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Acetone
Terms modified by Acetone Selected AbstractsOn the Anticonvulsant Effect of Acetone and the Ketogenic DietEPILEPSIA, Issue 12 2002Sergei S. Likhodii First page of article [source] Study of the Reaction of 3-Formylrifamycin SV with Gaseous Ammonia and Acetone,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2006Krzysztof Bujnowski Abstract In the second stage of our study concerning the search for new antibacterial rifamycin antibiotics, reaction of the aldehydes 3-formylrifamycin SV (1) and 25- O -deacetyl-3-formylrifamycin SV with ammonia and acetone has been investigated. A new synthetic method for the preparation of a new group of rifamycin derivatives with a cyclic substituent at C-3 having a 4-piperidone structure, represented by compounds 6a, 6b, and 7a, has been developed. The structures of the compounds and a reaction mechanism have been proposed on the basis of mass spectrometry results as well as 1D and 2D 1H and 13C NMR analysis. The results of the in vitro tests confirm the antituberculous activity of the synthesized compounds. Furthermore, 6a, which is isolated in good yield, is a promising substrate for a new class of rifamycin derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Kinetic and product study of the gas-phase reaction of sabinaketone with OH radicalINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 7 2007Nathalie Carrasco Sabinaketone is one major photooxidation product of sabinene, an important biogenic volatile organic compound. This article provides the first product study and the second rate constant determination of its reaction with OH radicals. Experiments were investigated under controlled conditions for pressure and temperature in the LISA indoor simulation chamber using FTIR spectrometry. Kinetic study was carried out at 295 ± 2 K and atmospheric pressure using the relative rate technique with isoprene as the reference compound. The rate constant was found to be ksabinaketone + OH = (7.1 ± 1.0) × 10,12 molecule,1 cm3 s,1. Acetone and formaldehyde were detected as products of the reaction with the respective yields of Racetone = 0.9 ± 0.2 and RHCHO = 1.2 ± 0.3. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 415,421, 2007 [source] Morpholinium Trifluoroacetate-Catalyzed Aldol Condensation of Acetone with both Aromatic and Aliphatic AldehydesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7 2010Kristina Zumbansen Abstract We report a highly efficient, general and practical method for the aldol condensation of acetone with aromatic and aliphatic aldehydes, using morpholinium trifluoroacetate as a catalyst. [source] Biomimetic Cyclization of Small Terpenoids Promoted by Zeolite NaY: Tandem Formation of ,-Ambrinol from Geranyl AcetoneADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Constantinos Tsangarakis Abstract Zeolite NaY promotes efficiently the biomimetic cyclization of small acyclic terpenes. Geranyl and neryl acetone undergo a novel tandem 1,5-diene cyclization/carbonyl-ene reaction to form the natural product ,-ambrinol isolated in >65% yield. [source] Influence of stationary phase chemistry and mobile-phase composition on retention, selectivity, and MS response in hydrophilic interaction chromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6-7 2010Kenneth J. Fountain Abstract A comprehensive retention and selectivity characterization of several hydrophilic interaction chromatography (HILIC) stationary phases was performed with 28 test probes in order to study the influence of particle type, surface chemistry, and mobile-phase pH on chromatographic retention, selectivity, and MS response. Selectivity differences were compared for columns operated at both low and high pH, while ESI-MS was used to study the effects of mobile-phase pH on signal response. Additionally, acetone was explored as a potential alternative to ACN as the weak HILIC solvent. Moderate differences in selectivity were observed on the same column operated at different pH, mostly due to acidic compounds. In addition, the MS response increased when a high pH mobile phase was used, particularly for analytes that were ionized with negative ESI-MS. Even larger selectivity differences were observed for different stationary phases evaluated with the same mobile phase. Acetone was not a suitable replacement for ACN in routine HILIC separations due to differences in selectivity and MS response. Finally, the data from this study were used to establish guidelines for rapid HILIC method development of polar compounds, which is demonstrated with a mixture