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101.
Abdelkrim El‐Ghayoury Albertus P. H. J. Schenning E. W. Meijer 《Journal of polymer science. Part A, Polymer chemistry》2002,40(22):4020-4023
An oligo(p‐phenylene vinylene) that contains terpyridine ligands has been synthesized. Upon addition of metal ions, a π‐conjugated metallo polymer is formed in which the well‐defined character of oligomers and the material properties of polymers are combined. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4020–4023, 2002 相似文献
102.
Summary The behaviour of codeine reineckate and codeine tetraphenylborate membrane electrodes has been observed with a respectiveNernstian response of 58 and 56 mV/decade for 9.3×10–5–1.3×10–3
M codeine sulfate solutions. The workingpH ranges were 5–8 and 4–8, respectively. The selectivity towards sugars, amines, amino acids, cations, and some pharmaceutical compounds was found to be satisfactory. The isothermal temperature coefficient was 0.0014 V/°C. The electrodes were applied successfully for the determination of codeine in some pharmaceutical dosage forms with a relative standard deviation range of 0.16–0.30% and an average recovery of 98.6±0.6%.
Herstellung und Charakterisierung einer codeinselektiven Elektrode
Zusammenfassung Das Verhalten von Codeinreineckat- und Codeintetraphenylboratmembranelektroden in 9.3×10–5–1.3×10–3 M Codeinsulfatlösungen wurde untersucht (Nernstscher Response: 58 bzw. 56 mV/Dekade). Der verwendetepH-Bereich für die beiden Elektroden war 5–8 bzw. 4–8. Ihre Selektivität gegenüber Zuckern, Aminen, Aminosäuren, Kationen und einigen pharmazeutisch aktiven Verbindungen ist zufriedenstellend. Der isotherme Temperaturkoeffizient beträgt 0.0014V/°C. Die Elektroden wurden erfolgreich zur Bestimmung von Codein in einigen pharmazeutischen Präparaten eingesetzt (relative Standardabweichung: 0.16–0.30%).相似文献
103.
104.
1-Phenyl-2-(benzenesulphonyl)-ethylene and 1-phenyl-2-(benzenesulphonyl)-prop-1-ene have been shown to undergo ,-photoisomerisation, whereas 2-benzenesulphonylindene readily forms [π2 + π2] photoadducts with 2,3-dimethylbut-2-ene, cyclopentene, and cyclohexene. 相似文献
105.
Magdalena Kurdziel Elżbieta Szczepaniec-Cieciak Monika Watorczyk Barbara Dabrowska 《Journal of solution chemistry》2004,33(5):453-464
The solubility of solid 2-methyl-1,3-butadiene (isoprene) in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K has been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in the solute. The experimental value of the mole fraction solubility of solid isoprene in liquid argon at 87.3 K is (1.41 ± 0.27) × 10–6 and (1.56 ± 0.36) × 10–7 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbon in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l
12 were also calculated. At 90.0 K liquid argon is a better solvent for isoprene than is liquid nitrogen. The experimental values of the solubilities of isoprene in liquid argon and nitrogen were compared with results obtained for selected unsaturated and aromatic hydrocarbons. 相似文献
106.
Chu I Liu F Soares A Kumari P Nomeir AA 《Rapid communications in mass spectrometry : RCM》2002,16(15):1501-1505
Rapid, generic gradient liquid chromatography/tandem mass spectrometry (LC/MS/MS) assays, designed to accelerate sample analyses, have been developed to keep pace with the productivity of advanced synthetic procedures. In this study, LC/MS/MS was combined with an in vitro, cell-based, blood-brain barrier (BBB) model to evaluate the potential of new chemical entities (NCEs) to cross the BBB. This in vitro assay provides the permeability of discovery compounds across a monolayer of a primary culture of bovine brain microvessel endothelial cells in a fraction of the time that is required for in vivo studies (brain/plasma concentrations), using only 2 mg of the compound. The results are consistent with in vivo brain/plasma concentration ratio data. 相似文献
107.
