Electrospray ionization-liquid chromatography

Electroslag remelting, 23 255 Electroslurry process, 23 576 Electrospinning, 11 186 Electrospray ionization, liquid chromatography, 4 625 Electrospray ionization source, 15 654-658 Electrostatic atomization, in spray coating, 7 72-73... 

Josefsson M, Kronstrand R, Andersson J, Roman M. 2003. Evaluation of electrospray ionization liquid chromatography-tandem mass spectrometry for rational determination of a number of neuroleptics and their major metabolites in human body fluids and tissues. J Chromatogr B Analyt Technol Biomed Life Sci 789 151. 

Lau JH, Khoo CS, Murby JE. 2004. Determination of clenbu-terol, salbutamol, and cimaterol in bovine retina by electrospray ionization-liquid chromatography-tandem mass spectrometry. J AOAC Int 87 31. 

Manners GD, Breksa AP III, Schoch TK, Hidalgo MB. Analysis of bitter limonoids in citrus juices by atmospheric pressure chemical ionization and electrospray ionization liquid chromatography-mass spectrometry. J Agric Food Chem 2003 51(13) 3709-3714. 

Basic Protocol 4 Electrospray Ionization Liquid Chromatography/Mass... 

Sanwald P, David M, Dow J (1996) Use of electrospray ionization liquid chromatography-mass spectrometry to study the role of C YP2D6 in the in vitro metabolism of 5-hydroxytryptam-ine receptor antagonist. J Chromatogr B 678 53-61... 

J.V. Headley, K.M. Peru and L.C. Dickson, Ion-exchange electrospray ionization liquid chromatography mass spectrometry and tandem mass spectrometry of alkanolamines in wetland vegetation exposed to sour-gas contaminated ground-water, Rapid Commun. Mass Spectrom., 13, 730-736 (1999). 

Mawhinney, D.B., et al. (2007) Enhancing the response of alkyl methylphosphonic acids in negative electrospray ionization liquid chromatography tandem mass spectrometry by post-column addition of organic solvents. Journal of the American Society for Mass Spectrometry, 18,1821-1826. 

Schoch T.K., Manners G.D., Hasegawa S. Analysis of limonoid glu-cosides from citrus by electrospray ionization liquid chromatography-mass spectrometry. Journal of Agricultural and Food Chemistry, 49 1102 1108 (2001). 

Exciting though the potential of electrospray ionization may seem, the use of electrosprays for liquid chromatography/mass spectrometry has been limited in practice by the severe restrictions on solvent composition and volumetric flow-rate that are amenable... 

For mixture.s the picture is different. Unless the mixture is to be examined by MS/MS methods, usually it will be necessary to separate it into its individual components. This separation is most often done by gas or liquid chromatography. In the latter, small quantities of emerging mixture components dissolved in elution solvent would be laborious to deal with if each component had to be first isolated by evaporation of solvent before its introduction into the mass spectrometer. In such circumstances, the direct introduction, removal of solvent, and ionization provided by electrospray is a boon and puts LC/MS on a level with GC/MS for mixture analysis. Further, GC is normally concerned with volatile, relatively low-molecular-weight compounds and is of little or no use for the many polar, water soluble, high-molecular-mass substances such as the peptides, proteins, carbohydrates, nucleotides, and similar substances found in biological systems. LC/MS with an electrospray interface is frequently used in biochemical research and medical analysis. 

Schematic diagram of an orthogonal Q/TOF instrument. In this example, an ion beam is produced by electrospray ionization. The solution can be an effluent from a liquid chromatography column or simply a solution of an analyte. The sampling cone and the skimmer help to separate analyte ions from solvent, The RF hexapoles cannot separate ions according to m/z values and are instead used to help confine the ions into a narrow beam. The quadrupole can be made to operate in two modes. In one (wide band-pass mode), all of the ion beam passes through. In the other (narrow band-pass mode), only ions selected according to m/z value are allowed through. In narrow band-pass mode, the gas pressure in the middle hexapole is increased so that ions selected in the quadrupole are caused to fragment following collisions with gas molecules. In both modes, the TOF analyzer is used to produce the final mass spectrum.

Smith, R.M., Gas and Liquid Chromatography in Analytical Chemistry, Wiley, Chichester, U.K., 1988. Smith, R.M. and Busch, K.L., Understanding Mass Spectra A Basic Approach, Wiley, Chichester, U.K., 1998. Snyder, A.R, Biochemical and Biotechnological Applications of Electrospray Ionization Mass Spectrometry, Oxford University Press, Oxford, 1998. 

