反相高效液相色谱法同时测定食品中锌铜铅镉

目的　探讨同时测定食品中锌、铜、铅、镉的方法。方法　用 meso-四 (对羟基苯 )卟啉作显色剂 ,采用高效液相色谱法同时检测食品中锌、铜、铅、镉。结果　提出以双硫腙—三氯甲烷溶液对样品进行前处理 ,能较好地去除干扰。对食品样品测定 ,四种金属离子测定的变异系数的变化范围在 3.7%～ 8.1%,检出限分别为 :Cd2 +0 .0 2 ng,Zn2 +0 .12 ng,Pb2 +0 .0 2 ng,Cu2 +0 .0 2 ng。另外还进行了方法的准确度实验 ,包括标准物质对照实验、加标回收实验和方法对照实验 ,结果均令人满意。结论　采用双硫腙—三氯甲烷溶液对样品进行前处理 ,用 m eso-四 (对羟基苯 )卟啉作显色剂的高效液相色谱法能够用于食品中锌铜铅镉四种金属离子的测定。

Simultaneous Determination of Zn2+, Cu2+, Pb2+ and Cd2+ by High Performance Liquid Chromatography in Foods

Objective This article reports the application of high performance liquid chromatography (HPLC) with meso-Tetrakis (4-hydroxyphenyl) porphine (THPP) as a color reagent to the determination of Zn 2+,Cu 2+,Pb 2+,Cd 2+ in food samples.Methods With HPLC as determination method, we tested different pretreatment methods in order to find out a pretreatment method that has little interference with the determination of four metal ions. Results Dithizone-chloroform was found to be a better pretreatment method.The coefficient of variety of sample determination ranged from 3.7% to 8.1%, the results were satisfactory. At the same time, the samples were analyzed by atomic absorption spectrophotometry. The results of the two methods coincided very well. The recovery rates ranged from 83% to 117%. Standard reference materials(tea and liver of cattle) were also datermined, the results were in accord very well with the denoted values. The minimum detectable quantities of four metal ions Zn 2+, Cu 2+, Pb 2+, Cd 2+ were 0.12ng, 0.02ng, 0.02ng, 0.02ng, respectively.Conclusion With dithizone-chloroform as a pretreament reagent and THPP as a color reagent, the method can be applied to the analysis of food samples.