KINETIC DETERMINATION OF ASCORBIC ACID a WITH SPECTROPHOTOMETRIC DETECTION

Abstract

A simple and rapid method has been developed for the determination of ascorbic
acid in fruit and pharmaceutical products. The method is based on the measurement
of the reaction rate between ammonium molybdate and ascorbic acid in acidic media.
The reaction was monitored spectrophotometrically at 800 nm by fixed-time and
variable-time methods. The calibration graph was linear in the range of 5 0 ×1 0 -
6.0 ×10 M ascorbic acid when using a fixed-time method. The relative standard
deviation for ten replicate analyses is 2.7% for 5.0 × 10 a scorbic acid. The limit of
detection is 2.0×10 M. T he effect ofvarious species was studied for this determination.