Anal. Chem. 1983, 55, 881-889
any given concentration of G-6-P dehydrogenase is added to the strip, fluorescence of NADPH increases with a characteristic rate. F'lotting the slope (in millivolts per minute) as a function of G-6-P dehydrogenase concentration in units per liter gives the dose response curve shown in Figure 4. The dose response curve shows that this assay is useful in the concentration range from 25 to 325 U/L. The second assay to be presented here is for AST determination on paper. This assay is based on the reactions aspartate
-
+ or-ketoglutarate
AST
+
MDH
+ glutamate malate + NAD'
oxaloacetate
oxaloacetate NADH The 0.5 cm by 1.0 cm reagent strip contains the dry reagents aspartate, a-kletoglutarate, malate dehydrogenase (MDH), NADH, and Tris (pH 8.0). The reaction is followed by observing the fluorescence of NADH a t 460 nm after excitation at 340 nm. The reaction shows a decrease of fluorescence with time.
881
This dose response curve is linear in analyte concentration from 10 U/L to 260 U/L. It is characterized by a slople of -0.12 (mV/min)/(U/L).
LITERATURE CITED Zipp, A. J . Autom. Chem. 1981, 3 , 71-74. Burd, J. F.; et al. Clln. Chem. (Winston-Salem, N.C.)1977,, 2 3 , 1402- 1408. Wong, R. C.; et al. Clin. Chem. (Winston-Salem, N.C.)1979, 25, 686-691. Li, T. M.; et al. Clin. Chem. (Winston-Salem, N . C . ) 1981, 27, 22-26, Greenquist, A. C.; Walter, B. W.; Ll, T. M. Clin. Chem. (Winston-Sa/em, N . C . ) 1981, 2 7 , 1814-1617. Walter, B.; Greenqulst, A. C.;Howard, W. E., 111 Anal. Chem. '1983, 55, 873. Chen, S. P.; Kuan, S. D.; Gullbault, G. G. Clin. Chim. Acta 1980, 100, 21-31. Lau, H. K.: Gullbault. G. G.: Clin. Chem. (Winston-Salem. N . C . ) 11973, 19, 1045-1047. Kuan, S. S.; Lau, H. K.; Gullbault, 0. G. Clln. Chem. (Winston-Salem, N . C . ) 1975, 21, 67-70.
RECEIVED for review June 10,1982. Resubmitted and accepted January 12, 1983.
Determination of 5 1 Priority Organic Compounds after Extraction from Standard Reference Materials Viorica Lopez-Avlla, * Raymond Northcutt, Jon Onstot, and Margie Wickham Mldwest Research Institute, 425 Volker Boulevard, Kansas City, Mlssouri 64 I 10
Stephen Billets U.S. Envlronmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnatl, Ohio 45268
An extraction technique, Involving homogenization of a sediment sample wlth dlchloromethane at dual pH and phase separatlon by centrlfugatlon, was used In the determination of 51 organic lprlority pollutants as Identifled in a standard reference sedlment sample. These compounds were splked Into the sediment and equlilbrated for a defined period of tlme. The extraction was performed first at pH >11 to Isolate the baselneutral compounds; acidic compounds were extracted at pH 11and then at pH 11,the sediment/water slurry was adjusted to pH 70%) were found at both spike levels for phenol, 2-chlorophenol, 2,4-dichlorophenol, 2,4-dimethylphenol, and pentachlorophenol. 4-Nitrophenol was not detected a t 400 ng/g; however its recovery was satisfactory at the higher spike level. The chromatographic behavior of this compound may have precluded its identification a t low spike levels. Identification of Compounds in the NBS Sediment Extract. The GC/MS analyses of the silica gel fractions and the GPC fraction generated from the NBS sediment extract resulted in the identification of over 100 base/neutral compounds and 11 acidic compounds, without considering the various isomers of many of these compounds. Table VI gives these identifications, grouped by chemical class. Figures 2-5 give the GC/MS chromatograms of the various fractions.
