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Ohne Zusammenfassung
On the analysis of organotin compounds
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The quantitative determination of mono-, di-, tri- and tetraalkyl tin compounds in mixture by GLC is possible after alkylation to mixed tetraalkyl tins. The alkylation with methyl-, butyl- and octyl magnesium chloride runs quantitatively without any change in the original alkyl groups attached to the tin. The method can be applied not only for alkyl tin oxides and chlorides but also directly for alkyl tin thioglycolates. The by-products resulting from the thioglycolic acid ester cleavage are absorbed on silica gel prior to GLC and the tetraalkyl tins are eluted with n-pentane. Gas-chromatographic analysis is carried out alternatively with carbowax and polyglycol 20000 at temperatures between 100 and 230° C. The peak areas correspond to the weight percentage of tetraalkyl tin.  相似文献   

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M. Pöhm 《Mikrochimica acta》1955,43(5-6):1016-1018
Zusammenfassung Es wird über eine spektrophotometrische Unterscheidung der bekannten Mutterkornalkaloide von Lumi-Lysergsäurederivaten sowie über deren Nachweismöglichkeit berichtet.
Summary A report is given of a spectrophotometric differentiation of the familiar ergot alkaloids from lumi-lysergic acid derivatives. The detection possibilities are pointed out.

Résumé On présente une communication relative à une différenciation spectrophotométrique des alcaloides connus de l'ergot de seigle et des dérivés de l'acide lumi-lysergique et à la possibilité de leur identification.
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Zusammenfassung Dihydro-4,4,6-trimethyl-2(1H)-pyrimidinone (1) bzw.-thione reagieren mit Schwefel und Morpholin zu Tetrahydro-2-oxobzw.-2-thiono-4,4-dimethylpyrimidin-6-thiocarbonsäuremorpholiden (3); mit Schwefel in Dimethylformamid bzw. Tetramethylharnstoff bilden sich Dihydro-3-thiono-3H-1,2-dithiolo-[4,3—d]pyrimidin-5(4H)-one (5) bzw.-3,5-dithione. Das Dihydro-6-methyl-4-phenyl-2(1H)-pyrimidinon2 bzw.-thion geben mit Schwefel und Tetramethylharnstoff das Dihydro-1-methyl-2-oxo-bzw.-2-thiono-4-phenylpyrimidin-6-trimethylcarboxamidin (7). Methylheterocyclen, wie Chinaldin, werden bei analoger Behandlung in Chinolin-2-thiocarbonsäuredimethylamid usw. übergeführt.
Reaction of sulfur + amines with dihydro-2 (1H)pyrimidinones and-thiones
Dihydro-4,4,6-trimethyl-2(1H)-pyrimidinones (1) and-thiones react with sulfur and morpholine to tetrahydro-2-oxo- and-2-thiono-4,4-dimethylpyrimidine-6-thiocarboxylic acid morpholides (3); with sulfur inDMF or tetramethylurea (TMU) the formation of dihydro-3-thiono-3H-1,2-dithiolo[4,3—d]pyrimidin-5(4H)-ones (5) or-3,5-dithiones, resp. was observed. Dihydro-6-methyl-4-phenyl-2(1H)-pyrimidinone (2) (-thione) with sulfur andTMU yields dihydro-1-methyl-2-oxo- and-2-thiono-4-phenylpyrimidin-6-trimethyl-carboxamidine (7). Methyl substituted heterocycles e.g. quinaldine, are converted under analogous conditions to quinoline-2-thiocarboxylic acid dimethylamide and corresponding compounds. *** DIRECT SUPPORT *** A3615139 00018
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Summary A method is described for the distinction between urea-formaldehyde and melamine-formaldehyde resins by precipitating the melamine derivates with picric acid. The analysis of this precipitation by urease-decomposition gives information whether urea and melamine are condensed with formaldehyde together or whether the investigated resin is only a mixture of an urea-formaldehyde and a melamine-formaldehyde resin.Moreover, it is possible to prove the formation of cocondensates of urea, melamine, and formaldehyde during the three-component condensation by combination of these two methods.  相似文献   

