TY - JOUR

T1 - First-Principles Modeling of Preferential Solvation in Mixed-Modifier Differential Mobility Spectrometry

AU - Bissonnette, Justine R.

AU - Ryan, Christopher R.M.

AU - Ieritano, Christian

AU - Hopkins, W. Scott

AU - Haack, Alexander

N1 - Funding Information: The authors would like to acknowledge the high-performance computing support from the Digital Research Alliance of Canada. W.S.H. would like to acknowledge the financial support provided by the Natural Sciences and Engineering Research Council (NSERC) of Canada in the form of Discovery and Alliance grants, as well as the government of Ontario for an Ontario Early Researcher Award. Further, W.S.H. acknowledges the support from the InnoHK Initiative and the Hong Kong Special Administrative Region Government. C.I. acknowledges financial support from the government of Canada for the Vanier Canada Graduate Scholarship. A.H. gratefully acknowledges this work being funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 449651261.

PY - 2023/7/5

Y1 - 2023/7/5

N2 - Differential mobility spectrometry (DMS) separates ions based on mobility differences between high and low electric field conditions. To enhance resolution, solvents such as water and acetonitrile are often used to modify the collision environment and take advantage of differing dynamic clustering behavior between analytes that coelute in hard-sphere environments (e.g., N2). When binary solvent mixtures are used to modify the DMS environment, one solvent can have a dominant influence over the other with respect to ion trajectories. For example, for quinoline derivatives, a 9:1 water:acetonitrile solvent mixture exhibited identical behavior to an environment containing only acetonitrile as a modifier. It was hypothesized that this effect arises due to the significantly different binding strengths of the two solvents. Here, we utilize a first-principles model of DMS to study analytes in single and binary solvent mixtures and explore the effects governing the dominance of one solvent over the other. Computed DMS dispersion curves of quinoline derivatives are in excellent agreement with those measured experimentally. For mixed-modifier environments, the predicted cluster populations show a clear preferential solvation of ions with the stronger binding solvent. The influence of ion-solvent binding energies, solvent concentration, and solvent molecule size is discussed in the context of the observed DMS behavior. This work can guide the usage of binary solvent mixtures for improving ion separations in cases where compounds coelute in pure N2 and in single-solvent modifier environments. Moreover, our results indicate that binary solvent mixtures can be used to create a relative scale for solvent binding energies.

AB - Differential mobility spectrometry (DMS) separates ions based on mobility differences between high and low electric field conditions. To enhance resolution, solvents such as water and acetonitrile are often used to modify the collision environment and take advantage of differing dynamic clustering behavior between analytes that coelute in hard-sphere environments (e.g., N2). When binary solvent mixtures are used to modify the DMS environment, one solvent can have a dominant influence over the other with respect to ion trajectories. For example, for quinoline derivatives, a 9:1 water:acetonitrile solvent mixture exhibited identical behavior to an environment containing only acetonitrile as a modifier. It was hypothesized that this effect arises due to the significantly different binding strengths of the two solvents. Here, we utilize a first-principles model of DMS to study analytes in single and binary solvent mixtures and explore the effects governing the dominance of one solvent over the other. Computed DMS dispersion curves of quinoline derivatives are in excellent agreement with those measured experimentally. For mixed-modifier environments, the predicted cluster populations show a clear preferential solvation of ions with the stronger binding solvent. The influence of ion-solvent binding energies, solvent concentration, and solvent molecule size is discussed in the context of the observed DMS behavior. This work can guide the usage of binary solvent mixtures for improving ion separations in cases where compounds coelute in pure N2 and in single-solvent modifier environments. Moreover, our results indicate that binary solvent mixtures can be used to create a relative scale for solvent binding energies.

KW - collision cross section

KW - differential ion mobility

KW - ion mobility

KW - microsolvation

KW - reaction kinetics

UR - http://www.scopus.com/inward/record.url?scp=85163432067&partnerID=8YFLogxK

U2 - 10.1021/jasms.3c00117

DO - 10.1021/jasms.3c00117

M3 - Article

C2 - 37262415

AN - SCOPUS:85163432067

VL - 34

SP - 1417

EP - 1427

JO - Journal of the American Society for Mass Spectrometry

JF - Journal of the American Society for Mass Spectrometry

SN - 1044-0305

IS - 7

ER -