2015•Unpublished venueRequires access
AUTOMATIC SPECTROPHOTOMETRIC PROCEDURE FOR DETERMINATION OF L-ASCORBIC ACID BASED ON REDUCTION OF IRON(III)-THIOCYANATE COMPLEX
Meissam Noroozifar, Mozhgan Khorasani-Motlagh, Abdol-Rahim Farahmand, Automatic Spectrophotometric Procedure, Meissam Noroozifar, A Mozhgan Khorasani-motlagh
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Abstract
A very simple spectrophotometric method has been developed for indirect determination of L-ascorbic acid using flow injection system based on the redox reaction between iron(III)-thiocyanate complex and L-ascorbic acid in acidic medium. A negative peak results from an injection of L-ascorbic acid into an iron(III)-thiocyanate complex carrier stream when absorbance is monitored at 462 nm. The height of the negative peak is proportional to the concentration of L-ascorbic acid in the sample. Figures of merit such as a relative standard deviation of 2.0 % (n=6), linearity range up to 100 µg/mL and detection limit of 0.36 µg/mL were obtained. No significant differences at the 95 % confidence level were observed in comparison with results obtained by a manual procedure. The proposed system allowed the determination of L-ascorbic acid in pharmaceutical formulations and foods.