碳酸酐酶法测定乳汁锌

Determination of milk Zinc by the reactivation of carbonic anhydrase

目的建立灵敏、准确、特异且试剂稳定的碳酸酐酶法测定乳汁锌。方法乳汁灰化后溶于0.1mol/LHCl,测定前先用0.01mol/LNaOH稀释并中和酸,测定时待分析液中锌离子复活脱辅基的碳酸酐酶,以醋酸对硝基酚作为酶促反应底物进行测定。结果线性范围达61.2μmol/L,回收率95.6%￣103.8%,批内和批间变异系数分别小于3.5%与4.9%,本法(X)与原子吸收分光光度法(Y)比较具有良好的相关性,Y=0.986X+0.033,r=0.988。Cu2+、Fe2+、Mn2+各200μmol/L对锌测定均无影响;Co2+10μmol/L以下对本法测定乳汁锌结果也无干扰。结论该法具有特异、准确、灵敏且试剂稳定等优点,适合于生化分析仪检测乳汁锌。

Objective To establish a sensitive, accurate, stable, specific enzymatic determination method for milk Zinc by carbonic anhydrase（CA） reactivation. Methods Incinerated milk dissolved in 0.1mol/L HCl and neutralized with 0.01mol/L NaOH, then milk Zinc was determined by the reactivation of carbonic anhydrase with two point rate assay. Results The linearity was up to 61.2 μmol/L. The recoveries ranged from 95.6% to 103.8%. The within-run and between-run CV were lower than 3.5% and 4.9% respectively. Comparing this method（X） with AAS（Y）, the regression equation showed Y=0.996X＋0.33, r=0.98. It was not interference with 200 μmol/L of Cu^2＋, Fe^2＋, Mn^2＋ or 10 μmol/L of Co^2＋ respectively. Conclusion It is a simple, accurate, sensitive method with stable reagents and adapt to automatic analyzer for milk Zine detection.