the eluate. Gas chromatographic

analysis was done on a WCOT CP Sii-7 column

(length 25 m, ID 0.25 mm, film thickness 0.h Dm, CP Sil-7 is a high-temperature siloxane gum - 5 % phenyl - comparable to SE-52). Temperature, min), programming at 33 °C/min to 215 °C,

programmed:

phenyl methyl

initial 83 °C (3

final hold about 35 min. During s~m~ie injection

(I WI) the splitter was closed and then opened after 2 min. Three minutes after injection the temperature programming was started. Split ratio I : 25. Flow-rate about sure controlled

(inlet

150 kPa ~ 1.5 atm). By-pass

1.5 ml/min He, pres-

(make-up gas and detector yurge together):

75 ml/min Ar/5 % CH,. PCB contents were calculated on the basis of a standard cf individual PCB components

(Table

]) by comparing peak areas.

167

TABLE I - Composition of the standard of individual PCB compounds in n-hexane; concentration of each compound 0.32 ug ml -I; dilute 1 ml to 10 ml and inject I ul.

Peak

IUPAC

number

number (8)

Structure

Relative Retention Time to No. 153

1

52

2,5,2' ,5

0.54

2

49

2,4,2' ,5

0.54

3

24

2 , 3 , 2 ' ,5

0-57

4

103

2,4,6,2' ,5

0.60

2,3,6,2' ,5

0.65

5

95~

6

121

2,4,6,3' ,5

0.66

7

155

2,4,6,2' ,4 ,6'

0.69

8

1oi

2,4,5,2' ,5

0.71

9

119

2,h,6,3' ,4

o ,74

10

97

2,4,5,2' ,3'

0.77

11

87

2,3,4,2' ,5'

O.78

12

136

2,3,6,2' ,3' ,6'

0.80

13

154

2,4,5,2' ,4',6'

0.82

14

151

15

149~"

2,3,6,2' ,4' ,5'

o.9o

16

140

2,3,4,2' ,4',6'

0.91

17

153

2 , h , 5 , 2 ' ,4',5'

1.00

2,3,4,2' ,3' ,6'

I .01

18

132~

19

141

20

138

21

187~

22

128

23

185

24

202

2,3,5,6,2' ,5'

2,3,4,5,2' ,5'

O.85

I .o6

2,3,4,2' ,4' ,5'

1.13

2,3,5,6,2 ' ,4' ,5'

1.23

2,3,4,2 ',3',4'

I .28

2,3,4,5,6,2

' ,5 1

I .33

2,3,5,6,2' ,3' ,5' ,6'

25

180~"

2,3,4,5,2 ' ,4' ,5'

I -59

26

170~

2,3,4,5,2' ,3' ,4'

I .85

27

201~

2,3,4,5,2' ,3',5',6'

I .96

These compounds were a gift from C.A. Wachtmeister, University of Stockholm, Sweden. Other compounds were purchased from Analab Inc, North Haven, Connecticut, USA, and Ultra Scientific Inc, I Main Street, Hope, Rhode Island, USA.

Perchlorination.

] ml of the concentrated petroleum ether extract corresponding to

10 g of sediment was brought in a chlorination tube (Sovirel no. 611.53). After addition of

168

28 *~31

AROCLOR 1 2 4 2

LL 20MIN.

INJ.

d_

10 •

fJ %

1007.

c.~ • ° o oooeo

RECOV E RY D • •

• u

u 1 MG)/KG

50~.

• 5 MG/K G

10~

2 0 MIN,

(

Figure

I - Capillary

RET. TIME

chrom~togram

10

of Aroclor

1242 and individual

coveries

of 13 major PCBs of Aroclor

sediment

samples spiked on two levels

12h2 determined

rein

(I and 5 mg kg -i).

169

0.5 ml of chloroform the solution was concentrated by a gentle stream of nitrogen at room temperature

to approximately

was repeated.

0.5 ml. After addition of 1.0 ml of chloroform the procedure

0.3 m/ of SbCl5 was added and the tube was immediately

3 h in an oil bath at 200 °C. After cooling to room temperature HCI was added to inactivate

the excess of the perchlorination

closed and heated for

2 ml of a 20 % solution of

reagent and the tube was heated

for 15 min in a heating block at 70 °C. DCB was extracted from the reaction mixture by 5 ml of hexane.

5 ~i of the extract were injected into a gas chromatograph

equipped with a 0.7 m x 2

mm ID glass column packed with a I : h mixture of 3 % 0V-17 and 3 % OV-210 on Chromosorb W-HP, 80-100 mesh at a temperature

of 205 °C. The decachlorobiphenyl

formed was determined by com-

paring the peak area with a standard of pure DCB.

RESULTS AND DISCUSSION The extraction, sediments

clean-up and capillary GC procedures

as shown by experiments

centration levels PCB components

(I and 5 mg kg -I on wet weight basis).

in Aroelor

gave good recoveries

carried out in samples spiked with Aroelor The individual

for PCBs in

1252 at two confor 13 major

recoveries

12h2 have been calculated and are graphically

illustrated

in Figure

I.

