QuEChERS-液相色谱-串联质谱法检测糙米中氟唑环菌胺的残留

采用QuEChERS前处理与液相色谱-串联质谱 (LC-MS/MS) 技术，建立了糙米中氟唑环菌胺残留的分析方法。样品采用V(乙腈) : V(水)=80 : 20混合溶液涡旋提取，经PSA分散固相萃取净化，LC-MS/MS测定，外标法定量。结果表明:在0.001~0.1 mg/L范围内，氟唑环菌胺的质量浓度与对应的峰面积间线性关系良好，R2 > 0.996。在0.004、0.01和0.1 mg/kg添加水平下，氟唑环菌胺在糙米中的回收率为83%~95%，相对标准偏差 (RSD) 为3.9%~12%。以最小添加浓度确定氟唑环菌胺在糙米中的定量限 (LOQ) 为0.004 mg/kg，远低于国际食品法典委员会规定的最大残留限量 (MRL) 0.01 mg/kg。所建方法操作简单、准确度和灵敏度高，可用于糙米中氟唑环菌胺残留的检测。对中国6个省 (市) 40个糙米样品进行检测，氟唑环菌胺的残留量均低于LOQ 0.004 mg/kg。膳食风险评估结果表明，氟唑环菌胺目前在中国水稻上使用对一般人群的的健康风险很低。

Determination of sedaxane in brown rice by QuEChERS-liquid chromatography-tandem mass spectrometry

An analytical method for the determination of sedaxane residues in brown rice was established by QuEChERS and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with a mixture of acetonitrile and water (80/20, V/V), purified by dispersion solid phase extraction with PSA as sorbent, and quantified using LC-MS/MS by external standard method. The results showed that good linearity was obtained in the range from 0.001 to 0.1 mg/L, with R² > 0.996. At the fortified levels of 0.004, 0.01 and 0.1 mg/kg, the recoveries of sedaxane in brown rice samples were 83%-95% with the relative standard deviations (RSD) of 3.9%-12%. The limit of quantitation (LOQ) was 0.004 mg/kg in brown rice samples, which was significantly lower than the maximum residue limit (MRL) of 0.01 mg/kg set by the Codex Alimentarius Commission. The proposed method is simple, accurate and sensitive. Hence, it could be used for the detection of sedaxane residues in brown rice. A market survey of 40 brown rice samples from 6 provinces was carried out, and the residual amount of sedaxane was less than 0.004 mg/kg in all samples. The dietary risk assessment showed that the use of sedaxane in rice was currently at a low risk in China.