Vials

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Vials

  • glass vial


  • Selected Abstracts


    Titelbild: Quelle: Robotic Arm Lifting Vial in Pharmaceutical Factory, PhotoDisc, Inc./Getty Images (Chem. Ing.

    CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 12 2007
    Tech. 12/2007)
    No abstract is available for this article. [source]


    Microwave Chemistry in Silicon Carbide Reaction Vials: Separating Thermal from Nonthermal Effects,

    ANGEWANDTE CHEMIE, Issue 44 2009
    David Obermayer Mag.
    Ölbadchemie unter Mikrowellenbestrahlung: In Reaktionsgefäßen aus Siliciumcarbid (SiC) können Experimente, wie sie in einem Autoklaven mit Wärmeübertragung ausgeführt würden, in einem Mikrowellenreaktor simuliert werden, weil das elektromagnetische Feld der Mikrowellen durch die SiC-Gefäße effizient abgeschirmt wird. Dieses Verfahren ermöglicht es, den Einfluss von Mikrowelleneffekten zu studieren. [source]


    Closeup of Pipette and Vials ©PhotoDisc/Getty Images (Chem. Eng.

    CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2008
    Technol.
    No abstract is available for this article. [source]


    ChemInform Abstract: Parallel Microwave Synthesis of 2-Styrylquinazolin-4(3H)-ones in a High-Throughput Platform Using HPLC/GC Vials as Reaction Vessels.

    CHEMINFORM, Issue 50 2009
    Mostafa Baghbanzadeh
    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 of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Utility of additional slides from residual PreservcytÔ material in difficult ThinPrep® gynecologic specimens: A prospective study of 58 cases

    DIAGNOSTIC CYTOPATHOLOGY, Issue 2 2001
    H. Daniel Hoerl M.D.
    Abstract ThinPrep® purportedly increases the sensitivity of cervicovaginal cytology for detecting abnormal squamous and glandular cells. The value of additional slides from residual PreservcytÔ material to characterize difficult lesions is unknown. Fifty-eight cases were studied to determine the utility of additional slides for diagnosis and to assess cellular uniformity. In 32 (55%), repeat slides helped make a definitive diagnosis, including 18 atypical squamous cells of uncertain significance (ASCUS) reclassified as low-grade squamous intraepithelial lesion (LGSIL) (13), high-grade squamous intraepithelial lesion (HGSIL) (4), or endometrial adenocarcinoma (1); 5 LGSIL reclassified as HGSIL; 3 atypical glandular cells of uncertain significance (AGUS) reclassified as LGSIL (1) or HGSIL (2); 2 LGSIL?HGSIL classified as LGSIL; and 4 cases confirmed as LGSIL (2) or HGSIL (2). Results were compared to follow-up clinical information, including subsequent cervicovaginal samples and biopsies. The number of abnormal cells was similar between slides in most cases. We conclude that, while ThinPreps prepared from the same vial have similar numbers of abnormal cells, additional slides can be helpful for diagnosis in select cases. Diagn. Cytopathol. 2001;25:141,147. © 2001 Wiley-Liss, Inc. [source]


    Commercial manufacturing scale formulation and analytical characterization of therapeutic recombinant antibodies

    DRUG DEVELOPMENT RESEARCH, Issue 3 2004
    Reed J. Harris
    Abstract Stable therapeutic antibody dosage forms present production technology challenges, particularly when high-concentration formulations are needed to meet the elevated dose requirements that are generally required for successful antibody therapy. Solid dosage forms, such as lyophilized powders, are generally more stable than liquid formulations. High-concentration drug products can be achieved by reconstitution of the lyophilisate in a smaller volume than its initial (pre-lyophilization) volume, but requires a significant vial overfill. High-concentration liquid formulations are becoming feasible as new techniques and technologies become available. Analytical methods to detect subtle molecular variations have been developed to demonstrate manufacturing consistency. Some molecular heterogeneity is contributed by conserved sites, such as Asn297 glycosylation and the loss of heavy chain C-terminal Lys residues. Characteristics that affect potency, stability, or immunogenicity must be elucidated for each therapeutic antibody. Drug Dev. Res. 61:137,154, 2004. © 2004 Wiley-Liss, Inc. [source]


    A minimalist approach to the effects of density-dependent competition on insect life-history traits

