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Mercury Lamp (mercury + lamp)
Selected AbstractsFast quantitative determination of diuretic drugs in tablets and human urine by microchip electrophoresis with native fluorescence detectionELECTROPHORESIS, Issue 16 2007Kamal Tolba Abstract Microchip electrophoresis (MCE) with native fluorescence detection has been applied for the fast quantitative analysis of pharmaceutical formulations. For this purpose, methods for fast separation and sensitive detection of the unlabeled diuretic drugs, amiloride, triamterene, bendroflumethiazide (BFMTZ), and bumetanide were developed. An epifluorescence setup was used enabling the coupling of different lasers into a commercial fluorescence microscope. The detection sensitivity of different excitation light sources was compared utilizing either a HeCd laser (,exc,=,325,nm), a frequency quadrupled Nd:YAG laser (,exc,=,266,nm), or a mercury lamp (,exc,=,330,380,nm). At optimal conditions using the HeCd laser, the drugs were separated within 15,s with LODs less than 1,,g/mL for the four compounds. A linear relationship between concentration and peak area was obtained in the concentration range of 0.05,20,,g/mL with a mean correlation coefficient of around 0.996 for all analytes. The method was successfully applied to the analysis of the respective drugs in commercial formulations and in human urine without interference from other constituents. These data show that MCE has a great potential for reliable drug analysis. [source] Photochemistry of Salicylaldoxime in Solid Argon: An Experimental and Theoretical StudyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 27 2010Joanna Grzegorzek Abstract The photochemistry of salicylaldoxime in solid argon has been investigated by FTIR spectroscopy and DFT calculations. The salicylaldoxime molecule trapped in the matrix from the vapor above the solid sample has the most stable syn1 conformation with an intramolecular hydrogen bond. Irradiation (, > 320 nm) leads to conversion of the syn1 conformer into the syn3 one, in which the C(H)NOH and (C)OH groups are rotated around the C,C and C,O bonds, respectively, and the intramolecular hydrogen bond is broken. The photochemistry of syn3 involves three possible routes: (i) conversion of syn3 into anti2 conformer, this process requires rearrangement of the NOH group with respect to the C=N bond; (ii) photodissociation of salicylaldoxime into 2-cyanophenol and water, which form a hydrogen-bonded complex; and (iii) regeneration of the syn1 conformer. The third route is a very small contribution to the overall process. The study performed with [D2]salicylaldoxime indicates that the dehydration reaction of salicylaldoxime involves cleavage of the N,O bond and formation of OH and Ph(OH)C(H)N radicals in the first step. Then, the OH radical abstracts a hydrogen atom from the CH group to form 2-cyanophenol and water molecules. When the sample is exposed to the full output of the mercury lamp the 2-cyanophenol complex with water becomes the dominating product. [source] Formal Synthesis of Olivacine via IndolylborateHELVETICA CHIMICA ACTA, Issue 10 2008Minoru Ishikura Abstract Palladium-catalyzed tandem cyclization,cross-coupling reaction of indolylborate 2 and vinyl bromide 5 was successfully applied in a short formal synthesis of olivacine. The reaction of 2 with 5 in the presence of Pd(OAc)2 readily afforded three kinds of products, triene derivative 6 and vinylindole derivative 7, along with a small amount of the piperidine derivative 8 (Scheme,2). On the other hand, the reactions of 2 with bromide 10 or 15 were also examined (Schemes,4 and 5), and their outcome markedly depended on the relative ease of ring closure as a function of ring size. Irradiation of 6 with a high-pressure mercury lamp (,9; Scheme,2), followed by removal of the N -[(benzyloxy)carbonyl] group and subsequent oxidation afforded, after deprotection, pyridocarbazole 23, and the conversion of 23 to olivacine is known (Scheme,6). [source] Synthesis of a new photoreactive gelatin with BTDA and HEMA derivativesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Fan-Chun Ding Abstract A novel bio-affinitive, photocuring, and membrane-forming gelatin derivative was synthesized in this study. This process was based on the amide formation between carboxylic acid and the amine in methanol,water media using dicyclohexyl-carbodiimide (DCC) as a condenser. Gelatin and glycine were the sources of amine in the model reaction. Since there were two anhydride groups in each 3,3,,4,4,-benzophenone