Tinii.- 



For a set of eight samples: Extraction of oil, 

 none; extraction of other samples. 4 h (or less); 

 cleanup, 1 h; separation of DDT and PCB, 4 h; and 

 transfer and dilution of samples for gas-liquid 

 chromatography, 1-2 h. 



Rt-aUfiits 



Analytical standards: U.S. Environmental Pro- 

 tection Agency, Health Effects Research Labora- 

 tory, Environmental Toxicology Division, Re- 

 search Triangle Park, N.C. 



Aroclor'^1254: Monsanto Company, St. Louis, 

 Mo. ( Aroclor 1254 was used as the analytical stan- 

 dard for PCB because it represented the PCB most 

 typically found in our samples. Snyder and 

 Reinert (1971) tested both Aroclor 1254 and Aro- 

 clor 1260. The suitability of the procedure for PCB 

 of other degrees of chlorination would need to be 

 verified.) 



Sodium sulfate: anhydrous, reagent grade. If 

 the blank indicates the sodium sulfate is contami- 

 nated, rinse with petroleum ether or hexane and 

 dry before use. 



Solvents: distilled-in-glass grade, Burdick & 

 Jackson. Muskegon, Mich. (The suitability of 

 other "pesticide" or "nanograde" solvents would 

 need to be determined.) 



Florisil: 60/100 mesh P.R. grade, Floridin Com- 

 pany, Pittsburgh, Pa. Store in the dark in tightly 

 closed, screw-cap, flint glass jars, and use without 

 further activation. 



Silica gel: grade 950, 60/200 mesh, desiccant, 

 Davidson Division, Grace Chemical Company, 

 Baltimore, Md. (The performance of other silica 

 gels would have to be evaluated.) 



Carborundum chips: 16 mesh. Use as a boiling 

 aid in all evaporation steps. (Whenever ebullition 

 is interrupted, new chips are necessary.) 



Aluminum foil: domestic grade. 



Teflon wash bottles: Nalgene Co., Rochester, 

 N.Y. Use for adding small amounts of solvents in 

 the boildown and chromatographic procedures. 

 Discard the contents of the wash bottle if left 

 longer than a day. 



Glass wool: borosilicate fiber glass, Corning 

 3950 or equivalent. Use directly from the package. 



Graduated centrifuge tubes: 50-ml, Kimax 

 45164 or equivalent, and stoppered 13-ml, 

 K-410550, Kontes Glass Co., Vineland, N.J., or 

 equivalent. 



Modified micro Snyder column: Kontes 

 K-569251 or equivalent. 



Chromatographic columns: 7 mm i.d. x 150 mm 

 and 9 mm i.d. x 150 and 250 mm glass tubing. (All 

 tubes are without stopcocks.) 



Storage bottles: 23-ml screw-cap, borosilicate 

 specimen bottles, Prescription Containers, Inc., 

 Brooklyn, N.Y., with Teflon cap liners, 2390-H62, 

 Arthur H. Thomas Co., Philadelphia, Pa. 



Pipettes: Class A. Use for preparation of stan- 

 dards. 



Pipettes: disposable glass. Use for quantitative 

 dilution and transfer of samples. 



Pipettes: disposable glass, Pasteur capillary, 

 Kimax 72000 or equilavent. Use for sample trans- 

 fer. (Disposable pipettes are preferred for handl- 

 ing samples in order to eliminate cross contamina- 

 tion.) 



Equipment 



Virtis homogenizer: Macro, Model 23 or 45, with 

 stainless steel blades. Teflon cap, and 10-50 ml 

 glass homogenizer flasks (No. 16-207), Virtis Co., 

 Gardiner, N. Y., or equivalent. ( Bearing lubricants 

 contaminate samples.) 



Tube heater: Kontes K-720000. (It is convenient 

 for evaporating solutions in 13-ml centrifuge 

 tubes.) 



Plastic and Rubber 



Avoid materials, such as gloves, flexible tubing, 



and polyethylene bags, which often contain PCB 



or substances which interfere with quantitation 



by gas chromatography with an electron-capture 



detector. (Teflon is the only plastic suitable for 



these analyses.) Wrap samples in aluminum foil 



for shipment to the laboratory. 



J 

 Washing Procedure 



Glas 



sware 



Glassware: borosilicate (DDT and TDE decom- 

 pose on contact with flint glass). 



•''Mention of trade names or companies does not imply en- 

 dorsement by the National Marine Fisheries Service, NOAA. 



Chlorinated hydrocarbons and some of the sub- 

 stances in samples adhere tenaciously to 

 glassware. To prevent contamination of future 

 samples, rinse glassware with an organic solvent 

 immediately after use, and then soak in water 

 until washing. 



881 



