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"Get the Most out of Your Mass Spectrometer: Significant Performance Improvements with Novel CE-MS Interfaces" Workshop
| Date: |
Sunday, March 21st, 2010 |
| Time: |
2:00 - 4:30 p.m. |
| Location: |
Clarion Congress Hotel Prague, Zenit Hall |
| Co-Chairs: |
Andre Deelder, Leiden University Medical Centre, Leiden, The Netherlands |
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Jerry Feitelson, Beckman Coulter, Inc., Brea, CA, USA |
Capillary electrophoresis (CE) is recognized as being a versatile, fast and highly efficient separation technique. Recent advances in CE-MS coupling have preserved the advantages of CE: ultra high separation efficiency, small sample sizes, speed, quantitation and automation. As a result, CE now emerges as a key technology for sample introduction into MS. Many scientists are ready to move beyond the existing capabilities of LC-MS for specific applications, and CE-ESI-MS is positioned to provide these new capabilities.
This workshop will highlight several successful applications of CE-MS, proving that the capabilities of mass spectrometry can be significantly enhanced by the use of novel CE interfaces and applications.
The following four seminars will be presented in the Workshop:
"Robust and Automated CE-MS is within Reach for Novice Users"
David D. Y. Chen1, E. Jane Maxwell1, Xuefei Zhong1, John Hudson2, Chitra Ratnayake2, and Hong Zhang1
1Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1 Canada
2Beckman Coulter, Inc., Discovery Solutions Business Center, Brea, CA, USA
The challenge of efficiently processing the often varied volumetric flow rate of CE effluent can be met by using a beveled electrosprayer tip, and the problem of often incompatible requirement of electrolyte composition for the optimum operations of CE and electrospray ionization can be alleviated by introducing a chemical modifier using the junction-at-the-tip configuration. A simple and robust stainless steel hollow needle electrode with a tapered inner cavity and a beveled outer tip is used to interface CE with MS, resulting in a stable yet highly sensitive electrospray ion source that is easily automated in CE-MS operations. The interface and its applications for different types of analyte, including small molecule pharmaceuticals and biomolecules, will be discussed.
"CE-HSPS-MS: Toward the Miniaturization of Proteomics"
Jean-Marc Busnel1, Jerald S. Feitelson1, Andre M. Deelder2, Oleg A. Mayboroda2
1Beckman Coulter, Inc., Discovery Solutions Business Center, Brea, CA, USA
2Leiden University Medical Centre, Biomolecular Mass Spectrometry Unit, The Netherlands
The success of liquid chromatography-mass spectrometry (LC-MS) in biological analysis and in proteomics, in particular, is not only due to its relatively high resolution and reproducibility but also to the relative simplicity for coupling it either to a fraction collector or to a mass spectrometer. As compared to LC, capillary electrophoresis (CE) has different characteristics, such as ultralow flow rates, a background electrolyte (BGE) that can be highly conductive, and most importantly, the need to maintain an electric field across the capillary during the separation. Because of these features, the popular adoption of CE-MS has taken much longer than LC-MS. Indeed, while the first reports describing interfacing of both techniques were published in the late 80's, research on these topics is still very active today.
Both liquid sheath and sheathless approaches have been demonstrated to couple CE via electrospray ionization to mass spectrometers. The sheath liquid interface has been the most popular so far despite its significantly lower sensitivity and resolution. Here we describe experiments to analyze peptide samples of increasing complexity (cytochrome C tryptic digest, E. coli total protein tryptic digest, and synthetic peptide libraries) using a prototype High Sensitivity Porous Sprayer (HSPS). To increase the mass loading of CE-HSPS-MS, the compatibility of the interface with online preconcentration methodologies has also been tested. Benchmarking studies compared the analysis of E. coli tryptic digests using the CE-HSPS-MS platform to conventional bioanalytical platforms, such as CE-MS with a sheath liquid interface and nanoLC-MS.
As compared to conventional approaches, the CE-HSPS-MS platform represents a real breakthrough in terms of bioanalytical performance. Indeed, while the CE advantages of high efficiency and rapid separations are retained, the platform also makes possible the use of the nanoflow regime of the HSPS-ESI process to provide exquisite sensitivity.
"CE-MS of Intact Proteins"
Rob Haselberg, Gerhardus J. de Jong, Govert W. Somsen
Utrecht University, Department of Biomedical Analysis, Utrecht, The Netherlands
In the biopharmaceutical field there is a growing demand for separation-detection methodologies that permit quality assessment of proteins in their native state. Capillary electrophoresis (CE) is an attractive separation technique for purity and stability analysis of proteins. Combination of CE with electrospray-ionization time-of-flight mass spectrometry (ESI-ToF MS) would provide a powerful tool for protein characterization. This presentation outlines the design and application of robust CE-MS methodologies for intact proteins. Reproducible CE performance for proteins was achieved by using capillaries coated with layers of charged polymers, which effectively reduce protein adsorption. The coatings are easy to produce and fully compatible with ESI-MS detection. Stable CE-MS profiles of basic protein mixtures could be obtained with migration-time RSDs below 1%. Use of a high sensitivity porous sprayer (HSPS) for sheathless CE-MS interfacing presented significant improvements in protein signal-to-noise ratios, yielding detection limits in the sub-nM range. Analyses of degraded biopharmaceuticals and drug-protein conjugates further demonstrated that efficient CE separation in combination with high-mass-accuracy ToF MS allows distinction and identification of highly related protein products.
"Exploring the Metabolome by CE-MS: From Study Design to Data Interpretation"
Oleg A. Mayboroda and Andre M. Deelder
Leiden University Medical Centre, Biomolecular Mass Spectrometry Unit, The Netherlands
The potential of Capillary Electrophoresis - Mass Spectrometry (CE-MS) as a method for analysis of complex biological matrices was immediately recognized after the introduction of modern ESI sources. However until recently, CE-MS has been mentioned in the literature as an analytical method that has yet to prove its utility as a routine tool for metabolomics studies. The goal of our presentation is to demonstrate that CE-MS is indeed a mature technology that had already passed “a proof of principle period.” Moreover, we demonstrate that CE-MS is an essential part of “the metabolomics toolbox” as it helps us to characterize portions of the metabolome typically difficult for other methods, such as LC-MS, GC-MS and NMR.
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