八极杆碰撞/反应池-ICP-MS法测定食品稳定剂CMC-Na中的重金属元素

Determination of Heavy Metal Elements in Carboxymethyl Cellulose Sodium as a Food Stabilizer by Inductively-Coupled Plasma Mass Spectrometry with Octopole Reaction System

采用微波消解-八极杆碰撞/反应池(ORS)-电感耦合等离子体质谱仪(ICP-MS)测定食品稳定剂羧甲基纤维素钠(CMC-Na)中Cr、Mn、Co、Ni、Cu、As、Cd、Sb、Hg、Pb十种重金属元素的含量。样品用硝酸-双氧水分解后,试液直接用ICP-MS法进行测定。应用ORS技术,有效消除多原子离子对待测元素的干扰,选用Sc、Y、In、Bi等元素作内标混合液校正基体效应和信号漂移,确定实验的最佳测定条件。结果表明,该方法对10种待测元素的检出限在0.003～0.043μg/L之间,相对标准偏差均小于3.06%。该方法简便、快速、准确,可以用于食品稳定剂CMC-Na的质量控制和安全评价。

An analytical method was established for the determination of 10 heavy metal elements including Cr,Mn,Co,Ni,Cu,As,Cd,Sb,Hg and Pb in carboxymethyl cellulose sodium as a food stabilizer using microwave digestion and inductively coupled plasma-mass spectrometry（ICP-MS） with octopole reaction system（ORS）.Samples were digested with HNO3 and H2O2 followed by dilution with ultrapure water.Then,10 elements in the solution were analyzed directly by ICP-MS.ORS was successfully applied to eliminate interferences from polyatomic ions.Sc,Y,In and Bi as internal standard elements were used to compensate matrix effect and signal drift.The optimal conditions for the determination were evaluated.Under the optimal conditions,the detection limits of 10 elements were in the range of 0.003–0.043 μg/L and the relative standard deviation（RSD） was less than 3.06%,showing the established method to be precise.The presented method is applicable for quality control and safety evaluation of CMC-Na as a food stabilizer.