论文部分内容阅读
测定马口铁中镀锡量,国内通用且已订为国家标准方法的碘量法,其分析程序为:溶样、稀释、分取、还原锡(Ⅳ)、滴定。我们研究整个分析过程,其分析步骤可大大简化。该方法的核心部分是定量测定锡(Ⅱ),因此如何简便快速地获得锡(Ⅱ)是问题的关键。针对马口铁中测定锡的具体情况,本文提出在隔绝空气下,一定浓度盐酸中溶样,并同时达到定量还原锡(Ⅳ),省去了稀释、分取溶液、加铝还原的过程。因锡极易溶解于热盐酸中,而溶样时就隔绝了空气,所以进入溶液中锡多为锡(Ⅱ),即使有少量锡(Ⅳ),在溶解完锡层后,出现的铁层马上对锡(Ⅳ)进行还原,整个过程进行的极为迅速,几分钟即可完成,然后采用碘酸钾标准溶液滴定锡。分析方法简单、快速、准确,效果令人满意。1 主要试剂
Determination of tin in tinplate, the domestic general and has been set as a national standard method of iodometric method, the analysis program is: dissolving, dilution, separation, reduction of tin (Ⅳ), titration. We study the whole analysis process and its analysis steps can be greatly simplified. The key part of this method is the quantitative determination of tin (II), so how to get tin (II) easily and quickly is the key issue. According to the determination of tin in tinplate, this paper proposes to dissolve the sample in hydrochloric acid at a certain concentration and to achieve the quantitative reduction of tin (Ⅳ) at the same time under the condition of isolated air, omitting the process of diluting, dispensing solution and adding aluminum. Since tin is easily dissolved in hot hydrochloric acid, the air is isolated when the sample is dissolved. Therefore, most of the tin in the solution is tin (II). Even if a small amount of tin (IV) is dissolved in the solution, the iron layer Immediately reduce the tin (IV), the entire process carried out very quickly, a few minutes to complete, and then use potassium iodate standard solution titration tin. Analysis method is simple, fast, accurate, the effect is satisfactory. 1 main reagent