Aplikasi Spektrofotometri Ultraviolet dengan Metode Zero Crossing pada Penetapan Kadar Campuran Vitamin C dan Kuersetin

Abstract

Background: Vitamin C and quercetin are active substances that have antioxidants that are highly effective and safely used as a treatment for infectious diseases. Determination of vitamin C and quercetin levels using the Zero Crossing (ZCR) method is one of the spectrophotometric methods that can be used to determine drug levels in the mixture simultaneously without prior separation. Objective: This study aims to develop and validate a spectrophotometric method via Zero Crossing on the determination of simultaneous levels of vitamin C and quercetin in capsules by means of ultraviolet spectrophotometry and complying to the requirements of validation method. Method: This study was conducted using zero crossing method to determine the levels of vitamin C and quercetin with methanol and then tested upon several validation method including linearity, accuracy, precision, LOD and LOQ parameters. Results: The results showed that the application of the zero crossing method in the determination of levels was carried out at λ 237.13 nm for vitamin C and λ 245.80 nm for quercetin.The validation test results obtained are linearity, r = 0.9975 for vitamin C and r = 0.9979 for quercetin. Precision test with RSD value was obtained to be 0.59% for vitamin C and 0.57% for quercetin. Limit of detection (LOD) were found to be 1.08 µg/mL for vitamin C and 0.85 µg/mL for quercetin. Limit of quantitation (LOQ) were obtained to be 3.62 µg/mL for vitamin C and 2.84 µg/mL for quercetin. These results to an accuracy test of 97.8% of recovery and thus the average levels of vitamin C and quercetin in NF capsules were (98.92 ± 1,24)% and (100.11 ± 0.94)% respectively. Conclusion: Based on the results of the study, it can be concluded that simultaneous determination of vitamin C and quercetin via Zero Crossing (ZCR) method met the requirements of the active substance levels listed in the Indonesian Pharmacopoeia VI edition (2020) and consequently the results of validation parameters have met the specified requirements.