Tandem differential mobility spectrometry with ion dissociation in air at ambient pressure and temperature

Abstract

Proton-bound dimers were dissociated to protonated monomers in air at ambient pressure and temperature using electric fields of ultrahigh Field Asymmetric Ion Mobility Spectrometry (ultraFAIMS) with the onset of dissociation for ethyl acetate as 96 Td and for dimethyl methyl phosphonate as 170 Td. Ions then were measured by differential mobility spectrometry (DMS). Fragment ions were formed with propyl acetate at electric fields of 90 Td or greater. The dissociation in ultraFAIMS of ions, with compensation fields near zero, to form smaller ions with new compensation fields, provided a method to improve peak capacity in DMS without gas modifiers. These findings also lay the foundation for a triple stage DMS with a centre stage for ion dissociation or fragmentation.

Analysis of Supramolecular Complexes of 3-Methylxanthine with Field Asymmetric Waveform Ion Mobility Spectrometry Combined with Mass Spectrometry

“…This demonstrates that supramolecular complexes of 3-MX may be transmitted through the FAIMS device in the presence of the alternating high and low electric fields and at a temperature of 150°C (stand-alone FAIMS is routinely used at much lower temperatures (i.e. atmospheric temperature) [38]. The hyphenation of FAIMS with MS allows ions of a single m/z to be selected as the CF is scanned at a fixed DF giving the characteristic FAIMS CF spectrum of each ion.…”

Identification and quantification of amino acids and related compounds based on Differential Mobility Spectrometry

“…It is indeed well-known that protonated homo-and hetero-dimers are typically transmitted at positive CV values. 54 And these dimers are partially fragmented in the source region, at the exit of the glass capillary, just downstream of the DMS device. 54 Due to this so-called "post-DMS fragmentation", their corresponding protonated monomers are observed at the corresponding transmission CV of the dimers.…”

“…54 And these dimers are partially fragmented in the source region, at the exit of the glass capillary, just downstream of the DMS device. 54 Due to this so-called "post-DMS fragmentation", their corresponding protonated monomers are observed at the corresponding transmission CV of the dimers. 55 Hence, in addition to the DMS peak of a given protonated monomer at m/z, peaks are also observed at positive CV values corresponding to maximum transmission of their proton bound dimers.…”

Developments in tandem ion mobility mass spectrometry

“…Both tandem-in-space and tandem-in-time IM-IM instruments have been developed. It should be noted that in this review we will only be discussing tandem IM coupled to massspectrometry; other types of tandem IM, such as the stand-alone DMA-DMA [51], FAIMS-DMA [52] and the DMA-DTIMS [38] used for aerosol analysis, will not be discussed.…”