Determination of trace organochlorine pesticides in soil using isotope dilution-high resolution gas chromatography-high resolution mass spectrometry

A method for the determination of trace organochlorine pesticides (OCPs) in soil using isotope dilution and high resolution gas chromatography-high resolution mass spectrometry (ID-HRGC-HRMS) was developed. The sample was extracted by accelerated solvent extractor (ASE) and cleaned-up by a Florisil solid phase extraction (SPE) cartridge. The analytes were separated by HRGC on a DB-5MS column (30 m x 0. 25 mm x 0. 25 mu m) and determined by HRMS. The identifications of OCPs were based on the retention time of C-13-labelled standard and the abundance ratio of the two exact mass-to-charge ratios. The quantitative analysis was performed using the ratios of the integrated areas of the C-13-labelled standards. This method has the recoveries ranging from 77. 3% to 114. 5% and the relative standard deviations (RSD) less than 10. 81% (n = 5). The limits of detection (LODs) of this method for all OCPs were lower than 0. 04 pg/g. The results indicated that the method is rapid, selective and sensitive for precise determination requirements of organochlorine pesticides at trace level in soil.