I
I
I
/
500
IO@@
16.10
33:20
,
,
I
,
l
!5@0 53:nn
,
,
/
,
Scan t i =
Flgure 2. Reconstructed ion chromatogram of fraction I of base/ neutral extract (silica gel chromatography; eluting solvent, hexane), temperature was programmed from 50 O C (held 4 min) to 300 O C at 4 'Clmin. I S . is the internal standard.
Flgure 3. Reconstructed Ion chromatogram of fraction I1 of base/ neutral extract (silica gel chromatography; eluting solvent, 10 % dichloromethane in hexane). Temperature was programmed from 50 O C (held 4 min) to 300 O C at 4 'C/min. Peak assignments are given in Table VI.
Because authentic reference standards were not analyzed for each compound, the identifications are tentative except for some compounds given in Table VI that were confirmed with standards. Most of the compounds listed in Table VI give mass spectra that matched the mass spectra in the NBS library (21). Identification of specific positional isomers (e.g., dimethylnaphthalenes, trimethylnaphthalenes, etc.) could not be obtained from the mass spectrometric information. The procedures used to identify each GC peak involved selection of a background substracted mass spectrum and the comparison of this mass spectrum against that contained in the NBS library. The computer search provided the match indexes (e.g., for Incos software FIT, PURITY, and RFIT indexes) that were used in identifying the compounds. Many of the mass spectra were also manually interpreted, especially when a match via library search was unsuccessful. A limiting factor in the mass spectra identifications was the purity of a compound (coelutingpeaks would give mass spectra with large FIT indexes but low PURITY indexes) and the availability of the compound mass spectrum in the data base. Whenever an identification was made, either by library search routines or by manual interpretation, mass chromatograms for the most intense ions in the mass spectrum were obtained. This allowed in many instances identification of other isomers and assignment of coeluting peaks. Although the library
ANALYTICAL CHEMISTRY, VOL. 55, NO. 6, MAY 1983
;E85
Table IV, Results of the Precision and Accuracy Evaluations for the Analysis of BaseINeutral Compounds in the Spiked NBS Sediment % recoverya spike level unspiked sedimentn spike level 4000 ng/g of cbncn (ng/g of 460 ng/g of compound dry sediment dry sediment) dry sediment compound no. 112 i 1 9 1 bis( 2-chloroethyl) ether 96 i: 23 NDe 1,3-dichlorobenzene 63 i 9 68 i 16 ND 2 66i: 14 75 i 22 1,2-dichlorobenzene ND 3 62 1 5 41 i 1 5 hexachloroethane ND 4 8 9 i 11 95 * 38 ND 5 N-nitrosodi-rz-propylamine 43+ 3 102 i 26 nitrobenzene ND 6 81 i 11 94 i: 39 bis( 2-ch1oroethoxy)methane ND 7 58i 13 67 i: 4 1,2,4-trichlorobenzene ND 8 70 i 35 880i 350 64 naphthalene 9 71 i: 17 63 i: 2 hexachlorobutadiene 10 ND 0 0 hexachlorocyclopentadiene 11 ND 94 i: 20 72 1 1 0 2-chloronaphthalene 12 ND 86 i 24 1820i: 350 13 d acenaphthylene 110 k 51 102 f 36 ND 14 2,6-dinitrotoluene 1 0 4 i 24 850 i 120 acenaphthene d 15 64 i: 50 49 2,4-dinitrotoluene 16 ND 82 i 7 d 1 5 8 0 i 130 fluorene 17 86 i: 42 74+7 4-chlorophenyl phenyl ether 18 ND 33 + 14 109 1 1 3 diethyl phthalate 19 ND 9 1 i: 50 89 + 2 4-bromophenyl phenyl ether 20 ND 4 6 1 10 53 ?. 4 hexachlorobenzene ND 21 8 3 i 26 d 3770 i 300 phenanthrene 22 25 i: 11 anthracene 2090 1 72 23 d 156c 100,137 di-n-butyl phthalate 5 8 0 i 65 24 174 5 78 Sluoranthene 14760 i 2810 d 25 148,252 pyrene d 20020 1 4630 26 0 benzidine 0 27 ND 97, 137 0 endosulfan sulfate 1160, 455 28 920 103‘ n-butyl benzyl phthalate 29 d lchrysene 30 27000 + 6500 d d 3,3’-dichlorobenzidine 0 0 31 ND bis( 2-ethylhexyl) phthalate d 32 d 7560, 10790 128 i 23 benzo [ulpyrene 33 22850 6200 d dibenz[ u,h ]anthracene 5960 i 420 113 i 42 34 d 60 i 1 9 3050 + 1270 d 35 r-BHC 2 2 i 13 aldrin 44c 36 ND 37 54i 9 0 heptachlor