of histidine dipeptides and organophosphonate nerve agent metabolites. [source] Investigation of factors influencing the performance of open-tubular stationary phases in capillary electrochromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 9-10 2003Ruth Freitag Abstract Silica-based, open-tubular capillary columns bearing C8-moieties were produced by the sol gel approach. The influence of experimental conditions adjusted during the preparation of the stationary phase on the performance of the resulting capillary column were investigated in terms of the plate height, the resolution, and the capacity factors, taking the separation of three non-charged polyaromatic hydrocarbons (naphthalene, phenanthrene, pyrene) as example. Acetone served as EOF marker. The optimal synthesis protocol was then used to prepare columns for an analogous investigation of the chromatographic parameters, namely the mobile phase composition, the applied voltage and temperature, as well as the column length, thickness, and inner diameter on the performance of the capillary columns. [source] Assessment of acetone as an alternative to acetonitrile in peptide analysis by liquid chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2009Ria Fritz Acetonitrile as a solvent used in liquid chromatography/mass spectrometry (LC/MS) of peptides and proteins is a relatively toxic solvent (LD50 oral; rat; 2,460,mg/kg) compared to alternatives like methanol (LD50 oral; rat; 5,628,mg/kg) and acetone (LD50 oral; rat; 5,800,mg/kg). Strategies to minimize its consumption in LC are either to reduce the inner diameter of the column or replace acetonitrile with a suitable alternative. Methanol is often recommended to replace acetonitrile in peptide analysis. In this study however, the main focus lies on another alternative solvent for LC/MS of peptides; acetone. A number of model proteins were tryptically digested and the peptide solutions were analyzed on a linear trap quadrupole (LTQ) mass spectrometer. The performances of acetonitrile, methanol and acetone were compared according to the quality of the chromatograms obtained and identification of the peptides using the BioWorksÔ software developed by Thermo Scientific. In accordance to the elutropic series, acetone was found to significantly reduce the retention times of peptides separated by C18 column material with regard to acetonitrile while methanol led to increased retention times. Acetone was the superior solvent to methanol for most of the tested model proteins reaching similar sequence coverage and numbers of identified peptides as acetonitrile. We therefore propose acetone as an alternative to acetonitrile in LC/MS of peptides. Copyright © 2009 John Wiley & Sons, Ltd. [source] A method for the histochemical localization of digestive enzymes in whole freeze-substituted larval fish embedded in glycol methacrylateAQUACULTURE RESEARCH, Issue 7 2009Grant W Vandenberg Abstract In order to study the localization of digestive enzymes in larval walleye (Sander vitreus vitreus), a novel method of low-temperature processing of whole, unfixed larvae and subsequent embedding in glycol methacrylate (GMA) was developed. Larval walleye aged 2,10 days post hatch were flash-frozen in liquid nitrogen and transferred into pre-chilled acetone for 12 h at a temperature of ,25 °C. Acetone was gradually replaced with increasing concentrations of GMA resin monomer over a 6-h period. The polymer (100%) was further allowed to infiltrate the larvae for 36 h. Resin-embedded larvae were transferred to embedding moulds and polymerized overnight at ,25 °C. Four micrometre sections were stained to identify either alkaline phosphatase, non-specific esterase, aminopeptidase M or dipeptidyl peptidase IV. All enzymes studied were readily detected and accurately localized, and no enzyme diffusion was observed. Therefore, freeze substitution combined with low-temperature GMA embedding allows the maintenance of excellent tissue morphology and accurate enzyme localization in whole larval walleye specimens from 2 to 10 days post hatch. It is recommended, however, that samples be frozen in pre-cooled fluorocarbon-based liquid coolants in order to assure optimal tissue preservation. [source] Enhanced Glucose to Fructose Conversion in Acetone with Xylose Isomerase Stabilized by Crystallization and Cross-LinkingBIOTECHNOLOGY PROGRESS, Issue 5 2004Kati M. Vilonen The effects of acetone and ethanol on glucose to fructose conversion catalyzed by soluble and cross-linked crystalline (CLXIC) xylose isomerase were studied. Relative to pure buffer solvent, the fructose