Comparative Determination of Ascorbic Acid in Apple (Malus Pumila), Lime (Citrus Aurantiifolia) andWatermelon (Citrullu Lanatus) Using Uv Spectrophotometric and Titrimetric Methods

Abstract

Abstract 
Ascorbic Acid, (Vitamin C), is an essential antioxidant needed by the human body. Ascorbic acid is of great 
importance in biochemical reactions as a reducing agent. This study was performed to compare UV
Spectrophotometry and Titrimetric quantitative methods of analysing ascorbic acid content of Apple (Malus 
pumila), Lime (Citrus aurantiifolia) and Watermelon (Citrullu lanatus). The identification tests for the standard 
Ascorbic acid and fruits samples were carried out using Standard Procedures. The melting point and absorbance of 
the standard Ascorbic acid were 190.3 0C-192.1 0C and 0.569 respectively. The chemical tests for the fruit samples 
were conducted and grey precipitates were observed, which confirmed the presence of Ascobic acid in the samples. 
The amount of Ascorbic Acid in Apple, Watermelon and Lime were 0.4209 g/L, 0.2906 g/L and 0.2639 g/L 
respectively using Titrimetric method. The amount of Ascorbic acid in Apple, Watermelon and Lime using UV
Spectrophotometry method, were 0.06207 g/L, 0.06982 g/L and 0.08382 g/L respectively.The difference between the 
two methods was large, as all the three fruits showed difference amounts. Although UV-Spectrophotometric method 
has been reported in other researches to be preferred, reliable, fast and accurate, this research concluded that 
Titrimetric method was more favourable for the determination of Ascorbic Acid in the fruits selected.