epoxide ND 7 6 1 32 41 38 340 i: 100 p,p’-DDE endrin 39 0 0 ND 40 120 121,186 104 i: 1 8 p,p’-DDD 41 p,p’-DDT 840 + 20 155 i 43 d 42 a-endosulfan 0 0 ND a Mean i standard deviation for three determinations; % recovery = (spiked sed. concn - unspiked sed. concn)/spike level. Single determination Benzidine not detected by GC/MS in any of the standards at concentrations < 20 ng per injection. Concentrations determined in the spiked reported; levels in the other replicates were below the unspiked sediment level, sediment were below the unspiked sediment level. e Not detected. ~
~
+_
Table V. Resullts of the Precision and Accuracy Evaluations for the Analysis of Acidic Compounds in the Spiked NBS Sediment % recovery a unspiked sediment spike level spike level compound concn (ng/g of 400 ng/g of 4000 ng/g of no. compound dry sediment) dry sediment dry sediment 1 phenol 1810, 2005 112,128 78 i 21 2 2-chlorophenol ND 106 i: 11 78i 18 3 2,4-dimethylphenol ND 99 i: 1 2 55+3 4 2,4-dichlorophenol ND 99 + 1 6 761 5 5 2,4,6-trichlorophenol ND 67 + 8 63 i: 10 6 4-nitrophenol ND 0 46 f 11 7 pentachlorophenol ND 95 1 2 71 i: 3 ‘ % recovery determined from triplicate measurements; recovery = spiked sed. concn - unspiked sed. concn/ spike added. Not detected.
-
search did indicate in many cases the positional isomers that best match a particular unknown mass spectrum, this was not sufficient for confirming the compound identity. Consequently, no indiication about the position of the substituent
or the particular alkyl radical has been made. Fractionation of the base/neutral extract by silica gel chromatography reduced sample complexity and, consequently, made possible identification of minor components
886
ANALYTICAL CHEMISTRY, VOL. 55, NO. 6, MAY 1983
Table VI. Organic Compounds Identified in the NBS Sediment compound no.
compound
I
silica gel fractions I1 I11
IV
Aliphatic Hydrocarbons 2 3
heptane Cl,Hl, (isomers) Cl,H,, (isomers)
4 5 6 7 8
benzene toluene xylene (isomers) C,-alkylbenzene styrene
1
X X X
Aromatic Hydrocarbons
9 10 11
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69
Polycyclic Aromatic Hvdrocarbons naphthalenea 1-methylnaphthalene 2-methylnaphthalene ethylnaphthalene dimethylnaphthalene (isomers) C,-alkylnaphthalene (isomers) C,-alkylnaphthalene (isomers) C, -alkylnaphthalene (isomers) 1-phenylnaphthalene 2-phenylnaphthalene phenylmethylnaphthalene (isomers) acenaphthylenea X biphenyl terphenyl acenaphthenea diphenyl ether fluorenea methylfluorene (isomers) dimethylfluorene (isomers) C,-alkylbiphenyl phenanthrenea anthracenea methylphenanthrene (isomers) methylanthracene (isomers) ethylphenanthrene or ethylanthracene dimethylphenanthrene (isomers) dimethylanthracene (isomers) C,-alkylphenanthrene (isomers) C,-alkylanthracene (isomers) 4H-cyclopenta [deflphenanthrene fluoranthenea pyrenea methylfluoranthene (isomers) methylpyrene (isomers) benzphenanthrene (isomers) benzanthracene (isomers) chrysene a methylbenzanthracene (isomers) methylchrysene (isomers) dimethylbenzanthracene (isomers) dimethylchrysene (isomers) dimethyltriphenylene (isomers) 1,l’-binaphthyl 1,2’-binaphthyl 2,2’-binaphthyl benzofluoranthene (isomers) benzo[a]pyrenea perylene methylbenzofluoranthene (isomers) methylbenzopyrene (isomers) dibenzoanthracene (isomers) benzochrysene (isomers) dibenz[a,h ]an thracenea benzo [ghilperylene indeno [1,2,3-cd]pyrene Sulfur-Containing Heterocyclics di-n-propylthiophene (isomers) dibenzothiophene methyldibenzothiophene (isomers) dimethyldibenzothiophene (isomers) dimethylnaphthothiophene (isomers) ethylnaphthothiophene
X X X X X
X X X X X X
X
X X
X X
X
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
X
X X
X X
X X
X
X
X
X
X X X X X
X X X X
X
ANALYTICAL CHEMISTRY, VOL. 55, NO. 6, MAY 1983
____-
887
-
Table VI (Continued) silica gel fractions b compounid no.
