Carbon Paste Electrode Modified With Molecularly Imprinted Poly(Methyl Red) for Determination of Ascorbic Acid by Voltammetric
<p align="justify">Ascorbic acid, which has benefits as an antioxidant, is one of important nutrients for body. Ascorbic acid cannot be synthesized naturally by the body, thus people can get ascorbic acid from vegetables, fruits, or commercial product. Consumption of ascorbic acid mu...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/26925 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | <p align="justify">Ascorbic acid, which has benefits as an antioxidant, is one of important nutrients for body. Ascorbic acid cannot be synthesized naturally by the body, thus people can get ascorbic acid from vegetables, fruits, or commercial product. Consumption of ascorbic acid must be in a certain amount, thus people require to choose certain methods to determine the amount of ascorbic acid from a certain product. Voltammetric method is one of certain methods for determining ascorbic acid because ascorbic acid is an electroactive compound. In voltammetric methods, current is measured as a potential function applied to the working electrode relative to the reference electrode. In this study, carbon paste electrode modified with Molecularly Imprinted Poly(Methyl Red) was used as the working electrode. To increase the sensitivity of carbon paste electrode for determination of ascorbic acid, electropolimerization technique was chosen because of its simplicity and did not take long to use. Methyl red was chosen as a monomer because it can form a hydrogen bond with ascorbic acid. The results showed that a maximum cycle of electropolimerization technique was 7 cycles with a methyl red and ascorbic acid composition was 1:1. The optimum condition of the measurement was obtained at pH 5. The linear consentration region was obtained in the range of 0,001-10 mM, the correlation coefficient was 0,9947 and limit of detection was 3 M. The analysis of scan rate showed that the electron transfer at the surface of carbon paste electrode was controlled by adsorption process. Determination of ascorbic acid from a commercial product showed that the recovery percentage were 96,7200% with voltammetric methods, 62,7317% with spectrophotometry UV-Vis method, and 93,5556% with acid-base titration method. The measurement of repeatability with the same carbon paste electrode showed a good result with the relative standard deviation percentage was 4,97%.<p align="justify"> <br />
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