Determination of 20 underivatized proteinic amino acids by ion-pairing chromatography and pneumatically assisted electrospray mass spectrometry.
A qualitative determination of 20 underivatized proteinic amino acids by LC-MS is reported. The need for chromatographic separation before mass spectrometry determination is demonstrated based on the study of several amino acid pairs which have some similar characteristics. Two suitable LC-MS systems are proposed for amino acid analysis. A preliminary optimization of these systems has been investigated using evaporative light scattering detection as these two detection modes have the same chromatographic requirements. The amino acid separation was achieved on a Purospher RP-18e or a Supelcosil ABZ+Plus column with tridecafluoroheptanoic acid or pentadecafluorooctanoic acid as volatile ion-pairing reagent in an acetonitrile-water mobile phase. In order to elute the most retained amino acids, an elution gradient based on simultaneously increasing the concentration of acetonitrile and decreasing the concentration of the ion-pairing reagent was used. The detection limits of the present work (without specialized optimization) varied from 0.5 to 1 mg 1(-1).
Chaimbault
P
P
Institut de Chimie Organique et Analytique (ICOA), CNRS UPRES-A 6005, Université d'Orléans, France.
Petritis
K
K
Elfakir
C
C
Dreux
M
M
D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity
D000596:Amino Acids