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1.
An HPLC assay for the determination of ketoconazole in common pharmaceutical preparations 总被引:3,自引:0,他引:3
An HPLC method is described using octadecylsilica (3 microns) with an acetonitrile phosphate buffer mobile phase containing diethylamine which is capable of separating ketoconazole [(+/-)-cis-1-acetyl-4-(4[2-(dichlorophenyl)-2- (1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl)pi perazine] from four related compounds, (R049223, R063600, R053165 and R039519) and from excipients in tablets, cream and shampoo. The method was validated using an external calibration method for tablets, shampoo and creams and a standard addition method for cream. The limits of detection for the related compounds in the presence of ketoconazole are also reported. 相似文献
2.
Hidetomo Ashitaka Kazuya Jinda Haruo Ueno 《Journal of polymer science. Part A, Polymer chemistry》1983,21(7):1989-1995
A mechanism is proposed for the polymerization of syndiotactic 1,2-polybutadiene (s-PB) with soluble cobalt-organoaluminum-CS2. The proposed active species have structures which consist of side-on coordination of CS2 to cobalt, anti-π-allyl growing end, cisoid bidentate coordination of butadiene, and activation by complex formation with organoaluminum at the nonbonded sulfur of the coordinated CS2. This proposal is based on findings for the aluminum-free catalyst Co(C4H6)(C8H13)-CS2. It is tentatively interpreted that syndiotactic 1,2 polymerization proceeds under the influence of the side-on coordinated CS2, by which the reactivity between the terminal carbons of butadiene and the C3 of the π-allyl end is enhanced. 相似文献
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Opium samples from four different locations and poppy straw from different plant varieties have been assayed using micellar capillary electrophoresis incorporating a sweeping technique. Individual alkaloids (morphine, codeine, papaverine, noscapine, thebaine, oripavine, reticuline and narceine) were quantitatively determined in the different samples by a validated capillary electrophoresis method. Unsupervised pattern recognition of the opium samples and the poppy straw samples using hierarchical cluster analysis (HCA) and principal component analysis (PCA), showed distinct clusters. Supervised pattern recognition using soft independent modelling of class analogy (SIMCA) was performed to show individual groupings and allow unknown samples to be classified according to the models built using the CZE assay results. 相似文献
5.
Maensiri S Nuansing W Klinkaewnarong J Laokul P Khemprasit J 《Journal of colloid and interface science》2006,297(2):578-583
This paper describes the fabrication of barium strontium titanate (Ba0.6Sr0.4TiO3 or BST) nanofibers by electrospinning method using a solution that contained poly(vinylpyrrolidone) and a sol-gel solution of BST. The as-spun and calcined BST/PVP composite nanofibers were characterized by TG-DTA, X-ray diffraction, FT-IR, SEM and TEM, respectively. After calcination of the as-spun BST/PVP composite nanofibers at above 700 degrees C in air for 2 h, BST nanofibers of 188+/-25 nm in diameter having well-developed cubic-perovskite structure were successfully obtained. The crystal structure and morphology of the nanofibers were influenced by the calcination temperature. Calcination at below 700 degrees C resulted in amorphous phase whereas BST with second phase such as barium titanate were formed at above 700 degrees C. Diameters of the nanofibers decreased from 208+/-35 to 161+/-18 nm with increasing calcination temperature between 600 and 800 degrees C. 相似文献
6.
Hidetomo Ashitaka Kazuya Jinda Haruo Ueno 《Journal of polymer science. Part A, Polymer chemistry》1983,21(7):1951-1972
Butadiene is polymerized by cobalt compound–organoaluminum–CS2 catalysts to give highly crystalline syndiotactic 1,2-polybutadiene (s-PB) having melting point up to 216°C. An aluminum-free catalyst, Co(C4H6)(C8H13)-CS2, is also effective. Syndiotactic polymerization with Co(C4H6)(C8H13)-CS2 is not interrupted by the addition of protic substances such as water and alcohol, but is influenced by donor or acceptor substances. The donor molecule, e.g., dimethylsulfoxide or dimethylformamide, decreases the stereoregularity, i.e., syndiotacticity and 1,2 content. An acceptor molecule of organoaluminum with appropriate acidity such as AlEt3-AlEt2Cl or tetraethylaluminoxane increases the molecular weight, stereoregularity, and yield of the polymer. In the presence of CS2 a mixture of cis-PB and s-PB was obtained by using Co(octoate)2-AlEt2Cl-H2O, with molar ratio H2O/Co less than unity. In the case of H2O/Co > 1, only cis-PB was obtained. By the addition of donor substances such as ester, ether, nitrile, and AlEt3, s-PB was obtained even when H2O/Co > 1. The amount and ratio of cis-PB and s-PB are dependent upon the nature and amount of the additives. 相似文献
7.
Jinda Khemprasit Suriyasit Kaen-ngam Bualan Khumpaitool Phalakorn Kamkhou 《Journal of magnetism and magnetic materials》2011,323(18-19):2408-2412
Iron-doped nickel oxide (Fe0.01Ni0.99O, abbreviated as FNO) nanoparticles were prepared by sol–gel process using 1,3-propanediol as a solvent and also as a chelating agent, and calcined at the various temperatures (400–1000 °C) for 2 h. The phase composition and the microstructure of the calcined products were investigated by X-ray diffraction and scanning electron microscopy techniques, respectively. Magnetic properties were measured at room temperature using a vibrating sample magnetometer. All calcined samples showed the single phase of FNO cubic rock-salt structure without the presence of any impurity phases. The crystallite size from XRD and particle size from SEM increased as calcining temperature increased. The FNO powders calcined at 400?600 °C revealed the uniform and dense spherical particles in nanosize. The room-temperature ferromagnetism was observed for all samples. When the calcining temperature was increased, the saturation magnetization decreased whereas the coercivity increased, corresponding to the less dense and larger particles. The calcined sample at 400 °C had the best magnetic properties with the highest Ms of 5.34 emu/g (at 10 kOe) and the lowest Hc of 372 Oe. 相似文献
8.
Highly crystalline gamma-Fe(2)O(3) nanoparticles with narrow size distributions that are coated with 1-undecanesulfonic acid were synthesized via two distinct approaches using oxidation and site-exchange reactions. However, similar nanocrystals protected with 1-octanol could only be achieved via the site-exchange method, while the oxidation approach led to Fe(2)O(3) nanoparticles of poor crystallinity and size uniformity. Our magnetization measurements confirmed the superparamagnetic nature of our Fe(2)O(3) nanoparticle products and the effects of the coating materials on magnetization properties. 相似文献
9.
Recycling of homogeneous catalysts could be achieved by using magnetic nanoparticles and solid-phase beads, but nanoparticle-supported catalysis proceeded much faster than its counterpart on resins. 相似文献