DOI: https://doi.org/10.55373/mjchem.v27i3.370

Keywords: Waste fish Oil; biodiesel; transesterification; GC-MS Analysis; FTIR Spectroscopy; NMR Spectroscopy

Abstract

This study presents a comprehensive characterization of wastes fish oil biodiesel using spectroscopic and chromatographic techniques, including Gas Chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) spectroscopy. The primary objective was to evaluate the molecular composition, purity, and structural integrity of biodiesel derived from waste fish oil through transesterification. GC-MS analysis identified a diverse range of fatty acid methyl esters (FAMEs), including saturated, monounsaturated, and polyunsaturated esters, reflecting the high degree of unsaturation characteristic of waste fish oil. The analytical results show successful transesterification of the detection of methyl tetradecanoate, 9-hexadecenoic acid methyl ester, and polyunsaturated eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) FAMEs. The characteristic ester carbonyl (1745 cm⁻¹), aliphatic chain (2923 cm⁻¹ and 2853 cm⁻¹) and double bond (1650–1600 cm⁻¹) absorption bands detected through FTIR Spectroscopy confirmed the investigation conclusions. The NMR spectroscopy provided molecular information through ¹H-NMR and ¹³C-NMR spectra which demonstrated that methyl esters appeared with signals at δ 3.6–3.7 ppm and δ 51.0–51.8 ppm while unsaturation levels became evident in the δ 127.0–130.0 ppm region. The results emphasis the process optimization because analysis shows the presence of phthalate derivatives and residual glycerol derivatives as well as other minor impurities. This study highlights the potential of waste fish oil as a sustainable feedstock for biodiesel production, contributing to renewable energy solutions and addressing environmental challenges.