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银量法在化学分析上尤其在工矿或药品分析上,应用得非常广泛。但由于各种方法的条件不同,应用时往往引起误差,因此有必要把有关的方法加以比较与说明,以供有关方面的参考。银量法可以测定 Cl~-、Br~-、I~-、Ag~+、CN~-、CNS~-等离子。在下文中皆以生成氯化银反应为代表作比较详细的介绍。基准物的选择与精制1.硝酸银:保证纯净的金属银是容易得到的,但是它不适用于直接制备硝酸银标准液,因为它必须溶解于硝酸中,而过量的硝酸在多数情况下应当除去,只在 Volhard 法中才允许硝酸存在。所以应当用 A.R.的硝酸银来直接制备硝酸银标准液。如果没有 A.R.的硝酸银,可以将不纯的加以精制。精制的方法是在硝酸中重结晶一次,过滤,收集结晶,洗涤,在110°干
Silver quantitative method in chemical analysis, especially in mining or pharmaceutical analysis, the application is very wide. However, due to the different conditions of various methods, the application often leads to errors. Therefore, it is necessary to compare and explain the relevant methods for the reference of relevant parties. Silver content method can be measured Cl ~ -, Br ~ -, I ~ -, Ag ~ +, CN ~ -, CNS ~ - plasma. In the following are all generated silver chloride reaction as a representative for more detailed introduction. Baseline Selection and Refining 1. Silver nitrate: Pure silver metal is readily available, but it is not suitable for the direct preparation of silver nitrate standards as it must be dissolved in nitric acid and excess nitric acid should, in most cases, Removal, nitric acid is allowed only in the Volhard method. Therefore, A.R. silver nitrate should be used to directly prepare silver nitrate standard solution. In the absence of A.R. silver nitrate, impurities can be refined. The method of purification is recrystallization in nitric acid once, filtration, crystallization, washing, drying at 110 ° C