High-performance liquid chromatographic determination of N-alpha-acetyl-L-carnosine in equine plasma

N-alpha-Acetyl-L-carnosine (NAcCAR) in perchloric acid extracts of equine plasma was assayed by high-performance liquid chromatography on a 3 mu m Hypersil ODS (150x4.6 mm I.D.) column eluted with 5 mM phosphoric acid-1 mill triethylamine, pH 2.58. NAcCAR was isolated by solid-phase extraction on Isolute PRS (propylsulphonyl) columns. The HPLC mean retention time for NAcCAR was 5.9+/-0.2 min. The recovery from plasma by solid-phase extraction was 93.9-99.7% and lower limit of detection in plasma was 0.18 mu M. The normal NAcCAR concentration in equine plasma was 2.4+/-0.3 mu M. The method was applied to the determination of plasma concentrations following oral and intravenous NAcCAR administration.