显色剂N-烯丙基-N′-(对苯磺酸钠)硫脲在鉴定铅中的掩蔽效应研究

Shading Effect of the N-allyl-N′-(sodium-p-benzenesulfonate)thiourea in the Identification of Lead

用玫瑰红酸钠试法或稀硫酸和硫化钠试法鉴定铅时,Ag+和Hg22+将产生干扰.研究发现,用N-烯丙基-N′-(对苯磺酸钠)硫脲可掩蔽Ag+和Hg22+的干扰,与传统的利用氯化银和氯化亚汞沉淀分离Ag+和Hg22+消除干扰的方法相比,不会造成Pb2+的损失,操作简便,掩蔽也很彻底.

As Ag^＋ and Hg2^2＋ interfere with Pb^2＋ during the qualitative analysis by traditional method, a new method which can eliminate the interference of Ag^＋ and Hg2^2＋ with the N-allyl-N＇- （sodium-p-benzenesulfonate）thiourea in the Pb2^2＋ qualitative identification has been studied. The result indicates that comparing with the traditional method using deposition reaction to eliminate the interference of Ag^＋ and Hg2^2＋, the new method is convenient,and doesn＇t lead to the loss of Pb^2＋. The shading effect is ,remarkable.