production rate was more than doubled in 50% acetone. The same kind of increase in the isomerization rate was not seen with ethanol. Increase both in acetone and in ethanol concentration in the reaction solvent enhanced the production of fructose. At 50 °C in pure buffer solvent the reaction mixture contained 49% fructose in equilibrium and in 90% acetone the fructose equilibrium content was 64%. Furthermore, CLXIC was relatively stable in the presence of high concentration of acetone: 70,80% of activity was left after incubation for 24 h at 50 °C in buffer solutions (pH 7.2) containing 10,90% acetone. In buffer containing 50% ethanol only 2% of the initial activity of CLXIC was retained after 24 h at 50 °C. Soluble xylose isomerase was considerably less stable than CLXIC in both acetone- and ethanol-containing solutions. These results show that the addition of acetone enhances the production of fructose from glucose by enhancing the reaction rate and shifting the equilibrium toward fructose. However, xylose isomerase must be in the form of cross-linked crystals for maximal activity and stability. [source] ChemInform Abstract: Noyori,s Ts-DPEN Ligand: Simple Yet Effective Catalyst for the Highly Enantioselective Michael Addition of Acetone to Nitroalkenes.CHEMINFORM, Issue 35 2010Lin Peng No abstract is available for this article. [source] ChemInform Abstract: One-Pot Synthesis of 1,2,3-Triols from Allylic Hydroperoxides and a Catalytic Amount of OsO4 in Aqueous Acetone.CHEMINFORM, Issue 10 2010Cemalettin Alp Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Ruthenium-Catalyzed Asymmetric Propargylic Substitution Reactions of Propargylic Alcohols with Acetone.CHEMINFORM, Issue 13 2006Youichi Inada Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Iridium-Catalyzed Oppenauer Oxidations of Primary Alcohols Using Acetone or 2-Butanone as Oxidant.CHEMINFORM, Issue 26 2003Takeyuki Suzuki Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of the First Chiral Bidendate Bis(trifluoromethyl)phosphane Ligand through Stabilization of the Bis(trifluoromethyl)phosphanide Anion in the Presence of AcetoneCHEMISTRY - A EUROPEAN JOURNAL, Issue 35 2006Berthold Hoge Priv.-Doz. Abstract Lewis acid/Lewis base adduct formation of the P(CF3)2, ion and acetone leads to a reduced negative hyperconjugation and, therefore, limits the CF bond activation. The resulting increased thermal stability of the P(CF3)2, ion in the presence of acetone allows selective substitutions and enables the synthesis of the first example of a chiral, bidentate bis(trifluoromethyl)phosphane ligand: a DIOP derivative, [(2,2-dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene)]bis(diphenylphosphane), in which the phenyl groups at the phosphorus atoms are replaced by strong electron-withdrawing trifluoromethyl groups. The resulting high electron-acceptor strength of the synthesized bidentate (CF3)2P ligand is demonstrated by a structural and vibrational study of the corresponding tetracarbonyl,molybdenum complex. The stabilization of the P(CF3)2, ion in the presence of acetone is based on the formation of a dynamic Lewis acid/Lewis base couple, (CF3)2PC(CH3)2O,. Although there is no spectroscopic evidence for the formation of the formulated alcoholate ion, the intermediate formation of (CF3)2PC(CH3)2O, could be proved through the reaction with (CF3)2PP(CF3)2, which yields the novel phosphane,phosphinite ligand (CF3)2PC(CH3)2OP(CF3)2. This ligand readily forms square-planar Pt(II) complexes upon treatment with solid PtCl2. [source] Ab initio Study of Mechanism of Forming a Germanic Hetero-Polycyclic Compound between Germylidene (H2C=Ge:) and AcetoneCHINESE JOURNAL OF CHEMISTRY, Issue 8 2010Xiuhui Lu Abstract The mechanism of the cycloaddition reaction of forming a germanic hetero-polycyclic compound between singlet germylidene (R1) and acetone (R2) has been investigated with CCSD(T)//MP2/6-31G* method. From the surface energy profile, it can be predicted that the dominant reaction pathway for this reaction consists of three steps: (1) the two reactants (R1, R2) firstly form a twisted four-membered ring intermediate (INT2); (2) the intermediate (INT2) reacts further with acetone (R2) to give another intermediate (INT4); (3) intermediate (INT4) isomerizes to a hetero-polycyclic germanic compound (P4) via a transition state TS4. The presented rule of this reaction: the [2+2] cycloaddition effect between the , orbital of germylidene and the , orbital of ,-bonded compounds leads to the formation of four-membered ring intermediate (INT2). The 4p unoccupied orbital and the lone-pair sp