Open access mass spectrometry

H. Tong, D. Bell, K. Tabei, M. M. Siegel Automated data massaging, interpretation, and e-mailing modules for high throughput open access mass spectrometry J. Am. Soc. Mass Spearom. 1999, 10, 1174-1187. 

C. D. Wagner, J. T. Hall, K. A. Hoffman, W. L. White, and J. D. Williams, Open-access mass spectrometry utilizing advanced protein search processing integrated with a multi-site protein analysis LIMS, in 52nd ASMS Conference on Mass Spectrometry and Allied Topics, Nashville, TN (Book of Abstracts), 2004. 

J. Greaves, Operation of an academic open access mass spectrometry facility with particular reference to the analysis of synthetic compounds, J. Mass Spectrom. 37 (2002), 777-785. 

Tong, H. Bell, D. Tabei, K. Siegel, M.M. Automated Data Massaging, Interpretation, and E-Mailing Modules for High Throughput Open Access Mass Spectrometry, J. Am. Soc. Mass Spectrom. 10, 1174-1187 (1999). 

Greaves, J. Operation of an Academic Open-access Mass Spectrometry Facility with Particular Reference to the Analysis of Synthetic Compounds, J. Mass Spectrom. 37,777-785 (2002). 

Automation has also allowed the use of open access mass spectrometry for chemical analysis. Initially developed for single analysis of chemical samples with no prior separation, the system simply requires sample details to be logged onto a computer. A choice of positive and/or negative ion APCI (or electrospray depending on the source available) is allowed. More recently LC/MS is available with perhaps a choice of two separation systems. The user is then directed to place the sample in a particular location in an autosampler tray. 

It is argued in this paper that routine, rapid generation of data in an open-access mass spectrometry laboratory can make the data acquired timely and thus increase its relevance. To achieve this goal, it was important to simplify both experimental protocols and instrument operation. 

On moving to the United States he spent 5 years at Mount Sinai School of Medicine and 7 years at the Virginia Institute of Marine Science, where he was involved with cancer and environmental research, respectively. He moved to the University of California, Irvine in 1992 where he has been particularly interested in the use of open access mass spectrometry to enable scientists lacking experience in the technique to facilitate their research by obtaining mass spectrometric data rapidly on a 24/7 basis. He has over 80 pubUcations. 

Thomas, S.R. and Gerhard, U. (2004) Open-access high-resolution mass spectrometry in early drug discovery. Journal of Mass Spectrometry, 39, 942-948. 

Development of the method involved the installation of a system in an existing mass spectrometry laboratory and working with chemists for 3 months to determine specific needs and to develop a consistent, reliable procedure. The instrument was moved to an open-access laboratory and chemists were trained in its use. A key to making this approach a success is the fact that instrument downtime was kept to a minimum. Understandably, maintenance is done at off-peak times, and support mechanisms are put in place so problems are immediately addressed. Training and education was highlighted as a key factor for the successful implementation of this LC/MS system to optimize performance and to reduce the possibility of instrument contamination. 

Cole et al., 1998) are likely to become more widespread. Instrument formats that feature high resolution chromatography and/or mass spectrometry may provide the required structural detail in some instances. Similar to small molecule analysis, the widespread use of open-access LC/MS systems for protein synthesis activities (Burdick and Stults, 1997) appears to be imminent. 

Taylor, L. C. E. Johnson, R. L. Raso, R. 1995. Open access atmospheric pressure chemical ionization mass spectrometry for routine sample analysis. /. Am. Soc. Mass Spectrom., 6,387-393. 

As FIA-MS and liquid chromatography mass spectrometry (LC-MS) become more pervasive in the analysis of compound libraries, open-access instrumentation is increasingly used in HTOS laboratories as well as in support of general medicinal chemistry. These open-access systems are most often used for reaction monitoring and optimization, and in some cases, for library quality control and synthesis product purification. 

Taylor, L.C.E. Johnson, R.L. Raso, L. Open-access Atmospheric Pressure Chemical Ionization Mass Spectrometry for Routine Sample Analysis, J. Am. Soc. Mass Spectrom. 6, 387-393 (1995). 

