The Experts below are selected from a list of 35622 Experts worldwide ranked by ideXlab platform
Min Wang - One of the best experts on this subject based on the ideXlab platform.
-
vanadyl sulfate a simple catalyst for oxidation of alcohols with molecular oxygen in combination with 2 2 6 6 tetramethyl piperidyl 1 oxyl
Catalysis Communications, 2010Co-Authors: Min Wang, Yizheng HuangAbstract:Abstract Inexpensive vanadyl sulfate was developed in combination with 2,2,6,6-tetramethyl-piperidyl-1-oxyl (TEMPO) for catalytic oxidation of alcohols with molecular oxygen. A wide range of alcohols were oxidized to the corresponding carbonyl compounds in good conversions under mild conditions. No ligands or extra bases were used. Acetonitrile was the Suitable Solvent to keep the high activity of this system.
Hosny Ibrahim - One of the best experts on this subject based on the ideXlab platform.
-
carbon paste electrode modified with silver thimerosal for the potentiometric flow injection analysis of silver i
Analytica Chimica Acta, 2005Co-Authors: Hosny IbrahimAbstract:Abstract The utility of carbon paste electrode modified with silver ethylmercurythiosalicylate (silver thimerosal) in both static mode and flow injection analysis (FIA) is demonstrated. The electrode was fully characterized in terms of composition, response time, thermal stability, usable pH and ionic strength ranges. It has been shown that diisononyl phthalate (DINP) acts as more Suitable Solvent mediator for preparation of the electrode, which exhibits linear response range to Ag(I) extending from 5.0 × 10 −7 to 1.0 × 10 −3 M with detection limit of 2.5 × 10 −7 M and Nernstian slope of 59.3 ± 1.0 mV/decade. The proposed chemically modified carbon paste electrode shows a very good selectivity for Ag(I) over a wide variety of metal ions and successfully used for the determination of the silver content of silver sulphadiazine (burning cream) and developed radiological films. The electrode was also used as an indicator electrode in the potentiometric titration of thiopental and thimerosal with AgNO 3 .
-
chemically modified carbon paste electrode for the potentiometric flow injection analysis of piribedil in pharmaceutical preparation and urine
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Hosny IbrahimAbstract:Abstract A new carbon paste electrode selective for piribedil (PD) was prepared and fully characterized in terms of composition, usable pH range, response time and thermal stability. The electrode active recognition is by liquid ion-exchange mechanism via the use of piribedil phosphomolybdate as ion-exchanger dissolved in tricresyl phosphate as a more Suitable Solvent mediator for the paste. The modified electrode showed a Nernstian slope of 58.4 ± 0.6 mV over the concentration range of 7.5 × 10 −7 to 1 × 10 −3 M with an average recovery of 98.3–101.0% and R.S.D. of 0.45–1.31%. The electrode exhibits good selectivity for PD with respect to a large number of inorganic cations, organic cations, sugars and amino acids. The developed electrode was successfully used for the potentiometric determination of PD in its aqueous solutions, pharmaceutical preparation, and urine in batch and flow injection analysis (FIA).
Yizheng Huang - One of the best experts on this subject based on the ideXlab platform.
-
vanadyl sulfate a simple catalyst for oxidation of alcohols with molecular oxygen in combination with 2 2 6 6 tetramethyl piperidyl 1 oxyl
Catalysis Communications, 2010Co-Authors: Min Wang, Yizheng HuangAbstract:Abstract Inexpensive vanadyl sulfate was developed in combination with 2,2,6,6-tetramethyl-piperidyl-1-oxyl (TEMPO) for catalytic oxidation of alcohols with molecular oxygen. A wide range of alcohols were oxidized to the corresponding carbonyl compounds in good conversions under mild conditions. No ligands or extra bases were used. Acetonitrile was the Suitable Solvent to keep the high activity of this system.
B Satyavathi - One of the best experts on this subject based on the ideXlab platform.
-
isobaric phase equilibrium of morpholine 1 decanol volumetric properties and molar refractivity from 293 15 to 333 15 k of morpholine 1 decanol and 1 octanol toluene system with applications of prigogine flory patterson theory
Thermochimica Acta, 2017Co-Authors: Alka Kumari, Vineet Aniya, Nilesh Vijay Rane, Prathap Kumar Thella, B SatyavathiAbstract:Abstract Morpholine, having its applications in process industries is also used as an anticancer agent as well as a building block in the preparation of linezolid antibiotic. 1-decanol can be used as a Suitable Solvent for recovery of morpholine from its aqueous stream. The present study involves VLE studies and volumetric properties of the morpholine + 1-decanol, at 13.32, 39.99, 66.66 and 94.90 kPa. Wilson, NRTL, and UNIFAC models were used to correlate and predict the experimental VLE data. Further, thermodynamic properties such as excess molar volume ( V m E ), and deviation in molar refractivity (ΔR). Partial molar volume ( V ¯ i ), apparent molar volume ( V ϕ i ) and excess partial molar volume ( V ¯ i E ) were also estimated. Moreover, all the above thermodynamic properties have also been estimated for the 1-octanol + toluene mixture at different temperatures. The applicability of Prigogine–Flory–Patterson theory and different mixing rules were tested for the excess molar volumes and refractive indices, respectively.
Changhai Wang - One of the best experts on this subject based on the ideXlab platform.
-
preparative separation and purification of alkaloids from rhizoma coptidis by high speed counter current chromatography
Separation and Purification Technology, 2011Co-Authors: Shaojun Zhang, Mingyv Wang, Changhai WangAbstract:Abstract A fast and simple Solvent system screening method was established based on average polarity, which was much easier to find a Suitable Solvent system for high-speed counter-current chromatography (HSCCC) separation. Six alkaloids were separated and purified simultaneously with n-hexane–ethyl acetate–methanol–water (2:5:2:5) on HSCCC in one step. As a result, 4.7 mg palmatine, 7.1 mg berberine, 0.8 mg worenine, 1.5 mg epiberberine, 1.9 mg coptisine and 0.6 mg jatrorrhizine from 20 mg Rhizoma coptidis extract were obtained with the purities of 98.5%, 94.1%, 90.4%, 95.5%, 88.4% and 91.1% respectively as determined by high-performance liquid chromatography (HPLC), and they were characterized by MS and 1 H NMR.
-
separation and purification of dl tetrahydropalmatine from corydalis yanhusuo w t wang by hsccc with a new Solvent system screening method
Journal of Liquid Chromatography & Related Technologies, 2008Co-Authors: Shaojun Zhang, Xiaolei Wang, Fan Ouyang, Changhai WangAbstract:A fast and simple Solvent system screening method was established based on average polarity, which was much easier to find a Suitable Solvent system for high speed countercurrent chromatography separation. Dl-tetrahydropalmatine was separated and purified in one step with n-hexane-ethyl acetate-methanol-water (4-6-5-5) on high speed countercurrent chromatography. Acetic acid was successfully used to adjust the pH value of the sample solution to improve recovery of the separation. As a result, 4.37mg dl-tetrahydropalmatine was separated from 25 mg crude extract at the purity of 92.7% with the recovery of 95.1%.