    ECOLOGICAL ENTOMOLOGY, Issue 4 2002
    Philip Agnew
    Abstract ,1. Due to its effects on the phenotypic and genotypic expression of life-history traits, density-dependent competition is an important factor regulating the growth of populations. Specifically for insects, density-dependent competition among juveniles is often associated with increased juvenile mortality, delayed maturity, and reduced adult size. 2. The aim of the work reported here was to test whether the established phenotypic effects of density-dependent competition on life-history traits could be reproduced in an experimental design requiring a minimal number of individuals. Larvae of the mosquito Aedes aegypti were reared at densities of one, two, or three individuals per standard Drosophila vial and in six different conditions of larval food availability. This design required relatively few individuals per independent replicate and included a control treatment where individuals reared at a density of one larva per vial experienced no density-dependent interactions with other larvae. 3. Increased larval densities or reduced food availability led to increased larval mortality, delayed pupation, and the emergence of smaller adults that starved to death in a shorter time (indicating emergence with fewer nutritional reserves). 4. Female mosquitoes were relatively larger than males (as measured by wing length) but males tended to survive for longer. These differences increased as larval food availability increased, indicating the relative importance of these two traits for the fitness of each sex. The role of nutritional reserves for the reproductive success of males was highlighted in particular. 5. This minimalist approach may provide a useful model for investigating the effects of density-dependent competition on insect life-history traits. [source]


    Combined use of supported liquid membrane and solid-phase extraction to enhance selectivity and sensitivity in capillary electrophoresis for the determination of ochratoxin A in wine

    ELECTROPHORESIS, Issue 7 2008
    Sara Almeda
    Abstract This paper proposes a novel strategy to enhance selectivity and sensitivity in CE, using supported liquid membrane (SLM) and off-line SPE simultaneously. The determination of ochratoxin A (OA) in wine has been used to demonstrate the potential of this methodology. In the SLM step, the donor phase (either a 20,mL volume of a standard solution at pH,1 or a wine sample at pH,8) was placed in a vial, where a micromembrane extraction unit accommodating the acceptor phase (1,mL water, pH,11) in its lumen was immersed. The SLM was constructed by impregnating a porous Fluoropore Teflon (PTFE) membrane with a water-immiscible organic solvent (octanol). In the off-line SPE step, the nonpolar sorbent (C-18, 4,mg) selectively retained the target ochratoxin, enabling small volumes of acceptor phase (1,mL) to be introduced. The captured analytes were eluted in a small volume of methanol (0.1,mL). This procedure resulted in sample cleanup and concentration enhancement. The method was evaluated for accuracy and precision, and its RSD found to be 5%. The LODs for OA in the standard solutions and wine samples were 0.5 and 30,,g/L, respectively. The results obtained demonstrate that SLM combined with off-line is a good alternative to the use of immunoaffinity columns prior to CE analysis. [source]


    Electrokinetic partial filling technique as a powerful tool for enantiomeric separation of DL -lactic acid by CE with contactless conductivity detection

    ELECTROPHORESIS, Issue 11 2007
    zslav Maier Dr.
    Abstract A modified partial filling method for chiral separation of DL -lactic acid as the model chiral compound with vancomycin chloride as the chiral selector was developed by CE with contactless conductivity detection. Electrokinetic partial filling technique (EK-PFT) was used as an alternative method to the conventional hydrodynamic partial filling method. EK-PFT, in contrast to the hydrodynamic partial filling technique, allowed the removal of the chloride counterions from the chiral selector which otherwise led to poor sensitivity in conductivity detection. The baseline separation of DL -lactic acid as the model analyte was achieved in 5,min in a polyacrylamide-coated capillary. The best resolution was achieved by electrokinetic partial filling of vancomycin cations from the injection solution containing 5,mmol/L oxalate L -histidinium at pH,4.5 with 10,mmol/L vancomycin chloride. Computer simulation was used to explain the observed phenomena in the boundary between the inject vial and the capillary during the EK-PFT of vancomycin cations. [source]


    Integrating Biosensors and Drug Delivery: A Step Closer Toward Scalable Responsive Drug-Delivery Systems

    ADVANCED MATERIALS, Issue 6 2009
    Han-Kuan Anthony Tsai
    A miniature biosensor immobilized on the backside of a gold lid is protected inside a microfabricated vial. To activate the protected biosensor, the conjugated polymer/gold lid is opened by the application of 800,mV. Both independent sensing and drug delivery from the microvalves are demonstrated. [source]


    Particulate contamination of lyophilized amphotericin B preparation during reconstitution process

    JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2001
    T. Sendo
    Objective:,To investigate the effect of the reconstitution methods for the commercial amphotericin B preparation with respect to particulate contamination. Methods:,The particle counts in amphotericin B solutions reconstituted according to three different methods and amphotericin B fluids made with intravenous fluids after reconstitution were performed using a light extinction method. The particle contaminants were identified with X-ray emission spectrometry attached to a scanning electron microscope. Results:,Amphotericin B in a vial induced particle contamination during the reconstitution process, and the contamination was especially marked by shaking vigorously after injecting water into the vial. From the X-ray analysis, it appeared that the increased number of particles was derived from the amphotericin B,deoxycholate complex containing substances such as silicone released from the vial components. Amphotericin B fluid made with intravenous fluids after reconstitution also contained particles over the acceptable limits according to the Japanese or US pharmacopoeia. Conclusion:,These findings suggest that reconstituted solutions should be filtered with membrane filters and diluted fluids with in-line filters. [source]


    Active Packaging of Fresh Chicken Breast, with Allyl Isothiocyanate (AITC) in Combination with Modified Atmosphere Packaging (MAP) to Control the Growth of Pathogens

    JOURNAL OF FOOD SCIENCE, Issue 2 2010
    Joongmin Shin
    ABSTRACT:,Listeria monocytogenes,and,Salmonella typhimurium,are major bacterial pathogens associated with poultry products. Ally isothiocyanate (AITC), a natural antimicrobial compound, is reportedly effective against these pathogenic organisms. A device was designed for the controlled release of AITC with modified atmosphere packaging (MAP), and then evaluated for its ability to control the growth of,L. monocytogenes,and,S. typhimurium,on raw chicken breast during refrigerated storage. In order to obtain controlled release during the test period, a glass vial was filled with AITC and triglyceride. It was then sealed using high-density polyethylene film. The release of AITC was controlled by the concentration (mole fraction) of AITC in the triglyceride and by the AITC vapor permeability through the film. The fresh chicken samples were inoculated with one or the other of the pathogens at 104 CFU/g, and the packages (with and without AITC-controlled release device) were flushed with ambient air or 30% CO2/70% N2 before sealing, and then stored at 4 °C for up to 21 d. The maximum reduction in MAP plus AITC (compared to MAP alone) was 0.77 log CFU/g for,L.,monocytogenes,and 1.3 log CFU/g for,S.,typhimurium. The color of the chicken breast meat was affected by the concentration of AITC. Overall, a release rate of 0.6 ,g/h of AITC was found to not affect the color, whereas at 1.2 ,g/h of AITC the surface of the chicken was discolored. [source]


    Blood Cyanide Determination in Two Cases of Fatal Intoxication: Comparison Between Headspace Gas Chromatography and a Spectrophotometric Method*

    JOURNAL OF FORENSIC SCIENCES, Issue 6 2007
    Veniero Gambaro M.Sc.
    Abstract:, Blood samples of two cases were analyzed preliminarily by a classical spectrophotometric method (VIS) and by an automated headspace gas chromatographic method with nitrogen-phosphorus detector (HS-GC/NPD). In the former, hydrogen cyanide (HCN) was quantitatively determined by measuring the absorbance of chromophores forming as a result of interaction with chloramine T. In the automated HS-GC/NPD method, blood was placed in a headspace vial, internal standard (acetonitrile) and acetic acid were then added. This resulted in cyanide being liberated as HCN. The spectrophotometric (VIS) and HS-GC/NPD methods were validated on postmortem blood samples fortified with potassium cyanide in the ranges 0.5,10 and 0.05,5 ,g/mL, respectively. Detection limits were 0.2 ,g/mL for VIS and 0.05 ,g/mL for HS-GC/NPD. This work shows that results obtained by means of the two procedures were insignificantly different and that they compared favorably. They are suitable for rapid diagnosis of cyanide in postmortem cases. [source]


    Towards stereoselective radiosynthesis of ,-[11C]methyl-substituted aromatic ,-amino acids , a challenge of creation of quaternary asymmetric centre in a very short time,

    JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5-6 2007
    Alexander Popkov
    Abstract In positron emission tomography (PET) , -methyl amino acids have two potential applications: As analogues of neutransmitter precursors for the study of neurodegenerative diseases; as non-metabolised analogues of proteinogenic amino acids for the study of amino acid uptake into normal and cancer cells. Clinical applications of such amino acids are strongly limited due to their poor availability. We carried out [11C]methylation of metalocomplex synthons derived from protected DOPA or tyrosine. For [11C]methylation, sodium hydroxide (5 mg of fine dry powder) was sealed in a vial, which was flushed with dry nitrogen before addition of a solution of the complex (10 mg) and 11CH3I in 1,3-dimethylimidazolidin-2-one (300 µl). After 10 min at 25°C, a 9% radiochemical yield (decay-corrected) of a mixture of the diastereomeric , -[11C]methylDOPA complexes or a 7% radiochemical yield of a mixture of the diastereomeric , -[11C]methyltyrosine complexes was achieved. Individual diastereomers were successfully separated by preparative HPLC, diluted with excess of water and extracted on C18 cartridges. Optimisation of the procedure including hydrolysis of the complexes (hydrolytic deprotection of enantiomerically pure amino acids) and subsequent purification of the enantiomers of , -[11C]methylDOPA and , -[11C]methyltyrosine is underway. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Physico-chemical characterisation of 99mTc-tin fluoride colloid agent used for labelling white cells

    JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 6 2006
    Chris Tsopelas
    Abstract 99mTc,tin fluoride colloid is an agent used to label leucocytes, for the imaging and diagnosis of inflammatory conditions including Crohn's disease. Despite previous investigations, this radiolabelling agent is still poorly characterised. The aim of this work was to examine the process of formation and stability of 99mTc,tin fluoride colloid using mass spectrometry, membrane filtration and atomic absorption spectrophotometric techniques. Tin-oxide bonds in tin clusters were identified in the stannous fluoride reagent vial by mass spectrometry. From radioactive particle size distribution experiments, the facile disruption of radiocolloid particles with excess oxygen gas contrasted to the partial hydrolysis of Sn(II) during the formation process. Under the standard conditions, 10% of particles were determined as 1,3 µm, and this population coordinated 96% of the 99mTc added. Colloid particle formation and the reduction of 99mTc-pertechnetate is discussed. Sodium fluoride may optimise 1,3 µm radioactive particle size, by regulating particle growth. 99mTc,tin fluoride colloid is affected by positive or negative charge, as either Al, Mo ions or solid membranes, resulting in either coagulation and/or deflocculation of the particles. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Characterization of natural wax esters by MALDI-TOF mass spectrometry

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2009
    Vladimír Vrkoslav
    Abstract The applicability of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) to the analysis of wax esters (WEs) was investigated. A series of metal salts of 2,5-dihydroxybenzoic acid (DHB) was synthesized and tested as possible matrices. Alkali metal (Li, Na, K, Rb, Cs) and transition metal (Cu, Ag) salts were studied. The matrix properties were evaluated, including solubility in organic solvents, threshold laser power that should be applied for successful desorption/ionization of WEs, the nature of the matrix ions and the mass range occupied by them, and the complexity of the isotope clusters for individual metals. Lithium salt of dihydroxybenzoic acid (LiDHB) performed the best and matrices with purified lithium isotopes (6LiDHB or 7LiDHB) were recommended for WEs. Three sample preparation procedures were compared: (1) mixing the sample and matrix in a glass vial and deposition of the mixture on a MALDI plate (Mix), (2) deposition of sample followed by deposition of matrix (Sa/Ma), and (3) deposition of matrix followed by deposition of sample (Ma/Sa). Morphology of the samples was studied by scanning electron microscopy. The best sample preparation technique was Ma/Sa with the optimum sample to matrix molar ratio 1 : 100. Detection limit was in the low picomolar range. The relative response of WEs decreased with their molecular weight, and minor differences between signals of saturated and monounsaturated WEs were observed. MALDI spectra of WEs showed molecular adducts with lithium [M + Li]+. Fragments observed in postsource decay (PSD) spectra were related to the acidic part of WEs [RCOOH + Li]+ and they were used for structure assignment. MALDI with LiDHB was used for several samples of natural origin, including insect and plant WEs. A good agreement with GC/MS data was achieved. Moreover, MALDI allowed higher WEs to be analyzed, up to 64 carbon atoms in Ginkgo biloba leaves extract. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Determination of polycyclic aromatic hydrocarbons in olive oil by a completely automated headspace technique coupled to gas chromatography-mass spectrometry

