QuEChERS-液相色谱-串联质谱法测定植物源食品中氟噻草胺和乙酰甲草胺残留被引量：18

Determination of flufenacet and diethatyl-ethyl in vegetative foods by QuEChERS-liquid chromatography-tandem mass spectrometry

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摘要建立了QuEChERS前处理-液相色谱-串联质谱仪(HPLC-MS/MS)测定植物源食品中氟噻草胺和乙酰甲草胺残留量的分析方法。样品经酸化乙腈(含0.1%甲酸的乙腈)提取,采用石墨化碳黑(GCB)净化,提取液经离心、过膜后直接上机检测。该方法采用C18色谱柱进行色谱分离,以0.1%甲酸水(含5mmol/mL乙酸铵)-甲醇为流动相,在0.25mL/min流速下梯度洗脱,电喷雾正离子电离(ESI+),多重反应监测模式(MRM)检测,以保留时间和特征离子对(母离子和两个碎片离子)信息比较进行定性,基质匹配曲线定量。在9种基质(葡萄、葡萄干、黄瓜、小麦粉、苹果、白菜、枸杞、西红柿和大米)中,氟噻草胺和乙酰甲草胺在0.25~25.0μg/L范围内线性关系良好,相关系数均大于0.997,两种化合物的方法定量限为0.5μg/kg;在0.5,1.0,5.0μg/kg3个添加水平下,氟噻草胺的平均回收率在82.5%~103.9%,相对标准偏差为2.9%~15%;乙酰甲草胺的回收率在81.7%~108.1%,相对标准偏差在3.1%~14%。方法灵敏度、准确度和精密度均符合农药残留检测要求。 A method for the determination of flufenacet and diethatyl-ethyl in vegetative foods using QuEChERS-high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） was developed. The sample was extracted with acidic acetonitrile （containing 0. 1% formic acid） , and cleaned up by graphitized carbon black （GCB） , and then the extracting solution was centrifuged and filtrated before detection. The method was performed on a Cls column with gradient elution of methanol and 0. 1% formic acid in water （including 5 mmol/mL ammonium acetate ） at a flow rate of 0. 25 mL/min. The mass spectrometer was carried out with electrospray positive ion source （ ESI ~ ）, and multiple reaction monitoring mode （MRM）. The qualitative analyses was based on the retention times and characteristic ion pairs consisting of one parent ion matched external standard method was used for quantification. and two fragment ions. The matrix- The results showed that calibration curves had good linearity for flufenacet and diethatyl-ethyl, and the correlation coefficients （r2） were larger than O. 997. The limits of quantification （ LOQs, S/N ≥ 10） of flufenacet and diethatyl-ethyl in 9 different matrix （rape, raisins, tomatoes, rice, apples, Chinese wolfberry, cucumber, flour and cabbage） were 0. 5 μg/kg. When the article was spiked three levels of 0. 5, 1.0 and 5.0 μg/kg, the recoveries of flufenacet ranged from 82.5% to 103.9% with the RSDs from 2.9% to 15%. And the recoveries of diethatyl-ethyl were from 81.7% to 108.1% with the RSDs from 3.1% to 14%. The method is highly effective, and the sensitivity, accuracy and precision can be suitable for the monitoring of pesticide residue analysis.