催化动力学光度法测定痕量锰

研究了在pH 10的氨缓冲溶液中,痕量M n（Ⅱ）对高碘酸钠氧化靛蓝褪色反应具有显著的催化作用,据此建立了催化动力学光度法测定M n（Ⅱ）的新方法。讨论了催化体系的反应条件,动力学参数和共存离子的影响。该催化反应为一级反应,检出限为6.4×10^-11g/mL。表观反应速率常数K=5.48×10^-4s^-1,表观活化能Ea为111.9kJ/mol,方法的线性范围为0—4μg/L（r=0.9999）,方法的相对标准偏差为3.3%,加标回收率为96%—104%。

Determination of Trace Manganese by Catalytic Kinetic Spectrophotometry

A new method for the determination of trace manganese was developed by catalytic kinetic spectrophotometry,that was based on the catalytic action of Mn（Ⅱ） on the oxidation fading reaction between indigo and NaIO4 in NH3-NH4Cl buffer at pH of 10.The reaction conditions of catalytic system,kinetic parameters and effects of the coexistent ions were investigated.The catalytic reaction was pseudo first-order reaction with apparent reaction rate constant（K） of 5.48×10-4s^-1 and apparent activation energy（Ea） of 111.9kJ/mol.The linear was 0—4μg/L（r=0.9999）,and the detection limit was 6.4×10^-11g/mL with the RSD of 3.3%,and the recoveries were in the range of 96%—104%.