electrons of Ge in the four-membered ring intermediate (INT2) react with the , orbital and the antibonding ,* orbital of ,-bonded compounds, respectively, forming the ,,p and sp, ,* cyclic donor-acceptor bonds, resulting in the generation of a stable germanic hetero-polycyclic compound (P4). [source] Performance of computationally intensive parameter sweep applications on Internet-based Grids of computers: the mapping of molecular potential energy hypersurfacesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2007S. Reyes Abstract This work focuses on the use of computational Grids for processing the large set of jobs arising in parameter sweep applications. In particular, we tackle the mapping of molecular potential energy hypersurfaces. For computationally intensive parameter sweep problems, performance models are developed to compare the parallel computation in a multiprocessor system with the computation on an Internet-based Grid of computers. We find that the relative performance of the Grid approach increases with the number of processors, being independent of the number of jobs. The experimental data, obtained using electronic structure calculations, fit the proposed performance expressions accurately. To automate the mapping of potential energy hypersurfaces, an application based on GRID superscalar is developed. It is tested on the prototypical case of the internal dynamics of acetone. Copyright © 2006 John Wiley & Sons, Ltd. [source] Stress Resistance and Environmental Dependency of Inbreeding Depression in Drosophila melanogasterCONSERVATION BIOLOGY, Issue 4 2000Jesper Dahlgaard Two important issues are whether stress and inbreeding effects are independent as opposed to synergistic, and whether inbreeding effects are general across stresses as opposed to stress-specific. We found that inbreeding reduced resistance to acetone and desiccation in adult Drosophila melanogaster, whereas resistance to knockdown heat stress was not affected. Inbred flies, however, experienced a greater proportional decrease in productivity than outbreds following heat stress. Correlations using line means indicated that all resistance traits were uncorrelated in the inbred as well as in the outbred flies. Recessive, deleterious alleles therefore did not appear to have any general deleterious effects on stress resistance. Inbreeding within a specific environment and selection for resistant genotypes may therefore purge a population of deleterious genes specific to only one environmental stress. Resumen: Tanto la endogamia como el estrés ambiental pueden tener efectos adversos sobre la adaptabilidad afectando la conservación de especies en peligro de extinción. Dos temas importantes son determinar si los efectos del estrés y la endogamia son independientes en lugar de ser sinérgicos, y determinar si los efectos de la endogamia son generales para distintos tipos de estrés o si son específicos para un tipo determinado de estrés. Encontramos que la endogamia reduce la resistencia a la acetona y la desecación en adultos de Drosophila melanogaster, mientras que la resistencia al efecto demoledor del estrés por calor no fue afectada. Sin embargo, las moscas endogámicas experimentaron una disminución proporcionalmente mayor en la productividad que aquellas moscas sin endogamia después de experimentar un estrés por calor. Las correlaciones obtenidas usando líneas medias indicaron que las características de resistencia no estuvieron correlacionadas ni en moscas con endogamia, ni en moscas sin ella. Aparentemente los alelos nocivos recesivos no tuvieron ningún efecto nocivo general en la resistencia al estrés. La endogamia dentro de un ambiente específico y la selección por genotipos resistentes podrían, por lo tanto, eliminar una población de genes nocivos específicos a un solo estrés ambiental. [source] Optimization of process parameters by Taguchi method in the recovery of lactose from whey using sonocrystallizationCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2010S. R. Patel Abstract Anti-solvent crystallization of lactose in the presence of ultrasound will reduce crystal size and the level of agglomeration as compared to the commercial cooling crystallization. It offers a potential route to enhance the physical properties as well as the rapid recovery of lactose. Since lactose recovery itself can reduce biological oxygen demand of whey by more then 80%, recovery of lactose from dairy waste stream (whey) solves the problems of dairy industries by improving economics of whey utilization and pollution reduction. In the present study, recovery of