LC-MS/MS as a tool for analysis of underivatized glutamic and aspartic amino acids residues from tetanus toxoid

Abstract

The fragmentation patterns of the precursor ions were compatibles with amino acid cleavages [M+H-H2O] + ; [M+H-NH3 ] + ; [M+H-HCO2H] + and [M+H-CH3CO2H]+. In order to perform SRM studies the transitions 148.1®84.1 and 134.1®74.0 were selected for glutamic and aspartic acids, respectively. The area obtained for the MS/MS peaks selected for glutamic acid was proportional to its concentration. The standard curve was linear in the interval of 2.0-100.0 pmol/ µL (R2> 0.99; SD <10;Bias % < 5). Conclusion: The results so far obtained suggest that LCMS/MS can be used to quantify amino acids targets with accuracy and precision. Subsequent experiments will be carry out with hydrolyzed MTT and its activated form.