豇豆中灭蝇胺残留分析与膳食风险评估

Analysis and Dietary Risk Assessment of Cyromazine Residue in Cowpea

摘要:

该文建立了一种简便、快速、准确的豇豆中灭蝇胺残留的液相色谱-串联质谱分析方法，优化了提取溶剂等提取条件，以乙腈（含15%乙酸，V%）为提取溶剂，利用QuEChERS法进行净化。结果表明，该方法线性范围0.005~1.00 mg/L，检出限为0.001 mg/kg，定量限为0.010 mg/kg。0.010、0.10、0.50、1.00 mg/kg 4个添加水平的回收率为76.2%~82.8%，相对标准偏差为1.0%~5.7%，满足农药残留分析的要求。采用该方法分析了本地市场上112个豇豆样品，灭蝇胺的检出比例为22.3%，超标比例4.5%。长期膳食风险评估结果表明，灭蝇胺的风险熵RQ为10.74%，不会对一般人群健康造成不可接受的风险。在室温（约20 ℃）或冷藏（4 ℃）贮藏条件下，灭蝇胺在豇豆样品中的残留消解动态规律符合一级动力学方程，消解半衰期分别为5.0和7.2 d。存放温度、存放时间均对豇豆中灭蝇胺的残留变化有影响，较高的温度有利于残留值降低。

Abstract:

A simple, rapid and accurate liquid chromatography-tandem mass spectrometry method was developed for the analysis of THE cyromazine residue in cowpea. The extraction conditions including the extraction solvent were optimized. Acetonitrile (containing 15% acetic acid, V%) was used as the extraction solvent, which was purified by the QuEChERS method. The linear range was 0.005~1.00 mg/L, with the limit of detection being 0.001 mg/kg and the limit of quantification being 0.010 mg/kg. The recoveries at 4 spiking levels (0.010, 0.10 0.50 and 1.00 mg/kg) were 76.2%~82.8% with the relative standard deviations in the range of 1.0%~5.7% (n=5), which met the requirements of pesticide residue analysis. The proposed method was used to analyze 112 cowpea samples from the local market, and the detection rate of cyromazine was 22.3%, (4.5% exceeded the standard limit). The results of long-term dietary risk assessment showed that the risk quotient (RQ) was 10.74%, indicating that the cyromazine in cowpea won’t pose an unacceptable risk to the health of the general population. Being stored at room temperature (about 20 ℃) or under cool conditions (4 ℃), the dissipation kinetics of cyromazine residue in cowpea followed the first-order kinetic equation with the half-lives being 5.0 and 7.2 days, respectively. Both the storage temperature and storage time had effects on the change of cyromazine residue in cowpea. Higher temperature would be beneficial to the dissipation of cyromazine residue.