Objective To establish a method for the determination of organophosphorus pesticides residues in tea and juice by dispersive liquid-liquid microextraction-liquid chromatography-tandem mass spectrometry assisted by salting-out and vortex.Methods Salting-out effect and vortex assisted dispersive liquid-liquid microextraction (DLLME) were used as pretreatment process.Methanol-water were used as mobile phase (containing 0.1％ formic acid).Triple quadrupole mass spectrometry detection was performed in the positive ion mode by multiple reaction monitoring (MRM).External standard method was used for quantitative analysis.Results The optimum conditions were as follows:7.5 mL n-propanol was used as disperser solvent,30 μtLl-bromo-3-methylbutane was used as extraction solvent,salt addition was 0.5 g NaC1,the first vortex time was 2 rmin,and the second vortex time was 50 s.Under the optimum conditions,the detection ranges of 6 organophosphorus were 10～25 ng/L,the limits of quantitation were 50 ng/L,the correlation coefficients were all over 0.990,enrichment factors ranged from 3640 to 4120 fold,and intra-day and inter-day RSDs were below 10.6％.The recovery rates of standard samples spiked at 200 and 800 ng/L were 85％～107％.Conclusion The optimized method has low organic solvent consumption,high enrichment factor and sensitivity,and low matrix effects,which is suitable for the detection of pesticides residues in food with complex matrix.%目的 建立盐析-涡旋辅助结合分散液液微萃取-液相色谱质谱联用法检测茶叶、果汁中有机磷杀虫剂残留的分析方法.方法 采用盐析效应、涡旋辅助分散液液微萃取(dispersive liquid-liquid microextraction, DLLME)前处理技术,甲醇-水为流动相(含0.1％甲酸),三重四级杆质谱正离子多反应检测(multiple reaction monitoring,MRM)模式,外标法定量分析.结果 最佳条件如下:7.5 mL正丙醇为分散剂,30 μL1-溴-3-甲基丁烷为萃取剂,加盐量0.5 g NaC1,前涡旋时间2 min,后涡旋时间50 s.敌敌畏、杀扑磷、马拉硫磷、三唑磷、乙拌磷、毒死蜱6种有机磷检出限范围为10～25 ng/L,定量限均为50.0 ng/L,相关系数＞0.990,富集倍数约为3640～4120,日内、日间相对标准偏差RSD＜10.6％,对加标200、800 ng/L进行回收实验,回收率为85％～107％.结论 该方法有机溶剂用量少,富集倍数和灵敏度高,基质影响小,适用于食品中较复杂基质的农药残留检测.
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