Application of HPLC-DAD after SPE/QuEChERS with ZrO2-based sorbent in d-SPE clean-up step for pesticide analysis in edible oils.

In this study, the solid-phase extraction/quick, easy, cheap, effective, rugged and safe (SPE/QuEChERS) technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis of edible oils. The proposed method is based on liquid-liquid partitioning with acetonitrile followed by dispersive solid phase extraction using zirconia-coated silica particles for extract purification. To evaluate the described method, 21 pesticides belonging to different chemical classes were analysed using high performance liquid chromatography with diode-array detection (HPLC-DAD). For validation purposes, recovery studies were performed at 75 ng g(-1), 125 ng g(-1), 250 ng g(-1), 500 ng g(-1) and 1000 ng g(-1) levels. Recoveries were over the range of 50-130% for most of the analytes, with relative standard deviations less than 15% being observed. HPLC-DAD provided suitable linearity, precision and accuracy. The validated method was successfully applied to the analysis of edible oil samples selected from the market.