Determination of trace ascorbic acid by inhibition kinetic spectrophotometry

  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.