Abstract
Method 8120 of EPA Manual SW-846 has been evaluated in a singlelaboratory study. Several modifications made to the current method were implemented to allow determination of selected chlorinated hydrocarbons in complex environmental samples. The 2 packed gas chromatographic columns specified in Method 8120 were replaced with 2 megabore fused-silica open tubular columns chemically bonded with trifluoropropylmethyl siloxane and polyethylene glycol, respectively. The list of target compounds was expanded from 15 to 22 to include all possible trichlorobenzenes, tetrachlorobenzenes, and hexachlorocyclohexane (BHC) isomers. The Florisil cleanup procedure was modified to allow quantitative recovery of 20 of the 22 target compounds. A procedure that uses 1 g Florisil disposable cartridges and hexane-acetone (9:1) eluant was developed. This latter procedure gives quantitative recovery of all 22 target compounds from all matrixes tested. The revised method was tested with a variety of sample matrixes. Detection limits for water samples ranged from 1.4 ng/L for hexachlorobutadiene to 1300 ng/L for 2-chloronaphthalene; detection limits for 15 compounds were below 40 ng/L. Because of background contamination, detection limits for soil and sediment samples need to be determined on a case-by-case basis.
