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Sample records for bead-injection lab-on-valve hyphenated

  1. Hyphenating multisyringe flow injection lab-on-valve analysis with atomic fluorescence spectrometry for on-line bead-injection preconcentration and determination of trace levels of hydride-forming elements in environmental samples

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald;

    2006-01-01

    of the functional moieties, so that maximum benefit can be taken from the application of the bead renewal strategy. The proposed procedure is characterized by a high tolerance to metal species and interfering hydride forming elements. In fact, ratios of Se(IV) to As ≤ 5000 and Sb(V) to As ≤ 500 are tolerated...... feasible by interfacing the micromachined LOV-module with AFS by a multisyringe flowing stream network for on-line post column derivatization of the eluate aimed at the generation of hydride species. The potential of this new hyphenated technique for environmental assays was ascertained via...

  2. Bead Injection Extraction Chromatography using High-capacity Lab-on-Valve as a Front End to Inductively Coupled Plasma Mass Spectrometry for Rapid Urine Radiobioassay

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    A novel bead injection (BI) extraction chromatographic microflow system exploiting high-capacity lab-on-valve (LOV) platform coupled with inductively coupled plasma mass spectrometric detection is developed for rapid and automated determination of plutonium in human urine. A microconduit (1 mL) i...

  3. A Universal Approach for Selective Trace Metal Determinations via Sequential Injection-Bead Injection-Lab-on-Valve (SI-BI-LOV) Using Renewable Reagent-loaded Hydrophobic Beads

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    -Lab-on-Valve (SI-LOV) mode. The methodology uses poly(styrene-divinylbenzene) beads containing pendant octadecyl moieties (C18-PS/DVB), which are pre-impregnated with a selective organic metal chelating agent prior to the automatic manipulation of the beads in the microbore conduits of the LOV unit. By adapting...

  4. Multisyringe flow injection lab-on-valve systems coupled to hydride generation atomic fluorescence spectrometry for on-line bead-injection preconcentration and determination of total inorganic arsenic in environmental waters

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald;

    conditions, a detection limit (3σ) of 0.02 ng mL-1 and a precision better than 6.0% at the 0.1 g L-1 level were obtained for the bead-injection mode whenever the loading sample volume was affixed at 3.0 mL. The procedure was validated by the determination of arsenic in certified reference materials...... inorganic arsenic in freshwaters. The method involves the preconcentration of arsenate(V) at pH 10 on a renewable anion exchanger, namely Q-Sepharose, packed in a LOV micro-column. The analyte species is afterwards stripped out, and concurrently pre-reduced, by a 0.25 mL of eluent containing 6 mol L-1 HCl...

  5. Exploiting the bead-injection approach in the integrated sequential injection Lab-on-Valve format using hydrophobic packing materials for on-line matrix removal and preconcentration of trace levels of cadmium in environmental and biological samples via formation of non-charged chelates prior

    DEFF Research Database (Denmark)

    Miró, Manuel; Jonczyk, Sylwia; Wang, Jianhua;

    2003-01-01

    The concept of renewable microcolumns within the conduits of an automated single injection lab-on-valve system was exploited in a sorption/elution fashion using sorbents of hydrophobic nature. The scheme's practical applicability was demonstrated for the electrothermal atomic absorption spectrome...

  6. On-line dynamic extraction and automated determination of readily bioavailable hexavalent chromium in solid substrates using micro-sequential injection bead-injection lab-on-valve hyphenated with electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2006-01-01

    ). The effect of simulated acidic rain on the accessibility of chromate forms for plant uptake was also investigated. The proposed approach offers several advantages over conventional speciation/fractionation protocols in the batch mode, including immediate separation with concomitant preconcentration...

  7. Sequential injection lab-on-valve: the third generation of flow injection analysis

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2003-01-01

    Termed the third generation of flow injection analysis, sequential injection (SI)-lab-on-valve (LOV) has specific advantages and allows novel, unique applications - not least as a versatile front end to a variety of detection techniques. This review presents snd discusses progress to date of the SI......-LOV approach as well as its applications in the automation and micro-miniaturization of on-line sample pre-treatment. Special emphasis is placed on using SI-LOV in conjunction with bead injection (BI) for on-line separation and pre-concentration of ultra-trace levels of metals by exploiting the renewable micro...

  8. Lab on valve-multisyringe flow injection system (LOV-MSFIA) for fully automated uranium determination in environmental samples.

