铜(Ⅱ)含量的酶法测定

Enzymatic determination of copper(Ⅱ)

基于乳酸脱氢酶(LDH)催化乳酸生成丙酮酸的反应中铜离子对酶的抑制作用原理,通过测定还原型烟酰胺腺嘌呤二核苷酸(NADH)吸光度的变化率得出其酶促反应速度,对应于铜离子浓度而制得标准曲线。检出限为3.8μmol/L。讨论了pH、温度以及共存组分对测定的影响。

An enzymatic method was applied to determining copper（ Ⅱ ） based on the inhibition of copper（ Ⅱ ） for the catalytic reaction of lactic acid to form pyruvate by lactate dehydrogenase （LDH）. The variation rate of the absorbance of nicotinamide adenine dinucleotide reduced form （NADH） was determined for calculating the velocity of the enzymatic reaction and calibration curve of copper（ Ⅱ） was prepared. The detection limit was 3.8umol/L. The effects of the pH value, temperature and the coexistent ions on the determination were discussed. The method has advantages of rapidity, simplicity and less interference.