改进QuEChERS-高效液相色谱-串联质谱法测定植物源食品中氟唑磺隆和氟吡磺隆残留量

Determination of Flucarbazone-sodium and Flucetosulfuron Residues in Foodstuffs of Plant Origin by Improved QuEChERS-High Performance Liquid Chromatography-Tandem Mass Spectrometry

建立了高效液相色谱-串联质谱法(HPLC-MS/MS)测定植物源食品中氟唑磺隆和氟吡磺隆残留量的分析方法。样品经乙腈+甲苯(体积比90∶10)提取,用改进的QuEChERS方法一步完成净化,富含色素样品经石墨化碳黑(GCB)和C_(18)净化;糙米、小麦等样品经C_(18)净化,提取液经离心过膜后上机检测。以0.1%甲酸含5 mmol/L乙酸铵水溶液-乙腈为流动相,在0.25 mL/min流速下梯度洗脱,采用C_(18)色谱柱进行液相分离,电喷雾正离子电离(ESI+),多重反应监测模式(MRM)检测,外标法定量。在菠菜、芹菜、土豆、西红柿、苹果、桃子、葡萄、糙米、小麦、核桃、大米11种基质中,氟唑磺隆和氟吡磺隆在0.5~100 ng/mL范围内线性关系良好,相关系数均大于0.998;方法检出限为2.0μg/kg,定量限为5.0μg/kg;在5、10、20、100μg/kg 4个浓度添加水平下,氟唑磺隆的回收率在78.5%~114.2%之间,相对标准偏差(RSD,n=6)在2.2%~14.9%之间;氟吡磺隆的回收率在77.4%~114.9%之间,RSD(n=6)在2.5%~14.8%之间。该方法准确、灵敏、快捷,适用于植物源性食品中氟唑磺隆和氟吡磺隆残留的快速确证和定量分析。

A method of high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)was developed to determine flucarbazone-sodium and flucetosulfuron residues in foodstuffs of plant origin.The sample was extracted with acetonitrile-toluene(90∶10)(V/V),and pretreated by a modified QuEChERS method that completed the extraction and clean-up steps in one procedure.The pigment-rich samples were cleaned up by graphitized carbon black(GCB)and a C_(18) column.Samples such as brown rice and wheat were purified by a C_(18) column,then centrifuged and filtrated before detection.The HPLC-MS/MS method was performed on a C_(18) column with gradient elution of acetonitrile and 0.1%formic-5 mmol/L ammonium acetate solution at a flow rate of 0.25 mL/min.The positive ion source(ESI+)under the multiple reaction monitoring(MRM)mode and external standard method was used for quantification.The results showed that calibration curves had good linearity and the correlation coefficients(R 2)were larger than 0.998.The limits of detection(LODs,S/N≥3)were 2.0μg/kg,and the limits of quantification(LOQs,S/N≥10)were 5.0μg/kg in 11 kinds of matrix(Cabbage,celery,potatoes,tomatoes,apples,peaches,grapes,brown rice,wheat,walnuts and rice).At the four spiked levels of 5,10,20,100μg/kg,the recoveries of flucarbazone-sodium ranged from 78.5%to 114.2%with the RSDs from 2.2%to 14.9%,and the recoveries of flucetosulfuron from 77.4%to 114.9%with the RSDs from 2.5%to 14.8%.The method is accurate,sensitive and effective,and precision can be suitable for the monitoring of pesticide residue analysis.