lactose from partially deproteinated whey using an anti-solvent (acetone) by sonocrystallization was optimized for finding the most influencing operating parameters; such as sonication time, anti-solvent concentration, initial lactose concentration in the whey and initial pH of sample mixture at three levels using L9 -orthogonal method. The responses were analyzed for recovery of lactose from whey. The anti-solvent concentration and the sonication time were found to be most influencing parameters for the recovery of lactose and the recovery of lactose was found to be 89.03% at the identified optimized level. The crystal size distribution of recovered lactose was found to be narrower (2.5 , 6.5 ,m) as compared to the commercial lactose crystals (3.5 , 9.5 ,m). (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth and properties of an organometallic nonlinear optical crystal: bis(isothiocyanato)-bis(4-methylpyridine)zinc(II) (Zn(SCN)2(C6H7N)2)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2006L. Y. Zhu Abstract Bis(isothiocyanato)-bis(4-methylpyridine)zinc(II)(Zn(SCN)2(C6H7N)2), (abbreviated as ZBNC) single crystals of optical quality have been grown from acetone solution by the slow temperature-lowering method. Its solubilities at different temperatures in acetone were measured. The X-ray powder diffraction (XRPD) spectroscopy of ZBNC crystal was performed at room temperature. The second harmonic generation (SHG) efficiency was determined by powder technique of Kurtz and Perry using Nd:YAG laser, which is equivalent to KDP crystal. The thermal decomposition process was characterized by thermal gravity and differential thermal analysis (TG\DTA). The specific heat of the crystal is 1440.67 J/mol·K at 325 K. The IR spectrum was recorded in the 500,3500 cm,1 region, using KBr pellets on a Nicolet 170sx FT-IR spectrometer. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and characterization of 4,4,-dihydroxy-,-methylstilbene crystalCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2006K. Rameshbabu Abstract 4,4,-dihydroxy-,-methylstilbene (DHAMS) was synthesized by condensation reaction with chloroacetone and phenol in the presence of concentrated sulfuric acid, and has been successfully grown by solution growth technique. This is the first report in the literature on the crystallization of DHAMS and exhibited the birefringent melt (liquid crystal property) of the optical properties. FTIR and FTNMR studies are in accordance with the structure. Good quality crystals were grown by slow evaporation technique by acetone as solvent. A transmission spectrum of the crystal was obtained in the region of 285 nm. The structural and optical properties were studied. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smearsCYTOPATHOLOGY, Issue 1 2010M. Uke M. Uke, B. Rekhi, D. Ajit and N. A. Jambhekar The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smears Objectives:, A diagnosis in pulmonary onco-cytopathology primarily necessitates distinguishing small cell carcinoma (SCLC) from non-small cell carcinoma (NSCLC), which includes squamous cell carcinoma and adenocarcinoma. Lately, p63 antibody has been used for distinguishing squamous cell carcinoma from SCLC and adenocarcinoma. We present an analysis of p63 expression in cytological smears from 100 bronchial lavage specimens comprising 51 cases of SCLC and 49 cases of NSCLC. Methods:, A single Papanicolaou-stained conventional smear was de-stained and re-fixed with cold acetone and methanol for immunocytochemical staining with p63 antibody. Staining results were graded as 0 (nil), 1+ (focal), 2+ (moderate, diffuse) and 3+ (strong, diffuse). Results:, Out of 100 cases, 21 were cytologically diagnosed as squamous cell carcinoma. Twenty of these showed 2+ or 3+ p63 positivity, whereas one, which was adenocarcinoma on histology, showed 1+ staining. Of seven cases cytologically diagnosed as adenocarcinoma, six showed no p63 staining, whereas one, which was squamous cell carcinoma on histology, showed 1+ staining. All 48 cases cytologically diagnosed as SCLC were confirmed as such on histology and showed no p63 staining. Four cases were cytologically designated as poorly differentiated carcinomas, of which three showed no p63 staining and one showed 3+ staining. The former three were found to be SCLC on histology while the latter was squamous cell carcinoma. The remaining 20 cases were cytologically designated as NSCLC. Of these, eight showed no p63 staining, whereas 10 showed 1+ and two showed 2+ staining. The former eight were adenocarcinoma on histology and the latter two were squamous cell