Determination of plasma amino acids by fluorescent derivatization and reversed-phase liquid chromatographic separation.

Amino acid analysis in physiological fluids remains expensive, as it usually requires a dedicated analyzer. We modified an RP-HPLC method originally devoted to peptide and protein hydrolysate analysis in order to apply it to plasma amino acid determination. The described method uses a commercial kit based on 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate derivatization followed by reversed-phase high-performance liquid chromatography. The described method is easy to use and allows the determination of twelve amino acids frequently involved in aminoacidopathies, thus enabling the diagnosis and follow-up of affected patients. The results obtained by this method are comparable to those obtained with a classical amino acid analyzer.