    Science.gov (United States)

    Avivar, Jessica; Ferrer, Laura; Casas, Montserrat; Cerdà, Víctor

    2011-06-15

    The hyphenation of lab-on-valve (LOV) and multisyringe flow analysis (MSFIA), coupled to a long path length liquid waveguide capillary cell (LWCC), allows the spectrophotometric determination of uranium in different types of environmental sample matrices, without any manual pre-treatment, and achieving high selectivity and sensitivity levels. On-line separation and preconcentration of uranium is carried out by means of UTEVA resin. The potential of the LOV-MSFIA makes possible the fully automation of the system by the in-line regeneration of the column. After elution, uranium(VI) is spectrophotometrically detected after reaction with arsenazo-III. The determination of levels of uranium present in environmental samples is required in order to establish an environmental control. Thus, we propose a rapid, cheap and fully automated method to determine uranium(VI) in environmental samples. The limit of detection reached is 1.9 ηg of uranium and depending on the preconcentrated volume; it results in ppt levels (10.3 ηg L(-1)). Different water sample matrices (seawater, well water, freshwater, tap water and mineral water) and a phosphogypsum sample (with natural uranium content) were satisfactorily analyzed.

  9. Universal approach for selective trace metal determinations via sequential injection-bead injection-lab-on-valve using renewable hydrophobic bead surfaces as reagent carriers

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2005-01-01

    involves the use of poly(styrene-divinylbenzene) beads containing pendant octadecyl moieties (C18-PS/DVB), which are preimpregnated with a selective organic metal chelating agent prior to the automatic manipulation of the beads in the microbore conduits of the LOV unit. By adapting this approach...

  10. New Trends in Flow Injection Analysis: Exploitation of Sequential and Lab-on-Valve Schemes

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    which are difficult or, in fact, otherwise impossible to do, thereby opening new and novel avenues for analytical methods relying on concepts such as kinetic discriminations schemes, exploitation of metastable constituents of attractive analytical characteristics, or utilisation of detection by bio...... has appeared, that is, the Lab-on-Valve (LOV) approach, the conceptual basis of which is to incorporate all the necessary unit operational manipulations required, and, when possible, even the detection device into a single small integrated microconduit, or “laboratory”, placed atop a selection valve...

  11. Automated total and radioactive strontium separation and preconcentration in samples of environmental interest exploiting a lab-on-valve system.

    Science.gov (United States)

    Rodríguez, Rogelio; Avivar, Jessica; Ferrer, Laura; Leal, Luz O; Cerdà, Victor

    2012-07-15

    A novel lab-on-valve system has been developed for strontium determination in environmental samples. Miniaturized lab-on-valve system potentially offers facilities to allow any kind of chemical and physical processes, including fluidic and microcarrier bead control, homogenous reaction and liquid-solid interaction. A rapid, inexpensive and fully automated method for the separation and preconcentration of total and radioactive strontium, using a solid phase extraction material (Sr-Resin), has been developed. Total strontium concentrations are determined by ICP-OES and (90)Sr activities by a low background proportional counter. The method has been successfully applied to different water samples of environmental interest. The proposed system offers minimization of sample handling, drastic reduction of reagent volume, improvement of the reproducibility and sample throughput and attains a significant decrease of both time and cost per analysis. The LLD of the total Sr reached is 1.8ng and the minimum detectable activity for (90)Sr is 0.008Bq. The repeatability of the separation procedure is 1.2% (n=10).

  12. Sequential injection/bead injection lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by ETAAS and ICPMS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald; Miró, Manuel

    2003-01-01

    , that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C18-PS/DVB). Using ETAAS as detection device, the easy...... analogous R.S.D.s and LODs with respect to the conventional approach, while those with PTFE beads result in slightly inferior R.S.D.s and LODs by similar comparison, yet offering a wider dynamic range than when using an external permanent column. Moreover, the hydrophilic materials result in much higher...... enrichment of the analyte than the hydrophobic ones, although PTFE is the packing material that exhibits the best retention efficiency....

  13. Atomic absorption spectroscopy for mercury, automated by sequential injection and miniaturized in lab-on-valve system.

    Science.gov (United States)

    Erxleben, Holger; Ruzicka, Jaromir

    2005-08-15

    Sodium borohydride-based hydride generation was automated by using programmable flow within the lab-on-valve module. Mercury vapor, generated in the reaction mixture, was extracted in a gas/liquid separator. The gas-expansion separator was miniaturized and compared with the performance of a novel gas separator that exploits the combination of Venturi effect and reduced pressure. Cold vapor atomic spectroscopy was used as a model system, with detection of mercury by absorption at 254 nm and limit of detection of 9 microg of Hg/L, using 300 microL of sample and 100 microL of borohydride. This work introduces, for the first time, sequential injection technique for hydride generation, highlights advantages of using programmable flow, and outlines means for miniaturization of assays based on spectroscopy of volatile species.