Three PCBs giving peaks in the beginning of the chromatogram had recoveries between 60 and 80 %, while the other ones had recoveries 12h2 of over 85 %. As recoveries may be expected

of over 90 %. This resulted

in a mean recovery

increase with decreasing volatility,

for PCB components

that originated

recoveries

from most industrial mixtures.

for Aroclor

of over 90 % A detection

limit of 0.5 ~g kg -l for each compound is possible although at times it may be too difficult to minimize background

contamination

levels sufficiently

to observe this level.

In reporting the results of PCB component analysis, as introduced by Ballschmiter sediments of 6 different

(8) is used. In Table 2

sampling sites are given. PCB components

185 could not be detected in the sediments, was doubtful. 153,

the IUPAC numbering of PCB compounds

the contents

of 17 individual

119, 121,

while the identification

High contents were observed with PCB components

lhO,

PCBs in

15h, 155 and

of 103, 132, 136 and 202

having numbers

52, 101, 138, Ih9,

180 and 95, of which the last one is a composite of number 95 and a tetrachlorobiphenyl.

The same individual

PCBs are major components

are the main compounds

in Aroclor

101, 95 and 52 originate organisms

in the industrial mixtures:

1260 and numbers

138 and Ih9 in Aroclor

components

other individual

(8). A/so in

(h, 9, 10, 12). Besides the

PCBs were present in the samples.

the contents of these components was necessary to get information PCBs. For that estimation

180 and 153

125h. The numbers

from PCB mixtures with a lower degree of chlorination

high levels of the same individual PCBs are reported

17 quantified

numbers

An estimation

of

about the total amount of

comparable ECD responses were assumed for PCB compounds with close

retention times and the content of a PCB compound not present in the standard was calculated on the basis of an adjacent PCB compound of the standard solution. individual total-PCB

contents

By summation of all the

in a sample, exactly quantified as well as estimated,

content was obtained,

in which the quantified PCBs contributed

an approximate 50 to 60 %. This

total-PCB content can be compared with that obtained by the perehlorination

method after re-

calculation

(Table 3).

of the data into ~mol kg T M by division by the molecular weights

O TABLE

2 - Contents of individual PCB components

in sediments of the River Rhine and its tributaries expressed in

Dg kg -l (dry weight basis). River IUPAC

Structure Hollands Diep

Haringvliet

(%)

30.5

42.3

52

2,5,2',5'

69

49

2,4,2',5'

56

44

2,3,2',5'

62

35

148

106

107

18

95 ~

2,3,6,2',5'

141

85

325

206

214

53

101

2,4,5,2',5'

82

54

218

117

129

42

97

2,4,5,2',3'

20

9

42

30

31

6

87

2,3,4,2',5'

26

9

35

35

26

8

number

Dry weight

Oude Maas

Waal

Boven Merwede

Lek

43.1

46.1

45.7

72.1

33

169

113

118

22

33

146

91

101

17

151

2,3,5,6,2',5'

20

19

63

24

31

22

149

2,3,6,2',4',5'

85

71

227

134

125

76

153

2,4,5,2',4',5'

79

61

206

87

107

79

141

2,3,4,5,2',5'

23

7

21

20

15

15

138

2,3,4,2',4',5'

79

57

179

93

101

68

187

2,3,5,6,2',4',5'

30

26

74

28

35

37

128

2,3,4,2',3',4'

10

7

23

11

18

7

180

2,3,4,5,2',4',5'

56

45

114

61

63

90

170

2,3,4,5,2',3',4'

30

17

44

43

33

31

201

2,3,4,5,2',3',5',6'

13

12

16

11

13

12

881

580

2050

1210

1267

603

Z 17 eomp.

* This content calculated on the basis of number 95 is a composite of number 95 and a tetrachlorobiphenyl.

1.1

1.9

3.7

PCB decachlorination PCB capillary GC

Ratio

3.1 6.2

9.2 18.4

Decachlorobiphenyl (Dmol kg -l)

3.2

10.7

6.6

Decachlorobiphenyl (mg kg -I)

1.7 5.0

O.9

Sum of 17 components (mg kg -l)

Estimated total-PCB (mg kg -l)

10.8

CaCO 3 (%)

Estimated total-PCB (Dmol kg -l)

O.6

10.7

34.9

Org. Mat. (%)

42.3

Haringvliet

30.5

Diep

Hollands

perchlorination, on dry weight basis.

1.1

11.4

5.7

10.7

3.9

2.1

9.8

2.3

9-9

43.1

Oude Maas

River

2.1

15.0

7.5

7.1

2.4

1.2

11.3

10.8

29.4

46.1

Waal

2.3

17.0

8.5

7-5

2.6

1.3

9-7

9.3

33.8

45.7

Boven Merwede

1.7

4.8

2.4

2.8

1.0

O.6

5.3

2.4

9.6

72.1

Lek

Comparison of PCB contents in river sediments determined via glass capillary gas chromatography and

55.3

-

Dry weight %

3

Silt (< 16 ~m) %

TABLE

172

95+7

I01 153 149 138

170 INJ.

40

MIN.

20

138

I" HCB

95+?

