Determination of 229 pesticides residue in edible oil samples using conventional QuEChERS method and solid phase microextraction based on monolithic molecularly imprinted polymer fiber and analysis with GC-MS

Abstract

The goal of this research is development of solid phase microextraction based on monolithic molecularly imprinted polymer fiber (SPME-MMIPF) method to determine 229 pesticides in edible oil samples using gas chromatography-mass spectrometry (GC-MS) and comparison of it with the common QuEChERS method. In QuEChERS method, acetonitrile used as extraction solvent and magnesium sulfate used as water absorbing agent. For SPME-MMIPF method, an MMIPF was synthesized by polymerization of methacrylic acid in presence of ethylene glycoldimethacrylate and azo (bis)-isobutyronitrile. The optimal conditions for the SPME-MMIPF method are: extraction time 30 min, desorption time with toluene 20 min and string speed of the aqueous sample 600 rpm. Under optimal extraction condition, the figures of merit were obtained for two methods and compared. The linear range of 1-300 µg kg^− 1 for SPME-MMIPF and 10–250 µg kg^− 1 for QuEChERS was obtained. The detection limit of SPME-MMIPF (0.321–0.335 µg kg^− 1) method was better than the QuEChERS (0.9–2.6 µg kg^− 1) method. The results showed a quantification limit of 0.8–2.2 µg kg^− 1 for SPME-MMIPF and 1.5–5.2 µg kg^− 1 for QuEChERS. The recoveries were in the range of 92–102% and 68–127% for SPME-MMIPF and QuEChERS, respectively.