  14. Interfacing microfluidic handling with spectroscopic detection for real-life applications via the lab-on-valve platform: A review

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel

    2008-01-01

    with syringe pump propelling devices as a front end to a plethora of spectroscopic detection schemes including UV-Vis spectroscopy, spectrofluorimetry, chemiluminescence, AAS, AFS and ICP-AES/MS. In contrast to lab-on-a-chip units, the versatile configuration of the micromachined LOV readily facilitates...... the implementation of on-line unit operations at will encompassing not merely the introduction of minute, well-defined volumes of sample followed by chemical derivatization, but the potential for accommodation of solid-phase extraction, hydride/vapour generation, precipitation/coprecipitation and bead injection...

  15. A green analytical method for rapid determination of pectin degree of esterification using micro sequential injection lab-on-valve system.

    Science.gov (United States)

    Naghshineh, Mahsa; Larsen, Jan; Georgiou, Constantinos; Olsen, Karsten

    2016-08-01

    A novel method for automated determination pectin degree of esterification (DE) using micro sequential injection lab-on-valve (μSI-LOV) system is developed. A face-centered central composite response surface methodology (RSM) was used to optimise system parameters. A calibration graph for determination of non-esterified galacturonic acid (GalA) content in pectin solutions with linear range of 0.08-0.34% (w/v) and the limit of detection (LOD) of 0.057% (w/v) under optimal condition was achieved. The difference between concentrations (w/v, %) of total GalA and non-esterified GalA was applied to estimate DE (%) of pectin samples. Results indicated a good agreement (tstatmanual reference method. The current method provided precision of less than 6% RSD, (n=10) with sample throughput of 15 samples h(-1). The presented method requires remarkably low consumption of sample and reagents and is thereby environmental friendly.

  16. An automatic micro-sequential injection bead injection lab-on-valve (muSI-BI-LOV) assembly for speciation analysis of ultra trace levels of Cr(III) and Cr(VI) incorporating on-line chemical reduction and employing detection by electrothermal atomic absorption spectrometry (ETAAS)

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2005-01-01

    and determination of trace levels of Cr(III) and Cr(VI) in environmental samples. The method was validated by determination of chromium species in CRM and NIST standard reference materials, and by spike recoveries of surface waters. Statistical comparison of means between experimental results and the total chromium...... certified values for the CRM and NIST materials revealed the non-existence of significant differences at a 95% confidence level....

  17. Evaluation of a novel PTFE material for separation and preconcentration of trace levels of metal ions in sequential injection (SI) and sequential injection lab-on-valve (SI-LOV) systems interfaced with detection by ETAAS

    DEFF Research Database (Denmark)

    Long, Xiangbao; Chomchoei, Roongrat; Gała, Piotr

    The operational characteristics of a novel PTFE bead material, granular Algoflon®, used for separation and preconcentration of metal ions via adsorption of on-line generated non-charged metal complexes, were evaluated in a sequential injection (SI) system furnished with an external packed column...... and in a sequential injection lab-on-valve (SI-LOV) system. Employed for the determination of cadmium(II), complexed with diethyldithiophosphate (DDPA), and detection by electrothermal atomic absorption spectrometry (ETAAS), its performance was compared to that of a previously used material, Aldrich PTFE, which had...... demonstrated that PTFE was the most promising for solid-state pretreatments. By comparing the two materials, the Algoflon® beads exhibited much higher sensitivity (1.6107 versus 0.2956 μg l-1 per integrated absorbance (s)), and better retention efficiency (82% versus 74%) and enrichment factor (20.8 versus 17...

  18. Separation and preconcentration of ultratrace levels of cadmium(II) in a sequential injection (SI) system with a PTFE packed column as a mimic sequential injection lab-on-valve (SI-LOV) system with renewable column employing detection by electrothermal atomic absorption spectrometry (ETAAS)

    DEFF Research Database (Denmark)

    Long, Xiangbao; Chomchoei, Roongrat; Gała, Piotr

    A sequential injection (SI) on-line separation and preconcentration system furnished with an external column packed with PTFE beads, serving as a mimic renewable microcolumn used in a sequential injection lab-on-valve (SI-LOV) system, was investigated for the determination of ultratrace levels...... of cadmium(II) by detection with electrothermal atomic absorption spectrometry (ETAAS). The non-charged complex formed between the analyste and the chelating reagent diethyldithiophosphate (DDPA) was selectively adsorbed on the surface of the PTFE beads and eluted by ethanol before being directed...... to the ETAAS. Two kinds of sorbents were investigated, that is, granular Algoflon® PTFE and Aldrich PTFE. A mimic external packed column was employed since difficulties of aspirating and discarding beads plus a high background signal were encountered in the renewable microcolumn SI-LOV system. As compared...

