Electrospray ionization weight distribution

Electrospray ionization is classihed as a soft ionization technique. It produces molecular-weight information and very little, if any, fragmentation of the analyte ion, unless induced in the vacuum region of the mass analyzer. The number of charges accumulated by an analyte ion is proportional to its number of basic or acidic sites. The spray polarity and conditions, solution pH and nature, as well as solute concentration will all effect the charge state distribution observed in the mass spectrum. Multiple charging of an analyte ion en-... 

Nohmi, T. and Penn, J. B. Electrospray mass spectrometry of poly(ethylene glycols) with molecular weights up to five million. /. Am. Chem. Soc., 114,3241,1992. Latomie, L., Blais, J.-C., Tabet, J.-C., and Cole, R.B. Desorption behavior and distribution of fluorinated p>ol3miers in MALDl and electrospray ionization mass sp>ectrometry Anal Chem., 69, 2742,1997. 

Field desorption (FD) and fast atom bombardment (FAB) mass spectrometry provides mass spectral information about compotmds that are not very volatile but these two techniques are not used often in polymer science since they have several disadvantages. Electrospray ionization (ESI) mass spectrometry can also be used to obtain the above information about polymers, but ESI spectra are generally complicated due to differences in charge state distributions. Static secondary ion mass spectrometry (static SIMS) is a surface-sensitive MS technique, which is suitable for studying the interfaces of polymers with respect to chemical structure and molecular weight as well as end groups and surface contaminants. Laser desorption... 

Gruendling, T, Guilhaus, M., Barner-Kowollik, C. (2009) Fast and accurate determination of absolute individual molecular weight distributions from mixtures of polymers via size exclusion chromatography-electrospray ionization mass spectrometry. MacromoL Rapid Commun., 30, 589-597. 

Roussis SG, ProulxR. Probing the molecular weight distributions of non-boiling petroleum fractions by Ag+ electrospray ionization mass spectrometry. Rapid Commun Mass Spectrom. 2004 18 1761 75. 

Mass spectrometer equipped with desorption electrospray (DESI) ion source is capable of detection and identification of different substances from the surface. Moreover, the information about spatial distribution of those substances is retained. Connection of this technique with TLC not only allows for the measurement of retention times for separated chemicals (spatial distribution), but also for their unambiguous identification, based on the molecular weight of certain substances and their fragmentation spectra. Additionally, because DESI works under ambient conditions, there is no need to apply a high vacuum system for the sample introduction. Moreover, samples analyzed by DESI practically do not require any kind of preparation (e.g., covering with matrix prior to MALDI analysis), thus connection of those two techniques is relatively easy. Certainly, not all the substances, due to their chemical features, may be detected with this technique. Only compounds, which are able to ionize in this type of ion source, may be analyzed. 

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