Mass spectrometry, complementation with

Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry complement each other mass spectrometry provides molecular weight data, while NMR spectroscopy provides stereochemical information based on the various kinds of protons present in a molecule and their relation to one another. A major advantage of NMR spectroscopy is that the sample is not altered or destroyed. NMR spectroscopy has two major limitations with respect to pesticide residue analyses—it is much less sensitive than mass spectrometry, infrared or ultraviolet spectroscopy, or gas chromatography and moderately pure (95%) compounds are required usually. Since pure materials are required, environmental sam-... 

It is clear that mass spectrometry imaging has great potential as a comprehensive analysis technique for endogenous peptides, particularly with a hardware configuration as evaluated in this chapter, where MALDI produced ions are analyzed in an ion trap - Orbitrap hybrid instrumentation. A single experiment can provide high mass accuracy data in combination with the spatial distribution of peptides in the tissue sample. With MS/MS experiments the molecular identity (accurate mass measurements complemented with MS" sequence data) can be confirmed firom a single or few scans only and from a few laser shots in total. 

The experiments described above indicate that technology is available to couple SPR with mass spectrometry. These methods should be useful for protein-protein interaction mapping. For example, immobilized proteins can be used as hooks for fishing binding partners from complex protein mixtures under native conditions. The coupling of techniques can lead not only to the rapid identification of interacting proteins but will also provide information on the kinetic parameters of the interaction. This approach should serve as an excellent complement to the use of in vivo techniques such as the yeast two-hybrid system. 

The results for bacterial whole-cell analysis described here establish the utility of MALDI-FTMS for mass spectral analysis of whole-cell bacteria and (potentially) more complex single-celled organisms. The use of MALDI-measured accurate mass values combined with mass defect plots is rapid, accurate, and simpler in sample preparation then conventional liquid chromatographic methods for bacterial lipid analysis. Intact cell MALDI-FTMS bacterial lipid characterization complements the use of proteomics profiling by mass spectrometry because it relies on accurate mass measurements of chemical species that are not subject to posttranslational modification or proteolytic degradation. 

Stanislaus, R., Jiang, L.H., Swartz, M., Arthur, J. Almeida, J.S. (2004). An XML standard for the dissemination of annotated 2D gel electrophoresis data complemented with mass spectrometry results. BMC Bioinformatics 5, 9. 

Unlu M et al. Detection of complement factor B in the cerebrospinal fluid of patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy disease using two-dimensional gel electrophoresis and mass spectrometry. Neurosci Lett 2000 282 149-152. 

Behavioral bioassays are inextricably linked with chemical studies to decipher the information content of olfactory signals (Albone 1984). As a complement to the experimental approach described above, several research groups have applied chemical approaches, particularly gas chromatography and mass spectrometry (GC-MS),... 

Nonetheless, during the first decades of analytical mass spectrometry low energy El spectra have been the only way to minimize fragmentation, and thereby to increase the relative intensity of a weak molecular ion peak. Nowadays, El mass spectra are preferably complemented with spectra obtained from so-called soft ionization methods (Chaps. 7-11). 

XPS will aid in understanding specifically the surface of the black deposit covering pictographs in Little Lost River Cave in Idaho. This work will complement other bulk analyses carried out with pyrolysis-GC-MS and thermally assisted hydrolysis /methylation (THM)-GC-MS (75). The objectives of this project were to use XPS to qualitatively determine the surface elemental composition of the black residue semiquantitatively characterize the surface, for comparison with other surface-related materials and examine the relationship between the chemistry and depth by using Ar+ sputtering. This, then, will aid in validating the radiocarbon date obtained through plasma-chemical oxidation and accelerator mass spectrometry by Steelman et al. (5). 

The gas-phase basicity (GB) of 3-thio-5-oxo 1, 5-thio-3-oxo 2, and 3,5-dithio 4 derivatives of 2,7-dimethyl-[l,2,4]-triazepine (Figure 1) has been measured by means of Fourier transform ion cyclotron resonance (FTICR) mass spectrometry and complemented with theoretical calculations. The experimental FTICR results are discussed in Section 13.14.4.1.l(i). The structures and vibrational frequencies of all stable protonated tautomers and all transition states connecting them have been obtained by means of the B3LPY density functional method, together with 6-31G basis set expansion. The final energies were obtained at the B3LYP/6-311 + G(3df,-2p) level (2002JPC7383). 

The FTIR is also useful in the identification of unknown solvents when performing trace analysis for residual solvents in bulks. The FTIR also must be looked upon as a complement to data collected by GC-MS. Reviews on the performance and application of the FTIR to various problems have been published [119,120]. Reviews on the use of the FTIR in combination with mass spectrometry have been published [121-123]. 

In an interesting experimental protocol, Silvestro et al. (1993) utilized HPLC-mass spectrometry with an ion spray (electrospray) interface for determination of PAF and lysoPAF in human PMN (neutrophils). Both unstimulated and stimulated (with complement-activated zymosan) cells were used as starting material. The total lipids were isolated in the usual way, and the PAF was isolated and purified by a combination of thin-layer chromatography, HPLC, and silica chromatography. This final PAF preparation was subjected to a bioassay with the inclusion of 3H 16 0 PAF to monitor recoveries. 

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