하수 슬러지 중의 PCBs 농도 분석

Abstract

PCBs in the sludge drying bed of Calumet East municipal wastewater treatment plant near Chicago was collected and analyzed to address the feasibility of accelerated solvent extractor (ASE) analysis method. Before the sludge samples were transferred to precleaned ASE cell, were added anhydrous sodium sulfate and Ottawa sand sequentially in a depth of approximately 1 cm, spiked with proper surrogate then transferred to accelerated solvent extractor. The sample were extracted with a 1:1 mixture of acetone and hexane. The extracts were then concentrated by using Zymark Turbovap II evaporator to final 1 mL under pure nitrogen blowing. The PCBs concentration was determined by means of GC/ECD with the application of dual column technique. Calibration curve was achieved based on the total sum of 144 PCBs congeners and showed very good correlation. (r2>0.999). Surrogate recoveries were turned out to be within the acceptable range (60-125%). The moisture contents of the actual samples were in the wide range of 20-80%. PCBs concentrations of the actual samples are 0.79-3.14 ug/g based on dry weight. According to the data, ASE extraction technique for solid samples can be considered as a potential analysis preparation technique over all.