分散液液微萃取-超高效液相色谱-串联质谱法测定市售凉茶中6种有机磷农药残留

Determination of 6 kinds of organophosphorus pesticide residues in commercial herbal tea by dispersive liquid-liquid microextraction-ultra performance liquid chromatography-tandem mass spectrometry

目的建立分散液液微萃取-超高效液相色谱-串联质谱法测定凉茶中6种有机磷残留量的方法。方法样品经N-丙基乙二胺(N-Propylethylenediamine,PSA)固相萃取剂预净化后,以甲醇为分散剂,三氯甲烷为萃取剂进行提取。在优化后的仪器条件下,采用电喷雾离子化正离子模式电离,多反应监测模式进行测定。结果6种有机磷的标准曲线在2.0~200μg/L范围内线性良好,相关系数r^2均大于0.9990,在添加水平为0.25、0.50和2.5μg/kg的加标回收试验中,平均回收率范围为73.6%~99.5%,相对标准偏差为1.14%~8.01%,方法检出限和定量限为0.02~0.04μg/kg和0.06~0.10μg/kg。结论该方法操作简单便捷、富集倍数高、灵敏度高、重现性好,可用于实际市售凉茶产品的质量监督。

Objective To establish a method for the determination of 6 kinds of organophosphorus pesticide residues in commercial herbal tea by dispersive liquid-liquid microextraction-ultra performance liquid chromatography-tandem mass spectrometry.Methods Sample was pre-purified by N-propylethylenediamine(PSA)solid phase extractant,then extracted by methanol and chloroform which used as dispersant and extractant respectively,finally ionized by electrospray ionization positive ion mode and detected by multi-selected reaction monitoring under optimized instrument conditions.Results The calibration curves of 6 organophosphorus pesticide exhibited a good linearity in the range of 2.0–200μg/L,all correlation coefficients were greater than 0.9990.In the spiked recovery test with addition levels of 0.25,0.50 and 2.5μg/kg,the average recoveries were 73.6%–99.5%,while the relative standard deviations were 1.14%–8.01%.The limits of detection and limits of quantitation were 0.02–0.04μg/kg and 0.06–0.10μg/kg,respectively.Conclusion This method is simple and convenient to operate,has high enrichment multiples,high sensitivity,and good reproducibility,and can be used for the quality supervision of actual commercially available herbal tea products.