Abstract

A derivatization procedure is described for the long chain fatty acid, lauric acid and metabolites using a fluorescent probe 4-(bromomethyl)-7-methoxycoumarin. The derivatives can be separated and detected in an isocratic high performance liquid chromatografic system using a fluorescence detector. The derivatization is rapid, simple and gives a good quantification by the use of an internal standard. The procedure has been applied on samples from a toxicity experiment with the plasticizer di (2-ethylhexyl)phthalate (DEHP). The activity of cytochrome P-450 IVA1 or lauric acid hydroxylase (LAH) in liver homogenates can be determined by the quantification of the 11- and 12-hydroxylated metabolites of lauric acid. The method turned out to be very sensitive and suitable to replace similar assays using radioactive compounds.