Mallis, L.M. Sarkahian, A.B. Kulishoff Jr, J.M. Watts Jr., W.L. Open-access Liquid Chromatography/Mass Spectrometry in aDrug Discovery Environment, J. Mass Spectrom. 37, 889-896 (2002). 

Bean, M.F. Jin, Q.K. Smeltz, D.L. Quinn, C.J. Hemling, M.E. "Open-Access MUX LCMS and Enterprise-Level Analysis Queue Management, in Proceedings of the 50th ASMS Conference on Mass Spectrometry and Allied Topics, Orlando, Florida, June 2-6, 2002. 

Online mass spectrometry data presented and discussed in the previous sections suggest that catalytic hypophosphite oxidation on nickel in D2O solutions proceeds via the coupling of anodic (19.11) and cathodic (19.12) half-reactions at the catalyst surface. The classical mixed-potential theory for simultaneously occurring electrochemical partial reactions [14] presupposes the catalyst surface to be equally accessible for both anodic (19.11) and cathodic (19.12) half-reactions. Equilibrium mixtures of H2, HD, and D2 should be formed in this case due to the statistical recombination of Hahalf-reactions (19.11) and (19.12) for example, the catalytic oxidation of hypophosphite on nickel in D20 solution under open-circuit conditions should result in the formation of gas containing equal amounts of hydrogen and deuterium (H/D=l) with the distribution H2 HD D2= 1 2 1 (the probability of HD molecule formation is twice as high as for either H2 or D2 formation [75]). Therefore, to get further mechanistic insight, the distribution of H2, HD, and D2 species in the evolved gas was compared to the equilibrium values at the respective deuterium content [54]. 

Technique Open-access instrumentation, electrospray ionization-mass spectrometry (ESl-MS), gas chromatography-mass spectrometry (GC-MS), matrix-assisted laser desorption/ionization (MALDl). 

Mass spectrometers were often the last portion of an analytical sequence that included thin-layer chromatography (TLC), infrared (IR), UV, and nuclear magnetic resonance (NMR). In synthetic chanistry MS was frequently used only to obtain accurate mass values because journals required such data. Open access allows mass spectrometry to be moved to the front of the analytical chain with rapid determination of the molecular masses of analytes. 

While the simplest approach may not always be the ideal one, open access makes the case for pleasing most of the people most of the time. The mass spectrometry facility described has 200-300 users who analyze over 20,000 samples annually. For most of these scientists, this is their first personal access to MS. Once the I need a molecular mass now population has been accommodated, more sophisticated questions can be undertaken in conjunction with the staff of the facility. Other open-access analyses may include (1) quantification, for which there are LC-QqQ-MS systems with appropriate open-access software (one has been added to the facility since the paper was written) and GC-MS systems (2) identification of unknowns using LC-TOF-MS and GC-MS and (3) the possibility of analyzing air-sensitive samples. 

A further advantage of open-access facilities is that students and researchers learn about the remarkable diversity and utility of mass spectrometry, knowledge they can carry forward as their careers progress. 

The method of choice for elucidating chemical stmctures is NMR spectroscopy, supplemented by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). In addition, a multitude of chromatographic and light-scattering methods provide access to the molecular weights and solution properties of these macromolecules. Based on these methods, a detailed understanding of the structure of hb polymers has been acquired since their discovery however, there remain a number of open questions that must be answered, mainly by method adaptation and development. 

Enclosed microchannels are by definition not accessible to laser desorption/ionization, which requires an open surface from which analytes can be sampled into the spectrometer. Several strategies have been adopted to circumvent this challenge, including the elution of bands of analytes from microfluidic devices onto an open substrate, where they are dried and analyzed. Alternatively, Musyimi et al. [11] employed a rotating ball to transfer analytes from polymer microchannels to a MALDl-MS system without compromising the vacuum required for mass spectrometry. 

The combination of molecular depth profiting and molecular imaging opens up the opportunity for 3D imaging. The possibility of carrying out 3D molecular analysis on biological systems, for example, is really exciting because in principle, mass spectrometry does not require active markers (as is the case for other optical techniques) and spatially resolved chemistry may be accessible without altering the system. 

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