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    QuEChERS前处理结合超高液相色谱-串联质谱法测定高硫蔬菜中16种氨基甲酸酯类农药残留

    Determination of 16 Carbamate Pesticide Residues in High-Sulfur Vegetables by UHPLC-MS/MS after Preparation of Sample with QuEChERS

    • 摘要: 采用QuEChERS结合超高液相色谱-串联质谱法(UHPLC-MS/MS)测定了洋葱、葱、韭菜、蒜薹、生姜和大蒜等6种高硫蔬菜中16种氨基甲酸酯类农药残留量。样品用冷冻后的乙腈涡旋提取,用无水硫酸镁及氯化钠盐析,用无水硫酸镁、N-丙基乙二胺(PSA)和C18对上层提取物进行分散固相萃取净化,待测液在优化的仪器工作条件下测定。在色谱分离中,选择Waters ACQUITY UPLC BEH C18色谱柱作固定相,用不同比例的含0.1%(体积分数)甲酸的乙腈溶液(A)和0.1%甲酸溶液(B)为流动相进行梯度洗脱;采用电喷雾离子源正离子(ESI+)和多反应监测(MRM)模式进行质谱分析。采用基质匹配标准溶液制作标准曲线,结果显示,16种农药的质量浓度均在一定的范围内与其对应的峰面积呈线性关系,检出限(3S/N)为0.1~20 μg·kg-1。对蒜薹进行3个浓度水平的加标回收试验,回收率为65.7%~112%,相对标准偏差(n=6)为1.5%~11%。按此方法分析了34批次高硫蔬菜,在其中2批洋葱中检出了乙霉威,其质量分数为0.040,0.178 mg·kg-1;1批生姜中检出仲丁威,其质量分数为0.092 mg·kg-1

       

      Abstract: A method based on UHPLC-MS/MS after preparation of sample with QuEChERS was developed for simultaneous determination of 16 carbamate pesticide residues in 6 high-sulfur vegetables, including onion, onionleek, Chinese chive, garlic scape, ginger and garlic. Samples were extracted with frozen acetonitrile and salted out with anhydrous magnesium sulfate and sodium chloride. The upper extract was purified by dispersion solid phase extraction with anhydrous magnesium, PSA and C18, the analytes were determined under the optimized working conditions of the instrument. In UHPLC analysis, Waters ACQUITYUPLC BEH C18 chromatographic column was adopted as stationary phase, and the mixed solution consisted of acetonitrile solution containing 0.1% formic acid (A) and 0.1% formic acid solution (B) with various ratios was used as mobile pahse for gradient elution. MS analysis was made under ESI+ and MRM mode. Matrix-matched standard solution series was prepared for making the standard curve, and results showed that the mass concentrations of 16 pesticides had linearity relationships with their respective peak areas in the definite ranges, with detection limits in the range of 0.1-20 μg·kg-1. Recovery test was made on garlic scape at the 3 concentration levels, giving recoveries in the range of 65.7%-112%, and RSDs (n=6) of the determined values were ranged from 1.5% to 11%. The proposed method was used for the analysis to the 34 batches of high-sulfur vegetable samples, diethofencarb was found in 2 batches of onions samples with mass fraction of 0.040, 0.178 mg·kg-1, and fenobucarb was detected in a batch of ginger sample with mass fraction of 0.092 mg·kg-1.

       

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