食品级己二酸中微量重金属元素的质谱分析

Determination of heavy metal elements in food grade adipic acid by inductively coupled plasma mass spectrometry

建立了电感耦合等离子体质谱（ICP-MS）测定食品级己二酸中V、Cr、Co、Ni、Cu、As、Cd、Hg、Pb等9种重金属元素的测定方法。采用无水乙醇溶解己二酸样品后直接测定,避免了样品预处理过程中的复杂操作。通过向等离子体中混入氧气,消除了纯有机溶剂进样时在质谱锥接口和离子透镜的积碳现象。为了减少有机溶剂高蒸汽压对等离子体的负载,实验优化了质谱工作参数。采用碰撞反应池（CRC）技术和内标法校正了干扰,提高了分析结果的准确度。将此方法与其他分析法进行了对照,所得结果基本一致,表明方法准确可靠。在确定的实验条件下,9种待测元素的检出限为0.08~1.29 ng/L,相对标准偏差（RSD）为0.93%~2.36%,加标回收率为94.80%~103.00%。方法简单可靠,能应用于食品级己二酸中微量重金属元素的检测与控制。

An inductively coupled plasma mass spectrometry （ICP-MS） was developed for the determination of V, Cr, Co, Ni, Cu, As, Cd, Hg and Pb in food grade adipic acid. The condensation and deposition of high concentrations of carbon in mass cone interface and ion lens, which will decrease the sensitivity of element analysis, can be avoided effectively by introducing O2 to plasma. To decrease the load of plasma from high vapor pressure of organic solvents, the working parameters of ICP-MS was optimized. Moreover, the interference was eliminated via collision reaction cell （CRC） technology and internal standard method. The analysis results were in well consistent with other analysis method indicating the accuracy and reliability of our approach. The results showed that the detection limits of the investigated elements were in the range of 0.08-1.29 ng/L, the recoveries of standard addition were in the range of 94.80%-103.00% and the RSD were 0.93%-2.36%. The approach is very reliable which could be applied in the detection and control of heavy metal element in food grade adipic acid.