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 6 2006
    Francisco J. Arrebola
    Abstract A new and completely automated method for the determination of ten relevant polycyclic aromatic hydrocarbons (PAHs) in olive oil is proposed using an extraction by the headspace (HS) technique. Quantification and confirmation steps are carried out by gas chromatography-mass spectrometry (GC-MS) combining simultaneously selected-ion monitoring (SIM) and tandem mass spectrometry (MS/MS). This combination offers on one hand an increased sensitivity and on the other hand, selective and reliable qualitative information. Sample pretreatment or clean-up are not necessary because the olive oil sample is put directly into an HS vial, automatically processed by HS and introduced into the GC-MS instrument for analysis. Because of its high selectivity and sensitivity, a triple-quadrupole (QqQ) detector coupled with the gas chromatograph allows us to limit handling. Each sample is completely processed in approximately 63 min (45 min for HS isolation and 18 min for GC-MS determination), a reduced time compared with previously published methods. The chemical and instrumental variables were preliminarily optimized using uncontaminated olive oil samples spiked with 25 µg kg,1 of each target compound. The final method was validated to ensure the quality of the results. The precision was satisfactory, with relative standard deviation (RSD) values in the range 3,9%. Recovery rates ranged from 96 to 99%. Limits of detection (LOD) were calculated as 0.02,0.06 µg kg,1 and the limits of quantification (LOQ) were obtained as 0.07,0.26 µg kg,1. It must be mentioned that the LOD and LOQ are much lower than the maximum levels established by the European Union (EU) in oils and fats intended for direct human consumption or for use as an ingredient in foods, which are set at 2 µg kg,1. All the figures of merit are completely in accordance with the latest EU legislation. This fact makes it possible to consider the proposed method as a useful tool for the control of PAHs in olive oils. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Fluoride release and uptake characteristics of aesthetic restorative materials

    JOURNAL OF ORAL REHABILITATION, Issue 8 2002
    N. Attar
    Summary The aims of this study were firstly to investigate the fluoride-releasing characteristics of two composite resins (Tetric and Valux Plus), two polyacid-modified resin composites (Compoglass and Dyract), and conventional glass,ionomer cement (Ceramfil ,). The second aim was to assess the fluoride uptake and subsequent release from the same range of materials. Fifteen discs (6 mm diameter and 1·5 mm height) were prepared for each material. Each disc was immersed in 4 ML of deionized water within a plastic vial. The release of fluoride was measured daily at 1, 2, 3, 4, 5, 15, 30 and 60 days. After daily fluoride release was measured for 60 days, samples were refluoridated in 1000-ppm sodium fluoride (NaF) solutions (pH 6·6) for 10 min and fluoride release was measured daily for a total of 5 days. The release of fluoride from aesthetic restorative materials was measured by using specific fluoride electrode and an ionanalyser. Results were statistically analysed by two-way repeated measure ANOVA and Duncan's multiple range test. The results revealed that all fluoride-containing materials (Ceramfil ,, Compoglass, Dyract, Tetric) released fluoride initially and the release was greatest at the first day. At any time during the test period Ceramfil , released the most and Valux Plus did not release any detectable fluoride (P < 0·01). Sample exposures to 1000 ppm NaF solution increased the 24-h fluoride release from all fluoride-containing materials. This difference lasted only 24,48 h after exposure. Ceramfil , had a tendency to recharge not seen with the other materials (P < 0·05). [source]


    Freeze-drying of tert- butanol/water cosolvent systems: A case report on formation of a friable freeze-dried powder of tobramycin sulfate

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2002
    Sakchai Wittaya-Areekul
    Abstract A case study is presented in which a tert -butanol (TBA)/water cosolvent system was found to be a useful means of producing freeze-dried tobramycin sulfate that readily forms a loose powder upon agitation in a specialized application in which a critical quality attribute is the ability to pour the sterile powder from the vial. Both formulation and processing variables are important in achieving acceptable physical properties of the cake as well as minimizing residual TBA levels. Liquid/liquid phase separation was observed above critical concentrations of both drug and TBA, resulting in a two-layered lyophilized cake with unacceptable appearance, physical properties, and residual TBA levels. However, the choice of tobramycin sulfate and TBA concentrations in the single-phase region of the phase diagram resulted in a lyophilized solid that can readily be poured from vials. Crystallization of TBA before drying is critical to achieving adequately low residual TBA levels, and this is reflected in the effect of thermal history of freezing on residual TBA levels, where rapid freezing results in incomplete crystallization of TBA and relatively high levels of residual solvent. Annealing at a temperature above T,g of the system after an initial freezing step significantly reduces the level of residual TBA. Secondary drying, even at increased temperature and for extended times, is not an effective method of reducing residual TBA levels. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91: 1147,1155, 2002 [source]


    Liquid,liquid,liquid microextraction followed by HPLC with UV detection for quantitation of ephedrine in urine