carcinoma. The 10 cases that showed 1+ p63 staining were adenocarcinomas (n = 5), squamous cell carcinoma (n = 4) and NSCLC, not otherwise specified (n = 1). Positive staining was seen in normal basal cells, which acted as an internal control. Overall sensitivity of p63 for squamous cell carcinoma was 100% and specificity was 90.4%. Conclusions:, p63 immunostaining on processed cytology smears can be used to help identify squamous cell carcinoma. Its diffuse expression was specific for squamous cell carcinoma while focal staining was also seen in adenocarcinoma. [source] Quantitation of valproic acid in pharmaceutical preparations using dispersive liquid-liquid microextraction followed by gas chromatography-flame ionization detection without prior derivatizationDRUG TESTING AND ANALYSIS, Issue 7 2010Hamid Reza Sobhi Abstract Dispersive liquid-liquid microextraction (DLLME), coupled with gas chromatography-flame ionization detection (GC-FID), has been successfully used for the extraction and determination of valproic acid (VPA) in pharmaceutical preparations. In the developed method, an appropriate mixture of extracting and disperser solvents was rapidly injected into an aqueous sample. Having formed a cloudy solution, the mixture was centrifuged and then the extracting solvent was sedimented at the bottom of a conical test tube. The extract was then injected into a GC system directly, without any further pretreatment. Initially, microextraction efficiency factors were optimized and the optimum experimental conditions found were as follows: tetrachloroethylene (9.0 µL) as extracting solvent; acetone (1.0 mL) as disperser solvent; 5 mL acidic aqueous sample (pH 1) without salt addition. Under the selected conditions, the calibration curve showed linearity in the range of 0.1,5.0 mg/L with regression coefficient corresponding to 0.9998. The limit of detection was found to be 0.05 mg/L. Finally, the method was applied for the determination of VPA in two different pharmaceutical preparations. A reasonable intra-assay (3.9,10.8%, n = 3) and inter-assay (5.6,11.4%, n = 3) precision illustrated the good performance of the analytical procedure. The protocol proved to be rapid and cost-effective for screening purposes. Copyright © 2010 John Wiley & Sons, Ltd. [source] Development of a new method for analysis of Sudan dyes by pressurized CEC with amperometric detectionELECTROPHORESIS, Issue 11 2007Shaofeng Liu Abstract A new analytical method, pressurized CEC (pCEC) with amperometric detection (AD) using 1.5,,m RP nonporous silica packed columns has been developed for the rapid separation and determination of four Sudan dyes in hot chilli. The influence of several experimental parameters on the retention behavior has been investigated. The electrochemical oxidation of Sudans I,IV separated by pCEC can be reliably monitored with a carbon electrode at +0.95,V (vs. Ag/AgCl). Fast and efficient separation of the analytes was achieved within 7,min by pCEC under the optimum conditions with an ACN/water (95:5%) mobile phase containing formic acid (pH,4.3), 5% acetone and 0.002% triethylamine using a separation voltage of 12,kV. The detection limits for four Sudan dyes ranged from 8.0,×,10,7 to 1.2,×,10,6,mol/L. To evaluate the feasibility and reliability of this method, the proposed pCEC-AD method was further demonstrated with hot chilli samples spiked with Sudan dyes. [source] Determination of sertraline and N -desmethylsertraline in human plasma by CE with LIF detectionELECTROPHORESIS, Issue 11 2007Alessandro Musenga Abstract A method has been developed for the analysis of the antidepressant drug sertraline together with its main metabolite N -desmethylsertraline (DMS) in human plasma. It is based on CE with LIF detection (,,=,488,nm). A SPE procedure is employed for biological sample pretreatment, followed by a derivatization step with FITC; reboxetine was the internal standard. The effect of CD, acetone and N -methyl- D -glucamine (GLC) as constituents of the BGE for analyte separation was investigated. The final BGE consisted of 20,mM carbonate buffer, pH,9.0, with 2.5,mM heptakis(2,6-di- O -methyl)-,-CD, 50,mM GLC and 20% v/v acetone. With 30,kV applied voltage, the electrophoretic run is completed in 7.5,min. Linearity was observed in the plasma concentration range from 3.0 to 500,ng/mL for sertraline and 4.0 to 500,ng/mL for DMS. Extraction yield was >97.1%, precision , expressed as RSD% , was <3.7, accuracy (recovery) was >95.6%. Due to its sensitivity and selectivity, the method was suited for the analysis of plasma samples from patients undergoing