Mass spectrometry , multivariate

IRMS LC MDGC MS MSA NIF NMR OAV OSV PCA RAS RP SDE SFE SIM SNIF SPME TIC TLC Stable Isotope Ratio Mass Spectrometry Liquid Chromatography MultiDimensional Gas Chromatography Mass Spectrometry Multivariate Sensory Analysis Nasal Impact Frequency Nuclear Magnetic Resonance spectroscopy Odor Activity value Odor Spectrum Value Principal Component Analysis Retronasal Stimulation Reversed Phase Simultaneous steam Distillation Extraction Supercritical Fluid Extraction Selected Ion Monitoring Surface of Nasal Impact Frequency Solid Phase Micro Extraction Total Ion Current Thin Layer Chromatography... 

Kuehl B, Marten SM, Bischoff Y, Brenner-Weiss G, Obst U. MALDI-TOF mass spectrometry-multivariate data analysis as a tool for classification of reactivation and non-culturable states of bacteria. Anal Bioanal Chem. 2011 401(5) 1593-600. 

Analysis of volatiles is frequently utilised in food industry to quality control food products and to determine shelf-life for various products. Some recent examples are the use of sensor arrays to differentiate milk products according to their aging times (12) and the use of solid phase microextraction-mass spectrometry-multivariate data system to predict the shelf-life of pasteurised milk (13). Volatiles emitted by plants have also been correlated to abiotic or biotic stress and the degree of damage caused by the stress (14). Similar principles should be applicable to polymeric materials i.e. the formation of certain volatiles or indicator products during degradation of the polymer is related to the changes in the polymer matrix (Fig. 1). 

Wilkes, J. G. Rushing, L. Nayak, R. Buzatu, D. A. Sutherland, J. B. Rapid phenotypic characterization of Salmonella enterica strains by pyrolysis metastable atom bombardment mass spectrometry with multivariate statistical and artificial neural network pattern recognition. J. Microbiol. Meth. submitted for publication. 

Goodacre, R. Trew, S. Wrigley-Jones, C. Neal, M. J. Maddock, J. Ottley, T. W. Porter, N. Kell, D. B. Rapid screening for metabolite overproduction in fermentor broths using pyrolysis mass spectrometry with multivariate calibration and artificial neural networks. Biotechnol. Bioengin. 1994, 44,1205-1216. 

Nilsson,T. Bassani, M. R. Larsen,T. O. Montanarella, L. Classification of species in the genus Penicillium by Curie point pyrolysis/mass spectrometry followed by multivariate analysis and artificial neural networks. J. Mass Spectrom. 1996, 31, 1422-1428. 

Sinha, A.E., Hope, J.L., Prazen, B.J., Fraga, C.G., Nilsson, E.J., Synovec, R.E. (2004a). Multivariate selectivity as a metric for evaluating comprehensive two-dimensional gas chromatography-time-of-fhght mass spectrometry subjected to chemometric peak deconvolution. J. Chromatogr. A 1056, 145-154. 

McCombie G, Staab D, Stoeckli M, et al. Spatial and spectral correlations in MALDI mass spectrometry images by clustering and multivariate analysis. Anal. Chem. 2005 77 6118-6124. 

Marti, M.R, Pino, J., Boque, R., Busto, O., Guasch, J. (2005) Determination of aging time of spirits in oak barrels i ing a headspace-mass spectrometry (HS-MS) electronic nose system and multivariate calibration. In Analytical and Bioanalytical Chemistry 382 (2) The European Conference on Analytical Chemistry XIII, pp 440-443. 

M. Rupprecht and T. Probst, Development of a method for the systematic use of bilinear multivariate calibration methods for the correction of interferences in inductively coupled plasma-mass spectrometry. Anal. Chim. Acta, 358, 1998, 205-225. 

M. S. Wagner, S. Pasche, D. G. Castner and M. Textor, Characterisation of poly(L-lysine)-graft-poly(ethylene glycol) assembled monolayers on niobium pentoxide substrates using time-of-flight secondary ion mass spectrometry and multivariate analysis, Anal. Chem., 16, 2004, 1483-1492. 

Plumb, R. S., Stumpf, C. L., Granger, J. H., Castro-Perez, J., Haselden, J. N., and Dear, G. J. (2003). Use of liquid chromatography/time-of-fhght mass spectrometry and multivariate statistical analysis shows promise for the detection of chug metabolites in biological fluids. Rapid Commun. Mass Spectrom. 17 2632-2638. 

Whenever the goals of curve resolution are achieved, the understanding of a chemical system is dramatically increased and facilitated, avoiding the use of enhanced and much more costly experimental techniques. Through multivariate-resolution methods, the ubiquitous mixture analysis problem in chemistry (and other scientific fields) is solved directly by mathematical and software tools instead of using costly analytical chemistry and instrumental tools, for example, as in sophisticated hyphenated mass spectrometry-chromatographic methods. 

Bezemer, E. and Rutan, S.C., Study of the hydrolysis of a sulfonylurea herbicide using liquid chromatography with diode array detection and mass spectrometry by three-way multivariate curve resolution-alternating least squares, Anal. Chem., 73, 4403 4409, 2001. 

As an example, consider a chromatogram in which a number of compounds are detected with different elution times, at the same time as a their spectra (such as UV or mass spectra) are recorded. Coupled chromatography, such as high-performance chromatography-diode array detection (HPLC-DAD) or liquid chromatography-mass spectrometry (LC-MS), is increasingly common in modern laboratories, and represents a rich source of multivariate data. These data can be represented as a matrix as in Figure 4.3. 

In comparison with NMR, mass spectrometry is more sensitive and, thus, can be used for compounds of lower concentration. While it is easily possible to measure picomoles of compounds, detection limits at the attomole levels can be reached. Mass spectrometry also has the ability to identify compounds through elucidation of their chemical structure by MS/MS and determination of their exact masses. This is true at least for compounds below 500 Da, the limit at which very high-resolution mass spectrometry can unambiguously determine the elemental composition. In 2005, this could only be done by FTICR. Orbitrap appears to be a good alternative, with a more limited mass range but a better signal-to-noise ratio. Furthermore, mass spectrometry allows relative concentration determinations to be made between samples with a dynamic range of about 10000. Absolute quantification is also possible but needs reference compounds to be used. It should be mentioned that if mass spectrometry is an important technique for metabolome analysis, another key tool is specific software to manipulate, summarize and analyse the complex multivariant data obtained. 

Windig W, Meuzelaar HLC, Shafizadeh F Kelsey RG (1984) Biochemical analysis of wood and wood products by pyrolysis mass spectrometry and multivariate analysis J Anal Appl Pyrolysis 6 233-250... 

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