Application of Photogenerated Iodine for Quantitative Determination of Water-Soluble Antioxidants
- PDF / 103,489 Bytes
- 6 Pages / 594 x 792 pts Page_size
- 96 Downloads / 175 Views
Pharmaceutical Chemistry Journal, Vol. 54, No. 8, November, 2020 (Russian Original Vol. 54, No. 8, August, 2020)
APPLICATION OF PHOTOGENERATED IODINE FOR QUANTITATIVE DETERMINATION OF WATER-SOLUBLE ANTIOXIDANTS E. V. Turusova1,* and O. E. Nasakin1 Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 54, No. 8, pp. 52 – 57, August, 2020.
Original article submitted December 22, 2019. A photochemical method for determination of water-soluble antioxidants was developed based on titration of the analyte by photogenerated iodine obtained by irradiating an auxiliary solution containing potassium iodide and a sensitizer at pH 5.6. Stabilization of the current in the cell indicated that the reaction went to completion because the content of titrant in the solution was monitored by voltammetry. The technique satisfied the validation criteria for linearity, precision, and accuracy. Application of the proposed method in analytical practice reduced not only the time for a single determination because solutions did not need to be standardized and routine analyses were avoided but also the cost of a single analysis because expensive equipment and reagents were not required. Keywords: photogenerated iodine, polyphenolic compounds, ascorbic acid, total antioxidant capacity, quantitative determination.
with a solution of photogenerated iodine (I2) produced via irradiation of potassium iodide (KI) in the presence of a sensitizer (sodium eosinate) at pH 5.6. The photochemical titration was accompanied by a decrease of the current in the amperometric cell circuit and its stabilization indicating that the reaction was finished because the titrant content was monitored by voltammetry. Further irradiation of the solution and measurement of the generation time required to destroy the titrant enabled quantitative determination of the antioxidants.
Oxidative stress due to overproduction of reactive oxygen species (ROS) is often associated with the development of chronic and degenerative oncological, cardiological, and autoimmune diseases [1 – 6]. The advisability of using synthetic antioxidants in therapeutic practice is currently under discussion because of the toxicity of several compounds of this class [7 – 9]. Medicinal plants may be the most environmentally benign source of antioxidants [10]. Herbal antioxidants were proposed to be capable of acting directly (in vivo) on the body and indirectly by inducing mechanisms related to antioxidant protection [11]. Thus, the total antioxidant capacity (TAC) is a suitable indicator for determining the additive antioxidant properties of plants [12]. Currently known methods give variable results for the determined TAC [11 – 22]. Therefore, the TAC must be determined by more than one method to obtain the true value [20]. The aim of the present study was to develop a photochemical method for determining the total content of water-soluble antioxidants based on titration of the reductants 1 *
EXPERIMENTAL PART Samples of plant raw material (PRM) collected in middle Volga republics were used in
Data Loading...
