痕量抗坏血酸的阻抑动力学光度法测定

Determination of trace ascorbic acid by inhibition kinetic spectrophotometry

摘要:
目的建立测定抗坏血酸的阻抑动力学光度分析的新方法。
方法在稀硫酸介质中, 利用抗坏血酸对亚硝酸根催化溴酸钾氧化二甲酚橙的阻抑作用, 用阻抑动力学光度法测定抗坏血酸。
结果测定的抗坏血酸线性范围为0.010~0.40 mg/L, 检出限为6.8×10^-6g/L。
结论该法简单、灵敏度高、选择性好, 可用于维生素C片和西红柿中微量抗坏血酸的测定。

Abstract:
Objective To establish a new inhibition kinetic spectrophotometric method for the determination of traceascorbic acid.
Methods Ascorbic acid was determined by inhibition kinetic spectro pho to metric method, which was based on the inhibition effect of ascorbic acid on the nitrite catalyzed ox idation of xylenol orange by potassium bromate in dilute sulfuric acid medium.
Results The linear range of determination was 01010~01 40 mg/L.T he detection limit was 6.8×10^-6 g/L.
Conclusion The method were simple, high sensitivity and good selectivity.T he method was applied successfully to the determination of ascorbic acid in vitamin C tablet and tomato.