An independent comparison between supercritical fluid extraction (SFE) and Soxhlet extraction methods was conducted as part of a certification of PCB congeners in industrial soil. The study was performed in the framework of the PCB group for the Measurements and Testing Program (former BCR) under the Commission of the European Union. It involved 21 selected and independent laboratories experienced in congener-specific PCB analysis. The comparison was performed using both interlaboratory and intralaboratoiy data. SFE was performed independently by three laboratories, and the obtained data showed that SFE is a very competitive alternative in terms of both accuracy and precision. The soil was certified for eight PCB congeners ranging from 7.0 to 137 //g/g with interlaboratory RSDs of 9-13% using all but two (out of 34) individual results from the SFE group.In recent years, supercritical fluid extraction (SFE) has gained increased interest because of the potential for reducing (1) the use of large amounts of hazardous organic solvents and (2) the work connected with conventional methods.1-8 Unfortunately, but also understandably, early SFE methods were developed using spiked or fortified samples on a variety of homemade instruments.9-11 The results obtained indicated that SFE had a very

A method for the rapid interference free analysis of PCB congeners in sulfur-containing sediments is presented. The method involves a sulfur cleanup at supercritical conditions and was developed on a sediment from the Rotterdam (NL) harbor that contains 1.5% sulfur and PCB congener concentrations ranging from 2 to 29 ng/g dry wt. The complete analysis time was less than 2.5 h, mainly depending on the GC analysis time, and did not involve any manual cleanup or pretreatment of the samples. HRGC-ECD analysis was done on two parallel coupled columns, a 60-m DB-17 column and a series combination of a 25-m SIL8 and a 25-m HT5 column.The supercritical fluid extraction was evaluated on three different trapping materials to investigate any differences in the purity of the extracts. The final analytical method was compaired to Soxhlet extraction, applied on a certified sewage sludge sample, and gave quantitative recovery detection limits of 1-2 ng/g dry wt and standard deviations less than 10%. The method developed was used on a survey of 27 sediments from Venice that contained 0.8-2.5% sulfur with a concentration range of 1.5-343 ng/g dry wt for single PCB congeners.Polychlorinated biphenyls (PCBs) are thermally stable chlorinated hydrocarbons with high dielectric constants, which have led to their application in a wide range of industrial products, properties that are also responsible for the widespread and lasting environmental contamination problems associated with PCBs.1•* 12 The potential environmental threat of the large amount of PCB still in use and the toxicity of certain congeners call for continued future monitoring of these compounds in the environment.3 4™5 PCBs enter the environment as longrange air-transported pollutants,6 7mainly originating from scattered dumps and waste incineration.7 One of the major environmental sinks for these pollutants is marine and lacustrine sediments, and these matrices play an important role in environmental monitoring.The analysis of PCB congeners in sediments classically includes three phases: extraction, purification of the extract, and separation and detection of the various congeners. The extraction of sediments can be carried out successfully with sonication or Soxhlet procedures. The primary purpose of the purification of the extract is the elimination of coextracted

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