PENGEMBANGAN DAN VALIDASI METODE SPEKTROSKOPI INFRAMERAH DEKAT (NIRS) UNTUK PENETAPAN KADAR ETANOL DALAM BIOETANOL

Abstract

This study aims to develop and validate the Near Infrared Spectroscopy (NIRS) method for determining ethanol content in bioethanol. This method is an alternative to determining ethanol content in bioethanol in laboratories, which currently use Gas Chromatography (GC), a method that is costly and time-consuming, as well as specific gravity measurement and refractive index reading methods, which are relatively inexpensive but have low accuracy. In addition to being faster and cheaper, the NIRS method can be used to determine ethanol content directly, without prior distillation, so that the determination can be done in real time. This research was conducted through method development and method validation.. In method development, ethanol standard spectrum readings were taken at several concentrations, and processed using NirCal Chemometric Buchi software to build a calibration model that produced a Standard Error of Calibration (SEC) value of 0.2234. The method validation parameter was for linearity, precision, and accuracy, all meet the AOAC acceptance criteria, linearity value of 0.999, precision value of %RSD ≤ 2/3 CV Horwitz, and accuracy value (% recovery) of 104.88% on average. As a comparison, ethanol content was determined using the visible spectrophotometer method. The T-test results showed that both methods no significantly different.