Matrix effect on supercritical fluid extraction of organochlorine pesticides from sulfur-containing soils

The influences of spiking method and matrix properties of total organic carbon, pH, moisture content, and grain size on supercritical fluid extraction efficiency of 16 organochlorine pesticides (OCPs) from soils were investigated. A direct on-line method using selective adsorbents of AgNO3 loaded silica in the extraction cell for simultaneous extraction and clean-up of sulfur-containing soils is developed. The procedures are simple, rapid, and require only small amounts of samples and solvents. With the right choice of extraction conditions and trapping materials, it may serve to analyze OCPs in sulfur-containing soils on a routine basis.