therapy with sertraline. [source] Utilization of tannery solid waste for protease production by Synergistes sp. in solid-state fermentation and partial protease characterizationENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2009Arumugam Ganesh Kumar Abstract Synergistes sp. DQ560074 produced a protease in submerged fermentation (SmF) at 400,420,U/mL and in solid-state fermentation (SSF) at 745,755,U/g. The protease, which belongs to the aspartic protease class, was active over a wide range of pH (5,7) and at high temperatures (25,45°C). The protease is stable and active in various polar protic solvents (50%,v/v) like ethanol, isopropanol, n,butanol, in polar aprotic solvents (50%,v/v) like acetonitrile, and in non-polar solvents (50%,v/v) such as ethylacetate and toluene, but not in hydrophilic organic solvents (methyl alcohol and acetone). As far as we know, this is the first contribution to the production of a mesophilic protease with solvent stability in SSF using a proteinaceous solid waste. [source] Impact of US and Canadian precursor regulation on methamphetamine purity in the United StatesADDICTION, Issue 3 2009James K. Cunningham ABSTRACT Aims Reducing drug purity is a major, but largely unstudied, goal of drug suppression. This study examines whether US methamphetamine purity was impacted by the suppression policy of US and Canadian precursor chemical regulation. Design Autoregressive integrated moving average (ARIMA)-intervention time,series analysis. Setting Continental United States and Hawaii (1985,May 2005). Interventions US federal regulations targeting precursors, ephedrine and pseudoephedrine, in forms used by large-scale producers were implemented in November 1989, August 1995 and October 1997. US regulations targeting precursors in forms used by small-scale producers (e.g. over-the-counter medications) were implemented in October 1996 and October 2001. Canada implemented federal precursor regulations in January 2003 and July 2003 and an essential chemical (e.g. acetone) regulation in January 2004. Measurements Monthly median methamphetamine purity series. Findings US regulations targeting large-scale producers were associated with purity declines of 16,67 points; those targeting small-scale producers had little or no impact. Canada's precursor regulations were associated with purity increases of 13,15 points, while its essential chemical regulation was associated with a 13-point decrease. Hawaii's purity was consistently high, and appeared to vary little with the 1990s/2000s regulations. Conclusions US precursor regulations targeting large-scale producers were associated with substantial decreases in continental US methamphetamine purity, while regulations targeting over-the-counter medications had little or no impact. Canada's essential chemical regulation was also associated with a decrease in continental US purity. However, Canada's precursor regulations were associated with purity increases: these regulations may have impacted primarily producers of lower-quality methamphetamine, leaving higher-purity methamphetamine on the market by default. Hawaii's well-known preference for ,ice' (high-purity methamphetamine) may have helped to constrain purity there to a high, attenuated range, possibly limiting its sensitivity to precursor regulation. [source] Comparative in vitro and in vivo genotoxicities of 7H -benzo[c]fluorene, manufactured gas plant residue (MGP), and MGP fractionsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2004Leslie Cizmas Abstract Manufactured gas plant residue (MGP) is a complex mixture of polycyclic aromatic hydrocarbons (PAHs) that is tumorigenic in the lungs of mice. This study compared the relative genotoxicity of 7H -benzo[c]fluorene (BC), a PAH component of MGP, with MGP and MGP fractions in order to assess the contribution of BC to the genotoxicity of MGP. An MGP sample was separated into seven fractions (F1,F7) using silica gel column chromatography with petroleum ether (PE) followed by PE:acetone (99:1 v/v, then 98:2). PAHs were quantified using gas chromatography/mass spectrometry. An aliquot of F2, the fraction with the highest BC concentration and highest weighted mutagenic activity in Salmonella typhimurium strain TA98, was further separated using silica gel thin-layer chromatography with hexane. The first F2 subfraction, sF2-a, was enriched in BC and coeluting compounds and contained 35,000 ppm BC and 216,109 ppm carcinogenic PAHs (cPAHs, the sum of seven PAHs categorized by the U.S. EPA as class B2 carcinogens). The second F2 subfraction, sF2-b, contained a ninefold