Optimization Method for Determining Organochlorine Pesticide Residues by Gas Chromatography-Mass Spectrometry

Multiresidue methods, which allow the identification/quantification of residues of different analytes at the same time, are advantageously used for monitoring purposes. The multiresidue analysis of OCPs in fat and meat samples involves several steps, first of all the selective extraction of the residues from the homogenized matrix. This work describes the optimization and validation of a multiresidue GC/MS method for the quantification of 18 OCPs in meat samples. An automated system allowed the extraction of 6 samples simultaneously with small volumes of solvent over a 24-hour period. Prior to the analysis, a rapid simple clean-up procedure by SPE (florisil, C18 cartridge) was carried out.An Shimadzu GC-MS System QP-20101, equipped with Autosampler AOC 5000 (Combi Pal). The chromatographic separation was achieved on a 50 m × 0.32 mm i.d. ZB-5ms capillary column (Phenomenex, USA) with 0.25 µm film thickness. Both data acquisition and processing were accomplished by software GC-MS – Solution Version 2.3.(Shimadzu Corporation) Performance parameters were determined to optimize the GC-MS method (R2, RSD%, limit of detection) as follows