Zusammenfassung Es wird der Gebrauch, von Murexid als Indicator für die ma\analytische Makro- und Mikrobestimmung des Kupfers mit einer Ma\lösung von 1,2-DiaminocyclohexantetraessigsÄure (DCyTE) vorgeschlagen.Teil XVI: Siehe Quím. e. Ind. (Bilbao), 6, Nr. 1 (1959). 相似文献
In the study of chemical evolution, experiments simulating primitive earth conditions have shown that many compounds of biological significance can be produced from simple precursors. In an attempt to search for the origin of polycarboxylic acids, the UV irradiation of aqueous acetic acid was performed. Among the products detected were succinic, citric and malonic acids which are key compounds in metabolic pathways, suggesting that these compounds might have been formed on the primitive Earth prior to life itself. 相似文献
Protein–protein interactions are an important element in the understanding of protein function, and chemical cross-linking shotgun mass spectrometry is rapidly becoming a routine approach to identify these specific interfaces and topographical interactions. Protein cross-link data analysis is aided by dozens of algorithm choices, but hindered by a lack of a common format for representing results. Consequently, interoperability between algorithms and pipelines utilizing chemical cross-linking remains a challenge. pepXML is an open, widely-used format for representing spectral search algorithm results that has facilitated information exchange and pipeline development for typical shotgun mass spectrometry analyses. We describe an extension of this format to incorporate cross-linking spectral search results. We demonstrate application of the extension by representing results of multiple cross-linking search algorithms. In addition, we demonstrate adapting existing pepXML-supporting software pipelines to analyze protein cross-linking results formatted in pepXML.
Polyurethanes prepared by reaction of methylene bis(4-phenylisocyanate) with diethylene glycol and with poly(ethylene glycol) with a moelcular weight of approximately 200 have been thermally degraded in the presence of ammonium polyphosphate (APP). Degradation has been carried out at temperatures up to 500°C and the volatile products and structural changes in the residue have been analysed in detail. In addition to the reactions which occur in the pure polymer, the presence of APP induces additional acid catalysed processes which make the overall reaction very much more complicated. From the experimental data, a comprehensive mechanism for the overall process has been deduced and discussed. 相似文献
Supramolecular dendrimers resulting from the dimerization of fullerene-functionalized dendrons through a quadruple hydrogen-bonding motif were prepared. The synthetic strategy is based on the esterification of a tert-butoxycarbonyl (Boc)-protected 2-ureido-4-[1H]pyrimidinone precursor possessing an alcohol function with fullerodendrons bearing a carboxylic acid unit at the focal point. Subsequent acidic treatment to cleave the protecting group and reaction of the resulting amine with octylisocyanate affords the targeted compounds. As demonstrated by the results of MALDI-TOF mass spectrometry and 1H NMR spectroscopy, both of the 2-ureido-4-[1H]pyrimidinone derivatives form self-assembled dimers spontaneously through hydrogen-bonding interactions, thus leading to supramolecular structures containing two or ten fullerene moieties. 相似文献