Application of Simultaneous Subcritical Water Extraction and Solid Phase Extraction to the Separation of Organochlorine Compounds from River Sediments

Active carbon fiber (ACF) was used as a solid extractant,and mixed homogenously with the sediment sample.The mixture was transferred to the extraction vessel to carry out the static subcritical water extraction (SCWE) at prescribed program.By the addition of ACF to the SCWT system,good results of simultaneous SCWT and solid phase extraction (SPE) were attanied.In the simultaneous SCWE and SPE,when 0.500 g of the sediment sample was treated with 0.050 g of ACF and 4.0 mL of super-pure water at 160 ℃,values of recovery of 4 organo chlorine pollutants,i.e.2-chlorophenol (2-CP),2,4,6-trichlorophenol (2,4,6-TCP),pentachlorophenol (PCP) and hexachlorobenzene (HCB) were found to be relatively higher than those of the off-line SCWE-SPE method,less influential by the cooling temperature of the extraction vessel,and particularly feasible for extraction of samples with high pollutant contents.The proposed extraction method in hyphenation with gas chromarograph has been applied to the determination of 4 organochlorine pollutants in sediment samples taken from the Yangtze River,giving results in consistency with the results obtained by USEPA standard method.