The study of the effect of ethyl alcohol concentrations on the antioxidant activity of ascorbic acid solutions




effect of ethanol; ascorbic acid; antioxidant activity; potentiometric method


Much attention is currently paid to the study of the antioxidant properties of various objects – individual antioxidants, dietary supplements, medicines, liquid plant extracts. Antioxidant medicines are widely used as the main or additional correction agents in the treatment of a number of diseases. Therefore, the study and development of procedures for determining the antioxidant activity is a prospective task for today.

Aim. To determine the contribution of different concentrations of ethanol to the level of the antioxidant activity (AOA) of ascorbic acid solutions by the potentiometric method.

Results and discussion. The different ethanol content in the solution had the following percent of the contribution to the value of AOA of ascorbic acid solutions – 1.85, 3.56, 4.89, 6.76, 7.63 % for 20, 40, 60, 80, 96 % ethanol, respectively. The linearity of the procedure was proven in the range from 0.039 to 0.31 mmol/L.

Experimental part. The object of the study was solutions of ascorbic acid prepared using ethanol of different concentrations – 20, 40, 60, 80, 96 %. Potentiometric measurements were conducted by a Hanna 2550 pH meter (Germany) with an EZDO 5010 combined platinum electrode. Weighing was carried out using an АN100 digital analytical balance (AXIS, Ukraine) with d = 0.0001 g. Ascorbic acid was purchased from Sigma Aldrich (≥ 99.0 %), K3[Fe(CN)6], K4[Fe(CN)6], NaHPO4, KH2PO4 were of analytical grade.

Conclusions. It has been found that ethyl alcohol affects the change of the potential in the electrochemical cell and the level of AOA of ascorbic acid solutions. The percentage of the contribution of different concentrations of ethyl alcohol to the AOA value ranges from 1.85 to 7.63 %. The approach and the formula for calculation that take into account the effect of ethyl alcohol on the final AOA result of the test sample of ascorbic acid in a water-alcohol solutions have been proposed. The results of this study can be used in the pharmaceutical and food industries to determine, assess and control the AOA level of dietary supplements, liquid extracts, tinctures, medicines, and alcoholic beverages.


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