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Zusammenfassung Die Dünnschichtchromatographie kann zur Identifizierung von Organozinnstabilisatoren herangezogen werden. Unter Verwendung des vorgeschlagenen Fließmittels Isopropyläther und 1,5% Eisessig ist es möglich, die vier Alkylierungsstufen von Organozinnderivaten zu trennen, ferner einwandfrei zwischen dem toxikologisch bedeutsamen Dibutylzinn und Dioctylzinn zu unterscheiden und die schwefelhaltigen Stabilisatoren entsprechend ihrer Zinn-Mercaptoverbindung zu charakterisieren. Die Carboxylate hydrolysieren während des Eluierens in das Diacetat. Ihre Trennung erfolgt nur in Abhängigkeit von der am Zinn gebundenen Alkylgruppe. 1 g Organozinn kann noch nachgewiesen werden.
Summary Thin-layer chromatography may be used for identification of organotin stabilizers. By the use of the proposed solvent, isopropylether with 1,5 v/v% acetic acid, it is possible to separate the four stages of alkylation, to distinguish the toxicologically most important dibutyl tin and dioctyl tin compounds and to characterize the sulphur containing stabilizers according to the tin-mercapto compound. The carboxylates are converted to the diacetates during elution. Their separation depends on the alkyl group. 1 g organotin may be detected.
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Departing from the until now well known A and B systems of the indium and gallium halide emissions the authors tried to find further spectra of molecule bands in flames. The following band systems were observed: InF1 (A, B and C systems), GaF1 (A, B and C systems), A1F1 (A system), T1C11, TlBr1, TII1 and the C systems of the GaCl, GaBr, InCl and InBr molecules.From the behaviour of the intensities of excited and nonexcited MeX species and the existence of InF-C bands (excitation energy 5.30 eV) in the hydrogen-nitrogen diffusion flame it could be derived that the excited state results from the reaction of metal and halogen atoms. Furthermore the experimental results of MeX intensity measurements indicate reactions of excited molecules with particles of flame gases. This is especially valid for the A and B systems of the indium and gallium halides (triplet states) which have as a result of the forbidden transitions a relatively long life time. Using other gas mixtures (Hr-air, propane-air) and observation of CuX and alkaline earth halide bands as well gave the possibility to set up a block diagram of optimum conditions for measuring the different MeX emissions.Examination of the analytical performance gave detection limits of 0.7 mgl for F?1 and about 4 mgl for Cl?, Br? and I? by means of InX emissions. The limits of the concentration ratios for the determination of traces were 1:640 (Cl? in HBr) up to 1:60,000 (I? in HF). The best determinations of other halogens are possible in HC1 and HF matrices.  相似文献   

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Zusammenfassung Eine Methode zur Bestimmung von Mikrogramm-Mengen Titan und Zirkonium in metallischem Molybdän und Wolfram bzw. in den Ausgangsstoffen MoO3 bzw. WO3 und H2WO4 wird vorgestellt. Die Methode beruht auf der Trennung der Titan- und Zirkoniumspuren von der Molybdänbzw. Wolframmatrix, wobei die Trennung durch Mitfällung der Spurenverunreinigungen erfolgt; als Kollektor findet Kobalthydroxid Verwendung. Die so erhaltenen Hydroxidniederschläge werden auf Filterpapier gesammelt und nach Trocknen derselben durch RFA vermessen. Mit dieser Arbeitstechnik erhält man bis zu 1 · 10–4 g Titan bzw. Zirkonium Eichgeraden; die Erfassungsgrenze für Titan kann mit 3,4 · 10–8 g, die für Zirkonium mit 5,0 · 10–7 g angegeben werden. Die Gesamtdauer für eine Einzelanalyse beträgt etwa 45 min, wobei aber mehrere Proben gleichzeitig analysiert werden können.
Determination of trace impurities of titanium and zirconium in molybdenum and tungsten and their oxygen compounds by X-ray fluorescence spectrometry
A method for the determination of trace impurities of titanium and zirconium in metallic molybdenum and tungsten or in their basic products MoO3, WO3 and H2WO4 is presented. The method is based on coprecipitation of the trace impurities titanium and zirconium with cobalt hydroxide as carrier from molybdenum and tungsten matrices. The hydroxide precipitates are collected on filter paper and measured by XRF after drying. In that way it is possible to get linear calibration curves up to 1 · 10–4 g; the limits of detection are determined to be 3.4 · 10–3 g for titanium and 5.0 · 10–7 g for zirconium. About 45 min are necessary for one analysis, but several samples can be analysed simultaneously.
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