极谱分析法连续测定痕量铅和镉  

Study on Continuous Determination of Trace Lead and Cadmium by Polarographic Analysis

作　　者：张卫华[1] 金贞淑[1] 赵丹庆[1] 马国春[1] 王凤权[1] 

机构地区：[1]内蒙古民族大学化学系,内蒙古通辽市028043

出　　处：《光谱实验室》2002年第3期335-337,共3页Chinese Journal of Spectroscopy Laboratory

摘　　要：研究了 Pb2 + 和 Cd2 + 与 KCl-酒石酸钠 -三乙醇胺 -明胶体系的二次导数极谱波。在 p H=4 .5的 HAc-Na Ac介质中 ,Pb2 + 和 Cd2 + 分别于 - 0 .4 6 V和 - 0 .6 4V电位处产生一良好的极谱波。峰电流与 Pb2 + 和Cd2 + 的浓度分别在 1× 10 -5— 3× 10 -1g· L-1和 5× 10 -5— 6× 10 -3 g· L-1范围内呈线性关系。 Pb2 + 和Cd2 +的检出限分别为 1× 10 -7g·L-1和 5× 10 -7g·L-1。本法准确、简便、快速、选择性高。已直接用于饮料中铅和镉的连续测定 ,同时也对酒及面粉样品进行了测定 ,回收率分别为 99.9%— 10 0 .1%和 97.0 %—10 4 .8%。In a solution of HAc NaAc at pH=4.5,the second derivative polarographic waves of the Pb 2+ and Cd 2+ with KCl Na 2C 4H 4O 6 C 6H 15 N gelation systems at the potential of -0.46V and -0.64V were obtained respectively.Peakcurrents are respectively linearly proportional to the concentration of Pb 2+ in the range of 1×10 -5 -3×10 -1 g·L -1 and the concentration of Cd 2+ in the range of 5×10 -5 -6×10 -3 g·L -1 .The detection limits of lead and cadmium are respectively 1×10 -7 g·L -1 and 5×10 -7 g·L -1 .The method is simple and rapid with high selectivity.It was applied to the continuous determination of lead and cadmium in beverages,white spirit and wheat flour.The rates of recoveries of the method are respectively 99.9%-100.1% and 97.0%-104.8%.

关 键 词：极谱分析法 连续测定 铅 镉 白酒 饮料 面粉 食品 痕量分析 

分 类 号：TS207.3[轻工技术与工程—食品科学]