In attempting to move towards a more environmentally benign
The composition of the FAME product was analyzed by gas chromatography (GC) using Ki16425 Shimadzu 14B gas chromatograph equipped with a 30-m DB-Wax capillary column and a flame ionization detector (FID). The column temperature was initially set at 110 °C, followed by elevating to 200 °C at a ramp rate of 8 °C min−1. The FAME yield (% (w/w)) was calculated based on the external standard method (EN 14103) using methyl heptadecanoate (C18H36O2, >99%, Aldrich) as the reference standard. The amounts of mono-, di- and tri-glycerides remaining were quantified according to the internal standard method (EN 14105) by GC using an Agilent 7890A gas chromatograph equipped with an auto-injector, a atom 15-m DB-1ht capillary column and a FID. The initial and final column temperatures were 50 and 370 °C, respectively. The oven heating rate was 10 °C min−1. Prior to the analysis, N-methyl-N-(trimethylsilyl)tri-fluoroacetamide (MSTFA, >97%, Fluka) was used to convert the monoglycerides and diglycerides to more volatile derivatives in which n-heptane was added as solvent. The internal standard used for calibration was tricaprin (C33H62O6, >98.5%, Aldrich).