大量锡的测定通常多应用容量法,这是以用各种氧化剂把锡(Ⅱ)氧化成锡(Ⅳ)的反应为基础的。试样熔融或溶解以后,锡在溶液中呈四价状态,所以,在滴定前必须把它还原。根据现有资料,几乎都认为锡的络合滴定法只是间接的、基于在各种指示剂存在下,返滴过量的EDTA 的方法。曾试图在热的盐酸溶液(pH=1～2) The measurement of a large amount of tin is usually carried out by the multi-use volumetric method, which is based on the reaction of oxidizing tin (II) to tin (IV) with various oxidizing agents. After the sample melts or dissolves, the tin is in the tetravalent state in solution, so it must be reduced before titration. Based on the available information, it is almost assumed that the complexometric titration of tin is only indirect, based on the method of returning an excess of EDTA in the presence of various indicators. Have tried in hot hydrochloric acid solution (pH = 1 ~ 2)