エレクトロスプレーイオン化質量分析法におけるヒドララジン-アルデヒド誘導体の新規脱水素イオン[M－H]⁺の生成機構
This study identified a previously unreported dehydrogenated ion species, [M-H]+, arising from hydralazine derivatives of aldehydes analyzed by electrospray ionization mass spectrometry (ESI-MS). The phenomenon was observed to be independent of liquid chromatography mobile phase composition and ESI source settings. Systematic investigation of multiple hydralazine-aldehyde derivatives revealed that the [M-H]+ ion formed specifically when the aldehyde possessed an sp3-hybridized carbon bearing a hydrogen at the alpha position. In contrast, the hydralazine derivative of acetone produced only the conventional [M+H]+ ion. A mechanistic proposal was advanced in which the protonated species [M+H]+ undergoes loss of a neutral H2 molecule to yield the observed [M-H]+ ion. Density functional theory (DFT) calculations provided computational support for this proposed ionization pathway.
DFT calculations support a mechanism in which the protonated ion [M+H]+ loses a neutral H2 molecule to generate the dehydrogenated [M-H]+ ion, a process specific to aldehyde derivatives with an sp3 alpha-carbon bearing hydrogen.
The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/30650224