石墨消解-电感耦合等离子体质谱法测定烟用香精中的重金属

Determination of heavy metals in tobacco flavors by graphite digestion-ICP-MS

【目的】优化和建立石墨消解-电感耦合等离子体质谱联用的方法测定烟用香精中的重金属。【方法】选择自主设计的新型消解罐,研究不同消化温度、不同消解液用量对样品消化的影响,将优化结果与微波消解-电感耦合等离子体质谱联用法对比检出限、定量限、加标回收率、RSD。并依据GB/T 27417—2017《合格评定化学分析方法确认和验证指南》对建立的方法进行方法学验证。【结果】一次性加入10 mL HNO_(3)与2 mL H_(2)O_(2)作为消解液,在170℃的最高消解温度下,烟用香精4.0 h内完成石墨消解,过程中无需补加消解液。对于烟用香精中不同重金属元素Cr、Cd、Ni、Pb、As的测定,本方法与微波消解-电感耦合等离子体质谱法相比,检出限、定量限无显著差异,RSD值更低。方法的测量范围、线性范围、检出限、定量限、精密度、正确度6个参数符合GB/T 27417—2017的指标要求。【结论】本实验构建的方法步骤简单、检出限低、回收率高、重复性好,满足烟用香精检验的要求,具有普遍适用性,适合大批量烟用香精样品的快速检测。

[Background]The graphite digestion-ICP-MS method for the determination of heavy metals in tobacco flavor was optimized and established.[Methods]The influence of digestion temperature and digestion solution dosage on sample digestion was studied by using a new self-designed digestion tank.The established method was compared with microwave digestion-ICP-MS method in terms of LOD,LOQ,standard recovery rate,RSD.Moreover,the established method was validated according to national standard GB/T 27417―2017 for conformity assessment.[Results]The results showed that under the maximum digestion temperature of 170℃and by using 10 mL HNO_(3)/2 mL H_(2)O_(2) as the digestion solution,the digestion was completed within 4.0 h.For the determination of different heavy metal elements Cr,Cd,Ni,Pb and As in tobacco flavor,the proposed method had no obvious difference in the LOD and LOQ compared with the microwave digestion-ICP-MS method and the RSD value was lower.The six parameters of the method,including measurement range,linear range,LOD,LOQ,precision and accuracy,were in accordance with the requirements of national standard GB/T 27417-2017.[Conclusion]The proposed method has the advantages of simple operation,low LOD,high recovery rate and good repeatability,which meets the requirement of tobacco flavor testing and is suitable for the rapid detection of large quantities of tobacco flavor samples.