compound
I
70 71 72 73 74 75 76 77 78
C,-alkyldibenzothiophene C,-alkyldibenzothiophene benzonaphthothiophene (isomers) methylbenzonaphthothiophene (isomers) benzophenanthrenothiophene anthrabenzothiophene C,,H,,S (isomers) dinaphthothiophene (isomers) thioxanthene
79
Oxygen-Containing Heterocyclics methyldibenzofuran (isomers)
I1
I11
IV
X X X X X X X X X X
Aldehydes and Ketones 80 81
82 83 84 85 86 87 88 89 90
X X X X X X X X X X X
benzaldehyde 1-phenylethanone fluorenone methylfluorenone (isomers) methylanthrone (isomers) cyclopenta[def]phenanthrenone
benzofluorenone (isomers) methylbenzofluorenone (isomers) benzanthracenequinone (isomers) indenoanthracenone (isomers) C ,,H 0 (isomers) Pesticides X 91 p,p' -DDEa X 92 p,p:-DDDa X X 93 p , p -DDTa X 94 r-BHCa Phenols phenola 95 Miscellaneous Compounds benzoic acid 96 97 ethylhexanol 1-(2-propeny1oxy)heptane 98 99 acetic acid phenylethyl ester 1-H-indene 100 di-n-butyl phthalatea 101 X X n-butyl benzyl phthalatea 102 bis( 2-ethylhexyl) phthalaten 103 X endosulfan sulfatea 104 methylcholestane 105 106 C,,H, 0 (possible ergosta-5,8-diene-3-01) X 107 sulfur X fatty acids 108 Confirmed with authentic compounds. Silica gel fractions: I, hexane; 11, 10% dichloromethane/hexane; 111, 50% dichloromethane/hexane; I V , 5% acetone/dichloromethane. in the sample. Furthermore, the chromatographic behavior on silica gel of several classes of compounds (e.g., sulfur containing heterocyclics, aldehydes, ketones) helped in the assignment of the identifications. For example, polar compounds such as benzofluorenone and methylbenzofluorenone were expected to elute in fraction IV. Indeed, benzofluorenone (mlz 230) was identified by reverse library search in fraction IV; however, no mass spectral match was found for the mass spectrum with a parent ion a t mlz 244. The assignment as methylbenzofluorenone for mass spectrum with a parent a t m / z 244 was based on two considerations: similar mass spectral fragmentation pattern with benzofluorenone and similar chromatographic behavior on silica gel of benzofluorenone and methylbenzofluorenone. The GC/MS chromatograms given in Figures 2-5 also show that most of thle compounds of environmental significance elute in fractions I1 and I11 (the compound numbers in Table VI correspond to the labeled peaks in Figures 2-5). Fraction I contains most1,y saturated hydrocarbons (alkanes) that were not resolved unlder the conditions used. Similarly, fraction
-
IV contains polar compounds (naturally occurring materials) that would interfere in the analysis, had the sample fractionation not been performed.
