水質汚濁指標に関する研究(第10報)酸性高温KMnO_4法COD測定における銀塩について

概要

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The kinds and amounts of silver salts used in the acidic COD-Mn determination were investigated. Ag_2SO_4 should be weighed every using time and mixed well for a long time with magnetic stirrer. If the mixing was imperfect, masking of chloride ion was insufficient and catalytic effect by Ag ion was weakend. On the other hand, AgNO_3 perfectly inhibited the consumption of KMnO_4 by Cl^- and was easy to be handled. The catalytic effect of AgNO_3 (20%, 5 ml in standard method) was sufficient unless the Cl^- concentration in a sample solution was not very high. If the sample solution contains large amount of Cl^- above 500 mg/l, the equivalent amount of AgNO_3 to the chloride ion should be further added. But the development of catalytic effect would be low when coexisting Cl^- was very high. On the determination of acidic COD values of environmental water samples, good agreement was obtained when Ag_2SO_4 or AgNO_3 was used carefully and so AgNO_3 can be used in any samples unless they contain specific contents predominantry.
社団法人日本薬学会の論文
1989-06-30