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1.
Tadalafil( TAD)and dapoxetine HCl( DAP)are recently co-formulated and both show native fluo-rescence. Therefore,a novel,accurate,specific and sensitive reversed-phase high performance liquid chroma-tographic method with fluorescence detection was developed and validated for their separation and quantitation in dosage form and human plasma using avanafil as an internal standard( IS). Separation was achieved using isocratic elution within 7. 0 min on C18 column and acetonitrile-0. 15% triethylamine( 40∶60,v/v;pH 4)as a mobile phase. The flow rate was 1. 0 mL/min and the detection was time-programmed at 330,410 and 370 nm for TAD,DAP and IS,respectively,after excitation at 236 nm. The linear ranges from 0. 01 to 30. 00 μg/mL for each drug with the limits of detection of 4. 20 and 7. 20 ng/mL for TAD and DAP,respectively. The method was validated in accordance to the International Conference on Harmonization( ICH)guidelines and was successful-ly applied to spiked human plasma with mean recoveries of 98. 17% and 98. 83% for TAD and DAP respectively. 相似文献
2.
Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for aqueous solutions of {ethambutol dihydrochloride (1) + HCl (2)} at 25 °C and various carrier solution compositions. Mutual diffusion coefficients estimated from limiting ionic conductivities using Nernst equations are used to discuss the composition dependence of the measured diffusion coefficients. 1H NMR studies, combined with DFT calculations, confirm a fully extended conformation for the diprotonated form of the drug present under these conditions, and are consistent with an electrostatic mechanism for the strongly coupled diffusion of diprotonated ethambutol and HCl. 相似文献
3.
《International journal of quantum chemistry》2018,118(4)
In the present work, an extended Hulburt–Hirschfelder oscillator model is proposed as a means of simplifying potential energy functions for direct‐potential‐fit analyses. The new potential energy function is joined smoothly to the long‐range inverse‐power dispersion energy expression. The new model is employed in direct‐potential‐fits using spectroscopic line positions that involve the ground electronic states of the principal isotopologues of hydrogen iodide and carbon monoxide, and the ground and first singlet‐sigma excited states of hydrogen fluoride and hydrogen chloride. The present methodology is found to lead to compact, flexible, and robust representations for the potential energy that compare favorably with the results of past work where more complicated models were employed. 相似文献
4.
Mudumala Veeranarayana ReddySomeshwar D. Dindulkar Yeon Tae Jeong 《Tetrahedron letters》2011,52(37):4764-4767
α-Aminophosphonates were synthesized in a simple and efficient method from the three-component condensation reaction of 5-amino 2,2-difluoro-1,3-benzodioxole, aromatic aldehydes, and diethyl phosphite by silica-supported boron trifluoride (BF3·SiO2) in ionic liquid ([bmim][HCl]) under solvent-free conditions at room temperature in good to excellent yields and short reaction times. The catalyst can be recovered and reused for several times without any significant loss of activity. It was observed that a homogeneous reaction medium proved beneficial for the yield of the reaction. 相似文献
5.
采用水热法制备了ZnIn2S4固溶体, 并通过用盐酸对其进行后处理获得了系列ZnmIn2Sm+3(m≥2, 整数)固溶体. 通过X射线衍射(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 X射线光电子能谱(XPS)、 紫外-可见漫反射光谱(UV-Vis DRS)、 荧光光谱(PL)和电化学测试对催化剂的组成、 结构和性能进行了表征. 研究了系列固溶体可见光光催化制氢活性. 结果表明, ZnIn2S4固溶体经0.5 mol/L HCl处理后能转化为Zn2In2S5固溶体, 其制氢活性为ZnIn2S4固溶体的2.2倍, 并且具有良好的稳定性. 相似文献
6.
7.