CONCLUSIONS The method described offers a rapid means of analyzing for organic compounds in a sediment matrix. Given the complexity of Chis matrix, the precision and accuracy results presented here demonstrate that the extraction procedure developed originally for sludge matrices can be applied with minor modifications to sediments. Fractionation of the base/neutral extract by silica gel chromatography and fractionation of the acidic extract by GPC are required to reduce sample complexity and have been evaluated a t two concentration levels for 51 priority organic compounds. Quantitative and reproducible recoveries were demonstrated for stalble compounds such as chlorinated benzenes, polynuclear aromatic hydrocarbons, bis(2-chloroethyl) ether, p,p'-DDD, and p,p'-DDT at both spike levels while polar and reactive compounds were not recovered.
ANALYTICAL CHEMISTRY, VOL. 55, NO. 6, MAY 1983
888
1.5.
RIC
I
,
Flgure 4. Reconstructed ion chromatogram of fraction I11 of baseheutral extract (silica gel chromatography; eluting solvent, 50 % dichloromethane in hexane). Temperature was programmed from 50 ‘C (held 4 mln) to 300 OC at 4 ‘Wmin. Peak assignments are glven in Table VI.
1 500 16:40
I000
1500
33.20
50:OO
?000 Scan 6R:JP time
Figure 5. Reconstructed ion chromatogram of fraction IV of base/ neutral extract (silica gel chromatography; eluting solvent, 5% acetone in dichloromethane). Temperature was programmed from 50 O C (hekl 4 min) to 300 O C at 4 ‘C/min. Peak assignments are given in Table
VI.
The inertness and excellent resolution of the capillary column allowed the detection of nanogram levels of phenols in the presence of high levels of interfering coextractants. Furthermore, tentative identifications were provided for the organic compounds extracted from sediment by the extraction and analysis procedures described in this paper. Most of the compounds identified in the silica gel and GPC fractions were polycyclic aromatic hydrocarbons, alkyl-substituted polyaromatics, sulfur-containing heterocyclics, alkyl-substituted sulfur-containing heterocyclics, and several polycyclic ketones.
ACKNOWLEDGMENT The authors thank Ron Hites, Jim Spigarelli, Denis Foerst, and James Eichelberger for reviewing the manuscript and Elaine Smith for typing it. Registry No. Bis(2-chloroethyl) ether, 111-44-4; 1,3-dichlorobenzene, 541-73-1; 1,2-dichlorobenzene, 95-50-1; hexachloroethane, 67-72-1;N-nitrosodi-n-propylamine, 621-64-7;nitrobenzene, 98-95-3; bis(2-~hloroethoxy)methane,111-91-1; 1,2,4-trichlorobenzene, 120-82-1; naphthalene, 91-20-3; hexachlorobutadiene, 87-68-3; hexachlorocyclopentadiene, 77-47-4; 2-chloronaphthalene, 91-58-7; acenaphthylene, 208-96-8;2,6-di-
