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81.
L. Légrádi 《Mikrochimica acta》1965,53(5-6):1038-1046
Zusammenfassung Die mit diazotiertem p-Nitranilin hergestellten Tetrazoverbindungen von Phenolderivaten geben mit Magnesium in alkalischem Mediumfarbige Komplexe. Die Farbe des Komplexes ist verschieden bei substituierten und nicht substituierten bzw. verschieden substituierten Phenolen. Damit kann man Phenol-, Kresol- und Chlorphenol-Isomere bzw. 2,4- und 2,6-Dichlorphenol unterscheiden.Beim Diazotieren von Nitranilin und Kuppeln mit Anilin entstehen. Indikatorsäuren; p-Nitranilin bildet die stärkste Indikatorsäure, m-Nitranilin die schwächste. Auf dieser Grundlage können alle drei Isomeren nebeneinander nachgewiesen werden. Außerdem bilden die aus p- und o-Nitranilin entstandenen Indikatoren mit Magnesium verschieden gefärbte Nitronsäurekomplexe, während m-Nitranilin, das zur Nitronsäuretautomerie nicht befähigt ist, keinen Komplex bildet.Naphthylamine geben mit diazotiertem p-Nitranilin in wäßrigem. Medium eine Indikatorbase, Anilin eine Indikatorsäure. In alkoholischem Medium führt-Naphthylamin bei Kupplung von diazotiertem p-Nitranilin zu einem amphoteren Säure-Base-Indikator, aber-Naphthylamin und Anilin zu Indikatorsäuren. Damit kann man Naphthylamin und Anilin nebeneinander nachweisen. Kuppelt man Phenyldiazoniumchlorid mit Naphthylamin, so erhält man mit-Naphthylamin eine starke Indikatorbase, mit- Naphthylamin eine schwache Indikatorbase. Auf der Basis dieser Indikatorwirkung kann man-Naphthylamin neben- Naphthylamin nachweisen.
Summary The tetrazo compounds of phenol derivatives prepared with diazotizedp-nitraniline yield colored complexes with magnesium in alkaline surroundings. The color of the complexes differs with substituted and non-substituted or variously substituted phenols. It is possible in this way to differentiate phenol, cresol and chlorophenol isomers, and also 2,4- and 2,6-dichlorophenol.Indicator acids result from diazotized nitraniline coupled with aniline;p-nitraniline yields the strongest indicator acid,m-nitraniline the weakest. With this information as a basis, all three isomers can be detected in the presence of each other. In addition, the indicators produced fromp- ando-nitraniline give nitronic acid complexes with magnesium that differ in color, whilem-nitraniline, which is not capable of nitronic acid tautomerism, forms no complex.Naphthylamines gives an indicator base in aqueous medium with diazotizedp-nitraniline, whereas aniline yields an indicator acid. In alcoholic medium, 1-naphthylamine on coupling with diazotizedp-nitraniline produces an amphoteric acid-base indicator, but 2-naphthylamine and aniline yield indicator acids. Naphthylamine and aniline can be detected in this way in the presence of each other. If phenyldiazonium chloride is coupled with naphthylamine, a strong indicator base is obtained with 1-naphthylamine, a weak indicator base with 2-naphthylamine. This indicator action is the basis of the detection of 1-naphthylamine in the presence of 2-naphthylamine.

Résumé Les composés tétrazoïques des dérivés phénoliques qui se forment avec lap-nitraniline diazotée, donnent avec le magnésium, en milieu alcalin, des complexes colorés. La couleur du complexe diffère suivant que les phénols sont substitués, non substitués ou différemment substitués. On peut ainsi distinguer le phénol, les crésols et les chlorophénols isomères, ainsi que les dichloro-2,4 et -2,6 phénols.En diazotant la nitraniline et en copulant avec l'aniline, des acides indicateurs prennent naissance, lap-nitraniline donnant l'acide indicateur le plus fort, lam-nitraniline le plus faible. En s'appuyant sur ce fait, on peut rechercher les trois isomères en présence les uns des autres. En outre, les indicateurs qui prennent naissance à partir de lap- et de l'o-nitraniline forment avec le magnésium différents complexes colorés acinitrés, alors que lam-nitraniline, qui n'est pas susceptible d'une tautomérie de l'acide nitronique, ne donne pas de complexe.Les naphtylamines donnent avec lap-nitraniline diazotée, en milieu aqueux, une base indicateur et l'aniline, un acide indicateur. En milieu alcoolique, l'-naphtylamine conduit par copulation de lap-nitraniline diazotée à un indicateur acide-base amphotère mais la-naphtylamine et l'aniline à des acides indicateurs. On peut ainsi rechercher la naphtylamine et l'aniline en présence l'une de l'autre. Si l'on copule le chlorure de phenyldiazonium avec la naphtylamine, on obtient avec la forme une base indicateur forte et avec la forme une base indicateur faible. En se fondant sur cette action d'indicateur, on peut rechercher l'-naphtylamine en présence de-naphtylamine.
  相似文献   
82.
Résumé Les monophénols sont isolés des condensats de fumées de cigarette par chromatographie sur couche mince de Kieselgel G avec un mélange (31) de cyclohexane et d'acétate d'éthyle extraits du support, puis séparé et dosés par chromatographie en phase gazeuse sur colonne capillaire. Le rendement de l;opération est de 80±2% pour le triméthyl 3,4,5 phénol, de 65% pour le triméthyl 2,3,5 phénol. Les teneurs obtenues sont de 8g de phénol, 3g de (para + méta) crésol et 0,5 g de diméthyl 2,6 phénol par mg de condensat. De nombreux autres alkylphénols ont été identifiés.
