Biomedical samples, mass spectrometry

Mass Spectrometer. The mass spectrometer is the principal analytical tool of direct process control for the estimation of tritium. Gas samples are taken from several process points and analy2ed rapidly and continually to ensure proper operation of the system. Mass spectrometry is particularly useful in the detection of diatomic hydrogen species such as HD, HT, and DT. Mass spectrometric detection of helium-3 formed by radioactive decay of tritium is still another way to detect low levels of tritium (65). Accelerator mass spectroscopy (ams) has also been used for the detection of tritium and carbon-14 at extremely low levels. The principal appHcation of ams as of this writing has been in archeology and the geosciences, but this technique is expected to faciUtate the use of tritium in biomedical research, various clinical appHcations, and in environmental investigations (66). 

K.L.Johnson, T.D. Veenstra,J.M. Londowski, A.J.Tomlinson, R. Kumar, S. Naylor, On-line sample clean-up and chromatography coupled with electrospray ionization mass spectrometry to characterize the primary sequence and disulfide bond content of recombinant calcium binding proteins, Biomedical Chromatography 13 (1999)37-45. 

Very few, if any, recent biomedical publications describe the use of ion-impact mass spectrometry without the use of GC or some other separation method because most biological samples are chemically complex. The production of clean and useful El mass spectrometric signals requires the substance of interest to be very pure, and thus direct El experiments are usually confined to preliminary studies of highly purified biomolecules or to studies on the metabolism of pure materials. Two publications that describe direct El methods applicable to biochemical analysis and neuropharmaceutical studies are those of Costa et al. (1992) and Karminski-Zamola et al. (1995). 

GAS CHROMATOGRAPHY/MASS SPECTROMETRY ANALYSIS PROCEDURES FOR BIOMEDICAL SAMPLES... 

Improvements in column technology, detector sensitivity and the development of new detection systems, have made possible the routine separation of picomole quantities of nucleic acid components in complex physiological matrices. The very sensitivity of most LC systems, however, which is invaluable in the analysis of biological samples, is often the limiting factor because of inadequate or ambiguous identification methods. Although tremendous advances have been made in the on-line combination of HPLC with spectroscopic techniques [e.g., mass spectrometry, Fourier transform infrared (FT/IR), nuclear magnetic resonance], their application has not become routine in most biochemical and biomedical laboratories. 

Vissers, I.P., Hulst, W.P., Chervet, l.P, et al. (1996) Automated on-line ionic detergent removal from minute protein/peptide samples prior to liquid chromatography-electrospray mass spectrometry. Journal of Chromatography B Biomedical Sciences and Applications, 686 (2), 119-128. 

From Low lA, Liu RH, Piotrowski EG, and Furner RL (1986) Gas chromatographic/mass spectrometric determination of carton isotope composition in unpurified samples methamphetamine example. Biomedical and Environmental Mass Spectrometry 531-534. 

McGaw, B. A., Milne, E. and Duncan, G. J. (1988) A rapid method for the preparation of combustion samples for stable carbon isotope analysis by isotope ratio mass spectrometry. Biomedical and Environmental Mass Spectrometry, 16, 269-73. 

An example of the application of these features to separation of some closely-related marine toxins (Vohner 2002) is shown in Figures 3.13 and 3.14. Many examples of the application of monolithic columns to biomedical applications can be cited. For example, it was shown (Dear 2001) that the use of short monolithic silica columns coupled to mass spectrometry dramatically reduced analytical run times for metabolite identification from in vitro samples with no loss in chromatographic performance. Six hydroxylated metabolite isomers were separated in one minute, with resolution and selectivity comparable to conventional analytical chromatography resulting in reduction of analysis time per sample from 30 to 5 minutes. Similar results were reported (Wu 2001 Hsieh 2002) for rapid qualitative and quantitative analyses in drug discovery programs (i.e., not fully validated). 

Smalley, J., Kadiyala, P, Xin, B., et al. (2006) Development of an on-line extraction turbulent flow chromatography tandem mass spectrometry method for cassette analysis of Caco-2 cell based bi-directional assay samples./oiemo/ of Chromatography B Analytical Technologies in the Biomedical and Life Sciences, 830,270-277. 

Carlsson, K.C., Rebsaet, J.L.E. (2004) Sample preparation and determination of gabapentin in venons and capillary blood using liquid chromatography-tandem mass spectrometry. Journal of Pharmaceutical and Biomedical Analysis, 34,415-423. 

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