Determination of Neonicotinoid Residues in Honey by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Combined with Salting-out Homogeneous Liquid-Liquid Extraction and Dispersive Solid-phase Extraction

KeyWord:salting-out  homogeneous liquid-liquid extraction  dispersive solid-phase extraction  ultra performance liquid chromatography-tandem mass spectrometry£¨UPLC-MS/MS£©  neonicotinoid pesticide  residue  honey

Abstract:

      An ultra performance liquid chromatography-tandem mass spectrometric£¨UPLC-MS/MS£© method was developed for the determination of six neonicotinoid pesticides£¨including imidacloprid,thiamethoxam,clothianidin,thiacloprid,acetamiprid and imidaclothiz£© residues in honey by using salting-out homogeneous liquid-liquid extraction£¨SHLLE£© and dispersive solid-phase extraction£¨d-SPE£© as sample preparation method.The samples were extracted with acetonitrile,and acetonitrile phase was separated from sample solution through salting-out phenomenon with sodium chloride.The acetonitrile solution was purified by dispersive solid phase extraction with 0.22 ¦Ìm filter membrane.The analytes were analyzed by ultra performance liquid chromatography-tandem mass spectrometry.Factors affecting the extraction efficiency were investigated,such as type and volume of extraction solvent and weight of sodium chloride.The performance of this method and matrix effects were evaluated under the optimal conditions.The results indicated that except for imidacloprid,the matrix effects of the rest neonicotinoid pesticides were more than 10%.The calibration curves for six pesticides were linear in the range of 0.2-100 ¦Ìg/L with correlation coefficients£¨r2£© of 0.998 1-0.999 7.The recoveries of six pesticides at three spiked levels of 1.0£¬5.0,50.0 ¦Ìg/kg were in the range of 77.0%-106%,with relative standard deviations of 2.4%-19.8%.The limits of detection for this proposed method were in the range of 0.2-0.4 ¦Ìg/kg and the limit of quantitation were all 1.0 ¦Ìg/kg.With the advantages of simple pretreatment,short analysis time,high accuracy,high sensitivity and good reproducibility,the developed method is suitable for the determination of six neonicotinoid pesticide residues in honey.