A green method for the quantitative assessment of neutral oil in palm fatty acid distillates by single bounce attenuated total reflectance Fourier-transform infrared spectroscopy

Abstract

This study developed a green, reliable, rapid and economical analytical method for the determination of neutral oil present in deodorizer distillates (DD) by Single Bounce Attenuated Total Reflectance (SB-ATR) Fourier-Transform Infrared (FT-IR) spectroscopy. Beer's Law was applied to develop calibration model based on the band height at 1744 cm⁻¹ with two point baseline between 1800 to 1600 cm⁻¹ of the carbonyl group (CO) related to triglycerides. It was found to be linear over wide concentration range of 0–100% for neutral oil with correlation coefficients greater than 0.999. No solvent or costly standards were used in the proposed method. The accuracy of the method was assessed by comparison to a conventional standard American Oil Chemists' Society (AOCS) titrimetric procedure, which provided good correlation (>0.999). Therefore, proposed method could be used as an environmentally friendly alternative to the AOCS titrimetric method for the quantitative determination of neutral oil in Palm Fatty Acid Distillates (PFAD) for the routine analysis in quality control laboratories of oil processing industries.