Are Clusters Important in Understanding the Mechanisms in Atmospheric Pressure Ionization? Part 1: Reagent Ion Generation and Chemical Control of Ion Populations.

TitleAre Clusters Important in Understanding the Mechanisms in Atmospheric Pressure Ionization? Part 1: Reagent Ion Generation and Chemical Control of Ion Populations.
Publication TypeJournal Article
Year of Publication2014
AuthorsKlee, Sonja, Derpmann Valerie, Wißdorf Walter, Klopotowski Sebastian, Kersten Hendrik, Brockmann Klaus J., Benter Thorsten, Albrecht Sascha, Bruins Andries P., Dousty Faezeh, Kauppila Tiina J., Kostiainen Risto, O'Brien Rob, Robb Damon B., and Syage Jack a
JournalJournal of the American Society for Mass Spectrometry
ISSN1879-1123
Keywordsatmospheric pressure ionization, cluster equilibria, ion, ion bound clusters, molecule reactions
Abstract

It is well documented since the early days of the development of atmospheric pressure ionization methods, which operate in the gas phase, that cluster ions are ubiquitous. This holds true for atmospheric pressure chemical ionization, as well as for more recent techniques, such as atmospheric pressure photoionization, direct analysis in real time, and many more. In fact, it is well established that cluster ions are the primary carriers of the net charge generated. Nevertheless, cluster ion chemistry has only been sporadically included in the numerous proposed ionization mechanisms leading to charged target analytes, which are often protonated molecules. This paper series, consisting of two parts, attempts to highlight the role of cluster ion chemistry with regard to the generation of analyte ions. In addition, the impact of the changing reaction matrix and the non-thermal collisions of ions en route from the atmospheric pressure ion source to the high vacuum analyzer region are discussed. This work addresses such issues as extent of protonation versus deuteration, the extent of analyte fragmentation, as well as highly variable ionization efficiencies, among others. In Part 1, the nature of the reagent ion generation is examined, as well as the extent of thermodynamic versus kinetic control of the resulting ion population entering the analyzer region.

URLhttp://www.ncbi.nlm.nih.gov/pubmed/24850441
DOI10.1007/s13361-014-0891-2