Determination of Five Organochlorine Pesticides Based on GC-MS Coupled with Deep Eutectic Solvent-Modified Magnetic Graphene Oxide-Improved QuEChERS in Vegetables

A novel deep eutectic solvent-modified magnetic graphene oxide (DES@MGO) was first synthesized. The microscopic structure, composition, and property of the new magnetic adsorbent was characterized. QuChERS-based DES@MGO was first investigated for the removal of impurities from vegetables. Various influencing factors, such as extraction solvent, the mass of anhydrous MgSO4, the mass of adsorbent, and the oscillation time, had been systematically tested. The linearity of the method for analysis of & alpha;-HCH, & beta;-HCH, & delta;-HCH, and p,p'-DDE was between the range of 5-100 & mu;g kg(-1), and for analysis of & gamma;-HCH was 10-100 & mu;g & BULL;kg(-1). The limits of detection, the limits of quantification, and correlation coefficients were 0.3-2.0 & mu;g kg(-1), 0.9-6.6 & mu;g kg(-1), and 0.9986-0.9997, respectively. In comparison to the traditional purification materials N-propylethylenediamine (PSA) and magnetic graphene oxide (MGO), DES@MGO exhibited superior adsorbent properties and purification performance with more fast adsorption rate, and could effectively remove the majority interfering substances in vegetable extract with achieving good retention of the 5 organochlorine pesticides (OCPs). In the meantime, as a pretreatment material, the DES@MGO showed the advantage of rapid separation with its favorable magnetism. Herein, the method is of easy operation and accurate quantification, which is suitable for the analysis of OCPs in vegetables.