Flame atomic absorption spectrometry for the automatic indirect determination of ascorbic acid based on flow injection and reduction of chromate

作者：Zhang ZQ^*; Jiang YC

来源：Atomic Spectroscopy, 2000, 21(3): 100-104.

A very simple flame atomic absorption spectrometry method has been developed for the indirect determination of ascorbic acid using a flow injection system based on the redox reaction between chromate and ascorbic acid in acid medium. The Cr(III), produced by Cr(VI) bring reduced with ascorbic acid, is adsorbed on a cation exchange resin micro-column, then eluted by 3 mol L-1 nitric acid to the nebulizer and measured by name atomic absorption spectrometry. The absorbance of Cr(III) is proportional to the concentration of ascorbic acid in the sample. When the reaction and adsorption time reached two minutes, a calibration graph ranging from 0.3 to 60 mu g mL(-1) of ascorbic acid was obtained, with a relative standard deviation of 2.5% at 20 samples per hour. This method has been applied to the determination of ascorbic acid in Vitamin C tablets, Vitamin C injections, and vegetables. The results obtained in the analysis compare well with those provided by lodimetry.

• 出版日期2000-6
• 单位陕西师范大学