Title of article :
Micro determination of ascorbic acid using methyl viologen
Author/Authors :
Janghel، نويسنده , , E.K. and Gupta، نويسنده , , V.K. and Rai، نويسنده , , M.K. and Rai، نويسنده , , J.K.، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2007
Abstract :
A new simple and sensitive analytical spectrophotometric method is developed for the determination of ascorbic acid reduces methyl viologen to form a stable blue coloured free radical ion. This method has a sensitivity and lower limit detection of 0.1 μg ml−1 of ascorbic acid (0.1 ppm) which is comparable to the flow injection analysis reported earlier. Beerʹs law is obeyed over the concentration range of 1.0–10 μg ml−1 of ascorbic acid per 10 ml of the final solution (0.1–1.0 μg ml−1) at 600 nm. The molar absorptivity and Sandellʹs sensitivity were found to be 1.5 × 105 ± 100 l mol−1 cm−1 and 0.001 μg cm−2, respectively. The method has been applied to the determination of ascorbic acid in food, pharmaceuticals and biological samples.
Keywords :
ascorbic acid , Methyl viologen , Spectrophtotometry , Environmental and biological samples