Multiresidue analysis of organochlorine pesticides in milk, egg and meat by GC-ECD and confirmation by GC-MS.

A multiresidue method was developed and optimized for the quantification of organochlorine pesticides (OCPs) in milk, egg and meat samples. Sample extraction was performed by adopting QuEChERS principle and the extracts were cleaned-up dispersive solid-phase extraction with primary secondary amine after salting out with NaCl and MgSO(4). Analysis was carried out by gas chromatography coupled with electron capture detector and confirmation by gas chromatography-mass spectrometry. The performance of the method was investigated in terms of linearity, accuracy, precision, detection limit and quantification limit (LOQ). Good linearity was obtained, with correlation coefficients (r(2)) higher than 0.992. Mean recoveries were found in the ranges 72%-108%, 74%-101% and 75.27%-104.56% for the milk, egg and meat, respectively, RSD % turned out to range from 0.28% to 10.05%. The method developed was successfully tested on commercial milk, egg, and meat samples from the markets of Tamil Nadu (India), proving to be a useful tool in routine analysis of OCPs for monitoring purposes. None of the compounds of interest were observed above their respective LOQ.