  19. Immanuel and Me With-Out Hyphen

    Directory of Open Access Journals (Sweden)

    Andre Gunder Frank

    2015-08-01

    Full Text Available This essay is my personal and intellectual tribute to Immanuel Wallerstein. It takes the form of my also personal intellectual account of our ?rst independent, then joint, and again increasingly separate journeys through the maze of the world [-] system with and without a hyphen. Imagine our relations as a horizontal Y shaped rope. It began with strands that, in the 1960s, ran parallel, becoming intertwined during the 1970s and 1980s until the strands (or at least some separated again in the 1990s, going off in increasingly different directions like a horizontal Y. Why? My answer is both circumstantial and personal, in which the personal choices and trajectories are driven primarily by world and local political circumstance. Of course, my account re?ects my own perspective on this story. However it also includes other colleagues and friends of Immanuel’s and mine, in particular our co-authors in several books and edited volumes, Giovanni Arrighi and Samir Amin, with whom I can check this account. Others, alas, are no longer with us.

  20. The Three Generations of Flow Injection Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Wang, Jianhua

    2004-01-01

    The characteristics of the three generations of flow injection analysis, that is, FIA, sequential injection analysis (SIA), and bead injection-lab-on-valve (BI-LOV), are briefly outlined, their individual advantages and shortcomings are discussed, and selected practical applications are presented....

  1. Editor's intervention in the register of compounds in archaic Portuguese texts: some reflections on the use of hyphen

    Directory of Open Access Journals (Sweden)

    Antonia Vieira dos Santos

    2014-07-01

    Full Text Available The use of hyphen within compounds was not built up before the nineteenth century. Thus, compounds spelled with hyphen in archaic Portuguese texts are a result of editing criteria adopted by editors. From this type of intervention, the relationship between hyphen use – result of a spelling convention – and the definition of compound adopted by the editor are discussed. Its absence is significant to the history of the language.

  2. Hyphenation of optimized microfluidic sample preparation with nano liquid chromatography for faster and greener alkaloid analysis

    NARCIS (Netherlands)

    Shen, Y.; Beek, van T.A.; Zuilhof, H.; Chen, B.

    2013-01-01

    A glass liquid–liquid extraction (LLE) microchip with three parallel 3.5 cm long and 100 µm wide interconnecting channels was optimized in terms of more environmentally friendly (greener) solvents and extraction efficiency. In addition, the optimized chip was successfully hyphenated with nano-liquid

  3. Multielemental speciation analysis by advanced hyphenated technique - HPLC/ICP-MS: A review.

    Science.gov (United States)

    Marcinkowska, Monika; Barałkiewicz, Danuta

    2016-12-01

    Speciation analysis has become an invaluable tool in human health risk assessment, environmental monitoring or food quality control. Another step is to develop reliable multielemental speciation methodologies, to reduce costs, waste and time needed for the analysis. Separation and detection of species of several elements in a single analytical run can be accomplished by high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC/ICP-MS). Our review assembles articles concerning multielemental speciation determination of: As, Se, Cr, Sb, I, Br, Pb, Hg, V, Mo, Te, Tl, Cd and W in environmental, biological, food and clinical samples analyzed with HPLC/ICP-MS. It addresses the procedures in terms of following issues: sample collection and pretreatment, selection of optimal conditions for elements species separation by HPLC and determination using ICP-MS as well as metrological approach. The presented work is the first review article concerning multielemental speciation analysis by advanced hyphenated technique HPLC/ICP-MS.

