草莓中棉隆及其代谢物异硫氰酸甲酯的分析方法与膳食风险评估

目的建立超高效液相色谱-串联质谱(ultraperformanceliquidchromatographytandemmass spectrometry, UPLC-MS/MS)和气相色谱(gas chromatography, GC)检测棉隆及其代谢物异硫氰酸甲酯在草莓中残留的检测方法。方法棉隆的前处理方法采用乙腈提取,氮吹至近干,用乙腈与0.1%甲酸溶液(体积比5:5)溶解,乙二胺-N-丙基硅烷吸附剂(N-(n-Propyl)ethylenediamine, PSA)净化。异硫氰酸甲酯的前处理方法采用乙酸乙酯提取,氮吹至1.0 mL以下,用乙酸乙酯定容。结果棉隆和异硫氰酸甲酯最小检出量分别为(1.0×10-11)和(5.0×10-11) g。在0.001～0.5 mg/L和0.05～10 mg/L浓度范围内线性良好,相关系数分别为1.0000和0.9985。棉隆和异硫氰酸甲酯在草莓中的添加水平为0.02～1.0mg/kg条件下,平均回收率分别为88%～111%和76%～87%,相对标准偏差分别为1.7%～2.7%和4.7%～9.5%。膳食摄入风险评估结果显示:普通人群棉隆的国家估算每日摄入量(National estimated daily intake, NEDI)是0.0056 mg,风险熵值(risk quotient, RQ)为2.22%。结论残留量对一般人群健康不会产生不可接受的风险。

Analysis method of dazomet and its metabolite methyl isothiocyanate in strawberry and dietary risk assessment

Objective To establish a method for the determination of dazomet and its metabolite methyl isothiocyanate residues in strawberry by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and gas chromatography (GC). Methods The pretreatment method of dazomet was acetonitrile extraction, nitrogen blowing to near dry, dissolving with acetonitrile and 0.1% formic acid solution (volume ratio 5:5), and purification by N?(n?Propyl) ethylenesilane (PSA). The pretreatment method of methyl isothiocyanate was ethyl acetate extraction, nitrogen blowing to less than 1.0 mL, and the volume was fixed with ethyl acetate. Results The minimum detectable amounts of dazomet and methyl isothiocyanate were (1.0×10-11) and (5.0×10?11) g, respectively. The linearity was good in the concentration range of 0.001?0.5 mg/L and 0.05?10 mg/L, and the correlation coefficients were 1.0000 and 0.9985, respectively. The average recoveries were 88%?111% and 76%?87%, respectively, and the relative standard deviations were 1.7%?2.7% and 4.7%?9.5%, respectively, when the addition levels of dazomet and methyl isothiocyanate were 0.02?1.0 mg/kg in strawberries. The results of dietary intake risk assessment showed that the National estimated daily intake (NEDI) of the general population was 0.0056 mg and the risk quotient (RQ) was 2.22%. Conclusion Residues do not pose unacceptable risks to the health of the general population.