Identification mass spectrometry application

Analytical applications Mass spectrometry has been applied to a variety of analytical problems related to expls, some of which have already been mentioned. Identification of the principal constituents of expls has been attempted from electron impact cracking patterns (Refs 34, 50 58), as well as chemical ionization spectra (Refs 69,70 71). Such methods necessarily include vapor species analysis and are directed to detection of buried mines (Refs 50, 58, 61,... 

Applications Mass spectrometry has often been used more as an auxiliary, rather than a primary, identification method for additives in polymers. Table 6.5 shows the suitability of various ionisation modes for oligomer (and polymer) analysis. 

In this chapter we will review proteomic investigations of cardiac proteins and focus on their application to the study of heart disease in the human and in animal models of cardiac dysfunction. The majority of these studies of the cardiac proteome have involved protein separation, visualisation and quantitation using the traditional 2-DE approach combined with protein identification by mass spectrometry. These essential technologies will be briefly described. However, there is increasing interest in using alternative gel-free techniques based on mass spectrometry or protein arrays for high throughput proteomics. These alternative approaches will be introduced, but further details can be found in Chapter 2 of this volume by Michel Faupel. 

See also Bioassays Overview. Drug Metabolism Metabolite Isolation and Identification. Infrared Spectroscopy Ovenriew. Liquid Chromatography Liquid Chromatography-Nuclear Magnetic Resonance Spectrometry Pharmaceutical Applications. Mass Spectrometry ... 

GC is applied in a variety of ways and is one of the most important separation techniques in this particular area. GC provides the retention time or retention index (RI) of an unknown substance that can be used for its identification. GC is routinely utilized to separate the analyte from endogenous interferences for more specific identification via mass spectrometry and can also be used to provide quantitative information about the drugs present. The following applications focus on the identification and quantification of drugs and volatiles in biological fluids by GC. 

Other methods of identification include the customary preparation of derivatives, comparisons with authentic substances whenever possible, and periodate oxidation. Lately, the application of nuclear magnetic resonance spectroscopy has provided an elegant approach to the elucidation of structures and stereochemistry of various deoxy sugars (18). Microcell techniques can provide a spectrum on 5-6 mg. of sample. The practicing chemist is frequently confronted with the problem of having on hand a few milligrams of a product whose structure is unknown. It is especially in such instances that a full appreciation of the functions of mass spectrometry can be developed. 

Chemical ionization mass spectrometry has rapidly found extensive application to many substances (Refs 15, 23 28). Of particular importance is identification of complex and... 

H. Kramer, S. Semel J.E. Abel, Trace Elemental Survey Analysis of Trinitrotoluene , PATR 4767 (1975) (An evaluation of the applicability of spark source mass spectrometry and thermal neutron activation for the detn of origin-related trace elemental impurities in TNT) 10) C. Ribando J. Haber-man, Origin-Identification of Explosives Via Their Composite Impurity Profiles I. The... 

One of the chief reasons for the recent extensive work in this field has been the recognition that ion-molecule reactions are highly relevant to radiation chemistry. The possibility that certain simple reactions, such as the formation of H3+, participate in the mechanism of product formation was appreciated much earlier 14), but wider applicability of this concept required that the generality of such reactions be demonstrated by an independent, unequivocal method. Mass spectrometry has been the predominant means of investigating ion-molecule reactions. The direct identification of reactant and product ions is appealing, at least in part, because of the conceptual simplicity of this approach. However, the neutral products of ion-molecule reactions cannot be determined directly and must be inferred. Gross chemical measurements can serve as an auxiliary technique since they allow identification of un-... 

The ultimate goal of microarray-based expression analysis is to acquire a comprehension of the entire cellular process, in order to exploit and to standardize the multidi-menisional relations between genotype and phenotype. However, an increasingly important parameter, which has not yet been substantially taken into account, is the role of cellular translation. This means that mRNA expression data need to be correlated with the assortment of proteins actually present in the cell. One approach is based on the use of microarrays containing double-stranded DNA probes for the analysis of DNA-protein interaction and, thus, the detection and identification of DNA-binding proteins by means of fluorescence [130] or mass spectrometry analysis [131]. Moreover, substantial efforts are currently under way to develop protein, antibody, or even cell arrays, applicable to the cor-... 

Advanced mass spectrometry enables the detection of higher-molecular-weight compounds that can be expected to retain more specific structure information contained in the original complex materials. The application of MS/MS using various scan modes will further extend the capabilities for identification of compounds in complex mixtures. Precursor scan techniques improve insight into the origin of ions in complex pyrolysates... 

