Document KRgGK3QMk2jKqmkp52G6jyb10

I 5 Edmondson Road, ?ge :enccs and ily of North Carolina 14 other Metabolism t of Environmental r/arland rvpid publication of contamination and n the introduction, >n ord8r t0 icnpi ght to be 1 on ti .ack inside is. particularly with .Vication. Complete *11 be published in 'nation potentially detailed so as to table for inclusion r research workers . and who welcome mually as demand *e. Now York, N.Y. 528 f .75 postage poisonol uso only. fer volumo. b |ng 3 V7 Ra,icl Scparalion of Polychlorinated Biphenyls from J)!)'' and I|h Analogues on Siliea Gel by Diane Snyder1 niul KnnnnT Keineut (/S. Fish nuri II iltllifr Srrvire Great ImUc* Fishvry Laboratory Ann Arbor, Michigan 48107 Polychlorinated biphenyls (PCB's), which are used in indus try worldwide (1), have been found as residues in numerous wild life species (2-7). Because of the similarity in chemical char acteristics, PCB compounds interfere with gas liquid chromato graphic (GI,C) analysis of certain chlorinated hydrocarbon insec ticides (8). In the present study, we sought a rapid microanalytical procedure for separation of PCB's from DDT and its analogues before analysis with GLC. A small silica gel column was found to be suitable for removing two of the Aroclor series of PCB's (1254 and 1260) from DDT and its analogues. Materials Silica gel used for the columns was grade 950 activated des iccant, 60-200 mesh, from the Davison Chemical Division of W. R. Grace, Baltimore, Maryland. Pentane and benzene, distilled in glass grade, were from Burdick and Jackson Laboratory, Inc., Muskegon, Michigan. Commercial PCB preparations containing 54 and 60 percent chlorine (Aroclor 1254 and 1260) wefe from the Monsanto Organic Chemicals Division of the Monsanto Co., St. Louis, Missouri. Standards for DDT and its analogues (DDT, DDD, DDE) were from the U.S. Public Health Service Pesticides Repository, Pesticide Research Laboratory, Perrine, Florida. The Method Transfer silica gel from a freshly opened can to a glass stoppered bottle and add enough pentane to cover the silica gel with at least 12 mm of pentane. If the silica gel has been pre viously exposed to air, reactivate it by placing it in an oven at 200 C for 8 hours before mixing it with the pentane. Quickly add the mixture of silica gel and pentane to a glasswool stoppered column (1.0 cm ID x 20 an long). A useful tool for packing the column is a disposable pipette from which the narrow portion of the tip has been removed. Small amounts of silica gel 1/ Present address: Johns Hopkins School of Hygiene, Department of Population Dynamics, Baltimore, Maryland. Bulletin of Environmental Contamination & Tnaieolnpy, Vol. 6, No. S, 1971, imhiishnd bjr Spritzer-VvlJag New York Inc. TOWOLDMONOQ54242 are drawn into the pipette with a rubber bulb, and expelled into the column. Gentle tapping of the column facilitates packing. Always keep enough pentane in the column to ensure that the silica gol being added will filter through the pentane, thus eliminating air bubbles. The column must be free of air bubbles or breaks in tho packing to ensure proper separation of the DDT complex from the PCB's. A length of 7.7 cm (about 3 g dry weight) of silica gel is required for each column. Wash the column with 5 ml of pentane. Place 1 ml of sample in pentane or hexane on the column. Rinse the tube which con* tained the sample twice with 1-ml portions of pentane and place tho rinse on the column. After the sample and rinse have been absorbed, collect the following solvent fractions separately in two 50-ml tubes: Fraction Solvent Ml collected Chemical eluted A Pentane 1-38 PCB's B Benzene 39 - 75 DDT and its analogues Concentrate each fraction to the desired volume and analyse with GLC. If the amounts of PCB or insecticide put on the column are large, poor separation results; therefore, only the amounts neces sary for determination by GLC analysis should be passed through the column. . Operating conditions for GLC and the methods for extraction and cleanup of fish samples before the extracts are placed on the silica gel column were described by Reinert (9). Concentrations of Aroclors are determined by planimetric readings of the GLC chromatograms. Areas for all the PCB compo nents collected in the pentane fraction arc compared with the areas for known amounts. This method yields a standard curve that is linear on semilog paper. Efficiency of the Method Efficiency of the silica gel column was measured by deter mining percentage recoveries when known amounts of Aroclors 1254 and 1260 and the DDT