Quantitation and accurate mass analysis of pesticides in vegetables by LC/TOF-MS
Quantitation and accurate mass analysis of pesticides in vegetables by LC/TOF-MS
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DOI：
10.1021/ac048458x
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发表时间：
2005-05-01
影响因子：
7.4
通讯作者：
Fernandez-Alba, AR
中科院分区：
文献类型：
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作者：
Ferrer, I;Thurman, EM;Fernandez-Alba, AR
建立了一种溶剂萃取-液相色谱/飞行时间质谱（LC/TOF-MS）联用技术，用于蔬菜沙拉中常用的3种氯烟碱类农药（吡虫啉、啶虫脒、噻虫啉）的定性和定量分析。在3 ppm误差内的准确质量测量获得的所有农药研究在各种蔬菜基质（黄瓜，番茄，生菜，辣椒），这使得目标农药的明确识别。覆盖2个数量级的校准曲线在研究的浓度范围内呈线性，从而显示了飞行时间质谱作为蔬菜中农药监测工具的定量能力。还使用基质匹配标准品评价了基质效应，显示基质和清洁浸提液之间无显著干扰。日内重现性RSD为2-3%，日间RSD为5%。质量测量的精密度（标准偏差）进行了评价，它是小于0.23 mDa之间的天。蔬菜中氯烟碱类杀虫剂的检出限为0.002 ~ 0.01 mg/kg。这些浓度等于或优于欧盟指令的蔬菜中的受控农药，表明LC/TOF-MS分析是鉴定蔬菜中农药的有力工具。该方法用于市售蔬菜样品的分析，具有良好的稳定性和适用性。在这些样品中发现的浓度范围为0.02-0.17毫克/千克蔬菜。
A quantitative method consisting of solvent extraction followed by liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) analysis was developed for the identification and quantitation of three chloronicotinyl pesticides (imidacloprid, acetamiprid, thiacloprid) commonly used on salad vegetables. Accurate mass measurements within 3 ppm error were obtained for all the pesticides studied in various vegetable matrixes (cucumber, tomato, lettuce, pepper), which allowed an unequivocal identification of the target pesticides. Calibration curves covering 2 orders of magnitude were linear over the concentration range studied, thus showing the quantitative ability of TOF-MS as a monitoring tool for pesticides in vegetables. Matrix effects were also evaluated using matrix-matched standards showing no significant interferences between matrixes and clean extracts. Intraday reproducibility was 2-3% relative standard deviation (RSD) and interday values were 5% RSD. The precision (standard deviation) of the mass measurements was evaluated and it was less than 0.23 mDa between days. Detection limits of the chloronicotinyl insecticides in salad vegetables ranged from 0.002 to 0.01 mg/kg. These concentrations are equal to or better than the EU directives for controlled pesticides in vegetables showing that LC/TOF-MS analysis is a powerful tool for identification of pesticides in vegetables. Robustness and applicability of the method was validated for the analysis of market vegetable samples. Concentrations found in these samples were in the range of 0.02-0.17 mg/kg of vegetable.