阻抑催化动力学光度法测定蔬菜中痕量草酸盐

Kinetic Spectrophotometry Determination of Trace Oxalate Based on Its Inhibitory Effect in Mn(Ⅱ)-Hyd

摘要: 在稀盐酸介质中,微量草酸根能有效地阻抑Mn2+对NaIO4氧化甲基紫褪色反应的催化作用,非离子表面活性剂TritonX-100对此体系有强烈的增敏作用,据此建立了表面活性剂增敏阻抑催化动力学光度法测定蔬菜中微量草酸盐的新方法.该方法测定波长为590 nm,方法的线性范围为0.10~0.84 mg/L,检出限为0.002 mg/L.该方法用于测定菠菜中草酸盐含量,结果令人满意.

Abstract: A simple and sensitive kinetic spectrohotometric method for determination of oxalate in vegetable is reported.The method is based on the inhibitory effect of oxalate on the catalytic oxidation reaction of methyl-purple with NaIO4 by Mn2+ in HCl and nonionic surfactant Triton X-100.The deterction limit for oxalate is 0.002 mg/L and the linear range of the determination is 0.10~0.84 mg/L.This method has been used to determine trace oxalate in spinach.The results obtained are satisfactory.