  4. Electrophoretic separation techniques and their hyphenation to mass spectrometry in biological inorganic chemistry.

    Science.gov (United States)

    Holtkamp, Hannah; Grabmann, Gerlinde; Hartinger, Christian G

    2016-04-01

    Electrophoretic methods have been widely applied in research on the roles of metal complexes in biological systems. In particular, CE, often hyphenated to a sensitive MS detector, has provided valuable information on the modes of action of metal-based pharmaceuticals, and more recently new methods have been added to the electrophoretic toolbox. The range of applications continues to expand as a result of enhanced CE-to-MS interfacing, with sensitivity often at picomolar level, and evolved separation modes allowing for innovative sample analysis. This article is a followup to previous reviews about CE methods in metallodrug research (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis, 2007, 28, 3436-3446; Electrophoresis, 2012, 33, 622-634), also providing a comprehensive overview of metal species studied by electrophoretic methods hyphenated to MS. It highlights the latest CE developments, takes a sneak peek into gel electrophoresis, traces biomolecule labeling, and focuses on the importance of early-stage drug development.

  5. Identification and characterization of related substances in pomalidomide by hyphenated LC-MS techniques.

    Science.gov (United States)

    Lu, Ping; Wang, Lei; Song, Min; Hang, Tai-Jun

    2015-10-10

    The current study dealt with the separation, identification and characterization of related substances in pomalidomide by hyphenated techniques. Complete separation was obtained with an Inertsil ODS-SP column (250 mm × 4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.1% formic acid solution and acetonitrile. They were characterized by hyphenated chromatographic techniques with the accurate mass determination using high resolution LC-TOF-MS methods as well as the product MS spectra determination and elucidation. The degradation behaviors of pomalidomide under ICH prescribed stress conditions were also conducted. Pomalidomide was found to be labile to degrade under acid, alkaline, oxidative and thermal stress conditions, while it was relatively stable to photolytic stress. 13 related substances were detected and identified to be 10 degradation products and three process related substances. The hyphenated LC-MS method with high resolution accurate mass determination facilitated the qualitative analysis of the unknown compounds than that of the conventional HPLC-UV. The related compounds identified are valuable for pomalidomide manufacturing process optimization and quality control.

  6. Advanced hyphenated chromatographic-mass spectrometry in mycotoxin determination: current status and prospects.

    Science.gov (United States)

    Li, Peiwu; Zhang, Zhaowei; Hu, Xiaofeng; Zhang, Qi

    2013-01-01

    Mass spectrometric techniques are essential for advanced research in food safety and environmental monitoring. These fields are important for securing the health of humans and animals, and for ensuring environmental security. Mycotoxins, toxic secondary metabolites of filamentous fungi, are major contaminants of agricultural products, food and feed, biological samples, and the environment as a whole. Mycotoxins can cause cancers, nephritic and hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders. Mycotoxin-contaminated food and feed can provoke trade conflicts, resulting in massive economic losses. Risk assessment of mycotoxin contamination for humans and animals generally depends on clear identification and reliable quantitation in diversified matrices. Pioneering work on mycotoxin quantitation using mass spectrometry (MS) was performed in the early 1970s. Now, unambiguous confirmation and quantitation of mycotoxins can be readily achieved with a variety hyphenated techniques that combine chromatographic separation with MS, including liquid chromatography (LC) or gas chromatography (GC). With the advent of atmospheric pressure ionization, LC-MS has become a routine technique. Recently, the co-occurrence of multiple mycotoxins in the same sample has drawn an increasing amount of attention. Thus, modern analyses must be able to detect and quantitate multiple mycotoxins in a single run. Improvements in tandem MS techniques have been made to achieve this purpose. This review describes the advanced research that has been done regarding mycotoxin determination using hyphenated chromatographic-MS techniques, but is not a full-circle survey of all the literature published on this topic. The present work provides an overview of the various hyphenated chromatographic-MS-based strategies that have been applied to mycotoxin analysis, with a focus on recent developments. The use of chromatographic-MS to measure levels of mycotoxins, including

  7. Application of Hyphenated Techniques in Speciation Analysis of Arsenic, Antimony, and Thallium

    Directory of Open Access Journals (Sweden)

    Rajmund Michalski

    2012-01-01

    Full Text Available Due to the fact that metals and metalloids have a strong impact on the environment, the methods of their determination and speciation have received special attention in recent years. Arsenic, antimony, and thallium are important examples of such toxic elements. Their speciation is especially important in the environmental and biomedical fields because of their toxicity, bioavailability, and reactivity. Recently, speciation analytics has been playing a unique role in the studies of biogeochemical cycles of chemical compounds, determination of toxicity and ecotoxicity of selected elements, quality control of food products, control of medicines and pharmaceutical products, technological process control, research on the impact of technological installation on the environment, examination of occupational exposure, and clinical analysis. Conventional methods are usually labor intensive, time consuming, and susceptible to interferences. The hyphenated techniques, in which separation method is coupled with multidimensional detectors, have become useful alternatives. The main advantages of those techniques consist in extremely low detection and quantification limits, insignificant interference, influence as well as high precision and repeatability of the determinations. In view of their importance, the present work overviews and discusses different hyphenated techniques used for arsenic, antimony, and thallium species analysis, in different clinical, environmental and food matrices.