nitrotoluene, 606-20-2;acenaphthene, 83-32-9; 2,4-dinitrotoluene, 121-14-2;fluorene, 86-73-7;4-chlorophenyl phenyl ether, 7005-72-3; diethyl phthalate, 84-66-2;4-bromophenyl phenyl ether, 101-55-3; hexachlorobenzene, 118-74-1;phenanthrene, 85-01-8; anthracene, 120-12-7;di-n-butyl phthalate, 84-74-2;fluoranthene, 206-44-0; pyrene, 129-00-0;benzidene, 92-87-5;endosulfan sulfate, 1031-07-8; n-butylbenzyl phthalate, 85-68-7; chrysene, 218-01-9; 3,3’-dichlorobenzidine, 91-94-1;bis(2-ethylhexyl) phthalate, 117-81-7; benzo[a]pyrene,50-32-8;dibenz[a,h]anthracene, 53-70-3;yBHC, 58-89-9;aldrin, 309-00-2; heptachlor epoxide, 1024-57-3;p,p’-DDE, 72-55-9;endrin, 72-20-8;p,p’-DDD, 72-54-8;p,p‘-DDT, 50-29-3; a-endosulfan, 959-98-8; phenol, 108-95-2;2-chlorophenol,95-57-8; 2,4-dimethylphenol, 105-67-9; 2,4-dichlorophenol, 120-83-2; 2,4,64richlorophenol, 88-06-2; 2,4-dinitrophenol, 51-28-5; 4nitrophenol, 100-02-7; 4,6-dinitro-o-cresol, 534-52-1; pentachlorophenol, 87-86-5;heptane, 142-82-5;benzene, 71-43-2;toluene, 108-88-3; xylene, 1330-20-7; styrene, 100-42-5; l-methylnaphthalene, 90-12-0; 2-methylnaphthalene, 91-57-6; ethylnaphthalene, 27138-19-8; dimethylnaphthalene, 28804-88-8;1phenylnaphthalene, 605-02-7; 2-phenylnaphthalene, 612-94-2; phenylmethylnaphthalene, 71697-04-6; biphenyl, 92-52-4; terphenyl, 26140-60-3; diphenyl ether, 101-84-8;methylfluorene, 26914-17-0; dimethylfluorene, 30582-01-5; methylphenanthrene, 31711-53-2;methylanthracene, 613-12-7; dimethylphenanthrene, 29062-98-4; dimethylanthracene, 29063-00-1; 4H-cyclopenta[deflphenanthrene, 203-64-5; methylfluoranthene, 30997-39-8; methylpyrene, 27577-90-8;benzphenanthrene, 65777-08-4;benzanthracene, 56-55-3; methylbenzanthracene, 43178-22-9; methylchrysene, 41637-90-5; dimethylbenzanthracene, 57-97-6;dimethylchrysene, 41637-92-7; dimethyltriphenylene, 60826-76-8; 1,l’-binaphthyl, 604-53-5; 1,2’-binaphthyl, 4325-74-0; 2,2‘-binaphthyl, 612-78-2; benzofluoranthene, 56832-73-6; perylene, 198-55-0;methylbenzofluoranthene, 73020-30-1;methylbenzopyrene, 65357-69-9;dibenzoanthracene,67775-07-9;benzochrysene, 57827-84-6; benzo[ghi]perylene, 191-24-2;indeno[1,2,3-cd]pyrene, 193-39-5;di-n-propylthiophene, 84987-78-0;dibenzothiophene, 132-65-0; methyldibenzothiophene, 30995-64-3; dimethyldibenzothiophene, 70021-47-5; benzonaphthothiophene,61523-34-0; dinaphthothiophene, 71012-24-3; thioxanthene, 261-31-4; methyldibenzofuran, 60826-62-2; benzaldehyde, 100-52-7; 1phenylethanone, 98-86-2; fluorenone, 84987-80-4; methylfluorenone, 79147-47-0; methylanthrone, 79075-29-9; cyclopenta[deflphenanthrenone,5737-13-3;benzofluorenone, 7672360-9; benzoic acid, 65-85-0; ethylhexanol, 75737-89-2; 1-(2propenyloxy)heptane, 16519-24-7;acetic acid phenylethyl ester, 103-45-7; 1-H-indene, 95-13-6.
