AN AUTOMATED GAS-LIQUID-CHROMATOGRAPHIC METHOD OF MEASURING FREE FATTY-ACIDS IN CANOLA

An automated method for measuring free fatty acids (FFA) in canola seed was developed by using gas-liquid chromatography (GLC). The results from the GLC method were linearly related (r2 = +0.98) to those obtained with the traditional method involving Soxhlet extraction followed by a titration. In a nested experiment of over 11 different seedlots, the extraction and injection errors were 0.11 and 0.018%, respectively, of the total variation. The variation attributed to sampling within a seedlot was twice the variation attributed to extraction and injection errors combined. A seed sample size of at least 10 mL was needed to prevent the standard deviation from increasing as the FFA mean increased. The GLC method was precise and rapid, and also identified which fatty acids were being cleaved from the oil, but a linear adjustment improved accuracy.