Thin layer chromatography/flame ionization analysis of transesterified vegetable oils

Abstract

Abstract A quantitative method was developed for analyzing mixtures containing fatty esters and tri‐ (TG), di‐ (DG) and monoglycerides (MG) obtained by the transesterification of vegetable oils. Analyses were performed by thin layer chromatography (TLC)/flame ionization detection (FID) with an Iatroscan TH‐10 instrument. Stearyl alcohol served as an internal standard. From plots of area and weight ratios of methyl linoleate and tri‐, di‐ and monolinolein, linear equations were developed from which response factors were calculated. Hydrogen flow rate and developing solvent strongly influenced resolution and baseline stability. Variations in scan speed affected completeness of burning and response factors, but not measured composition. Sample weight also affected response factors but not measured composition. A computerized procedure for data analysis was developed so that 30 samples can be completed in 2–3 hr. Relative standard deviations were 1–2% for major components in the 90–100% range and 6–83% for minor components in the 1–2% range.