Capillary electrophoresis mass spectrometry coupling

As in HPLC, the coupling of MS detection with CE has provided an excellent opportunity for more selective analysis, but the much reduced flow rates, small injection volumes, limitations in the types of buffers used [since electrospray ionization (ESI) is used in capillary electrophoresis/mass spectrometry (CE/MS)], and need to... 

Liu, C. C., Jong, R., and Covey, T. (2003). Coupling of a large-size capillary column with an electrospray mass spectrometer. A reliable and sensitive sheath flow capillary electrophoresis-mass spectrometry interface.. Chromatogr. A 1013, 9-18. 

Because of the small amounts of sample that are usually obtained, coupled GC-MS is the method of choice for analysis of volatile pheromones. The analysis of the less-volatile lipids and polar pheromone components may require derivatization and microchemical tests, both to improve chromatographic characteristics and to provide information about the structures. It is likely that chromatographic techniques with high separation power and high sensitivity for polar compounds, such as coupled capillary electrophoresis-mass spectrometry, will prove useful for analysis of spider extracts in future studies. 

Capillary electrophoresis mass spectrometry (CE-MS) Direct coupling of capillary electrophoresis (CE) and MS, where the mass spectrometer serves as the detector. Biomolecules are separated through the narrow capillary of the CE system and then interface with the MS for subsequent analysis. 

Capillary Electrophoresis-Mass Spectrometry The first report on coupling capillary electrophoresis with mass spectrometry was published in 1987,-" Since then, it has become obvious that this hyphenated method will become a powerful and important tool in the analysis of large biopolyniers. such as proteins, polypeptides, and DNA species. In most of the applications reported to date, the capillary effluent is passed... 

Figure 6.6 Schematic drawing of commonly used CE-ESi-MS interfacing sheath-flow and sheathless coupling [5], Reproduced from Mischak, H., Coon, j.j., Novak, ]., Weissinger, E.M., Schanstra, ].R, Dominiczak, A.E (2009) Capillary Electrophoresis-Mass Spectrometry as a Powerful Tool in Biomarker Discovery and Clinical Diagnosis an Update of Recent Developments. Mass Spectrom. Rev. 28 703-724 with permission from John Wiley and Sons...

B. Santos, B.M. Simonet, B. Lendl, A. Rios, M. Valcarcel, Alternatives for coupling sequential injection systems to commercial capillary electrophoresis-mass spectrometry equipment, J. Chromatogr. A 1127 (2006) 278-285. 

Hutton, T. and Major, H.J., Characterizing biomolecnles by electrospray ionization-mass spectrometry coupled to liqnid chromatography and capillary electrophoresis, Biochem. Soc. Trans., 23, 924, 1995. 

Characterization of Organic Natural Dyes by Electrospray Mass Spectrometry Coupled with HPLC and/or Capillary Electrophoresis... 

M. Puchalska, M. Orlinska, M.A. Ackacha, K. Polec Pawlak and M. Jarosz, Identification of anthraquinone coloring matters in natural red dyes by electrospray mass spectrometry coupled to capillary electrophoresis, J. Mass Spectrom., 38, 1252 1258 (2003). 

For capillary zone electrophoresis (CZE) mass spectrometry coupling, another modification of an ESI interface has been developed. This interface uses a sheath flow of liquid to make the electrical contact at the CZE terminus, thus defining both the CZE and electrospray field gradients. This way, the composition of the electro sprayed liquid can be controlled independently of the CZE buffer, thereby providing operation with buffers that could not be used previously, e.g., aqueous and high ionic strength buffers. In addition, the interface operation becomes independent of the CZE flow rate. [62]... 

Sutton, K. L., and Caruso, J. A. (1999). Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry. LC-GC 17, 36—44. 

Eanali, S., Desiderio, C., Schulte, G., Heitmeier, S., Strickmann, D., Chankvetadze, B., and Blaschke, G. (1998). Chiral capillary electrophoresis-electrospray mass spectrometry coupling using vancomycin as chiral selector. /. Chromatogr. A 800, 69—76. 

G Schulte, S Heitmeier, B Chankvetadze, G Blaschke. Chiral capillary electrophoresis-electrospray mass spectrometry coupling with charged cyclodextrin derivatives as chiral selectors. J Chromatogr A 800 77-82, 1998. 

Lu, Q.H., Bird, S.M. and Barnes, R.M. (1995) Interface for capillary electrophoresis and inductively coupled plasma-mass spectrometry. Anal. Chem., 67, 2949-2956. 

Michalke, B. and Schramel, P. (1996) Hyphenation of capillary electrophoresis to inductively coupled mass spectrometry as an element-specific detection method for metal speciation. J. Chromatogr. A, 750, 51-62. 

In order to analyse a complex mixture, for example natural products, a separation technique - gas chromatography (GC), liquid chromatography (LC) or capillary electrophoresis (CE) - is coupled with the mass spectrometer. The separated products must be introduced one after the other into the spectrometer, either in the gaseous state for GC/MS or in solution for LC/MS and CE/MS. This can occur in two ways the eluting compound is collected and analysed off-line or the chromatograph is connected directly to the mass spectrometer and the mass spectra are acquired while the compounds of the mixture are eluted. The latter method operates on-line. Reviews on the coupling of separation techniques with mass spectrometry have been published in the last few years [1-4]. 

As a rule, a separation method should be used for both purification and concentration of the sample. The classic method for peptides and proteins is a reverse-phase liquid chromatography preparation of the sample, followed by a concentration step (often lyophiliza-tion) of the fraction of interest. During those steps performed on very small quantities of sample, loss on the sample can occur if care is not taken to avoid it. Lyophilization, for instance, can lead to the loss of the sample absorbed on the walls of the vial. The use of separation methods on-line with the mass spectrometer often are preferred. Micro- or nano-HPLC [32,33] and capillary electrophoresis [34], both coupled mainly to electrospray ionization/mass spectrometry (ESI-MS), are used more and more. 

Simo, C., Moreno-Arribas, M.V. Cifuentes, A. (2008). Ion-trap vs. Time-of-flight mass spectrometry coupled to capillary electrophoresis to analyze biogenic amines in wine. J. Chromatogr. A, 1195, 150-156. 

Michalke, B., Schramel, P. Selenium speciation by interfacing capillary electrophoresis with inductively coupled plasma-mass spectrometry. Electrophoresis 19, 270-275 (1998)... 

Detection techniques of high sensitivity, selectivity, and ease of coupling with sample preparation procedures are of special interest for measuring PGM content in biological and environmental samples. ICP MS, electrothermal atomic absorption spectrometry (ET AAS), adsorptive voltammetry (AV), and neutron activation analysis (NAA) have fotmd the widest applications, both for direct determination of the total metal content in the examined samples and for coupling with instrumental separation techniques. Mass spectrometry coupled with techniques such as electrospray ionization (ESI) and capillary electrophoresis (CE) (e.g., ESI MS", LC ESI MS", LC ICP MS, CE MS", and CE ICP MS) offer powerful potential for speciation analysis of metals. MS is widely used for examination of the distribution of the metals in various materials (elemental analysis) and for elucidation of the... 

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