Analysis of multiple pesticide residues in different citrus matrices by magnetic dispersive solid phase extraction-QuEChERS combined with gas chromatography-tandem mass spectrometry

In this study, a rapid multi-residue detection method for 75 pesticide residues in 5 citrus, including mandarin, orange, lemon, pummelo and kumquat, was developed. Pesticide residues were extracted from citrus by magnetic dispersive solid phase extraction (MDSPE)-QuEChERS pretreatment and analyzed by gas chromatography-tandem mass spectrometry(GC-MS/MS). Graphitized carbon black (GCB), primary secondary amine (PSA) and magnetic nanoparticles (MNPS) were used as adsorbents in the (MDSPE)-QuEChERS pretreatment. In order to obtain the optimum recovery rate of pesticide analysis, the amounts of the adsorbents were investigated. Under the optimized conditions, a simple, fast, safe, cheap, reproducible, and applicable multi-residue method was established. Acceptable linearity was maintained at the concentration of 0.01 to 0.5 mg/kg, the average recoveries were in the range of 63% to 118%, and the relative standard deviations (RSDs) ranged from 0.30% to 16%. Also, the limits of detection (LODs) ranged from 1 to 7 μg/kg and the limits of quantification (LOQs) were in the range of 10-20 μg/kg.