complex were washed through the column (Table 1). Fraction A recoveries for 1254 and 1260 averaged 97 and 102 percent, respectively. No peaks with retention times sim ilar to those of DDT and its analogues were found in fraction B. Measured amounts of Aroclors 1254 and 1260 were added to hexane extracts from fish. The fish--one coho salmon, Oncorhynchus kisutch, and two lake trout, Salvelinus namaycush, from Lake Michigan--contained substantial concentrations of DDT and its 386 Percent* o Fraction cheraic.i Fraction t Aroclor Aroclor Fraction l pp DDE op DDT pp DDD pp DDT analogues analyzed t column ef' its analo> Chrc; cleanup o 1254 are Jbi sepnf Little]pr the small taneously achieved tativc re Jjut 0248017 TOWOLDMONOQ54243 TABLE 1 Percentage recoveries for known amounts of Aroclor 1254 and 1260 and the DDT complex after separation on silica gel columns Fraction and chemical Concentration Number of Percentage recovery (lX10_Bg/ml) trials Average Range Fraction A Aroclor 1254 50.0-100.0 15 97 66-118 Aroclor 1260 50.0 13 102 80-130 Fraction B pp DDE op DDT . pp DDD pp DDT 4.0- 10.0 0.5- 10.0 0.5- 10.0 4.0- 10.0 15 12 12 12 89 . 93 96 97 72-110 78-114 83-114 72-118 analogues. Three samples of each of the spiked extracts were analyzed with GLC after separation on silica gel. The silica gel column effectively separated Aroclor 1254 and 1260 from DDT and .its analogues in extracts from fish (Table 2). Chromatograms taken at various stages during the silica gel cleanup of the hexane extract of a lake trout spiked with Aroclor 1254 are shown in Figure 1. The silica gel column described here rapidly and efficiently separates the two Aroclors tested from DDT and its analogues. Little prior preparation of the silica gel is needed. Because of the small size of the columns, numerous samples can be run simul taneously on individual columns in a small area. Separation is achieved in about 1 hour. Reproducibility of results and quanti tative recoveries from samples were good. 387 wr ^80l8 TOWOLDMONOQ54244 TABLE 2 Percentage recoveries from silica gel columns for Aroclors 1254 and 1260 and the DDT complex in hexane extracts from coho salmon and lake trout Species and chemical component Concentration Percontaoib recovery. <1X10 g/ml) Fraction A Trial Trial Trial Fraction B* Trial Trial Trial 123 123 Ooho salmon Aroclor 1254 pp DDE ' op DDT pp DDD pp DDT Lake trout Aroclor 1254 pp DDE Op DDT pp DDD PP DDT Lake trout Aroclor 1260 pp DDE op DDT pp DDD pp DDT 50.0 8.0 1.0 1.0 4.0 50.0 13.0 1.0 2.0 6.0 50.0 10.0 1.0 1.0 5.0 108 108 108 --------- 90 90 100 -------"- 130 120 110 ------"" - -- 100 72 94 100 100 62 100 100 85 125 114 100 --- 96 76 100 80 100 87 87 80 67 91 91 82 .-_ 80 90 110 83 100 100 100 83 83 89 89 110 * Percentage recoveries for the DDT complex were calculated by comparing the amounts of insecticide found in the hexane ex tracts from fish with the amounts found after the separation procedure on silica gel columns. P.P' DDE I o o < 0V9 oZ1'9 TOWOLDMONOQ54245 fSt f5t l! 3 W M- C OZO'**' Figure 1* Chromatograms of the hexane extract of a lake trout before and after the addition of 0.5 ug of Aroclor 1254. (A) Hexane extract of a lake trout after the initial cleanup (9), showing DDT and its analogues. (B) Hexane extract after addition of 0.50 pg of Aroclor 1254. (c) Pentane fraction of the hexane extract after cleanup on silica gel, showing Aroclor 1254* (D) Benzene fraction of the hexane extract after cleanup on silica gel, showing DDT and its analogues. i TOWOLDMONOQ54246 References U) C. G. GUSTAFSON. Environ. Scl. and Tech. 10, 814 (1970) (2) T. W. DUKE, J. F. LOWE, AND A. J. WILSON, JR. Bull. Environ. Oontam. and Tox. _5, 171 (1970) (3) A. V. HOLDEN, and K. MARSDEN. Nature. 219, 1274 (1967) (4) D. C. HOMES, J. H. SIMMONS, and J. O'G. TATTON. Nature. 216, 227 (1967) (5) S. JENSEN, A. G. JOHNELS, M. OLSON, and M. GOTTERLIND. Nature. 224, 247 (1969) (6) J. H. KOEMAN, M. C. TEN NOEVER DE BRAUW, and R. H. DE VOS. Nature. 221, 1126 (1969) (7) R. W. RISEBROUGH, P. RIECHE, D. B. PEAKALL, S. G. HERMAN, and M. N. KIRVEN. Nature. 220, 1098 (1968) (8) L. REYNOLDS. Bull. Environ. Contain, and Tox. 4^ 128 (1969) (9) R. E. REINERT. Pest. Monitoring J. 3_, 223 (1970) o One Insect'ici of animal constant reaches and excrc mates ini of excrei 11 zing er enzymes < stances i carbon hi because c The of detoxi dleldrln Feni ment. Tl Laboratci llsm cagi six groui 0 and 1 ` body wel' mixed coi a tracer times thi Condu requlrem Dakota S 2 Suppl 2 ppm of 1,4,4a ,5 (HEOD). an Bulletin of f Vol. 6, No. i 02* 6021 O TOWOLDMONOQ54247