盐析辅助均相液液萃取/分散固相萃取-超高效液相色谱串联质谱法测定蜂蜜中新烟碱类农药残留

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

以盐析辅助均相液液萃取结合分散固相萃取作为前处理方法,建立了超高效液相色谱串联质谱快速检测蜂蜜中吡虫啉、噻虫嗪、噻虫胺、噻虫啉、啶虫脒及氯噻啉6种新烟碱类农药残留的分析方法。样品用乙腈提取,氯化钠盐析分层,提取液经分散固相萃取法净化,采用超高效液相色谱串联质谱检测器进行分析。考察了萃取剂种类、体积及氯化钠质量对萃取效率的影响,评估了在优化实验条件下的基质效应和方法性能。结果表明：除吡虫啉外,其余5种新烟碱类农药的基质效应均大于10%。6种新烟碱类农药在0.2～100μg/L范围内线性关系良好,相关系数（r2）为0.998 1～0.999 7。加标浓度为1.0～50.0μg/kg时,6种新烟碱类农药的加标回收率为77.0%～106%,相对标准偏差为2.4%～19.8%。方法的检出限为0.2～0.4μg/kg,定量下限为1.0μg/kg。该方法前处理简单,分析时间短,准确度和灵敏度高,重现性好,适用于蜂蜜中6种新烟碱类农药微量残留的快速测定。

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 μm 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 sixpesticides were linear in the range of 0. 2- 100 μg / 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 μg / 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 μg / kg and the limit of quantitation were all 1. 0 μg / 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.