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含硒化合物一般以氧化剂硝酸或有盐酸存在情况下用过氧化氫处理而成亚硒酸后,再用还原剂还原为元素硒测定之。所用还原剂文献上記載颇多:有二氧化硫、亚硫酸盐、碘化物、抗坯血酸、硫脲等。方法缺点是灵敏度不高,而且有很多元素的干扰。新近,Sukuki于磷酸溶液使吡咯(Pyrrole)与亚硒酸反应,得到組分不明的一种藍綠色染料的混合物;Pribil与Chang用Fe~(2+)-EDTA还原方法,灵敏度虽有增加,但还不能令人滿意。基于氧化还原反应測定硒的方法,1956年Cheng曾发表文章提到其缺点。
Selenium compounds are generally treated with hydrogen peroxide in the presence of an oxidizing agent nitric acid or hydrochloric acid to form selenite, which is then reduced to elemental selenium with a reducing agent. Reducing agent used in the literature a lot of records: a sulfur dioxide, sulfite, iodide, anti-stachyose, thiourea and so on. The disadvantage of the method is the sensitivity is not high, but there are many elements of interference. Recently, Sukuki reacted with pyrrole and selenite in a phosphoric acid solution to obtain a mixture of cyan and cyan dyes of unknown composition. Although the sensitivity of Pribil and Chang was reduced with Fe 2+ (2 +) - EDTA, But still not satisfactory. Based on the redox reaction determination of selenium, Cheng published a paper in 1956 referred to its shortcomings.