Effects of a proton‐conducting ionic liquid on secondary ion formation in time‐of‐flight secondary ion mass spectrometry

Abstract

Since [dema][TfO] can act as a proton source, its primary beam can effectively generate protonated secondary ions of analytes. Consequently, proton-conducting ionic liquids such as [dema][TfO] are expected to have great potentials as primary ion beams in TOF-SIMS.

Time‐of‐flight secondary ion mass spectrometry using a new primary ion beam generated by vacuum electrospray of a protic ionic liquid, propylammonium nitrate

“…To be more precise, we have used diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), which is a commercially available PIL, and demonstrated that a primary [dema][TfO] cluster ion beam was effective in protonating arginine . Since a [dema][TfO] molecule has an active proton, it is likely that its beam irradiation can promote proton transfer reactions to form secondary ions [M + H] + . However, the [dema][TfO] cluster beam was not effective in protonating polyethylene glycol …”

“…Since a [dema][TfO] molecule has an active proton, it is likely that its beam irradiation can promote proton transfer reactions to form secondary ions [M + H] + . However, the [dema][TfO] cluster beam was not effective in protonating polyethylene glycol …”

“…The results obtained can be explained by considering the proton affinities (PAs) of analytes and [dema][TfO] constituents . In the case of [dema][TfO], protonated molecules [M + H] + can be formed by proton transfer reactions from [dema] + cations to analytes M: where [dema‐H] 0 corresponds to (CH 3 CH 2 ) 2 NCH 3 (Brønsted base B in Equation ) …”

Development of a Primary Ion Column for Mass Spectrometry-Based Surface Analysis

“…voltage, yet this generally implies low source brightness and a preferential formation of smaller droplets 129 . They also have utilized the ionic liquids as matrix-coating materials (enhances ionization and yields) to match the projectile types 129 .…”

“…They also have utilized the ionic liquids as matrix-coating materials (enhances ionization and yields) to match the projectile types 129 . …”