tetra-carboxylic dianhydride (BTDA) molecule, two 2-hydroxyethyl methacrylate (HEMA) molecules were used to induce the ring-opening reaction of BTDA and release two carboxylic acid groups. The resulting photoreactive gelatin was called GE-BTHE, of which the photoreactive component was the ketone groups of BTDA and HEMA that played the role of double bond supplier. This photoreactive gelatin could be converted from the transparent liquid phase into swollen membrane by a 6-min irradiation of high pressure mercury lamp. The most efficient irradiation was at 267 nm and the highest degree of swelling of the cured GE-BTHE membrane could reach 5.9. The elongation from the dried gel remained 5,10%, i.e., relatively elastic. The properties of this gelatin derivative were investigated using amide formation analysis, calculation of the gel content and the swelling ratio, and monitoring of the photocuring process. The GE-BTHE synthesized in this study should be very potential in applications such as protective wound dressings and hemostatic absorbents for minimally invasive surgery. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Sterilization system for air purifier by combining ultraviolet light emitting diodes with TiO2JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2009Xiaohui Huang Abstract BACKGROUND: Ultraviolet light emitting diodes (UV LEDs) were used as a light source in TiO2 photocatalysis because of their many advantages, such as, long life, safety, low pollution, etc. In this experiment, a light source panel was successfully fabricated with UV LEDs, the light intensities of which were relatively uniform. RESULTS: The sterilization process comprised two steps. First, an aerosol was blocked by high efficient particulate air (HEPA) filter paper coated with TiO2 photocatalyst. Second, Staphylococcus aureus in the aerosol decreased gradually in the photocatalysis process of UV LED/TiO2. After 52 h irradiation all the S. aureus were killed. CONCLUSION: The UV LED light source panel had a larger surface for irradiation than a mercury lamp. Thus, its sterilization efficiency was much better than that of traditional methods. The feasibility of UV LED/TiO2 for photocatalysis was proved. Copyright © 2009 Society of Chemical Industry [source] Hydrodynamic Cavitation to Improve Bulk Fluid to Surface Mass Transfer in a Nonimmersed Ultraviolet System for Minimal Processing of Opaque and Transparent Fluid FoodsJOURNAL OF FOOD SCIENCE, Issue 9 2007P.J. Milly ABSTRACT:, Ultraviolet (UV)-induced chemical reactions and inactivation of microorganisms in transparent and opaque fluids are strongly dependent upon the homogenous exposure of the target species to the UV irradiation. Current UV technologies used in water disinfection and food preservation applications have limited efficacy due to suspended particles shading target species. An Ultraviolet-Shockwave PowerÔ Reactor (UV-SPR) consisting of an inner rotating rotor and a stationary quartz housing and 2 end plates was used to induce ,controlled cavitation.' Eight UV low-pressure mercury lamps spaced uniformly were installed lengthwise around the quartz housing periphery. A KI to I3,chemical dosimeter for UV was used to quantify photons received by fluid in the annular space of the SPR. UV dose (J/m2) increased from 97 J/m2 at 0 rpm to over 700 J/m2 for SPR speeds above 2400 rpm. Inactivation of E. coli 25922 in apple juice and skim milk in the UV-SPR at exit temperatures below 45 °C was greater than 4.5 and 3 logs, respectively. The UV-SPR system proved successful in increasing the mass transfer of transparent and opaque fluid to the UV irradiated surface. [source] Identification of flurbiprofen and its photoproducts in methanol by gas chromatography,mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 5 2007Su-Hui Chao Abstract A sample of 10 mm flurbiprofen in methanol (or ethanol) was photoirradiated with sixteen 8 W low-pressure quartz mercury lamps irradiated at 306 nm in a Panchum PR-2000 photochemical reactor. In total, four major photoproducts derived from each sample were observed from the HPLC chromatogram. The photoproducts were separated and their structures elucidated by various spectroscopic methods. Alternatively, using GC-MS, 11 major photoproducts were observed. A reaction scheme of flurbiprofen in methanol is proposed: the photochemical reaction routes occur mainly via esterification and decarboxylation, followed by oxidation with singlet oxygen to produce a ketone, alcohols and other derivatives. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||