  8. MetAlign: Interface-Driven, Versatile Metabolomics Tool for Hyphenated Full-Scan Mass Spectrometry Data Preprocessing

    NARCIS (Netherlands)

    Lommen, A.

    2009-01-01

    Hyphenated full-scan MS technology creates large amounts of data. A versatile easy to handle automation tool aiding in the data analysis is very important in handling such a data stream. MetAlign software-as described in this manuscript-handles a broad range of accurate mass and nominal mass GC/MS a

  9. The re-emergence of hyphenated history-and-philosophy-of-science and the testing of theories of scientific change.

    Science.gov (United States)

    Laudan, Larry; Laudan, Rachel

    2016-10-01

    A basic premise of hyphenated history-and-philosophy-of-science is that theories of scientific change have to be based on empirical evidence derived from carefully constructed historical case studies. This paper analyses one such systematic attempt to test philosophical claims, describing its historical context, rationale, execution, and limited impact.

  10. Determination of Low Level Concentrations of Metals by Means of Sequential Injection (SI) and Lab-on-Valve (LOV) Methodologies

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    in the increasing number of papers appearing in the scientific literature. These novel generations of flow injection analysis have demonstrated themselves as attractive substitutes for labour-intensive, manual sample pre-treatment and solution handling methods prior to analyte detection by atomic absorption...... to handle solid samples of environmental interest as demonstrated by the accommodation of both single and sequential extraction schemes for metal fractionation of solid samples of environmental concern (e.g. soils and sediments) packed within dedicated microcartridges. A brief account of the construction...

  11. Determination of Low Level Concentrations of Metals by Means of Sequential Injection (SI) and Lab-on-Valve (LOV) Methodologies

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel; Petersen, Roongrat

    in the substantial number of papers that have emerged in the scientific literature. These novel generations of flow injection analysis have demonstrated themselves as attractive substitutes for labour-intensive, manual sample pre-treatment and solution handling methods prior to analyte detection by atomic absorption...... of environmental interest as demonstrated by the accommodation of both single and sequential extraction schemes for metal fractionation of solid samples of environmental concern (e.g. soils and sediments) packed within dedicated microcartridges. An account of the construction and the experimental modes of operandi...

  12. Speaking the Unspeakable - The Hyphenated in the Irish-Caribbean Dialogue

    Directory of Open Access Journals (Sweden)

    Mahmoud Gewaily

    2014-12-01

    Full Text Available Speaking the unspeakable is to see how far the creative acts of cultural translation in the conflict between history and memory sharpen a natural native knack to converge in a polyphonic way. I pay special attention to the influence that the archetypal theme of speaking the unspeakable in the novel through the initiation experience of the subaltern develops and exerts in the context of increased intercultural awareness. This awareness of the cultural dilemma seems especially important because, in my observation, there is as much alienation and chaos among individuals in the daily contexts of speech communication as among heroes in the imagined communities of literary texts. The hyphenated Irish-Caribbean dialogue of this article aims to bridge cultures in the literary thought of the many writers. Padraic O Conaire and George Lamming, in the two works of Exile (E and The Pleasures of Exile (PE, respectively, are given as examples of the dialogic interlocution.

  13. Use of ionic liquids as stationary phases in hyphenated gas chromatography techniques.

    Science.gov (United States)

    Ragonese, Carla; Sciarrone, Danilo; Tranchida, Peter Quinto; Dugo, Paola; Mondello, Luigi

    2012-09-14

    In the past decades a consistent number of ionic liquids have been specifically synthesized and evaluated as stationary phase in gas chromatography. Ionic liquid, also defined as "molten salts", are a class of organic non-molecular solvents liquid at room temperature (RTILs) that satisfy most of the requirements of a GC stationary phase, among which a high viscosity, the possibility to tune the selectivity (by changing the cation-anion combination) and a high thermal stability. The choice of the proper stationary phase plays a key role in the improvement/optimization of a GC method, and although the use of IL as stationary phases is still not well-established, the general interest in their applications has greatly increased, thanks to their particular properties. The present contribution provides an overview on recent evaluations and applications of IL stationary phases, focusing in particular on the use of these novel tools in hyphenated GC-based techniques.

