阻抑动力学光度法间接测定痕量EDTA

Indirect determination of trace EDTA by inhibition kinetic-spectrophotometry

研究了在pH8．5的NaB4O7-HCl缓冲溶液中，Fe（Ⅲ）崔化H2O2氧化茜素红褪色的反应可被痕量EDTA有效地阻抑，被过量EDTA有效的终止，据此建立了动力学光度法测定痕量EDTA的新方法。用固定时间法在474nm波长处检测阻抑反应。方法的线性范围为0～50．0μg／50mL，检出限为2．2×10^-6mg／mL。方法已用于罐头等食品中EDTA的测定。

In NaB4O7-HCl solution, the catalytic action of Fe（Ⅲ）on the oxidation of alizarin red by H2O2 was effectively inhibited by EDTA. The reaction was effectively stopped by superfluous EDTA. The decrease in absorbance was measured at 474 nm at fixed time intervals. The linear determination range is between 0 and 50.0μg/50 mL of EDTA.