用赤霉素作新还原剂还原砷钼杂多酸分光光度法测定钢铁中的微量砷

Spectrophotometric Determination of Trace Arsenic in Steel by Reducing Arsenic Molybdnum Heteropoly Acid With Gibberellins as New Reducing Agent

用赤霉素作新还原剂，对砷钼杂多酸的还原反应进行了系统研究．在０．６６ｍｏｌ／ＬＨ２ＳＯ４介质中，赤霉素能将砷钼杂多酸还原成十分稳定的砷钼杂多蓝，其最大吸收峰位于８３５ｎｍ处，表观摩尔吸光系数为２．６４×１０４Ｌ／ｍｏｌｃｍ．Ａｓ（Ⅴ）浓度在０～１．２ｍｇ／Ｌ范围内符合比耳定律．本法灵敏度高，选择性好，应用于钢铁中微量砷的测定，获得了满意的结果．

The reducing reaction of As Mo heteropoly acid with gibberelins as new reducing agent is studied systematically.As Mo heteropoly acid can be reduced to a very stable As Mo heteropoly blue.Its maximum absorption wavelength is at 835nm. The apparent molar absorptivity is 2.64×10 4L/mol·cm.Beers law is obeyed in the concentration range of 0￣1.2mg/L for arsenic.The method has been used to determine trace arsenic in steel with satisfactory results.