Simultaneous identification and quantitation of selected organochlorine pesticide residues in honey by full-scan gas chromatography-mass spectrometry

In this work, we report a reliable method for simultaneous identification and quantitation of 11 organochlorine pesticide (OCP) residues (α-HCH, HCB, β-HCH, alachlor, heptachlor, aldrin, primiphos-ethyl (internal standard), endosulfan II, 4,4′-DDE, dieldrin, endrin and 4,4′-DDD) in honey. The method features the simultaneous identification and quantitation of targeted pesticides and the possibility of identification of any other eluting compounds. The method is based on liquid-liquid extraction (LLE) with a mixture of petroleum ether and ethyl acetate (80:20, v/v) and a cleanup with a Florosil cartridge, followed by gas chromatographic separation and a full-scan mass spectrometric detection (full-scan GC-MS). The method presents a new validation parameter, limit of identification (LOI) which is defined as the lowest analyte concentration that yields a library searchable mass spectrum. The method is linear over the range 5.0-100 μg kg−1. Uncertainties of slopes vary between 2.0 and 13%. Correlation coefficients vary between 0.988 for 4,4′-DDE and 0.998 for α-HCH, alachlor and aldrin. Limits of detection (LODs) vary between 0.65 and 2.5 μg kg−1, limits of quantitation (LOQs) vary between 2.2 and 7.5 μg kg−1, and LOIs vary between 1.0 and 3.0 μg kg−1. The method was applied by analyzing 15 local and 10 imported honey samples in Jordan.