As part of an ongoing evaluation of new sample preparation techniques by the U.S. Environmental Protection Agency (EPA), especially those that minimize waste solvents, microwave-assisted extraction (MAE) of organic compounds from solid materials (or "matrices") was evaluated. Six certified reference materials containing polynuclear aromatic hydro-Base/Neutral Compounds 18 dibenzofuran 25 9H-carbazole 19-1,2-dichlorobenzene 26 di-n-butyl phthalate 20 1,3-dichlorobenzene 27 bis(2-ethylhexyl) phthalate 21 N-nitroso-di-n-propylamine 28 isophorone 22 nitrobenzene 29 4-chlorophenyl phenyl ether 23 1,2,4-trichlorobenzene 30 butyl benzyl phthalate 24 2,4-dinitrotoluene Phenols 31 phenol 38 4-chloro-3-methylphenol 32 2-chlorophenol 39 2,4,6-trichlorophenol 33 2-methylphenol 40 2,4-dinitrophenol 34 3-methylphenol 41 4-nitrophenol 35 2-nitrophenol 42 2,3,4,5-tetrachlorophenol 36 2,4-dimethylphenol 43 2-methyl-4,6-dinitrophenol 37 2,4-dichlorophenol 44 pentachlorophenol Organochlorine Pesticides 45 a-BHC 55 dieldrin 46 d-BHC 56 4,4'-DDE 47 7-BHC 57 endrin 48 5-BHC 58 endosulfan-II 49 heptachlor 59 4,4'-DDD 50 aldrin 60 endrin aldehyde 51 heptachlor epoxide 61 endosulfan sulfate 52 7-chlordane 62 4,4'-DDT 53 endosulfan-I 63 endrin ketone 54 a-chlordane 64 methoxychlor13 compounds (base/neutral) in Table 1 (except dibenzofuran, which was bought from Supelco as neat material) were purchased as individual stock solutions from ChemService (West Chester, PA) and Supelco, Inc., and were combined with the PAH stock solution to make the working calibration standards for the GC/MS analysis. Dibenzofuran was dissolved separately in methanol at 5 mg/mL and was combined with the PAH stock solution to make the working calibration standards. The purities of all compounds were

Concern over rising costs and increasing sample loads has led to the * ELISA is enzyme-linked immunosorbent assay. 6 RIA is radioimmunoassay.

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H The wastewater from a small speciality chemicals manufacturing plant located on the Pawtuxet River (Rhode Island, USA) has contaminated the water and sediment of that river, the Pawtuxet Cove, the Providence River, and (to a lesser extent) the Narragansett Bay. Since the compounds found in this system cover a wide range of functionalities, polarities, and water solubilities, a detailed study of this system has allowed us to assess the environmental behavior of seueral compound types in one aquatic system. We find that the aqueous concentrations of the various compounds follow the rules of simple dilution and that those compounds with the highest octanol-water partition coefficients (log P ) are strongly associated with the particulate matter in the water and are found in the sediment at the greatest distance from the plant. The sediment concentrations (C) of a given compound can be predicted from its log P value and from its concentration in the wastewater (CO) by log (CoIC) = bo + b2(dist/log P ) where dist is the distance of the sediment sample from the plant and bo and bz are constants fitted to the data.The deposition of potentially toxic organic compounds from the wastewaters of chemical processing plants into aquatic sediments is a known phenomenon. Petroleum hydrocarbons ( I ) and Kepone (2) are two examples. Our previous study ( 3 ) on the environmental impact of a small chemical plant is another. In that study, we identified over 120 different organic compounds in the wastewater of a specialty chemicals manufacturing plant and in the nearby river water and sediment. The maximum concentrations of these compounds were 15 ppm in the wastewater, 0.2 ppm in the river water, and 700 ppm in the river sediment. With the exception of some interesting phenol oxidation reactions (which we will report on elsewhere), there were no chemical transformations observed in this system.Unlike most sediment studies, in which only one or a few coi,ipounds have been identified and quantitated, we measured many compounds covering a wide range of functionalities, polarities, and water solubilities ( 3 ) . This was a rare opportunity to study in one aquatic system the behavior of seueral compound types. Therefore, we have carried out a detailed study of this system. This paper summarizes the results of our field measurements and presents some useful generalizations by which the sedimentary behavior of industrial organic compounds can be predicted. Experimental SectionSampling Area. The plant setting and the receiving water system are described by the maps shown in Figures 1 and 2.

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