The application of an improved gas-liquid chromatographic method for the determination of the long chain non-esterified fatty acid pattern of blood plasma in children.

An accurate, practicable and fast method for the quantitative determination of the non-esterified fatty acid (NEFA) pattern in plasma is described. After extraction, thin-layer chromatography and methylation, the NEFAs are quantitated by injection on a gas chromatographic column. A precise method with a mean recovery of 96% and a coefficient variation of the total NEFA concentration between 4 and 5% has been developed by the addition of the internal standard before the extraction, the deduction of a blank value and the use of constant quantities of silicagel, taken from the thinlayer plates. The height X retention time of each methyl ester peak is calculated after injection on a free fatty acid phase (FFAP) column. The total NEFA concentration and the plasma NEFA pattern of Belgian schoolboys (15 to 17 years old) have been determined.