ICP-MS检测海藻类食品中重金属铅

Determination of Lead in the Seaweed Food by ICP-MS

采用正交试验优化海藻类食品的消解方法,建立基于电感耦合等离子体质谱(ICP-MS)的海藻类食品中重金属铅的检测方法。采用正交试验优化微波消解的消解条件,采用三因素三水平正交试验优化微波消解的样品称样量、硝酸加入量、30%双氧水加入量;试验考察方法的检出限、定量限、线性范围、加标回收、精密度等指标;在此基础上,对市面上随机抽取的10份海藻类食品中铅进行测定。方法学考察结果表明,铅在0~20 ng/mL浓度范围内线性关系良好(r=0.9999);方法检出限为0.01 mg/kg、方法定量限为0.03 mg/kg,试验在4,8和16 ng/mL 3个水平下精密度(n=3)分别为0.44%,0.17%和0.10%;试验在加标质量为0.5,1.0和1.5 mg/kg 3个水平下加标回收率为106.5%~102.8%。该方法具有快速简便、准确可靠、灵敏度高、操作简单、消解完全、稳定性好等特点,适用于海藻类食品中铅含量的测定。

The orthogonal experiment was used to optimize the digestion methods of seaweed food,and a method based on inductively coupled plasma mass spectrometry(ICP-MS)for the determination of heavy metal lead in seaweed foods was developed.The digestion condition of microwave digestion was optimized by orthogonal test,and the parameters,such as sampling,nitric acid addition,30%hydrogen peroxide addition,were optimized by orthogonal test using L9(33).The limits of detection,the limits of quantitation,the linear range,the standard recovery and the precision of the method were investigated.On this basis,the lead in 10 samples of seaweed food which were randomly selected from the market was tested.The results of methodological investigation showed that the calibration curve of lead was linear in 2.0-10.0μg/mL(r=0.9999);Detection limit was 0.01 mg/kg;Limit of quantitation was 0.03 mg/kg;The precision were 0.44%,0.17%and 0.10%at 4,8 and 16 ng/m L three levels.The average recovery rate was 106.5%-102.8%at adding 0.5,1.0 and 1.5 mg/kg three levels,and the method was proved to be simple,reliable,complete digestion,high sensitivity accurate,and could be used for determination of lead in the seaweed food.