Determination of 30 organochlorine pesticides in animal-originated food products using combined purification by gel permeation chromatography and solid-phase extraction coupled with gas chromatography-mass spectrometry

A new analytical method was developed for the determination of 30 organochlorine pesticides (OCPs) in animal-originated food, including pork, chicken, fish and shrimp. The combined purification by gel permeation chromatography (GPC) and solid-phase extraction (SPE) were established by optimizing different fraction collection times. The detection conditions can be achieved by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM). Isotopic internal standards were used for the quantitative determination of the 30 OCPs. The sample pretreatment procedure was based on acetonitrile extraction and combined purification of GPC and Florisil SPE cartridge. The experimental results showed that the linear ranges for 30 OCPs were 5.0-500.0 mu g/L, the correlation coefficients were better than 0.996, and the method detection limits (MDLs) of the 30 OCPs were 0.2-2.7 mu g/kg. The spiked recoveries at three levels of 5.0, 10.0 and 20.0 mu g/kg using pork, chicken, fish and shrimp samples as blank matrices were in the range of 55.0%-119.1%, the relative standard deviations (RSDs) were in the range of 0.4%-15.0%. The method has the advantages of wide linear range, high sensitivity and efficient clean-up procedure, and consistent with the demand of pesticide routine analysis.