The chirality determination of amino acids by forming complexes with cyclodextrins and metal ions using ion mobility spectrometry, and a DFT calculation

Chiral Derivatization-enabled Discrimination and Visualization of Proteinogenic Amino Acids by Ion Mobility Mass Spectrometry

“…Due to the use of sodium bicarbonate buffer in the reaction mixtures, [FDAA-D-Ser + 2Na – H] + is observed at m/z 402.063 in the mass spectrum. According to previous studies, the formation of metal ion adducts facilitates the differentiation of chiral amino acids 21,22,24,25,29,30,41 , especially the [M + 2Na - H] + ionic form of the AAs’ derivatives 22,30 . Since diastereomers have exactly the same molecular weight, their separation is achieved exclusively by IMS.…”

“…Due to the use of sodium bicarbonate buffer in the reaction mixtures, [FDAA-D-Ser + 2Na -H] + is observed at m/z 402.063 in the mass spectrum. According to previous studies, the formation of metal ion adducts facilitates the differentiation of chiral amino acids 21,22,24,25,29,30,41 ,…”

Evaluating the Utility of Temporal Compression in High-Resolution Traveling Wave-Based Cyclic Ion Mobility Separations

“…Specifically, we were interested in developing a method to rapidly separate out various d / l monosaccharide enantiomer pairs with cIMS-MS and then subject each formed complex to a post-cIMS temporal compression step. As has been well stated in previous literature, enantiomeric separations remain one of the most challenging problems in the IMS-MS community. − Most previously developed methods for resolving enantiomers with IMS-MS have revolved around the formation of chiral, noncovalent, complexes and rely on not only the suitable formation of the initial complex but also that the formed diastereomeric complexes will be different enough in their structure to be separated. − …”

“…For this study, we chose the d / l pairs for glucose, galactose, and mannose. While the d -enantiomers are more common, the l -forms can also be present in an unknown biological sample. − We chose α-cyclodextrin (αCD) as the complexing molecule since previous work has shown for it to be effective in the enantiomeric separation of other small molecules, but it was unclear whether this would hold up for these highly polar monosaccharides (see Figure for the structures of the monosaccharides and αCD). − Furthermore, rather than rely on metal adduction, which introduces ambiguity as to the actual metal concentration and thus precludes lab-to-lab reproducibility, we chose to analyze these complexes in negative ion mode as their deprotonated adducts. Each d / l pair was subjected to direct infusion both as an equimolar mixture as well as individually (see the Supporting Information for individual traces).…”

Chiral derivatization-enabled discrimination and on-tissue detection of proteinogenic amino acids by ion mobility mass spectrometry

“…24 Nevertheless, enantiomers could not be separated directly by IMS since they have the same mobility in the gas phase. 25,26 Therefore, different methodologies, (i) the introduction of volatile chiral reagents into the IMS dri tube, 27 (ii) formation of noncovalent complexes, 23,25,[28][29][30][31][32][33] and (iii) chemical derivatization methods, 26,34,35 have been developed for chiral IMS analysis. In general, the core principle of methods (ii) and (iii) is transforming enantiomers into diastereomers to generate CCS differences between pairs of original enantiomers in IMS.…”