Gas chromatography-mass spectrometry based sensitive analytical approach to detect and quantify non-polar pesticides accumulated in the fat tissues of domestic animals.

Abstract

A fast and simple technique is proposed for the detection and quantitative determination of six non-polar pesticides including pyrethroids (cypermethrin, deltamethrin), organochlorines (hexachlorobenzene, α-hexachlorocyclohexane) and organophosphorus (chlorpyrifos, fenitrothion) accumulated in fat tissues of local cattle, sheep and goats. Gas chromatography coupled to mass spectrometry detection (GC–MS) adapted to cleanup procedures based on solid-phase extraction from QuEChERS method was adopted. The work was performed for quantitative affirmation of most customarily used pesticides in Sulaymaniyah, Kurdistan Region of Iraq and also the impact of boiling (100 °C, 30 min) and broiling (176 °C, 20 min) on chosen pesticides was evaluated. Among the results of 150 fat samples presented, the dominant compound in cattle samples was hexachlorobenzene (0.236 mg kg−1); while, in sheep and goats it was deltamethrin (0.248 and 0.122 mg kg−1 respectively). Boiling reduced pesticide concentration significantly (P < 0.05) and the most reduced group was pyrethroids in both techniques. Good responses for the six analytes were obtained at validation level of 0.01–0.1 mg kg−1. The linear coefficient was between 0.9997 and 0.9999 and limits of detection (LOD) and quantification (LOQ) ranged 0.0052–0.014 mg kg−1 and 0.015–0.044 mg kg−1 respectively. Acceptable recoveries (81.5–98.6%) and relative standard deviation (0.3–9.3%) were obtained in different spiked levels. The validation results confirmed that the proposed GC–MS technique can be utilized as a dependable screening apparatus for the quantitative screening of studied pesticides in fat tissues with accuracy and sensitivity, if deployed along with solid-phase extraction based QuEChERS method.