Analysis of the monophenolic fraction of tobacco smoke condensates by a combination of chromatographic methods
Summary Monophenols are separated from tobacco smoke condensates by thin-layer chromatography on Kieselgel G using a 31 mixture of cyclohexane and ethylacetate. The monophenolic fraction is recovered from the support and analyzed by GC on a capillary column. The yield is 80±2% for 3,4,5 trimethylphenol and 65% for 2,3,5 trimethylphenol. The concentration determined for phenol, (para+meta) cresol and 2,6 dimethylphenol are 8,3 and 0.5 g per mg of condensate respectively. Numerous other alkyl phenols have been identified.
  相似文献   
83.
Equilibrium liquid crystal (LC) layer on an interface between crude oils and water was observed at high pH. This layer is composed mainly of sodium naphthenates produced in situ at the water/oil interface. Transient LC layer was also evolved at the interface of aqueous phase of sodium hydroxide solutions and oleic phase of naphthenic acid (NA) solutions as result of a chemical reaction between NaOH and NA. This chemical reaction causes transport process resulting in a disturbance of the interface. Optical observation of this interface disturbance reviled that the interface covered with LC shows considerably lower flexibility as compared to LC free interface. The LC layer eventually dissolves in the water phase at low oil-to-water ratio, while at high oil-to-water ratio it can form an equilibrium phase, which spreads spontaneously at the oil-water interface.  相似文献   
84.
Capillary electrochromatography (CEC) was used to separate alkyl phenol ethoxylates (APEs) as model diblock copolymers, with monolithic polymers as stationary phases. The order of elution indicate that the two polymer blocks follow distinct chromatographic modes: size-exclusion for the poly(oxyethylene) group and adsorption interaction for the alkyl part. Therefore, our experimental results were compared to the theory describing liquid exclusion-adsorption chromatography (LEAC). They were found in perfect agreement with the theory, which turned to be verified for the first time over the full range of polymer lengths.  相似文献   
85.
The structure and properties of non-pyrophoric skeleton catalysts prepared from NiSi, NiAlSi, NiMg and NiZn alloys have been studied—apart from other thermal methods—by means of the derivatograph.Our experimental results have contributed to the explanation of the non-pyrophoric behaviour of these catalysts. We demonstrated that the desorption of the hydrogen content in our catalysts is not accompanied by the oxidation of active nickel. This oxidation takes place only at higher temperatures, above 200°C, at a rate proportional to the amount of active nickel.Other constituents of the catalysts (adsorbed water, hydroxide content) were also determined from the experimental data. The outstandingly high Mg(OH)2 content of the NiMg catalyst indicates that its structure is dissimilar: Mg(OH)2 also acts as support for the catalyst.  相似文献   
86.
87.
The energy route to the equation of state of hard-sphere fluids is ill defined since the internal energy is just that of an ideal gas, and thus it is independent of density. It is shown that this ambiguity can be avoided by considering a square-shoulder interaction and taking the limit of vanishing shoulder width. The resulting hard-sphere equation of state coincides exactly with the one obtained through the virial route. Therefore, the energy and virial routes to the equation of state of hard-sphere fluids can be considered as equivalent.  相似文献   
88.
The thermal behaviour of tetrahydroperparine (THP) and its derivatives with various acids has been investigated. The acid is liberated from the formate derivative basically in two steps, while the other aliphatic acids are released quantitatively before the thermal decomposition of the THP molecule. The thermoanalytical curves, electrical conductivity data measured in the molten phase, and infrared spectra prove that while part of the formic acid is hydrogen-bonded the other part is bound ionically in the molecule. It may be assumed that the marked biological activity of the compound can be explained by this difference in the nature of the bonds.  相似文献   
89.
Summary Two new analytical techniques are described. The so-called injection technique operates on evaluating a dynamic concentration signal as a result of following the concentration change in a certain part of a flow-through channel after injecting a sample or reagent at a small volume into the current of an appropriate solution flowing at a constant rate.The second technique, the programmed coulometric titration technique, also uses the flow-through channel principle; that means this novel technique allows the more precise titrimetric way of analysis in flowing solutions. In the case of both techniques potentiometric and voltammetric detectors were involved. Several examples proved the multifold advantages of these techniques for environmental analysis.
Neue elektroanalytische Verfahren für die Umweltanalyse
Zusammenfassung Zwei neue Methoden werden beschrieben. Die sog. Injektionstechnik wertet ein dynamisches Konzentrationssignal aus, das sich aus der Änderung in einem Durchflußkanal ergibt, wenn Probe oder Reagens in kleinen Volumina in einen konstant fließenden Flüssigstrom injiziert werden. Das zweite Verfahren, die programmierte coulometrische Titration, erlaubt die Anwendung der genaueren titrimetrischen Technik auf fließende Lösungen. Bei beiden Methoden werden potentiometrische und voltammetrische Detektoren verwendet. Mehrere Beispiele zeigen die vielfachen Vorteile dieser Verfahren bei der Anwendung auf die Analyse von Umweltmaterial.
Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria  相似文献   
90.
The "palladiazo" reagent has been subjected to a detailed spectrophotometric investigation in concentrated perchloric acid, different aqueous buffers and concentrated sodium hydroxide solutions. K(1)-K(10) and (1)-(10) values corresponding to the instability constants of the protolytic equilibria involved and to the molar absorptivities at 540 and 630 run of the different proton complex species of the system have been calculated by a number of analytical and graphical spectrophotometric methods. Special attention has been paid to the study of the complicated phenomena implied by the interaction of the reagent with perchloric acid, which has been shown to give rise to alteration of the initial isomeric composition of the reagent and to the formation of addition and/or oxidation products derived from side-reactions undergone by the reagent with the medium. All the instability constants and molar absorptivities, which have been determined by several methods, are tabulated for comparison.  相似文献   
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