Electrospray ionization mass spectrometry negative ions

L. Konermann and D. J. Douglas. Unfolding of Proteins Monitored by Electrospray Ionization Mass Spectrometry A Comparison of Positive and Negative Ion Modes. J. Am. Soc. Mass Spectrom., 9(1998) 1248-1254. 

Also, a brief note has appeared concerning electrospray ionization mass spectrometry of mixtures of -carotene with ft- and with y-cyclodexlrin in aqueous methanol solutions. Whereas negative ion ESI produced 1 1 adduct ions of -carotene with both of the cyclodextrin isomers, positive ESI gave these adducts only in the case of ft-cyclodextrin302. 

Ding J., Burkhart W., and Kassel D.B. (1994), Identification of phosphorylated peptides from complex mixtures using negative-ion orifice-potential stepping and capillary liquid chromatography/electrospray ionization mass spectrometry, Rapid Commun. Mass Spectrom. 8 94—98. 

Electrospray ionization mass spectrometry (ESI-MS) negative ions, 693... 

Figure A.3A.3 LC/MS analysis of a dietary supplement consisting of extract of Trifolium pratense (red clover). Reversed-phase C18 HPLC and negative ion electrospray ionization mass spectrometry were used with a quadrupole mass spectrometer analyzer (Agilent also see Table A.3A.1). The map illustrates the abundance of information provided by this hyphenated technique with HPLC mass chromatograms in one dimension and mass spectra in another dimension.

AJP Hofte, RAM van der Hoeven. Characterization of hop acids by liquid chromatography with negative ion electrospray ionization mass spectrometry. J Am Soc Brew Chem 56 118-122, 1998. 

Using electrospray ionization mass spectrometry in both positive and negative ion modes, the on-line scanning of the Morita-Baylis-Hillman reaction in the presence of imidazolium ionic liquids has been investigated. The interception of several supramolecular species indicated that ionic liquids co-catalyse the reactions by activating the aldehyde toward nucleophilic enolate attack and by stabilizing the zwitterionic species that act as the main intermediates.175... 

Carbon dioxide protected pyrroles and indole (carbamates), generated by treatment of the iV-lithiated heterocycles with gaseous CO2, can be easily tracked by negative ion electrospray ionization mass spectrometry (ESI-MS) revealing invariable loss of CO2 from the anion <2002JMP541>. 

The cyanocuprates of thiophene have been discussed earlier <1996CHEC-II(2)491>. An attempt has been made to use negative ion electrospray ionization mass spectrometry for obtaining information on the solution composition of organocuprates such as 225 and 226 in THF <19990M1571>. 

Ghassempour, A. et al. Monitoring of N-nitrosodiethanolamine in cosmetic products by ion-pair complex liquid chromatography and identification with negative ion electrospray ionization mass spectrometry. J. Chromatogr. A. 2008, 1185,43-48. 

Analysis of acetochlor metabolites (ESA and OXA) in groundwater was carried out by reverse-phase liquid chromatography and detection by electrospray ionization/mass spectrometry (ESl/MS) in single ion monitoring and negative modes. 

Kidwell, H., Jones, J. J., and Games, D. E., Separation and characterization of five polar herbicides using countercurrent chromatography withy detection by negative ion electrospray ionization mass spectrometry. Rapid Commun. Mass Spectrom., 15, 1181-1186, 2001. 

Lytle, C.A., Can, Y.D. and White, D.C. (2000) Electrospray ionization/mass spectrometry compatible reversed-phase separation of phospholipids piperidine as a post-column modifier for negative ion detection, youma/ of Microbiological Methods 41,22 7-234. 

W. Chai, V. Piskarev, and A. M. Lawson, Branching pattern and sequence analysis of underivatized oligosaccharides by combined MS/MS of singly and doubly charged molecular ions in negative-ion electrospray ionization mass spectrometry, J. Am. Soc. 