149

180 21

52 44

170

J.

40

20

MIN. (

Figure 2 - Capillary

RETENTION

chromatograms

Merwede River

TIME

of sediment extracts of the Boven

(A), with dominating low chlorinated biphe-

nyls and the Lek River (B), with dominating high chlorinated biphenyls.

Numbers correspond to structures.

173

The PCB contents

obtained

via perchlorination

were

to 3.7 times higher than the total-PCB

1.1

contents obtained by the capillary method. Similar observations of printing conversion

were reported for PCB analysis

inks, paper and sewage sludge by Kok (13), who ascribed too high results to the of other environmental

gas chromatographic

contaminants

characteristics

into either decachlorobiphenyl

closely analogues

or products

having

to those of DCB.

The capillary method gives reliable contents of individual PCBs and an approximation a total-PCB

content, which will be more reliable as more components will be quantified.

in routine analysis

the determination

sive and a limitation

of all PCB components

of 6 to I0 compounds

in the composition of the PCB contamination

chromatogr~ns

(12).

about the contents of individual

can be observed,

(Figure 2). Tetra- and pentachiorobiphenyls

can dominate,

as i]lustrated

Sudden changes

(hexa- and hepta-)

in the composition

can be demonstrated

of

of the high chlo-

as in the Lek River sediment

may indicate discharges

tography may be used in identifying

PCBs,

in the

as in the sediments

the Boven Merwede River and the Waal River, or a more important contribution rinated biphenyls

However,

will be very complicated and expen-

has to be considered

Because the capillary method provides information differences

of

(Table 4).

of PCBs and so capillary gas chroma-

sources of PCBs in the envircnment.

TABLE I~ _ Composition of the PCB contamination as percentage

in the river sediments

of the sum of 17 components

(%).

RIVER: Hollands

Hating-

Oude

Diep

vliet

Maas

Tetrachlorobiphenyl

21.2

17.4

Pentachlorobiphenyl

30.6

Hexachlorobiphenyl

33.6

l{eptaehlorobiphenyl

13.2

There

is a lack of knowledge

Waal

Boven

Lek

Merwede

22.5

25.6

25.7

9.L

27.2

30.2

32.1

31.6

18.1

38.2

35

30.6

31.8

hL.2

15.2

11.3

10.9

10.3

26.1

about the pollution of sediment by PCBs and several parame-

ters, like granular size, dry weight and organic matter, will influence the contents of these compounds

in sediments.

of different

analytical

b]e. TotaI-PCB

contents

Considrring

this together with the differences

in results as eons.~quence

methods only a very rough comparison with data of other areas is I,oSSidetermined

in the sediments of the Rhine River and its tributaries

(I.0-

3.9 mg kg -I) are higher than those reported in the Great Lakes (up to 0.25 mg kg -:) and in European and African

lakes and rivers

(up to 0.32 mg kg -l). In the St. Lawrence River contents

are on the same level, while several river sediments Hhine River sediment.

in the USA contain more F'CBs than the

The highest PCB contents in sediments are reported in the Hudson River

with 6.6 to 67,000 mg kg -i occurring near the waste disposal of two plants that used PCBs in producing

transformers

and capacitors

in the past (14).

174

REFERENCES

I. C.L. Stratton, J.M. Allen and S.A. Whitlock, Bull

Environm. Contam. Toxicol. 2 1 (1979),

230-237. 2. A. de Kok, R.B. Geerdink, R.W. Frei and U.A.Th. Brinkman, Intern. J. Environ. Anal. Chem. (1981), 301-318. 3. F.L. Beezhold and V.F. Stout, Bull. Environm. Contam. Toxicol.

10 (1973), 10-16.

h. E. Sehulte and L. Acker, Z. Anal. Chem. 268 (1974), 260-267. 5. K. Furukawa, N. Tomizuka and A. Kamibayashi, Appl. Environ. Microbiol.

3__88(1979), 301-310

6. S. Jensen and G. Sundstr6m, Ambio 3 (1974), 70-76. 7. J.D. McKinney and P. Singh, Chem. Biol. Interactions, 3 3 (1981), 271-283. 8. K. Ballschmiter and M. Zell, Fresenius Z. Anal. Chem., 302 (1980), 20-31. 9- M. Zell and K. Ballschmiter, Fresenius Z. Anal. Chem., 304 (1980), 337-349. 10. L.G.M.T. Tuinstra, W.A. Traag and H.J. Keukens, J. Assoc. Off. Anal. Chem. 63 (1980), 952-958. 11. S. Jensen, L. Renberg and L. ReutergKrdh, Anal. Chem. 49 (1977), 316-318. 12. M. Kerkhoff, J. de Boer, A. de Vries, paper in preparation. 13. A. de Kok, R.B. Geerdink, R.W. Frei and U.A.Th. Brinkman, Intern. J. Environ. Anal. Chem. In press. 14. Committee on the Assessment of Po]ychlorinated Biphenyls in the Environment, Polych]orinated Biphenyl, National Academy of Sciences (1979).

(Received

in T h e

Netherlands

13 O c t o b e r

1981)