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    多壁碳纳米管基质固相分散萃取-高效液相色谱法测定蔬菜中7种氨基甲酸酯类农药残留量

    Determination of Residual Amounts of Seven Carbamate Pesticides in Vegetables by HPLC after Pretreatment of MWCNTs-MSPD

    • 摘要: 建立一种测定蔬菜中涕灭威砜、灭多威、3-羟基克百威、涕灭威、克百威、甲萘威和异丙威等7种氨基甲酸酯类农药的多壁碳纳米管基质固相分散萃取-高效液相色谱法(MWCNTs-MSPD-HPLC)。将样品与活化好的MWCNTs和无水硫酸镁混合研磨后装柱,用20 mL乙腈洗脱柱子,洗脱液供HPLC分析。以RRHD SB-C18色谱柱为固定相,以不同体积比的乙腈-水为流动相进行梯度洗脱,分离出的7种农药分别在检测波长为220 nm (甲萘威)、230 nm (灭多威)、200 nm (其余5种农药)处进行测定。在优化的仪器工作条件下,7种农药的保留时间分别为3.625,4.297,6.153,12.686,17.265,18.780,21.075 min。结果表明,7种农药的质量浓度均在0.025~5.00 mg·L-1内与其对应的色谱峰面积呈线性关系,检出限(3S/N)为0.002 7~0.011 0 mg·kg-1。对空白空心菜样品进行3个浓度水平的加标回收试验,回收率为68.8%~108%,测定值的相对标准偏差(n=5)为0.90%~7.5%。按此方法分析了6种蔬菜,在白菜和结球甘蓝中检出了灭多威,在扁豆中检出了甲萘威,含量均在GB 2763-2014规定的限值范围内。将此方法扩展应用于水果中上述7种农药残留量的测定,得到的精密度和回收率试验结果满足农药残留的分析要求。

       

      Abstract: A method was developed for determination of seven carbamate pesticides, including aldicarb sulfone, methomyl, 3-hydroxycarbofuran, aldicarb, carbofuran, carbaryl and isoprocarb in vegetables by MWCNTs-MSPD-HPLC. Sample was homogenized with activated MWCNTs and anhydrous magnesium sulfate in a mortar, then the mixture was packed into a column, which was eluted with 20 mL of acetonitrile. The eluent was analyzed by HPLC. RRHD SB-C18 chromatographic column was used as stationary phase, and the mixture of acetonitrile and water with various volume ratios was used as mobile phase for gradient elution. The seven pesticides separated were determined at detection wavelength of 220 nm (for carbaryl), 230 nm (for methomyl) and 200 nm (for the other five pesticides). Under the optimized working conditions, the retention times of the 7 pesticides were 3.625, 4.297, 6.153, 12.686, 17.265, 18.780 and 21.075 min. The results showed that linearity relationships between mass concentrations of the 7 pesticides and their corresponding chromatographic peak areas were kept in the same range of 0.025-5.00 mg·L-1, with detection limits (3S/N) in the range of 0.0027-0.0110 mg·kg-1. The spiked recovery test was made on the blank spinach sample at three concentration levels, giving recoveries ranged from 68.8% to 108%, with RSDs (n=5) in the range of 0.90%-7.5%. Six vegetables were analyzed by the prescribed method, the methomyl was detected in Chinese cabbage and cabbage, carbaryl was detected in lentil, and their contents were all within the limits specified in GB 2763-2014. This method was extended for the analysis of the seven carbamate pesticides in fruit samples, and the results of tests for precision and recovery both met the requirements of pesticide residue analysis.

       

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