Abstract
The gas-phase adsorption of N(2) on protonated serine (Ser, C(3)H(7)NO(3)), threonine (Thr, C(4)H(9)NO(3)), glycine (Gly, C(2)H(5)NO(2)), and 2-aminoethanol (C(2)H(7)NO) was investigated using a tandem mass spectrometer equipped with an electrospray ionization source and a cold ion trap. N(2) molecules were adsorbed on the free X-H (X=O and N) groups of protonated molecules. Gas-phase N(2) adsorption-mass spectrometry detected the presence of free X-H groups in the molecular structures, and was applied to the structural elucidation of small molecules. When the 93 structures with an elemental composition of C(3)H(7)NO(3) were filtered using the gas-phase N(2) adsorption-mass spectrometry results for Ser, the number of possible molecular structures was reduced to 8 via the quantification of the X-H groups. Restricting and minimizing the number of possible candidates were effective steps in the structural elucidation process. Gas-phase N(2) adsorption-mass spectrometry combined with mass spectrometry-based techniques has the potential for being useful for elucidating the molecular structures of a variety of molecules.