  14. SFC-APLI-(TOF)MS: Hyphenation of Supercritical Fluid Chromatography to Atmospheric Pressure Laser Ionization Mass Spectrometry.

    Science.gov (United States)

    Klink, Dennis; Schmitz, Oliver Johannes

    2016-01-05

    Atmospheric-pressure laser ionization mass spectrometry (APLI-MS) is a powerful method for the analysis of polycyclic aromatic hydrocarbon (PAH) molecules, which are ionized in a selective and highly sensitive way via resonance-enhanced multiphoton ionization. APLI was presented in 2005 and has been hyphenated successfully to chromatographic separation techniques like high performance liquid chromatography (HPLC) and gas chromatography (GC). In order to expand the portfolio of chromatographic couplings to APLI, a new hyphenation setup of APLI and supercritical-fluid chromatography (SFC) was constructed and aim of this work. Here, we demonstrate the first hyphenation of SFC and APLI in a simple designed way with respect to different optimization steps to ensure a sensitive analysis. The new setup permits qualitative and quantitative determination of native and also more polar PAH molecules. As a result of the altered ambient characteristics within the source enclosure, the quantification of 1-hydroxypyrene (1-HP) in human urine is possible without prior derivatization. The limit of detection for 1-HP by SFC-APLI-TOF(MS) was found to be 0.5 μg L(-1), which is lower than the 1-HP concentrations found in exposed persons.

  15. [Novel Hyphenated Techniques of Atomic Spectrometry for Metal Species Interaction with Biomolecules].

    Science.gov (United States)

    Li, Yan; Yan, Xiu-ping

    2015-09-01

    Trace metals may be adopted by biological systems to assist in the syntheses and metabolic functions of genes (DNA and RNA) and proteins in the environment. These metals may be beneficial or may pose a risk to humans and other life forms. Novel hybrid techniques are required for studies on the interaction between different metal species and biomolecules, which is significant for biology, biochemistry, nutrition, agriculture, medicine, pharmacy, and environmental science. In recent years, our group dwells on new hyphenated techniques based on capillary electrophoresis (CE), electrothermal atomic absorption spectrometry (ETAAS), and inductively coupled plasma mass spectroscopy (ICP-MS), and their application for different metal species interaction with biomolecules such as DNA, HSA, and GSH. The CE-ETAAS assay and CE-ICP-MS assay allow sensitively probing the level of biomolecules such as DNA damage by different metal species and extracting the kinetic and thermodynamic information on the interactions of different metal species with biomolecules, provides direct evidences for the formation of different metal species--biomolecule adducts. In addition, the consequent structural information were extracted from circular dichroism (CD) and X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The present works represent the most complete and extensive study to date on the interactions between different metal species with biomolecules, and also provide new evidences for and insights into the interactions of different metal species with biomolecules for further understanding of the toxicological effects of metal species.

  16. Basic Principles of Planar Chromatography and Its Potential for Hyphenated Techniques

    Science.gov (United States)

    Tuzimski, Tomasz

    Sample preparation, detection, identification, and quantitative determination of biomolecules are presented in this chapter. Advantages of planar chromatography and the basic principles (chambers, sample application, and chromatogram development) are also described. Rapid detection of biomolecules plays a strategical role in their investigation. Hyphenated techniques such as planar chromatography coupled to UV diode array detection and to mass spectrometry provide on-line extensive structural information on the metabolites prior to their isolation. In this chapter, the combination of thin-layer chromatography (TLC) with biomolecules specific detection by diode array scanning (DAD), mass spectrometry (MS), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (TLC-FTIR) is discussed. In the last part of the chapter, the reader will gain useful information about a recent method of planar chromatography - multidimensional planar chromatography (MD-PC) and information on application of different modes of multidimensional planar chromatography and combination of this technique with diode array detection (MD-PC-DAD) and HPLC-DAD for separation, detection, and qualitative and quantitative determination of biomolecules. Planar chromatography as a pilot technique for HPLC is also described.

