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. © 1999 Elsevier Science B.V. All rights reserved