LITERATURE CITED ( 1 ) Bellar, T. A.; Llchtenberg, J. J. “Water Quality Parameters”; American Society for Testing and Materials: Phlladelphla, PA, 1975; Special Technical Publication 573. (2) Jensen, S.; Renberg, L.; Reutengardh, L. Anal. Chem. 1977, 4 9 , 316-31 8. (3) Zitko, V. Paper presented before the Division of Envlronmental Chemistry American Chemical Society, Honolulu, HI, April 1979. (4) Johnsen, R. E.; Starr, R. I . J . Agrlc. FoodChem. 1072, 20,51. (5) Veith, G. D.; Kiwus, L. M. Bull. Environ. Confam. Toxlcol. 1077, 77, 631-636. ( 6 ) Rudling, L. “Oil Pollution in the Baltic Sea. A Chemical Analytical
Search for Monitoring Methods”; Statens Naturvardsverk: Stockholm; SNVPM 783, 1976. (7) Goerlltz, D. F.; Law, L. M. J . Assoc. Off. Anal. Chem. 1974, 5 7 ,
176-181. (8) Glger, W.; Blumer, M. Anal. Chem. 1974, 4 6 , 1663-1671. (9) Hllpert, L. R.; May, W. E.; Wise, S. A,; Chesler. S. N.; Hertz, H. S. Anal. Chem. 1078, 5 0 , 458-463. (IO) Lopez-Avlla, V.; Hites, R. A. Organic Compounds in an Industrial Wastewater: A Case Study of Their Envlronmental Impact”; 1980; National Technical Information Servlce Report No. P.B. 80-124704 (price code A I 2 ) . (11) Bellar, T . A,; Llchtenberg, J. J.; Lonneman, S. C. I n “Contaminants and Sediments”; Baker, R. A,, Ed.; Ann Arbor Science Publishers: Ann Arbor, MI, 1980; Vol. 2, p 57. (12) Bierl, R. H.; Cueman, M. K.; Smith, C. L.; Su, C. W. Int. J . Envlron. Anal. Chem. 1078, 5,293-310. (13) Nowlckl, H. G. J . Assoc. Off. Anal. Chem. 1981, 6 4 , 16-18. (14) Stalling, D.L.; Pew, J. D.;Smith, L. M. J . Chromatogr. Scl. 1981, 19,
18-26. (15) Kuehl, D. W.; Leonard, E. N. Anal. Chem. 1978, 50, 1982-1985. (16) Laflamme, R. E.; Hites, R. A. Geochim. Cosmochlm. Acta 1078, 42, 289-303. (17) Acurex Corp. “Method Development for Fused Slllca Capillary Column GWMS”, final report, Sept. 1981; under EPA Contract 68-03-3043.
Anal. Chem. 1983,55, 889-892 (18) Midwest Research Institute “Protocol for the Analysis of Extractable Organic Priority Pollutants in Industrlal and Municipal Wastewater Treatment Sludge”: under EPA contract 66-03-2695. (19) National Bureau of Standards, Certificate ob Analysls, Standard Reference Materieiis, River Sediment, Washlngton, DC, Nov 16, 1978. (20) Eichelberger,,J. W.; Harris, L. E.; Budde, L. E. Anal. Chem. 1075, 47, 995- 1000. (21) Heiier, S. R.; Mllne, G. W. A. EPAINIH Mass Spectral Data Base, Natl.
889
Stand. Ref. Data Ser. ( U S . Net/. Bur. Stand.) 1878, 1 - 4 , 63.
RECEIVEDfor review May 20, 1982. Resubmitted January 25, 1983. Accepted January 25, 1983. Support for this research was provided by the US. Environmental Protection Agency, Contract No. 68-03-2711.
Determination of Nitroaromatics in Biosludges with a Gas Chromatograph/ThermaI Energy Analyzer John H. Phillips, Robert J. Coraor, and Steven R. Prescott” Alr Products and Chemlcals, Inc., Box 538, Allentown, Pennsylvanla 18105
A method is deecrlbed for the determination of nltroaromatics in blosludges. N shakeout-centrlfugatlon procedure Is used to Isolate the nltroaromatlcs from the blosludge and quantltatlon Is carrled out wtth a gas chromatograph/thermaI energy analyzer (GCAEA). The detectlon limlt of the method Is 0.05 mg/L and the preclslon of the method et the detectlon limlt Is 9-14% relatlve standard deviation. The preclsion of the method at 1.0 mg/L Is 2 4 % relatlve standard deviation. The recoverles of thie nltroaromatics averaged 81% at the detection limit to 816% at 1.0 mg/L. The use of the TEA in the quantltation of the nitroaromatlcs In the biosiudge extracts ellmlnates the nleed for any further sample cleanup.
