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91.
First, standard mixtures of trimethylsilyl (TMS) derivatives of amino acid and organic acid are analyzed by comprehensive two-dimensional (2D) gas chromatography (GC) coupled to time-of-flight mass spectrometry (GC × GC/TOFMS) in order to illustrate important issues regarding application of the technique. Specifically of interest is the extent to which the peak capacity of the 2D separation space has been utilized and the procedure by which the derivative standards are identified in the 2D separations using the mass spectral information. The resulting 2D separation is found to make extensive use of the GC × GC separation space provided by the complementary stationary phases employed.Second, in order to demonstrate GC × GC/TOFMS on two real sample types, trimethylsilyl metabolite derivatives were analyzed from extracts of common lawn grass samples (i.e., perennial rye grass), as a means to provide insight into both the pre and post harvest physiology. Various chemical components in the two rye grass extract samples were found to either emerge or disappear in relation to the trauma response. For example, a significant difference in the peak for the TMS derivative of malic acid was found. The successful analysis of various components was readily facilitated by the 2D separation, while a 1D separation would have produced too much peak overlap, thus impeding the analysis. The importance of using a GC × GC separation approach for the analysis of complex samples, such as metabolite extracts, is therefore demonstrated. The real-time analysis capability of GC × GC/TOFMS for multidimensional metabolite analysis makes this technique well suited to the high-throughput analysis of metabolomic samples, especially compared to slower, stopped-flow type separation approaches. 相似文献
92.
Highly efficient separation, recovery and recycling of the fluorous-tagged catalyst, [Ni[F13C6C(O)CHC(O)C6F13]2], can be achieved with fluorous solid-phase extraction, after the Lewis acid catalysed synthesis of enaminodiones in conventional organic solvents. 相似文献
93.
Halochromic Molecules. Synthesis and Acidobasic Behaviour of Substituted 3′,6′-Bis(dimethylamino)-spiro [5H-imidazo [2,1-α]isoindolin-5,9′-xanthenes] Substituted 3′,6′-Bis (dimethylamino)-spiro [5H-imidazo [2, 1-α]isoindolin-5,9′-xanthenes] are prepared and their 1H-NMR. spectra are discussed. An investigation of the complex protonation equilibria is made by stopped flow kinetic and spectrophotometric methods. pK values are determined and the results are discussed. 相似文献
94.
The reactions of a wide range of transition-metal carbonyls with anhydrous HF are described. In particular, Ru3(CO)12, Os3(CO)12 and Ir4(CO)12 give the solution stable [Ru3(CO)12H]+, [Ru(CO)5H]+, [Os3(CO)12H]+, [Os(CO)5H]+ and [Ir4(CO)12H2]2+ respectively, which have been characterised by a combination of 1H and 13C NMR spectroscopy. 相似文献
95.
96.
Ohne Zusammenfassung 相似文献
97.
98.
Dr. Sigmund Fränkel Dr. Alfred Wogrinz 《Monatshefte für Chemie / Chemical Monthly》1901,23(3):236-238
Ohne Zusammenfassung 相似文献
99.
M. Leprince R. Lecoq Napoleone Passerini H. Wagner G. Schöler W. E. Joseph M. E. Slater H. S. Grindley H. C. Eckstein J. C. Ross Sigmund Hals Sverre Heggenhougen Erich Ewers C. J. Lintner G. Belschner O. Wenglein Dowzard H. Weller Syniewski F. Mach P. Lederle Honcamp Ries Ad. Beneschovsky Wilk Nördlinger Ralph M. Bohn Krauss A. Jentsch Tacke und E. Blanck 《Fresenius' Journal of Analytical Chemistry》1920,59(1):33-48
Ohne Zusammenfassung 相似文献
100.