The thermodynamic properties of the mixed aqueous electrolyte of ammonium and alkaline earth metal nitrates have been studied using the hygrometric method at 25?°C. The water activities of these {yNH4NO3+(1?y)Y(NO3)2}(aq) systems with Y ≡ Ba2+, Mg2+ and Ca2+ were measured at total molalities ranging from 0.10 mol?kg?1 to saturation for different NH4NO3 ionic-strength fractions of y=0.20, 0.50 and 0.80. These data allow the calculation of osmotic coefficients. From these measurements, the ionic mixing parameters are determined and used to calculate the solute activity coefficients in the mixtures at different ionic-strength fractions. The results of these ternary solution measurements are compared with those for binary solutions of the alkaline earth nitrates of magnesium, calcium and barium with ammonium nitrates. The behavior of the aqueous electrolyte solutions containing mixtures of barium or calcium or magnesium with ammonium nitrates are correlated and show that ionic interactions are more important for the system containing Mg2+ than for Ca2+ or Ba2+. The trends are mainly due to the effects of the ionic size, polarizability and the hydration of the ions in these solutions. 相似文献
108.
Studies on 16-Membered Azothia- and Azoxythiacrown Ethers as Ion Carriers in Ion Selective Membranes
Jolanta Szczygelska-Tao Jan F. Biernat Łukasz Górski Elżbieta Malinowska 《Journal of inclusion phenomena and macrocyclic chemistry》2004,49(1-2):167-171
16-Membered azothia- and azoxythiacrown ethers have been studied as ion carriers in ion-selective membranes. Their selectivities towards alkali, alkaline earth, transition and heavy metal cations were evaluated. The complex formation constants for these compounds with chosen cations have been determined using segmented sandwich membranes method. 相似文献
109.
A silica-based stationary phase with surface bound silylpropyl trialkylammonium functions was introduced and evaluated in the capillary electrochromatography of alkylbenzenes and pesticides. This stationary phase is referred to as octadecyldimethyl(3-trimethoxysilylpropyl) ammonium-silica (ODAS) and has quaternary amine functions that generate an anodic electroosmotic flow (EOF) and octadecyl functions that are responsible for solute retention by a reversed-phase chromatography mechanism. The ODAS stationary phase was characterized over a wide range of elution conditions in term of EOF and retention behavior of alkylbenzene homologous series. The ODAS stationary phase proved useful in the separation of pesticides as well as in the on-column preconcentration of dilute pesticide samples, thus permitting the detection of solution at 7 x 10(-7) M using a UV detector. 相似文献
110.
Ayoub Mourjane Hafida Hanine El Mustapha El Adnany Mourad Ouhammou Nadia Hidar Bouchra Nabil Ahcne Boumendjel Khalid Bitar Mostafa Mahrouz 《Molecules (Basel, Switzerland)》2022,27(10)
Argania spinosa L. Skeels is an emblematic tree in Morocco, known worldwide for its medicinal and nutritional value. Its fruits contain kernels used to prepare an edible oil, the leaves are used to feed livestock, and its wood is used as fuel. If the oil acquires high importance, the other components of the fruit of the argan are undervalued. Our objective is to invest the waste of the argan industry. Particularly, our study aimed to assess the effect of thermal activation of argan pulp on its therapeutic value, its phenolic profile and its functional and physicochemical properties. After heat treatment, the HPLC analysis for the average total phenolic content varied from 2% to 37%, depending on temperature. The antioxidant activity was increased with heat treatment. Higher values of antioxidant activity, polyphenol and pigment content were recorded at 70 °C. Functional properties analysis indicated that water solubility index and water absorption capacity were significantly affected by heat stress. Physicochemical analysis showed that moisture content, titratable acidity and soluble solids were affected. 相似文献