Electrosonic spray ionization

Wiseman, J. M., Takats, Z., Gologan, B., Davisson, V. J., and Cooks, R. G. (2005). Direct characterization of enzyme-substrate complexes by using electrosonic spray ionization mass spectrometry. Angew Chem. Int. Ed. Engl. 44 913-916. 

Takats, Z., Wiseman, J.M., Gologan, B., Cooks, R.G. (2004) Electrosonic Spray Ionization. A Gentle Technique for Generating Folded Proteins and Protein Complexes in the Gas Phase and for Studying Ion-Molecule Reactions at Atmospheric Pressure. Anal. Chem. 76 4050-4058. 

Touboul, D., Jecklin, M.C., Zenobi, R. (2007) Rapid and Precise Measurements of Gas-phase Basicity of Peptides and Proteins at Atmospheric Pressure by Electrosonic Spray Ionization-Mass Spectrometry. J. Phys. Chem. B 111 11629-11631. 

Cl, chemical Ionization EESI, electrosonic spray Ionization El, electron ionization ICR, ion cyclotron resonance OIT, orbital Ion trap QqQ, triple quadrupole S, seaor SALDI, surface-assisted laser desorptlon/lonizatlon V-EASI, Venturi easy ambient sonic-spray ionization, n.d.. No data. 

Ionization techniques derived from ESI, such as electrosonic spray ionization (ESSI), are also suitable for studies of fragile molecules. The ESSI-MS approach enables observation of non-covalent complexes of myoglobin, protein kinase A/ATP complex, and other proteins [47]. It can be used to study on-line deprotonation reactions on peptides and proteins [48,49]. Such analyses can be done by introducing volatile bases between the ion source and mass analyzer. This method is fast one reference base can be scanned in a time interval of 1 min. The desorption electrospray ionization (DESI) technique was also implemented in the study of protein conformation in solution [50]. The interaction time between the spray solvent and the protein was estimated to be 1 ms, and it was suggested that this timescale would be too short for the studied proteins to unfold [50]. 

Nefliu, M., Venter, A., Cooks, R.G. (2006) Desorption electrospray ionization and electrosonic spray ionization for sohd- and solution-phase analysis of industrial polymers. Chem. Common., 8,888-890. 

An early example of an ion/molecule reaction carried out in an atmospheric-pressure capillary inlet reactor based on an ESI interface to a quadrupole mass spectrometer involved the study of proton transfer between amines and multiply protonated proteins by Smith (333, 334]. Smith also observed protonated adenosine 5 -monophosphate (AMP) as the product of charge inversion in the reaction of [AMP-H] with multiplyatmospheric pressure 335j. In addition, the formation of TNT Meisenheimer complex (336) and the interaction between piperidine and multiply-charged lysozyme ions generated by electrosonic spray ionization (ESSI) [337] under atmospheric pressure has been reported. Eberlin reactions (i.e., the gas-phase transacetalization reaction) of acylium ions have also been observed to occur at atmospheric pressure under in-source ion/molecule reaction conditions [338]. 

Takats, Z. Wiseman, J.M. Gologan,B. Cooks, R.G. Electrosonic spray ionization. A gentle technique for generating folded [aoteins and [S otein complexes in the gas phase and for studying ion molecule reactions at atmospheric pressure. Anal Chem. 2004, 76, 4050-4058. 

Several modifications of the ESI principle were described, such as the desorption electrospray ionization (DESI), the desorption atmospheric pressure photoionization (DAPPI), the electrospray-assisted pyrolysis ionization (ESPI), the ambient sonic spray ionization (SPI), " the electrosonic spray ionization (ESSI), but also combined MALDI/ESI techniques, such as the matrix-assisted laser desorption electrospray ionization (MALDESI). ... 

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