A new method for the macro- and microdetermination of tri- and tetrathionate

Autor: I. M. Issa, K. A. Idriss, M. R. Mahmoud
Rok vydání: 1977
Předmět:
Zdroj: Canadian Journal of Chemistry. 55:3887-3893
ISSN: 1480-3291
0008-4042
DOI: 10.1139/v77-550
Popis: A rapid and precise method is described for the determination of tri- and tetrathionate. It is based on oxidation of S3O62− or S4O62− with KMnO4 in sulphuric acid medium in the presence of fluoride, required for preventing the formation of insoluble oxides of manganese. The optimum conditions for both the visual and potentiometric end-point detection are 0.1–0.16 M H2SO4 and 0.24–0.38 M NaF. Trithionate is oxidized to sulphate as an end product, whereas the oxidation product of tetrathionate comprises dithionate and sulphate according to[Formula: see text]Examination of the potentiometric titrations and the spectrophotometric scans of samples being titrated showed the presence of intermediate equilibria in solution. The species produced are identified and a theory is given for the net reactions. The method is thoroughly dependable for the determination of amounts of S3O62− or S4O62− corresponding to 0.1–10 mg of sulphur.
Databáze: OpenAIRE