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2008
    Habib Bagheri
    Abstract Liquid,liquid,liquid microextraction (LLLME) in combination with HPLC and UV detection has been used as a sensitive method for the determination of ephedrine in urine samples. Extraction process was performed in a homemade total glass vial without using a Teflon ring, usually employed. Ephedrine was first extracted from 3.5 mL of urine sample (pH 12) into a microfilm of toluene/benzene (50:50). The analyte was subsequently back extracted into an acidic microdrop solution (pH 2) suspended in the organic phase. The extract was then injected into the HPLC system directly. An enrichment factor of 137 along with a good sample clean-up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 0.01,50 mg/L with regression coefficient corresponding to 0.998. The LODs and LOQs, based on a S/N of 3 and 10, were 5 and 10 ,g/L, respectively. The method was eventually applied for the determination of ephedrine in urine sample after oral administration of 5 mg single dose of drug. [source]


    Preliminary study on the monitoring of glutathione S-tranferase activity toward styrene oxide by electromigration methods

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 12 2005
    ková
    Abstract A new method has been developed for the monitoring of glutathione S-tranferase (GST) detoxification activity toward styrene oxide (SO). The enzymatic reaction was carried out directly in a thermostatted autosampler vial and the formation of conjugates between glutathione (GSH) and SO was monitored by sequential MEKC runs. The determinations were performed in a 50-,m fused silica capillary using 50 mM SDS in 20 mM phosphate 20 mM tetraborate buffer (pH 8.3) as a background electrolyte; separation voltage 28 kV (positive polarity), temperature of capillary 25°C, and detection at 200 nm. The method is rapid, amenable to automation, and requires only small amounts of samples, which is especially important in the case of GST isoenzyme analyses. [source]


    Solid phase microextraction sampling and gas chromatography/mass spectrometry for field detection of the chemical warfare agent O -ethyl S -(2-diisopropylaminoethyl) methylphosphonothiolate (VX)

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 12-13 2003
    Gary L. Hook
    Abstract A rapid detection method for the chemical warfare nerve agent VX was developed using SPME and gas chromatography/mass spectrometry (GC/MS). Five commercially available SPME fiber coatings were evaluated to determine the optimal fiber coating and conditions for extraction. The use of silanized vials was found to be necessary to limit interaction of the basic tertiary amine component of VX with the acidic silanols present in standard glass vials. The polydimethylsiloxane (PDMS) fiber was ultimately selected for completion of this work with extractions being performed at 50°C. Clothing material was spiked in the laboratory with 1 ,L of neat VX, placed in a sealed vial, and taken into the field for SPME sampling, using optimized conditions studied. GC/MS analysis was also completed in the field using van-mounted instrumentation. With sampling and analysis completed in less than 20.0 minutes, detection of VX contamination was relatively rapid, especially considering the quality of the resulting data. The use of SPME also provides increased safety for the field analysis of VX since it does not require the handling of solvents for sample preparation and samples are not handled directly by the analyst. [source]


    Optimization of solid-phase microextraction methods for GC-MS determination of terpenes in wine

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2005
    Rosa M Peña
    Abstract Solid-phase microextraction using a 100 µm poly(dimethylsiloxane) fiber, followed by gas chromatography,mass spectrometry determination, has been optimized for the analysis of some terpenes in wine samples. The best results were obtained by direct immersion of the fiber using a sampling period of 15 min with constant magnetic stirring (1100 rpm) and an extraction temperature of 20 °C. The sample volume was 7 ml with 25% NaCl, in a 15 ml capped vial. Desorption was performed directly in the gas chromatograph injector port over 5 min at 250 °C using the splitless mode. The method is sensitive, with detection limits between 11 and 25 µg l,1, precise, with variation coefficients in the range 1.28,3.71%, and linear over more than one order of magnitude. The related conditions were used for wine sample analyses with recoveries between 71.8 and 90.9%. Solid-phase microextraction remains an attractive alternative technique due to its rapidity and because it is a solvent-free extraction. Copyright © 2005 Society of Chemical Industry [source]


    Evaluation of model compounds,polypropylene film interactions by Fourier transformed infrared spectroscopy (FTIR) method

    PACKAGING TECHNOLOGY AND SCIENCE, Issue 3 2008
    Laurent Safa
    Abstract The interactions of methyl esters, methyl ketones and aldehyde compounds with polypropylene (PP) film were investigated. PP film, placed on a glass vial, was immersed in aqueous solution containing a model flavour compound. After a determined time at 45°C, the PP film was analysed by Fourier transform infrared spectroscopy (FTIR), allowing us to follow the speed of sorption and to quantify its relative rate. ,,For PP films, we observed that the sorption strongly depended on the structure of sorbed molecules. For each functional group of flavour compounds, the sorption increased as the carbon chain number increased. A linear chain of 12,14 carbons favours the sorption more than a linear chain of eight carbons. ,,Concerning functions, the rate of sorption usually decreases from esters to ketones and to aldehydes. ,,High sorption was observed for flavour compounds with a low difference of solubility parameter (SP) value between the film and flavour [(,polymer , ,flavour)2 value]. Furthermore, by using the proposed thermodynamic affinity concept, represented as the contribution of three interactive molecular forces [dispersion (dd), polar (dp) and hydrogen bonding (dh)] between two SP values of film and flavour, packaging materials with high flavour preservation against sorption can be designed. ,,We have a good correlation between the kinetic sorption by FTIR and the SP concept. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Using community pharmacies to conduct an HSV-1 prevalence study

    PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 5 2002
    Joseph C. Veltri PharmD
    Abstract Purpose To describe the effectiveness of community-based pharmacists in conducting a study to measure the baseline prevalence of Herpes simplex virus, type-1 susceptibility to two antiviral medications in subjects with recurrent Herpes labialis Method A cross-sectional study conducted in 47 US community pharmacies. The pharmacist obtained a viral sample from the surface of the lesion, placed the virus-laden swab in a vial of holding medium, and stored it in a refrigerator until shipment to a central laboratory. Results The population that had swabs processed for viral isolation (1795) was predominantly white (90.1%) and female (67.9%) with a mean age of 37.5 years. A total of 1087 (60.3%) swabs were positive for HSV-1. On-site monitoring revealed 219 protocol deviations related to the stage of the lesion (124), not properly dating or signing the consent form (80), and indeterminate age (15). Conclusions This study demonstrates the ability of pharmacists to conduct a large surveillance study in busy community pharmacies. A population of RHL sufferers with active lesions was recruited to study pharmacies during a 5-month period. Pharmacists successfully obtained viral samples from cold sore lesions at a rate comparable to physician-conducted studies. Protocol deviations were generally not serious, and did not compromise the study results or endanger the rights or welfare of participants. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    A salivary collection method for young children

    PSYCHOPHYSIOLOGY, Issue 3 2008
    Laura K. Zimmermann
    Abstract Salivary assays are a major physiological measure in studies of child development. Traditional collection techniques have generally involved children chewing on sterile dental cotton rolls. However, research suggests that, for an accurate assay, potential contaminants need to be minimized, both from oral stimulants and the collection device. Moreover, the use of cotton requires that additional saliva be collected to compensate for the amount absorbed by the cotton itself. For these reasons I adapted the passive drooling collection protocol for use with young children. To this end, a game was created which involves frog puppets constructed so that a funnel, which serves as the frog's mouth, connects to a cryogenic vial housed in the frog's body. Details on the specifics of this methodology as well as the effectiveness of this approach are discussed. [source]


    A simple method for oxygen-18 determination of milligram quantities of water using NaHCO3 reagent

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2003
    Akira Ijiri
    This paper presents a modified H2OCO2 equilibration method for stable oxygen isotopic composition (,18O) analysis of water. This method enables rapid and simple ,18O analysis of milligram quantities of water, by employing solid reagent NaHCO3 as the CO2 source, a small (0.6,mL) glass vial for the equilibration chamber, and an isotope-monitoring gas chromatography/mass spectrometry (irm-GC/MS) system for analysis. This method has several advantages, including simple handling for the H2OCO2 equilibration (without purging and/or evacuation treatments), rapid and easy ,18O analysis of equilibrated CO2, and highly sensitive and highly precise ,18O analysis of H2O, using samples as small as 10,mg and with a precision of less than ±0.12,. The time needed to attain oxygen isotopic equilibration between CO2 and water is also comparable (17,h for 10,mg H2O and 10,h for 100,mg H2O) to other previous methods using CO2 gas for the CO2 source. The extent of ,18O variation of sample water from its initial ,18O value due to isotope exchange with added NaHCO3 is also discussed. It is concluded that the correction needed is negligible (less than 0.1,) as long as the oxygen atom ratio () is less than 3.3,±,10,3 and provided the determination is made by comparing ,18O of CO2 equilibrated with sample water and that equilibrated with standard water of a moderately close ,18O value, less than 30, difference. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Two polymorphs of 20-desmethyl-,-carotene

