Determination of Free and Esterified Carnitine in Tissues of Rainbow Trout by High-Performance Liquid Chromatography

Free carnitine, acid-soluble total carnitine, and long-chain acylcarnitines in fish tissues were determined by high-performance liquid chromatography (HPL) equipped with a Cosmosil 5C sub(8) or 5C sub(18)-AR column. Free and acid-soluble total carnitine was extracted from such tissues as ordinary muscle, liver, kidney, heart tissue, and plasma of rainbow trout with 6% perchloric acid containing 20 mM 2-mercaptoethanol. Acetylcarnitine and short-chain acylcarnitines (C sub(3)-C sub(10)) in the extract were hydrolyzed to free carnitine by alkaline to analyze acid-soluble total carnitine. Long-chain acylcarnitines (C sub(12)