Determination of 7 kinds of pesticide residues in foods by improved QuEChERS-high performance liquid chromatogra-phy-tandem mass spectrometry
摘要
建立了一种改进的QuEChERS结合高效液相色谱-串联质谱法(HPLC-MS/MS)测定食品中7种新型农药残留环吡氟草酮、氯氟吡啶酸、氯氟吡啶酯、哌虫啶、丙硫菌唑、脱硫丙硫菌唑和氟酮磺草胺的方法.食品基质在柠檬酸缓冲体系下,经乙腈提取,采用十八烷基硅烷(C18)和石墨化多壁碳纳米管(XFM40)净化.以0.1%甲酸(含2 mmol/L乙酸铵)水溶液和乙腈作为流动相梯度洗脱,JADE-PAK KF-C18色谱柱分离,采用多反应监测(MRM),正离子和负离子同时扫描,基质匹配外标法定量.在7种食品基质中,7种目标农药在相应的范围内具有良好的线性关系,相关系数(R2)均大于0.9951,定量限(LOQs)为0.1～9.6 µg/kg,在1倍、10倍和50倍定量限3个加标水平下,平均回收率为75.9%～115.0%,相对标准偏差(RSDs)为5.1%～13%.该方法能够满足食品中7种新型农药残留的检测.
A method for the determination of 7 kinds of new pesticide residues(cypyrafluone,florpyrauxifen,florpyrauxifen-benzyl,paichongding,prothioconazole,prothioconazole-desthio,and triafamone)in food was develop by using improved QuEChERS combined with high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The food matrix was extracted with acetonitrile under citric acid buffer system and purified by octadecylsilane(C18)and graphitised multi-walled carbon nanotubes(XFM40).The separation was performed on a JADE-PAK KF-C18 column with a gradient elution of 0.1%formic acid(containing 2 mmol/L ammonium acetate)solution and acetonitrile as the mobile phases.Multiple reaction monitoring(MRM)was used for the simultaneous scanning of positive and negative ions,and the quantification was performed by the matrix-matched external standard method.Among the 7 food substrates,7 target pesticides had good linear relationships in their corresponding linear ranges,the determination coefficient(R2)was greater than 0.9951,the limits of quantification(LOQs)were 0.1‒9.6 µg/kg,and the average recoveries were 75.9%‒115.0%at the three spiked levels of 1 LOQ,10 LOQ and 50 LOQ.The relative standard deviations(RSDs)ranged from 5.1%to 13%.The method can meet the requirements for detection of 7 kinds of new pesticide residue in food.