Figure 5.1 Pesticides included in the systematic investigations on APCI-MS signal response dependence on eluent flow rate the parameter IsTow represents the distribution coefficient of the pesticide between n-octanol and water. Reprinted from J. Chromatogr, A, 937, Asperger, A., Efer, 1., Koal, T. and Engewald, W., On the signal response of various pesticides in electrospray and atmospheric pressure chemical ionization depending on the flow rate of eluent applied in liquid chromatography-mass spectrometry , 65-72, Copyright (2001), with permission from Elsevier Science.

Figure 5.62 Product-ion MS-MS spectra of the molecular ions from 8-hydroxy-2 -deoxyguanosine, obtained by (a) positive, and (b) negative ionization. Reprinted by permission of Elsevier Science from Comparison of negative- and positive-ion electrospray tandem mass spectrometry for the liquid chromatography-tandem mass spectrometry analysis of oxidized deoxynucleosides , by Hua, Y., Wainhaus, S. B., Yang, Y., Shen, L., Xiong, Y., Xu, X., Zhang, F. Bolton, J. L. and van Breemen, R. B., Journal of the American Society for Mass Spectrometry, Vol. 12, pp. 80-87, Copyright 2000 by the American Society for Mass Spectrometry.

Wu, X. and Prior, R.L., Identification and characterization of anthocyanins hy high performance liquid chromatography-electrospray ionization-tandem mass spectrometry in common foods in the United States vegetables, nuts, and grains, J. Agric. Food Chem., 53, 3101, 2005. 

Paganga, G. et al.. The polyphenolic content of fruit and vegetables and their antioxidant activities what does a serving constitute Free Radical Res., 30, 153, 1999. Maatta, K.R. et al.. High-performance liquid chromatography (HPLC) analysis of phenolic compounds in berries with diode array and electrospray ionization mass spectrometric (MS) detection Rihes species, J. Agric. Food Chem., 51, 6736, 2003. 

Stintzing, F.C., Schieber, A., and Carle, R., Identification of betalains from yellow beet (Beta vulgaris L.) and cactus pear (Opuntia ficus-indica (L.) Mill.) by high-performance liquid chromatography-electrospray ionization mass spectrometry, J. Agric. Food Chem., 50, 2302, 2002. 

Li, H. et ah. Determination of carotenoids and all-fra 5-retinol in fish eggs by liquid chromatography-electrospray ionization-tandem mass spectrometry, J. Chromatogr. B, 816, 49, 2005. 

Tian, Q. et al., Screening for anthocyanins using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry with precursor-ion analysis, product-ion analysis, common-neutral-loss analysis, and selected reaction monitoring, J. Chromatogr. A, 1091, 72, 2005. 

Black, G.E. and Fox, A., Liquid chromatography with electrospray ionization tandem mass spectrometry profiling carbohydrates in whole bacterial cell hydrolysates, in Biochemical and Biotechnological Applications of Electrospray Ionization Mass Spectrometry, ACS Symposium Series, Snyder, A.P. and Anaheim, C.A., Fids., Washington, D.C., 1995, chap. 4. 

Gosetti, F. et ah. Oxidative degradation of food dye El33 Brilliant Blue FCF. Liquid chromatography-electrospray ionization mass spectrometry identification of the degradation pathway, J. Chromatogr. A, 1054, 379, 2004. 

The method for chloroacetanilide soil metabolites in water determines concentrations of ethanesulfonic acid (ESA) and oxanilic acid (OXA) metabolites of alachlor, acetochlor, and metolachlor in surface water and groundwater samples by direct aqueous injection LC/MS/MS. After injection, compounds are separated by reversed-phase HPLC and introduced into the mass spectrometer with a TurboIonSpray atmospheric pressure ionization (API) interface. Using direct aqueous injection without prior SPE and/or concentration minimizes losses and greatly simplifies the analytical procedure. Standard addition experiments can be used to check for matrix effects. With multiple-reaction monitoring in the negative electrospray ionization mode, LC/MS/MS provides superior specificity and sensitivity compared with conventional liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/ultraviolet detection (LC/UV), and the need for a confirmatory method is eliminated. In summary,... 

LC/MS/MS. LC/MS/MS is used for separation and quantitation of the metabolites. Using multiple reaction monitoring (MRM) in the negative ion electrospray ionization (ESI) mode, LC/MS/MS gives superior specificity and sensitivity to conventional liquid chromatography/mass spectrometry (LC/MS) techniques. The improved specificity eliminates interferences typically found in LC/MS or liquid chro-matography/ultraviolet (LC/UV) analyses. Data acquisition is accomplished with a data system that provides complete instmment control of the mass spectrometer. 

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