Abstract

Estimation of serum free fatty acids (FFA) in serum based on the formation of inorganic phosphate has been simplified by eliminating complex stages. The principle of the present method is based on breakdown of pyrophosphate, formed by thioesterification of free fatty acids with ATP and CoA with the aid of acyl-CoA synthetase (EC 6.2.1.3) to inorganic phosphate. This is measured using the reaction with molybdate. The reaction equations are as follows:

The recovery of free fatty acids was 96 %. The interferences of citrate, phosphatidylserine, succinate, ascorbic acid and lecithin were between 0.5 and 2 %. The correlation between the new enzymatic and the classic enzymatic method was 0.966. The lower detection limit was 0.018 mmol/I. The method was linear between 0.02 and 2.0 mmol/I. The within-assay and between-assay imprecision (CV) of control sera was 5.5 % and 8 %, respectively.