CARBON PASTE ELECTRODE MODIFIED BY MOLECULARLY IMPRINTED POLY(METHYL ORANGE) FOR ASCORBIC ACID ANALYSIS BY VOLTAMMETRY

• Main Author: NABILAH OKTAVIANI NIM : 10514070, NYIMAS
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29858
• Institution: Institut Teknologi Bandung

Ascor <br /> <br /> bic acid is an important daily intake for normal growth. Human does not hav <br /> <br /> e <br /> <br /> l <br /> <br /> - <br /> <br /> gluconolactone oxidase, making human can <br /> <br /> not synthesize ascorbic acid him <br /> <br /> self. Lack of <br /> <br /> ascorbic acid causes a lethal deficiency. Therefore, an accurate ascorbic acid analysis <br /> <br /> me <br /> <br /> thod is required. In this study, ascorbic acid was analyzed by voltammetric method <br /> <br /> using a modified carbon paste electrode by molecularly imprinted polymer technique. <br /> <br /> The modification was performed by electropolimerization using methyl orange as <br /> <br /> monomer <br /> <br /> an <br /> <br /> d ascorbic acid as <br /> <br /> analyte with 1: <br /> <br /> 1 ratio <br /> <br /> for <br /> <br /> 20 cycles with cyclic <br /> <br /> voltammetric technique. Ascorbic acid was <br /> <br /> measured by differential pulse voltammetry <br /> <br /> technique under optimum conditions, <br /> <br /> p <br /> <br /> H 6. Linearity was obtained at a concentration <br /> <br /> range of 400 &#956;M to <br /> <br /> 6 mM and a detection limit of 447 &#956;M. Scan <br /> <br /> rate analysis showed <br /> <br /> that electron transfer reactions in ascorbic a <br /> <br /> cid analysis are controlled by <br /> <br /> diffusion <br /> <br /> process. <br /> <br /> Repeatability test result showed that the value of rela <br /> <br /> tive standard deviation <br /> <br /> obtained <br /> <br /> is lower than <br /> <br /> Horwitz <br /> <br /> relative standard deviation <br /> <br /> which signifies the precise test <br /> <br /> res <br /> <br /> ults. The accuracy test p <br /> <br /> rovided a recovery result of 91. <br /> <br /> 6 <br /> <br /> - <br /> <br /> 105%. <br /> <br /> Real sample analysis <br /> <br /> using <br /> <br /> differential pulse voltammetr <br /> <br /> y <br /> <br /> technique gave results that did not differ <br /> <br /> s <br /> <br /> ignificantly with the <br /> <br /> comparison <br /> <br /> method <br /> <br /> which is <br /> <br /> titrimetry <br /> <br /> .