Mechanism of Electrospray Ionization

Currently, it is generally believed that the IDM model applies to ions with significant surface activity (i.e., hydrophobic molecules) and the CRM model applies largely to hydrophilic species. Thus, proteins and metal cations may follow CRM, whereas peptide and fatty acids follow IDM. As a consequence, the ESI response depends on the nature of the analyte. Enke has put forward an 

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We have previously considered the mechanism of electrospray ionization in terms of the charging of droplets containing analyte and the formation of ions as the charge density on the surface of the droplet increases as desolvation progresses. The electrospray system can also be considered as an electrochemical cell in which, in positive-ion mode, an oxidation reaction occurs at the capillary tip and a reduction reaction at the counter electrode (the opposite occurs during the production of negative ions). This allows us to obtain electrospray spectra from some analytes which are not ionized in solution and would otherwise not be amenable to study. In general terms, the compounds that may be studied are therefore as follows ... 

Kebarle, P Tang, L. From Ions in Solution to Ions in the Gas Phase The Mechanism of Electrospray Ionization Mass Spectrometry, Anal. Chem. 65, 972A-986A (1993). 

There are two definitions for the word novice. The first is that a novice is a person new to or inexperienced in a field. Yes, this book is addressed to novices in mass spectrometry. A novice is also described as a person who has entered a religious order and is under probation before taking vows. Perhaps this is a stretch, but many mass spec-trometrists (particularly the older ones) believe that the field (or art ) of mass spectrometry is not unlike a religious order—once entered, you are in it for keeps. And when is your probation over What do you have to know before you are confirmed When is a novice no longCT a novice Are we all novices forever because there is always something more to comprehend, to learn, and then apply Do even the high priests of the discipline understand the mechanism of electrospray ionization Such meditations are probably way too philosophical. So let s say to the novice mass spectrometrists please just learn what s in this book, and you will be ready to take your vows. 

Konermann, L., Ahadi, E., Rodriguez, AT)., Vahidi, S. (2013) Unraveling the Mechanism of Electrospray Ionization. Anal. Chem. 85 2-9. 

Ahadi, E., Konermann, L. (2012) Modeling the Behavior of Coarse-Grained Polymer Chains in Charged Water Droplets Implications for the Mechanism of Electrospray Ionization. J. Phys. Chem. B 116 104-112. 

Kebarle, P. and Ho, Y. (1997) On the mechanism of electrospray ionization, in Electrospray Ionization Mass Spectrometry... 

Konermann L, Ahadi E, Rodriguez AD, Vahidi S. Unraveling the mechanism of electrospray ionization. Anal Chem. 2013 85 2-9. 

On the Mechanism of Electrospray Ionization Mass Spectrometry (ESIMS)... 

Chapter 1 On the Mechanism of Electrospray Ionization Mass Spectrometry (ESIMS) Table 1.1. Onset Voltages, Von. for Solvents with Different Surface Tension, y... 

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