Application of a novel cyclic ion mobility‐mass spectrometer to the analysis of synthetic polymers: A preliminary evaluation

Abstract

Rationale Mass spectrometry (MS) is often employed in the characterisation of synthetic polymers. As polymer architecture becomes more complex, ion mobility (IM) is increasingly being coupled with MS to provide an additional dimension of separation, along with structural information. In this study, we explore the use of a novel cyclic ion mobility (cIM) mass spectrometer for the analysis of a co‐polymer sample. Methods A solution of poly(ethylene glycol)–poly(propylene glycol) random co‐polymer (PEG‐ran‐PPG) was used as a representative polymer sample. The solution was infused into a cIM‐enabled quadrupole time‐of‐flight mass spectrometer. An m/z region of interest, selected using the quadrupole, was passed around the cIM device multiple times. Subsequently, regions of an arrival time distribution were ‘sliced’ and subjected to tandem mass spectrometric (MS/MS) analysis. Results Typical, multiply charged series were observed for the polymer under electrospray ionisation. Multiple passes of the cIM device resulted in the separation of otherwise‐overlapping charge states within a narrow m/z window (~3 m/z units), allowing individual selection of ions. These isolated ions were then subjected to post‐mobility fragmentation resulting in clean, high‐resolution product ion spectra, with a significant reduction in interference. Conclusions Scalable IM separation (IMS), brought about by passing ions multiple times around the cIM device, was demonstrated to provide increased IM resolution for ions in the selected m/z window. After multiple passes, deconvoluted high‐resolution MS/MS product ion spectra were successfully acquired for ions that previously had interfering overlapping species present.

Isomer and Conformer-Specific Mass Distribution-Based Isotopic Shifts in High-Resolution Cyclic Ion Mobility Separations

“…Following this single-cycle separation, we sliced/selected the closed conformer, while simultaneously ejecting out the open conformer, and vice versa in a separate experiment. For more details on how slicing/selecting species is performed using the flexible capabilities of the cIMS array, please refer to refs , , , and . Each conformer was then individually subjected to a 35 m cIMS-MS separation.…”

Exploring Complex Mixtures by Cyclic Ion Mobility High-Resolution Mass Spectrometry: Application Toward Petroleum

“…The instrument and the cIMS device were described in detail elsewhere (Scheme S1). ,, The cIMS platform allowed for the high reproducibility of the drift time measurements with a general day-to-day deviation of below 2%. Mass spectra were acquired in positive ion mode for m / z 50–1000 and for 3 min, accounting for roughly 180 scans.…”

Cyclic Ion Mobility Spectrometry Coupled to High-Resolution Time-of-Flight Mass Spectrometry Equipped with Atmospheric Solid Analysis Probe for the Molecular Characterization of Combustion Particulate Matter

“…Aside from a higher resolving power, a higher number of data points (bins) are beneficial for an accurate description of the IMS-profile of complex isomeric mixtures. − A very recent technology is cyclic ion mobility spectrometry (cIMS), allowing for the ions to pass multiple times in a circular traveling wave array, increasing the IMS resolving power by a factor of the square root of the pass number. In combination with an ion storage device before and after the cyclic array as well as with an option for collision-induced dissociation (CID), enormous flexibility is enabled for detailed molecular description.…”