Determination of iodine in multivitamin preparations by cathodic stripping voltammetry
https://doi.org/10.29235/1561-8331-2019-55-1-32-37
Abstract
The possibility to determine iodide ions by stripping voltammetry has been demonstrated in multivitamin preparations against the background of redox active components with a concentration exceeding the iodide content of 600–1000 (ascorbic acid), 8–20 (thiamine, riboflavin), 20–40 (iron ions), 10–12 (manganese ions), 4–6 (copper ions) times. The method is based on the anodic concentration of iodide in the form of mercury iodide Hg2I2 on an amalgamated silver indicator electrode at a potential of 0.0 V (vs. Ag/AgCl reference electrode), followed by recording the cathode current peak in a potentiodynamic voltammogram in 0.4 mol/dm3 formic acid aqueous solution in the range of electrode potential from +0.1 to–0.7 V. The method is applicable for the determination of iodide ions in a solution with 0.5–100 μg/dm3 concentration; the relative standard deviation decreases from 6.1 to 3.2 % with an increase in the concentration of iodide from 0.5 to 5.0 μg/dm3, and in the range of 10–100 μg/dm3 is 2.4–3 %.
About the Authors
A. I. Kulak
Institute of General and Inorganic Chemistry of the National Academy of Sciences of Belarus
Belarus
Belarus
Anatoly I. Kulak – Corresponding Member of the National Academy of Sciences of Belarus, D. Sc. (Chemistry), Professor, Director.
9/1, Surganov Str., 220072, Minsk.
N. P. Matveiko
Belarusian State Economic University
Belarus
Belarus
Nikolai P. Matveiko – D. Sc. (Chemistry), Professor, Head of the Department of Physical Chemistry of Materials and Manufacturing Technologies.
7/5, Sverdlov Str., 220030, Minsk.
A. M. Braikova
Belarusian State Economic University
Belarus
Belarus
Alla M. Braikova – Ph. D. (Chemistry), Associate Professor.
7/5, Sverdlov Str., 220030, Minsk.
V. V. Sadovsky
Belarusian State Economic University
Belarus
Belarus
Viktor V. Sadovsky – D. Sc. (Chemistry), Professor.
26, Partizanski Ave., 220070, Minsk.
References
1. Švancara I., Ogorevc B., Nović M., Vytřas K. Simple and rapid determination of iodide in table salt by stripping potentiometry at a carbon-paste electrode. Analytical and Bioanalytical Chemistry, 2002, vol. 372, no. 7-8, pp. 795–800. https://doi.org/10.1007/s00216-002-1263-5
2. Campos M. L. New approach to evaluating dissolved iodine speciation in natural waters using cathodic stripping voltammetry and a storage study for preserving iodine species. Marine Chemistry, 1997, vol. 57, no. 1–2, pp. 107–117. https:// doi.org/10.1016/S0304-4203(96)00093-X
3. Luther G. W., Swartz C. B., Ullman W. J. Direct determination of iodide in seawater by cathodic stripping square wave voltammetry. Analytical Chemistry, 1988, vol. 60, no. 17, pp. 1721–1724. https://doi.org/10.1021/ac00168a017
4. Holak W. Determination of iodine in foods by cathodic stripping voltammetry. Analytical Chemistry, 1987, vol. 59, no. 17, pp. 2218–2221. https://doi.org/10.1021/ac00144a047
5. Yang S., Fu S., Wang M. Determination of trace iodine in food and biological samples by cathodic stripping voltammetry. Analytical Chemistry, 1991, vol. 63, no. 24, pp. 2970–2973. https://doi.org/10.1021/ac00024a031
6. Yang L., Zou L., Li G., Ye B. Simple and rapid determination of trace iodide by cathodic stripping voltammetry. Talanta, 2016, vol. 147, no. 1, pp. 634–640. https://doi.org/10.1016/j.talanta.2015.09.048
7. Boult E. H., Thirsk H. R. The structure of anodic films formed on mercury in halide solutions. Transactions of the Faraday Society, 1954, vol. 50, pp. 404–412. https://doi.org/10.1039/TF9545000404
8. Metodicheskiye ukazaniya IUK 4.1.1106-02. Methodical instructions of the IUK 4.1.1106-02. Determination of the mass fraction of iodine in food products and raw materials by the titrimetric method. Moscow, Ministry of Health, 2002. 21 p. (in Russian).
Review
Views: 603
Email this article 