应用ICP-MS与AAS测定食品中铅、镉、铜方法研究及比较

目的:建立微波消解、电感耦合等离子体质谱法(ICP-MS)同时测定食品中微量元素的方法,并与国标法原子吸收分光光度法(AAS)进行了比较。方法:应用微波消解进行样品前处理,使用电感耦合等离子体质谱与原子吸收分光光度计分别测定三十余种食品中铅、镉、铜含量。结果:线性相关系数均大于三个9,方法的精密度均小于8.0%,国家标准物质:小麦粉(GBW08503b)、杨树叶(GBW08513)、贻贝(GBW08571)测定值均在标准值范围内,两种方法的测定值基本吻合。结论:ICP-MS法3种元素可同时分析,抗干扰强,但仪器成本高;AAS法每一元素需分别测定,测定周期较长,干扰较大,特别是高盐样品需稀释后测定,但仪器成本低,普及率高。

Comparison between ICP - MS and AAS for determination of lead, cadmium and copper in food

Objective:To establish an inductively coupled plasma-mass spectrometry(ICP-MS) method with microwave digestion for the determination of Pb,Cd and Cu in food.The analytical result was compared with the National Standard Method.Methods:Thirty kinds of food were pretreated by microwave digestion and then analyzed by ICP-MS and AAS,respectively.Results:The linear correlation coefficients for all elements were good(r>0.999).The precision of the methods(RSD) was lower than 8.0%.The results are within the range of the standard reference materials of GBW08503b,GBW08513 and GBW08571.The results of the two methods agreed well.Conclusion:Although,Pb,Cd and Cu can be analyzed simultaneously by ICP-MS with strong resistance to interferences from sample matrix,the instrument is expensive.The AAS method can analyze the above three elements separately,which usually takes a long time.The samples with high concentration of salts must be diluted before analysis due to the interferences from sample matrix.However,the instrument is cheap and widespread.