Hgure 5 Negative ion electrospray ionization mass spectrum of calmodulin (SOiimoll ) in the presence of melittin (SOnmoll ) and lOOiimoll calcium acetate, pH 5.7. Ions in the range between m/z 900 and 1600 represent uncomplexed calmodulin and ions in the range between m/z 1700 and 3000 represent the noncovalent calmodulin/melittin complex. (Reprinted by permission of Elsevier from Low temperature aqueous electrospray ionization mass spectrometry of noncovalent complexes by Veenstra TD, Tomlinson AJ, Benson L, Kumar R, and Naylor S, Journal of the American Society of Mass Spectrometry 9 580-584, 1998, by the American Society for Mass Spectrometry.)... 

Figure 9.12 Direct electrospray ionization-mass spectrometry analysis of human erythrocyte plasma membrane phospholipids (A) A positive-ion electrospray ionization (ESI) mass spectrum of erythrocyte plasma membrane phospholipid extract showing 14 molecular species of glycerophospholipids and 4 molecular species of sphingomyelin (B) A negative-ion ESI mass spectrum of the same extract of plasma membrane phospholipids showing more than 25 molecular species of ethanolamine glycerophospholipids and 8 molecular species of serine and inositol glycerophospholipids. Reprinted with permission from Han, X. and Gross, R. W., Electrospray ionization mass spectroscopic analysis of human erythrocyte plasma membrane phospholipids, Proc. Natl Acad. Scl USA, 91(22), 10635-9. Copyright (1994) National Academy of Sciences, USA.

Mathis, J.A., McCord, B.R. (2005) The analysis of high explosives by liquid chromatography/electrospray ionization mass spectrometry multiplexed detection of negative ion adducts. Commmunications in Mass Spectrometry,19,99-104. 

Several methods have been developed specifically for naphthenic acids, a class which includes the surface active carboxylate surfactants. Naphthenic acids are present as a complex mixture of a number of homologues with only a small range in molar mass (166-450 mol/g), little change in solubility character, and have been difficult to assay using conventional analytical methods. Methods such as negative ion-mode mass spectrometry using fast atom bombardment (FABMS), have been successfully applied to the analysis of naphthenic acid mixtures [93, 94], Other promising techniques include fluoride ion chemical ionization mass spectrometry (FI-MS) [95], and electrospray ionization mass spectrometry (ESIMS), which may allow for the quantification of the various naphthenic acid fractions [96]. 

ESIMS Electrospray ionization mass spectrometry FABMS Fast atom bombardment (negative ion-mode) mass spectrometry... 

Harvey, G. J. and Dunphy, J. C. Characterisation of cationic, anionic, and nonionic surfactants by positive and negative ion electrospray ionization mass spectrometry. Proceedings of the 40th ASMS Conference on Mass Spectrometry and Allied Topics, Washington, DC, May 31-June 5, 1992. 

Zhu, J. Cole, R.B. Formation and Decompositions of Chloride Adduct Ions, [M-hC1], in Negative Ion Electrospray Ionization Mass Spectrometry. J. Am. Soc. Mass Spectrom. 2000,11. 932-941. 

Cole, R. B. Zhu, J. H. Chloride ion attachement in negative ion electrospray ionization mass spectrometry. Rapid Commun. Mass Spectrom. 1999,75(7), 607-611. Appfel, a. Chakel, J. A. Fischer, S. Lichtenwalter, K. Hancock, W. S. Analysis of oligonucleotides by HPLC-electrospray ionization mass spectrometry. Ana/. Chem. 1997, 69(7), 1320 1325. 

Fig. 3. Electrospray ionization mass spectrometry of the product generated by recombinant GalNAcT. Spectra were acquired in the negative mode. The molecular weight of globotetraose is 706.8. The ion peak at tn/z 705.83 is attributed to the molecular ion [M-H] of globotetraose.

Wu, Z., Gao, W., Phelps, M.A., et al. (2004) Favorable effects of weak acids on negative-ion electrospray ionization mass spectrometry. Analytical Chemistry, 76,839-847. 

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