Flow injection spectrophotometric or conductometric determination of ascorbic acid in a vitamin C tablet using permanganate or ammonia

• Main Authors: Grudpan K., Kamfoo K., Jakmunee J.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.ncbi.nlm.nih.gov/pubmed/3502482; http://cmuir.cmu.ac.th/handle/6653943832/6077
• Institution: Chiang Mai University

Two simple flow injection (FI) procedures for the determination of ascorbic acid content in a vitamin C tablet are proposed: spectrophotometric involving injection into a stream of acidic potassium permanganate solution and monitoring its color change due to the redox reaction; FI conductometry based on the neutralization of ascorbic acid injected into a flowing ammonia solution yielding a change in conductivity. The procedures have been applied to the analysis of locally commercial vitamin C tablet samples. A through-put of at least 90 injections h(-1) can be achieved. The relative standard deviation was found to be 2.5% (for a 50 mg vitamin C tablet; n=7) for both. Results obtained by either procedure agree with a standard titrimetric method.