Koji Hashimoto 《Applied Surface Science》2011,257(19):8141-8150
Amorphous alloys have many attractive characteristics including extremely high corrosion resistance if the sufficient amounts of corrosion-resistant elements are added. The superiority of amorphous alloys is based on the homogeneous single phase nature without any chemical and physical heterogeneities. Although there are processing limitations to avoid the formation of heterogeneous crystalline structure in addition to no welding technology without crystallization, the application of corrosion-resistant amorphous alloys is expected particularly to the very aggressive environments, where any conventional crystalline metallic materials cannot be used. Some amorphous bulk alloys showed zero corrosion mass loss due to spontaneous passivation even in 12 M HCl. Production of amorphous bulk alloys became possible for selected compositions. The homogeneous single phase nature is also effective to form useful catalysts with unique composition and structure. An example of catalysts is for carbon dioxide methanation useful for supply of renewable energy in the form of methane. 相似文献
8.
In this study, effect of lanthanum substitution on the phase composition, lattice parameters and magnetic properties of barium hexaferrite has been studied in samples synthesized in ammonium nitrate melt. Samples, prepared with different lanthanum amount and having various initial Fe/(Ba+La) ratios in between 12 and 2 {(Ba1−xLax)·n Fe2O3, where 0≤x≤1 and 1≤n≤6)}, are sintered at temperatures from 800 to 1200 °C. The lattice parameters, both a and c, decreases with increasing La amount which results in a decrease of the unit cell volume. The scanning electron microscope micrographs show that the pure and La-substituted sample with x=0.3, both calcinated at 1000 °C, have grain sizes smaller than 1 μm. The coercivities of the La-substituted samples increase with increasing La amount and reaches to a maximum value of 5.73 kOe, when x=0.3. Sintering at higher temperatures (above 1000 °C) decreases the coercivity, resembling a transition from single to multi-domain behavior of the particles, while saturation magnetization of the samples continues to increase due to the increasing grain size. Magnetization measurements of the samples prepared with different Fe/(Ba+La) molar ratios, n's, revealed that the specific saturation magnetization slightly increases with decreasing n, while coercivities fluctuates around 5.5 kOe. However, a sharp increase in the saturation magnetization has been observed in the sample having n=1 and washed in HCl. It was measured as 59.2 emu/g at 15 kOe, which is higher than that of the pure sample (57.5 emu/g). Thus, the magnetic parameters are optimized in the sample Ba0.7La0.3Fe12O19 so as to maximize both coercivity and specific saturation magnetization in the HCl-washed sample synthesized by starting with an unusually low Fe/(Ba+La) molar ratio of 2 (or n=1). 相似文献
9.
以硝酸铈,硫酸钛为前驱体,用氨水共沉淀法制备了一系列CexTi1-xO2催化剂.利用XRD、Raman、N2吸附-脱附、H2-TPR对催化剂进行了表征并考察了其催化HCl氧化制Cl2的性能.结果表明:复合氧化物较CeO2和TiO2更加分散甚至高度弥散,大大增加了其比表面积,最高可达170.5 m2·g-1,同时CeO2与TiO2之间的相互作用显著提高了其可还原氧物种数目,改善了其氧化还原性能.催化反应结果表明,复合氧化物的活性较CeO2和TiO2显著提升,Ce0.1Ti0.9O2表现出了良好的氯化氢催化氧化能力和较好的催化稳定性,在430℃时氯气产率可以达到0.90 gCl2·gcat-1·h-1,反应60 h后,氯气产率稳定在0.76 gCl2·gcat-1·h-1. 相似文献
10.
A distinct approach for the synthesis of α-aminonitriles has been discovered by three-component reaction of nitroarenes, aldehydes, and TMSCN using indium in dilute aqueous HCl at room temperature. The products were formed in high yields (86-96%) within a short period of time (5-20 min). This one-pot conversion consists of the following steps: (i) reduction of nitro compounds to amines, (ii) formation of imines from amines and aldehydes and (iii) addition of cyanide anion to the imines. 相似文献