Abstract
Simultaneous chiral separations of underivatized amino acids have been performed 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 positional isomeric amino acids (e.g., l, d-Leu/Ile, or l, d-Val/Iva). Due to the specificity of tandem mass spectrometry, co-eluting enantiomers of different amino acids could also be determined. Fifteen chiral underivatized proteinogenic and non-proteinogenic amino acids were analysed simultaneously under isocratic conditions (acetonitrile–water, 75:25) in less than 25 min. For maximum sensitivity, post-column addition of 500 m M aqueous HCOOH was necessary. Detection limits varied from 2.5 to 50 μg l −1 depending on the amino acid. The signal vs. concentration relationship was linear for all d- and l-amino acids (0.9995≤ r 2≤1) for three orders of magnitude.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have