Development and Validation of GC-ECD Method Using QuEChERS for Pesticide Residue Determination in Cucumber.

Herein a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled to gas chromatography with electron capture detector (GC-ECD) was developed for simultaneous determination of selected electronegative pesticides viz.,chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutnil (5), ethion (6), fenpropathrin (7) and cypermethrin (8) in vegetables with high water content. The selected compounds and some of their metabolites have even been found in human body fluids. In addition, some of them are known or suspected carcinogens according to the World Health Organization. Extraction and clean up parameters were optimized, thus the original QuEChERS method was modified to decrease solvent usage by making study eco-friendly. The developed method was validated in terms of selectivity, specificity, linearity, precision and accuracy by following SANTE guidelines. Calibration curves showed good linearity (r>0.99) within test range. Precision was evaluated by intra-and inter-day experiments with acceptable range <20.0% RSD. Recovery was evaluated at LOQ level and was found in the range of 70-120% with RSDs lower than 4.21%. The proposed methodology is applicable for detection and monitoring of selected pesticides in one run not only in fruits and vegetables with high water content, but also in samples containing large amounts of pigments/dyes.