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2008
    Madeleine Helliwell
    Two polymorphs of 20-desmethyl-,-carotene (systematic name: 20-nor-,,,-carotene), C39H54, in monoclinic and triclinic space groups, were formed in the same vial by recrystallization from pyridine and water. Each polymorph crystallizes with the complete molecule as the asymmetric unit, and the two polymorphs show differing patterns of disorder. The , end rings of both polymorphs have the 6- s - cis conformation, and are twisted out of the plane of the polyene chain by angles of ,53.2,(8) and 47.3,(8)° for the monoclinic polymorph, and ,43.6,(3) and 56.1,(3)° for the triclinic polymorph. The cyclohexene end groups are in the half-chair conformation, but the triclinic polymorph shows disorder of one ring. Overlay of the molecules shows that they differ in the degree of nonplanarity of the polyene chains and the angles of twist of the end rings. The packing arrangements of the two polymorphs are quite different, with the monoclinic polymorph showing short intermolecular contacts of the disordered methyl groups with adjacent polyene chain atoms, and the triclinic polymorph showing ,,, stacking interactions of the almost parallel polyene chains. The determination of the crystal structures of the two title polymorphs of 20-desmethyl-,-carotene allows information to be gained regarding the structural effects on the polyene chain, as well as on the end groups, versus that of the parent compound ,-carotene. The absence of the methyl group is known to have an impact on various functions of the title compound. [source]


    Dose rounding of chemotherapy in colorectal cancer: An analysis of clinician attitudes and the potential impact on treatment costs

    ASIA-PACIFIC JOURNAL OF CLINICAL ONCOLOGY, Issue 3 2010
    Kathryn FIELD
    Abstract Aim: The aims of this study were to calculate theoretical cost savings of oxaliplatin dose rounding in colorectal cancer (CRC), and to assess clinician attitudes to chemotherapy dose rounding. Methods: Data were obtained from a prospective data repository (BioGrid Australia) from four hospitals regarding the use of oxaliplatin, given at a standard dose of 85 mg/m2. We examined potential cost savings for patients with a body surface area (BSA) between 1.77 m2 and 1.94 m2, resulting in a calculated dose up to 10% above 150 mg (a 100 mg and 50 mg vial). The attitudes of oncologists at these hospitals toward minor dose reductions were assessed. Results: From January 2003 to June 2008, of 676 patients with Stages III or IV CRC, 227 (33.58%) received oxaliplatin. Overall 66 patients (29%) had a calculated BSA between 1.77 m2 and 1.94 m2. The potential cost saving for these hospitals in one year, if oxaliplatin doses were rounded down to 150 mg, is $AU51 898. Extrapolated to the Australian population, estimated savings are over $AU2.5 million per year. Three of nine (33.3%) oncologists were comfortable with an initial dose reduction of up to 10% in the adjuvant disease setting, and seven of nine (77.8%) in the setting of metastatic disease. Conclusion: Minor dose reductions for CRC to accommodate vial sizes would lead to significant cost savings. Oncologists are more comfortable with minor dose reductions when treatment is given in a palliative setting. [source]


    Comparison of a self-administered tampon ThinPrep test with conventional pap smears for cervical cytology

    AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 3 2005
    Mardi BUDGE
    Abstract Aim: To assess a self-administered tampon specimen as an alternative method of detecting cytological abnormalities and its acceptability in comparison with a conventional Papanicolou (pap) smear. Design: Comparative observational study. Setting/population: Two hundred and seventeen women were recruited from the colposcopy clinic of an outer urban public teaching hospital and from sexual health clinics at suburban and major metropolitan hospital clinics. Methods: Participants inserted and immediately withdrew a tampon, then placed it into a vial of ThinPrep PreservCyt fluid. This was analysed by a local private pathology laboratory. Results were compared to a pap smear performed the same day or within the previous 6 months. All women with an abnormal result (tampon or pap smear) underwent a colposcopy, with or without biopsy as necessary. Participants completed a questionnaire after performing the tampon test. Outcome measures: Probabilities of tampon test detecting (i) a high grade abnormality (pHG), (ii) any cervical intraepithelial neoplasia (CIN) changes (pCINany), and (iii) any abnormalities (pabn) compared to the conventional pap smear and, if abnormal, compared to the biopsy taken at colposcopy. Acceptability of the tampon test and conventional pap smear were also measured. Results: Probabilities of the tampon test compared to pap smear: pabn sensitivity 33%, specificity 89%, PPV 59%, NPV 73%; pCINany sensitivity 23%, specificity 97%, PPV 71%, NPV 79%; pHG sensitivity 19%, specificity 98%, PPV 63%, NPV 89%. Acceptability for tampon test was 91.21% and for pap smear, 45.85%. Conclusions: Although the self-administered tampon ThinPrep method is a poor detector of cervical abnormalities compared to pap smear, it is highly acceptable to women. It has a relatively good negative predictive value (NPV). Our study suggests that if a more acceptable, sensitive method of cervical screening was found, which removed some of the existing barriers to conventional pap testing, screening rates for cervical cancer may improve. [source]