S. M. TALEBI AND M. IRA VANI
Abstract
A new spectrophotometric method based on reduction of chromium(VI) was developed for the determination of trace ascorbic acid. Chromium (VI) was reduced to Cr (III) by ascorbic acid. A solid phase extraction using cellulose was proposed to separate Cr (III) from the remainder of Cr(VI). The excess Cr (VI) was finally determined and used for calculation of ascorbic acid concentration. The parameters affecting the reaction of ascorbic acid with Cr (VI) and also those affecting the separation efficiency of remainder Cr (VI) were optimized. The proposed method showed capability for sensitive determination of trace ascorbic acid. The method was successfully applied to the determination of ascorbic acid in fruit juice and pharmaceutical.