Mass spectrometry (MS) in its various forms, and with various procedures for vaporization and ionization, contributes to the identification and characterization of complex species by their isotopomer pattern of the intact ions (usually cation) and by their fragmentation pattern. Upon ionization by the rough electron impact (El) the molecular peak often does not appear, in contrast to the more gentle field desorption (FD) or fast-atom bombardment (FAB) techniques. An even more gentle way is provided by the electrospray (ES) method, which allows all ionic species (optionally cationic or anionic) present in solution to be detected. Descriptions of ESMS and its application to selected problems are published 45-47 also a representative application of this method in a study of phosphine-mercury complexes in solution is reported.48... 

Eichhom P, Lopez O, Barcelo D (2005) Application of liquid chromatography-electrospray-tandem mass spectrometry for the identification and characterisation of linear alkylbenzene sulfonates and sulfophenyl carboxylates in sludge-amended soils. J Chromatogr A 1067 171-179... 

In our particular application, we do not have an absolute method of calibration because the alkyl chain length affects the EO distribution retention. However, mass spectrometry would be an ideal third dimension. The automated combination of two-dimensional chromatography and mass spectrometry is the next step toward the future of simultaneous separation and identification of very complicated samples. 

One often finds that when high resolution separation schemes are utilized, other techniques and disciplines must participate in the scheme of understanding and effectively utilizing the separation with subsequent identification of the resulting zones. A rigorous and often multidimensional detection scheme such as mass spectrometry and/or fluorescence is found both for the life science and industrial polymer applications. Other disciplines including informatics and statistics are often... 

It should be emphasized that the nature of all presented protocols is very general and, thus, their application for a comprehensive characterization of your favorite multiprotein complex (YFMPC) in yeast might require only minor modifications. The logical sequence of all required steps is schematically shown in Fig. 2.1. The initial large-scale Ni affinity isolation of eIF3 followed by mass spectrometry (MS) of its subunit composition has already been described (Asano et al, 2002), and methods for identification of protein-protein interactions such as yeast two-hybrid (Y2H) and in vitro glutathione-S-transferase (GST) pull-down analysis are presented in volume 429. This chapter focuses on a description of the small-scale one-step in vivo affinity purification techniques that were used to determine the effects of deletions and... 

The above-mentioned method is effective in identifying the molecules of detected ions. However, because PVDF film is not permeable to light, it is difficult to observe tissue sections. To resolve this problem, we developed a method to fix tissue sections on transparent film, and then performed MS on those sections.6 We used a conductive film because we expected the ionization efficiency would increase when the electric charge accumulation on the sample was reduced. The film used for this purpose was a polyethylene terephthalate (PET) film with a thickness of 75-125 pm, having a 5 15-nm-thick layer of evaporated oxidation indium tin (ITO) upon it (ITO film). This film is used in touch-panel displays because of its high transparency and superior conductivity. We used it to perform MS/MS for tissue sections and succeeded in identifying multiple proteins from mass spectra.6 Therefore, the further development of this method will enable the application of the mass-microscopic method to observe tissue by optical microscope and to perform tandem mass spectrometry (MSn) at the observation part, simultaneously, enabling the identification of molecules included the part. 

The type of proteinaceous binder was correctly identified in all model samples. In only one case (S10), the animal glue was additionally identified, although the restorer who prepared these model samples declared that the sample contained only egg binder. It is possible that this sample was contaminated during its preparation or during laboratory treatment. The results indicate that this method does not allow reliable identification of the presence of individual egg yolk and egg white most probably it is caused by the presence of a trace of egg white that is always present in the egg yolk preparations (and vice versa) and can be detected by the highly sensitive PMM method. The identification of individual types of animal glues will never be reliable by MALDI-TOF mass spectrometry because of their similar composition the application of ESI (electrospray ionisation)-MS/MS (Section 6.5) could possibly overcome this problem. Only the fish glue, whose peptide... 

R. Lletf, L.A. Sarabia, M.C. Ortiz, R. Todeschini, M.P. Colombini, Application of the Kohonen Artifical Neural Network in the Identification of Proteinaceous Binders in Samples of Panel Painting using Gas Chromatography Mass Spectrometry, Analyst, 128, 281 286 (2003). 

Stobiecki M. 2000. Application of mass spectrometry for identification and structural studies of flavonoid glycosides. Phytochemistry 54(3) 237-256. 

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