lower concentration of BC, with 3,900 ppm BC and 45,216 ppm cPAHs. Female ICR mice received topical application of crude MGP, crude MGP spiked with analytical-grade BC, F2, sF2-a, sF2-b, or analytical-grade BC. DNA adduct levels were analyzed by nuclease P1-enhanced 32P-postlabeling. In lung DNA of mice receiving 0.48 or 3.0 mg/mouse, net total RAL × 109 values were F2, 30.8 and 87.2; sF2-a, 24.8 and 106.7; and sF2-b, 19.6 and 151.0, respectively. Mice dosed with 0.10 mg analytical-grade BC (the mass of BC in 3.0 mg sF2-a) exhibited a net total RAL × 109 value of 7.03 in lung DNA. This was equal to approximately 7% of the total RAL × 109 value produced by 3.0 mg sF2-a. Thus, although BC appears to make an appreciable contribution to pulmonary adduct formation, the results suggest that MGP components other than BC play an important role in lung DNA adduct formation following topical MGP administration. Environ. Mol. Mutagen. 43:159,168, 2004. © 2004 Wiley-Liss, Inc. [source] Characterization and uncertainty analysis of VOCs emissions from industrial wastewater treatment plantsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2010Kaishan Zhang Abstract Air toxics from the industrial wastewater treatment plants (IWTPs) impose serious health concerns on its surrounding residential neighborhoods. To address such health concerns, one of the key challenges is to quantify the air emissions from the IWTPs. The objective here is to characterize the air emissions from the IWTPs and quantify its associated uncertainty. An IWTP receiving the wastewaters from an airplane maintenance facility is used for illustration with focus on the quantification of air emissions for benzyl alcohol, phenol, methylene chloride, 2-butanone, and acetone. Two general fate models, i.e., WATER9 and TOXCHEM+V3.0 were used to model the IWTP and quantify the air emissions. Monte Carlo and Bootstrap simulation were used for uncertainty analysis. On average, air emissions from the IWTP were estimated to range from 0.003 lb/d to approximately 16 lb/d with phenol being the highest and benzyl alcohol being the least. However, emissions are associated with large uncertainty. The ratio of the 97.5th percentile to the 2.5th percentile air emissions ranged from 5 to 50 depending on pollutants. This indicates point estimates of air emissions might fail to capture the worst scenarios, leading to inaccurate conclusion when used for health risk assessment. © 2009 American Institute of Chemical Engineers Environ Prog, 2010 [source] A breath test to assess compliance with disulfiramADDICTION, Issue 12 2006Keron Fletcher ABSTRACT Aims To evaluate the ability of a hand-held breath analyser, the Zenalyser® (Zenics Medical), to identify alcohol-dependent patients receiving disulfiram therapy and to assess the sensitivity and specificity of the instrument at different time intervals post-disulfiram dosing. Design Breath samples were taken from two groups of alcohol-dependent patients, one group on a daily disulfiram regimen and one group receiving no disulfiram. The breath samples were analysed for the combined concentration of carbon disulphide and acetone produced from the metabolism of disulfiram. From these data, two reference ranges were prepared and used for sensitivity and specificity assessments. Setting Breath samples for the reference ranges were obtained from patients at Shelton Hospital, Shrewsbury. Breath samples used to assess the sensitivity and specificity of the instrument were obtained from patients at the Edinburgh Alcohol Problems Clinic. Participants Twenty in-patients from Shelton Hospital receiving a daily 200 mg disulfiram regimen and 20 in-patients receiving no disulfiram. At the Edinburgh Clinic, 54 patients taking a thrice-weekly disulfiram regimen and 22 patients not on disulfiram. Measurements A total of 489 breath samples from Shelton Hospital and 391 breath samples from the Edinburgh Clinic were analysed for the combined concentrations of carbon disulphide and acetone. Findings The breath analyser produced results that distinguished between the disulfiram-treated and untreated groups (P < 0.001). At 1 day post-dose, the sensitivity was 100% and the specificity was 100%. At 2 and 3 days post-dose, the sensitivities and specificities were 84.6% and 100% and 88.2% and 100%, respectively. Conclusion The breath analyser can improve the assessment of the compliance status of patients receiving a daily dose regimen of disulfiram, but is less useful for this purpose if disulfiram is taken on a thrice-weekly regimen. [source] | ||||||||||||||||||||||||||||||||||||||||||||||