阻抑高碘酸钠氧化依莱铬红B褪色光度法测定痕量Sn(Ⅱ)

Determination of Trace Tin (Ⅱ) by Inhibitory Oxidation Eriochrome Red B with NaIO_4 Discoloring Spectrophotometry

在加热和 NH3 - NH4Cl(p H=9.2 5 )缓冲溶液介质中 ,痕量 Sn( )能抑制高碘酸钠氧化依莱铬红 B褪色反应 ,据此建立了测定痕量 Sn( )的动力学光度分析新方法。该方法在锡的浓度为 0 .5— 9.0μg/ 2 5 m L范围内有良好的线性关系 ,方法的检出限为 2 .33× 10 -9g/ m L Sn( )。该方法用于测定天然水中痕量锡( ) 。

A discoloring spectrophotometric method for the determination of trace Sn(Ⅱ) was established based on its inhibitory effect on the oxidation discoloration reaction of eriochrome red B in NH 3-NH 4Cl(pH=9.25) with NaIO 4 and heating.Beer's law is obeyed in the concentration range of 0.5- 9.0μg/25mL Sn(Ⅱ),the detection limit is 2.33×10 -9g/mL.The method was applied to determine trace Sn(Ⅱ) in the water of nature with satisfactory results.