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Development of a CE‐ESI‐ITMS method for the enantiomeric determination of the non‐protein amino acid ornithine
Author(s) -
DomínguezVega Elena,
SánchezHernández Laura,
GarcíaRuiz Carmen,
Crego Antonio L.,
Marina Maria Luisa
Publication year - 2009
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200800679
Subject(s) - chemistry , chromatography , tandem , selectivity , enantiomer , ornithine , tandem mass spectrometry , amino acid , analytical chemistry (journal) , mass spectrometry , stereochemistry , materials science , organic chemistry , arginine , biochemistry , composite material , catalysis
Unequivocal enantiomeric determination by CE‐MS 2 of the non‐protein amino acid ornithine (Orn), previously derivatized with FITC, was carried out in this work. A CE‐tandem MS system was used to combine the potential of CE in chiral separations with the sensitivity and selectivity of tandem MS detection. The electrospray‐coaxial sheath flow interface conditions were optimized and an IT analyzer working in the MS 2 mode was employed to provide the best sensitivity and selectivity. Satisfactory results were obtained in terms of linearity ( r 2 >0.99), precision (RSD from 1.3 to 2.3% for migration times and from 11.0 to 18.6% for corrected peak areas), and LOD (2×10 −9 M). Interestingly, the CE‐MS 2 method developed allowed a sensitivity enhancement of 100 folds with respect to UV detection. The results demonstrated the feasibility for carrying out quantitative CE‐ESI‐MS 2 determinations of Orn enantiomers in beers. Thus, L ‐Orn was found in the 16 beer samples analyzed at concentrations ranging from 1×10 −6 to 2×10 −5 M, whereas the percentages of D ‐Orn with respect to the total amount of Orn reached values between 1.5 and 10.0%.