[Spectral-photometric determination of L-ascorbic acid with N-bromsuccinimide and starch iodide (author's transl)].

A new spectrophotometric method for the determination of L-ascorbic acid (AS) with N-bromosuccinimide (NBS) and starch iodide as an indicator was developed. The questions of pH-dependence, sensitivity and specificity of the oxidation-reduction process were investigated. The method is suitable for the determination of AS in acid solutions; the best pH was 2.6. The specificity of the method for AS cannot be considered as definitely better than other methods. Its sensitivity, however, is higher than when using 2.6-dichlorophenol-indophenol (DIP). When applied the method usually yielded results close to the DIP method and due to its high sensitivity AS determinations in very dilute and hazy solutions are possible.