QuEChERS-高效液相色谱法同时检测蔬果中吡虫啉和多菌灵

Simultaneous Determination of Imidacloprid and Carbendazim in Fruits and Vegetables by QuEChERS-High Performance Liquid Chromatography

建立QuEChERS-高效液相色谱法(QuEChERS-high performance liquid chromatography)同时对蔬果中吡虫啉和多菌灵残留量的检测方法。样品充分粉碎混匀,加入乙腈高速均质提取,加入无水硫酸镁(magnesium sulfate,MgSO_(4))、氯化钠(sodium chloride, NaCl)、柠檬酸钠(sodium citrate, TSCD)和柠檬酸氢二钠(disodium hydrogen citrate,DHS)高速离心分层,取上清液,经无水硫酸镁和N-丙基乙二胺(disodium hydrogen citrate sesquihydrate, PSA)分散萃取净化,高效液相色谱-紫外检测器测定,外标法定量。建立吡虫啉和多菌灵的线性方程;以3倍信噪比法确定吡虫啉和多菌灵分别在蔬果中的检出限;在黄瓜、梨样品中分别添加高、中、低3组不同浓度的吡虫啉和多菌灵,测定回收率和精密度。结果表明:该方法吡虫啉线性浓度范围0.05~1μg/mL,标准曲线相关系数为0.999 81,多菌灵线性浓度范围为0.1~1μg/mL,标准曲线相关系数为0.999 72;吡虫啉和多菌灵在果蔬中检出限均为0.01 mg/kg;吡虫啉相对标准偏差1.39%~4.99%,平均回收率78%~96.5%,多菌灵相对标准偏差0.94%~4.36%,平均回收率85.3%~94.2%,满足农药残留分析方法要求。采用该方法对蔬果中吡虫啉和多菌灵进行同时检测,前处理步骤简单、快速、成本低,测定结果准确度高,稳定性好。

Establish an analytical method for the simultaneous determination of imidacloprid and carbendazim residues in fruits and vegetables by QuEChERS-high performance liquid chromatography.The samples were thoroughly crushed and mixed,then acetonitrile was added for high-speed homogeneous extraction,adding magnesium sulfate,sodium chloride,sodium citrate and disodium hydrogen citrate,and high-speed centrifugation,purified by magnesium sulfate and disodium hydrogen citrate sesquihydrate,determined by UV detector,and quantified by external standard method.The detection limits of imidacloprid and carbendazim in fruits and vegetables were determined by a 3-fold signal-to-noise ratio method,the linear equations of imidacloprid and carbendazim were constructed,and three different concentrations of imidacloprid and carbendazim were added to cucumber and pear samples to determine the recovery and precision.The results showed that the linear concentration range of imidacloprid was 0.05-1μg/mL,and the correlation coefficient of imidacloprid standard curve was 0.99981;The linear concentration range of carbendazim was 0.1-1μg/mL,and the correlation coefficient of carbendazim standard curve was 0.99972;The detection limits of imidacloprid and carbendazim in fruits and vegetables were 0.01 mg/kg;The relative standard deviations of imidacloprid were 1.39%-4.99%,and the average recoveries were 78%-96.5%;The relative standard deviations of carbendazim were 0.94%-4.36%,and the average recoveries were 85.3%-94.2%,which met the requirements of pesticide residue analysis.The method has the advantages of simple,rapid,low cost,high accuracy and good stability.