PENGEMBANGAN DAN VALIDASI METODE PENENTUAN KADAR ASAM ASKORBAT SECARA FLUORIMETRI MENGGUNAKAN CERIUM (IV) SULFAT

• Main Author: Lidya Situmorang, Melisa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44152
• Institution: Institut Teknologi Bandung

Ascorbic acid or vitamin C is one of the important nutrients to maintain a healthy immune system. The human body is unable to synthesize ascorbic acid, so that to meet the needs of vitamin C could be done by consuming fruits, vegetables, foods or drinks, and pharmaceutical dosage forms. The aim of this research was to develop a valid analytical method for determining ascorbic acid by the spectrofluorometry method through the reduction of Ce (IV) sulfate by ascorbic acid into fluorescent Ce (III). The fluorescence intensity of Ce (III) would increase along with the increasing of ascorbic acid concentration that reacts with Ce (IV) sulfate. The method had good specificity because other components in the matrix were not interfering the analysis. A linear relationship between fluorescence intensity and ascorbic acid concentrations was obtained in the range of 10 - 5 -7 × 10 -5 M with correlation coefficient was 0.9994 and the coefficient of variance in linear regression was 1.48%. The detection limit and the quantification limit based on the calibration curve were 2.5 × 10 -6 and 8.32 × 10 -6 M. The standard addition method was applied for testing accuracy and precision of the method. For accuracy test, the percent recovery results were in the range of 98.33-101.45%. For interday precision test, the relative standard deviation were in the range of 0.37-1.97%, while for intraday precision test, the relative standard deviation were in the range of 0.7-1.48%. The samples which were used in this research were tablets and isotonic drinks, but the result of tablet sample test did not meet the tablet criteria. It could be concluded that the spectrofluorimetry method was successfully developed and validated therefore it could be applied to determine ascorbic acid in tablets and isotonic drinks.