Liquid chromatographic determination of the sphinganine/sphingosine ratio in serum

The fumonisin mycotoxins, which are worldwide contaminants of corn, inhibit de novo sphingolipid biosynthesis leading to elevation in the ratio of the sphingoid bases, sphinganine and sphingosine, in the serum of animals exposed to fumonisins. A new HPLC method for the determination of the ratio of these bases in serum has been developed involving lipid extraction, clean-up on a silica minicolumn and alkaline hydrolysis prior to precolumn o-phthaldialdehyde derivatisation and HPLC separation and quantification by fluorescence detection. Based on serum from both normal and fumonisin-exposed vervet monkeys, the method was shown to be reproducible (R.S.D.<10%).