Distinguishing Chiral Amino Acids Using Chiral Derivatization and Differential Ion Mobility Mass Spectrometry

The precise differentiation of chiral amino acids (AAs) holds significant potential for elucidating health and disease status. Herein, we developed an analytical strategy integrating chiral derivatization with differential ion mobility spectrometry (DMS)-mass spectrometry (MS) to achieve the enantiomeric separation of AAs. Utilizing <i>N</i>-(4-nitrophenoxycarbonyl)-l-phenylalanine 2-methoxyethyl ester (S-NIFE) as a chiral derivatization reagent, sodium-adducted S-NIFE-AA ions were generated and resolved via DMS-MS. By using the optimized carrier gas with 0.2% 1-propanol as a modifier, baseline separation of 11 enantiomeric AA pairs was successfully achieved. Compared with existing reports on DMS-based chiral AAs separation, the method proposed in this work exhibits a better separation efficiency for chiral AAs pairs. This further demonstrates the potential of DMS for chiral AAs and other metabolite analyses in the future.