食具镉污染检测的新光度方法

Study on the New Analytical Method for CadmiumPollution of Food Vessels

通过对新试剂2,6-二甲苯基重氮氨基偶氮苯与镉显色反应研究,建立了检测食具镉污染的新方法 在0 2mol/L的氨水介质中,镉可与2,6-二甲苯基重氮氨基偶氮苯发生灵敏的显色反应,生成物质的量比为1∶3红色配合物,配合物最大吸收峰位于522nm,表观摩尔吸光系数达2 03×105L/(mol·cm);在室温下,显色反应立即完成,而配合物吸光度可以稳定24h以上 25mL标准溶液中Cd(Ⅱ)含量为0～12μg服从比耳定律,在不加任何掩蔽剂的条件下,常见金属离子有较大的允许量 与其它试剂相比,2,6-二甲苯基重氮氨基偶氮苯与镉的显色反应在灵敏度和选择性方面均有明显地改进,用于实际样品的分析。

A new analytical method for deleterious cadmium of food vessel is developed in the paper. The method is based on the reaction of the reagent 2,6-dimethyphenyldiazoaminoazobenzene with cadmium(II). In (0.2) mol/L ammonia media, cadmium(II) reacts with 2,6-dimethy-phenyldiazoaminoazobenzene to form a 1:3 red complex, which has an maximum absorption peak at 522nm. It is found that apparent molar absorptivity of the complex is 2.03×10^(5) L/(mol·cm). The reaction was instantaneous under room temperature and the absorbance stable for 24 h and 0～12 g Cd(II) in 25 mL soution obey Beer's law. Most of metal ion can be tolerated in considerable amounts. In general, proposed method is very sensitive, selective and rapid. It has been used to determine cadmium in real samples with satisfactory results.