微波消解KED-ICP-MS法测定海藻碘食用盐中的重金属含量

Determination of Heavy Metals in Seaweed Iodine Edible Salt by KED-ICP-MS with Microwave Digestion

建立微波消解法处理海藻碘食用盐,通过KED-ICP-MS内标法测量其中镉(Cd)、铬(Cr)、镍(Ni)、铜(Cu)、砷(As)、汞(Hg)、铅(Pb)含量的方法。试验对盐环境进行模拟,从消解试剂、消解温度和消解时间三个方面进行研究。根据试验结果得出结论:(1)在盐浓度为0. 1%时,KED及内标法可以有效降低高盐基体对ICP-MS检测结果的干扰;(2)硝酸作为消解试剂,进入系统后既可达到微波消解作用又可减少对系统干扰的引入;(3) Cr随着消解温度增加回收率降低,各重金属180℃消解温度时结果均可接受;⑷消解10 min既能满足试验要求,又可降低能耗。最终运用KED-ICP-MS测量各海藻碘食用盐的重金属,回收率为83%～110%。

Using microwave extraction as pre-treatment,establish the KED-ICP-MS method for the determination of heavy metals,including Cd,Cr,Ni,Cu,As,Hg,Pb in Seaweed iodine edible salt. Simulating the salt environment,the experiment studied the digestion reagent,digestion temperature and digestion time. Based on the test result,the best technology condition:Kinetic Energy Discrimination and internal standard method reduced the interference of high salt matrix on ICP-MS detection effectively,when the salt concentration is 0. 1%;As a digestion reagent,nitric acid can achieve microwave digestion and reduce the introduction of system interference;As digestion temperature increase,the recovery rate of Cr is reduced. The determination of heavy metals is acceptable when digestion temperature is 180 ℃;The digestion time of 10 min not only meets the test requirements,but also reduces the energy consumption. Finally,the recovery rate of KED-ICP-MS method for the determination of heavy metals in Seaweed iodine edible salt is 83% ~ 110%.