Selective pressurized liquid extraction for the analysis of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans in soil.

During this study a high throughout selective pressurized liquid extraction (SPLE) method was developed and validated for the simultaneous extraction of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/PCDFs) and polychlorinated biphenyls (PCBs) from soil. To that end, extraction rates of PCBs from soil utilizing different extraction solvents and different extraction temperatures were investigated whereas extraction rates were comparable for toluene, n-hexane and dichloromethane (extraction conditions for all utilized solvents: 33mL PLE extraction cell, extraction temperature: 110°C, static extraction time: 5min, flush volume: 60%, purge 90s). Ratios of native PCBs and PCDD/PCDFs congener concentrations after Soxhlet and selective pressurized liquid extraction (SPLE) showed that SPLE is an alternative sample preparation step for the simultaneous determination of PCDD/PCDFs and PCBs in soil. Additional clean-up steps for the separation of PCBs and PCDD/PCDFs utilizing alumina were performed in order to avoid interferences between the component classes.