Simultaneous analysis of underivatized chiral amino acids by liquid chromatography-ionspray tandem mass spectrometry using a teicoplanin chiral stationary phase

Simultaneous chiral separations of underivatized amino acids have been perf ormed using a teicoplanin-based chiral stationary phase and ionspray tandem mass spectrometry for their ionisation and detection. Different amino acid enantiomer pairs were separated simultaneously, including those of positio nal isomeric amino acids (e.g., L,D-Leu/Ile, or L,D-Val/Iva). Due to the sp ecificity of tandem mass spectrometry, co-eluting enantiomers of different amino acids could also be determined. Fifteen chiral underivatized proteino genic and non-proteinogenic amino acids were analysed simultaneously under isocratic conditions (acetonitrile-water, 75:25) in less than 25 min. For m aximum sensitivity, post-column addition of 500 mM aqueous HCOOH was necess ary. Detection limits varied from 2.5 to 50 mug l(-1) depending on the amin o acid. The signal vs. concentration relationship was linear for all D- and L-amino acids (0.9995 less than or equal to r(2) less than or equal to1) f or three orders of magnitude. (C) 2001 Elsevier Science BN. All rights rese rved.