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引言微克量锑的光度测定法目前多利用五价锑离子的缔合显色反应。这类反应虽很灵敏,但有以下的缺点:1)显色系不稳定;2)试液中锑离子的价态可能为+3或+5,也可能为+4。后者不能直接氧化至五价,须先还原至三价,除去多余的还原剂后始能由三价氧化至五价。氧化后既须将多余的氧化剂与游离氯(氧化过程中的副产物)除去,又须防止五价锑离子的再度还原。因此反应过程极为复杂,也难掌握。3)由于在盐酸介质中进行氧化,氧化后的SbCl_6~-离子易水解为不起显色反应的
Introduction Micrometer antimony photometry at present more use of antimony pentavalent association color reaction. Although this type of reaction is very sensitive, it has the following disadvantages: 1) The color system is unstable; 2) The antimony ion in the test solution may have a valence of +3 or +5 or +4. The latter can not be directly oxidized to pentavalent, must be reduced to trivalent, after removing excess reductant can be oxidized from trivalent to pentavalent. After oxidation, it is necessary to remove excess oxidant and free chlorine (byproducts in the oxidation process) and to prevent the further reduction of pentavalent antimony ions. Therefore, the reaction process is extremely complicated and difficult to grasp. 3) due to the oxidation in hydrochloric acid medium, oxidation of SbCl_6 ~ - ions easily hydrolyzed to afford the color reaction