The determination of nitroaromatics in complex environmental matrices such as sludges and sediments requires selective and sensitive analytical techniques. Nitroaromatics have been widely used in the production of explosives, dyestuffs, and urethane products. The toxic pollutant list published by the EPA (1) includes nitrobenzene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene for which the EPA has reported water quality criteria as specified in Section 304(A) of the Clean Water Act (2, 3). Nitroaromatics have been analyzed by using gas chromatography with a variety of detectors. These detectors include nonselective gas chromatographic detectors such as the flame ionization detector (FID) ( 4 , 5 ) and selective gas chromatographic detectors such as the thermionic specific detector (TSD) (6),the electron capture detector (ECD) (6,7), and the Hall electrolytic conductivity detector (HECD) (8). The EPA, in its proposed methods for analyzing priority pollutants in municipal and industrial discharges (Nitroaromatics and Isophorone, Method 609), recommends the determination of nitrobenzene by jlame ionization gas chromatography and the determination of dinitrotoluenes by electron capture gas chromatography (9). A novel method for the determination of nitroaromatics was recently published in which a gas chromatograph was coupled with a nitric oxide selective pyrolysis/chemiluminescence detector (TEA) (lo). This detector has been extensively used to analyze N-nitrosamines in a wide variety of matrices (11-14). It was found that by operating the pyrolyzer of the TEA above 800 “C, molar or nearly molar yields of nitric oxide could be obtained from a series of nitrotoluenes. This paper describes an evaluation of the TEA for measuring the concentrations of several nitroaromatics in complex
sludge extract,s obtained from a large activated sludge treatment plant. A comparison of the results obtained by using the TEA vs. results obtained by using other selective gas chromatographic detectors (TSD, ECD, HECD) is reported. Also discussed is a method for the stabilization and extraction of nitroaromatics from biologically active sludges. This method coupled with TEA analysis precludes the necessity for further sample fractionation or cleanup.
EXPERIMENTAL SECTION Apparatus and Experimental Conditions. Thermionic Specific Detector. A Varian 3700 gas chromatographequipped with a thermionic specific detector was used in the sludge extract analyses. The detector gas flows were hydrogen (4.1 mL/min) and air (150 mL/min). The bias voltage was maintained at -4 V and the bead current at 5.85 scale divisions as suggested by the manufacturer. The remaining chromatographic conditions for the TSD, ECD, HECD, and TEA are listed in Table I. Electron Capture Detector. A Perkin-Elmer Sigma 4 gas chromatographfitted with an electron capture detector was used in this work. Argon/methane (5%) served as the carrier and makeup gas. The ECD was operated with a standing current of 1.0 nA. Hall Electrolytic Conductivity Detector. A Tracor Model 560 gas chromatograph equipped with a Tracor 700A HECD was operated in the nitrogen mode. The HECD nitrogen mode parameters were aa follows: reactor temperature, 800 “C; reactor gas, hydrogen at SO ml/min; electrolyte, water/l-propano1(5060) at 0.5 mL/min; resin, IRN-78/IRN-150 (67% /33%); vent time, 1.0min. A halogen/sulfur scrubber consisting of KOH treated quartz thread in a copper tube was mounted between the reactor and the conductivity cell. Thermal Energy Analyzer. A Thermo Electron Corp. TEA Model 502A/610R Analyzer interfaced to a Perkin-Elmer 39’20 gas Chromatograph was operated in the “nitroso mode”. The pyrolyzer temperature was 950 “C. The oxygen flow rate to the ozonator was 25 mL/min and the reaction chamber pressure w,as approximately 0.4 torr (53 Pa) in the GC mode. A solid sorbent device (“CTR”, Thermo Electron Corp.) was used to remove pyrolysis products from the gas stream. Chromatography Data System. Analog signals from the foiur gas chromatograph-selective detector systems described above were processed by a Varian Vista 401 chromatography data system for peak integration. The signal output from the TEA analyzer was fiitered with a Model 921 electronic filter (SpectrumScientific Corp.) at a cutoff frequency of 0.1 Hz. Chemicals. The 2,4-dinitrotoluene, 2,6-dinitrotoluene, and 3,4-dmitrotoluene isomers were obtained from Aldrich (Milwaukee, WI) and recrystallized from methanol twice before use. Nitrobenzene and copper(I1) sulfate were purchased from Fisher Scientific Co. (Pittsburgh, PA) and used as provided. Di-
0003-2700/83/0355-0889$01.50/00 1983 Amerlcan Chemical Societv
