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本文报道十二烷基二甲基苄基氯化铵(Zeph)对HCl-H_2C_2O_4体系中锡、铅极谱波的影响。在5×10~(-5)M Zeph-0.5M HCl-0.1M H_2C_2O_4溶液中,锡和铅的导数波相瓦分离约300mV,这就可同时测定锡、铅两种元素。当富集60s后,锡浓度在1×10~(-8)～1×10~(-6)M范围内、铅浓度在2×10~(-8)～6×10~(-6)M范围内与各自的导数波高成线性关系。本法用于罐头汁中痕量锡、铅的同时测定,结果满意。阳极溶出伏安法同时测定锡和铅比较困难,因为锡易水解,锡、铅的峰不易分开,而且存1M或0.5M HCl中分别加入甲醇或碘化铵用交流极谱进行测定,锡、铅峰也只不过分开约70mv。采用表面活性剂则能改变电活性物质的峰高和峰电位。因此表面活性剂作为电化学掩蔽剂是有效的。本文探讨在含有表面活性剂Zeph的情况下,在HCl-H_2C_2O_4
This paper reports the influence of dodecyl dimethyl benzyl ammonium chloride (Zeph) on the polarography of tin and lead in HCl-H 2 C 2 O 4 system. In the solution of 5 × 10 -5 M Zeph-0.5M HCl-0.1M H 2 C 2 O 4, the derivative waves of tin and lead are separated by about 300 mV, which makes it possible to determine both tin and lead simultaneously. When the concentration of tin was in the range of 1 × 10 -8 ~ 1 × 10 -6 M after 60s enrichment, the concentration of lead was in the range of 2 × 10 -8 -6 × 10 -6. M range with the respective derivative wave height into a linear relationship. This method is used for simultaneous determination of traces of tin and lead in canned juices with satisfactory results. Anodic stripping voltammetry simultaneous determination of tin and lead is more difficult, because the tin hydrolysis, tin, lead peak is not easy to separate, and stored 1M or 0.5M HCl, respectively, by adding methanol or ammonium iodide determined by AC polarography, tin, Lead peak is only about 70mv apart. Surfactants can change the peak height and peak potential of electroactive substances. Surfactants are therefore effective as electrochemical masking agents. This article explores the use of the surfactant Zeph in the presence of HCl-H 2 C 2 O 4