  17. Chromatographic analysis of Polygalae Radix by online hyphenating pressurized liquid extraction

    Science.gov (United States)

    Song, Yuelin; Song, Qingqing; Li, Jun; Shi, Shepo; Guo, Liping; Zhao, Yunfang; Jiang, Yong; Tu, Pengfei

    2016-06-01

    Practicing “green analytical chemistry” is of great importance when profiling the chemical composition of complex matrices. Herein, a novel hybrid analytical platform was developed for direct chemical analysis of complex matrices by online hyphenating pressurized warm water extraction followed by turbulent flow chromatography coupled with high performance liquid chromatography-tandem mass spectrometry (PWWE-TFC-LC-MS/MS). Two parallel hollow guard columns acted as extraction vessels connected to a long narrow polyether ether ketone tube, while warm water served as extraction solvent and was delivered at a flow rate of 2.5 mL/min to generate considerable back pressure at either vessel. A column oven heated both the solvent and crude materials. A TFC column, which is advantageous for the comprehensive trapping of small molecular substances from fluids under turbulent flow conditions, was employed to transfer analytes from the PWWE module to LC-MS/MS. Two electronic valves alternated each vessel between extraction and elution phases. As a proof-of-concept, a famous herbal medicine for the treatment of neurodegenerative disorders, namely Polygalae Radix, was selected for the qualitative and quantitative analyses. The results suggest that the hybrid platform is advantageous in terms of decreasing time, material, and solvent consumption and in its automation, versatility, and environmental friendliness.

  18. Hyphenated GC-FTIR and GC-MS techniques applied in the analysis of bioactive compounds

    Science.gov (United States)

    Gosav, Steluta; Paduraru, Nicoleta; Praisler, Mirela

    2014-08-01

    The drugs of abuse, which affect human nature and cause numerous crimes, have become a serious problem throughout the world. There are hundreds of amphetamine analogues on the black market. They consist of various alterations of the basic amphetamine molecular structure, which are yet not yet included in the lists of forbidden compounds although they retain or slightly modify the hallucinogenic effects of their parent compound. It is their important variety that makes their identification quite a challenge. A number of analytical procedures for the identification of amphetamines and their analogues have recently been reported. We are presenting the profile of the main hallucinogenic amphetamines obtained with the hyphenated techniques that are recommended for the identification of illicit amphetamines, i. e. gas chromatography combined with mass spectrometry (GC-MS) and gas chromatography coupled with Fourier transform infrared spectrometry (GC-FTIR). The infrared spectra of the analyzed hallucinogenic amphetamines present some absorption bands (1490 cm-1, 1440 cm-1, 1245 cm-1, 1050 cm-1 and 940 cm-1) that are very stable as position and shape, while their intensity depends of the side-chain substitution. The specific ionic fragment of the studied hallucinogenic compounds is the 3,4-methylenedioxybenzyl cation (m/e = 135) which has a small relative abundance (lesser than 20%). The complementarity of the above mentioned techniques for the identification of hallucinogenic compounds is discussed.

  19. 英语构词法中连字符构词功能分析%The Compounding Function of Hyphen in English Word-Building

    Institute of Scientific and Technical Information of China (English)

    李凤东

    2010-01-01

    连字符(hyphen)是英语书面语中一个常见符号,除一些基本语法功能外,连字符(hyphen)还具有很强的构词功能,这在很大程度上弥补了派生、转性等构词法的不足,在英语学习过程中我们应对连字符的构词功能给予足够重视.

  20. Determination of Oleanolic and Ursolic Acids in Hedyotis diffusa Using Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography

    Directory of Open Access Journals (Sweden)

    Ming-Chi Wei

    2015-01-01

    Full Text Available Oleanolic acid (OA and ursolic acid (UA were extracted from Hedyotis diffusa using a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC–CO2 extraction at different temperatures, pressures, cosolvent percentages, and SC–CO2 flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant and UA (3.540 mg/g of dry plant were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v cosolvent (ethanol/water = 82/18, v/v and SC–CO2 flowing at 2.3 mL/min (STP. The extracted yields were then analyzed by high performance liquid chromatography (HPLC to quantify the OA and UA. The present findings revealed that H. diffusa is a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA from H. diffusa at high concentrations.

  1. Hyphenation of infrared spectroscopy to liquid chromatography for qualitative and quantitative polymer analysis: Degradation of poly(bisphenol A)carbonate

    NARCIS (Netherlands)

    Coulier, L.; Kaal, E.; Hankemeier, T.

    2006-01-01

    Hyphenation of infrared spectroscopy (IR) to liquid chromatography (LC) has been applied to study chemical changes in poly(bisphenol A)carbonate (PC) as a result of degradation. Especially coupling of LC to FTIR through solvent elimination is a sensitive approach to identify changes in functionality

  2. Determination and identification of estrogenic compounds generated with biosynthetic enzymes using hyphenated screening assays, high resolution mass spectrometry and off-line NMR

    NARCIS (Netherlands)

    Vlieger, de J.S.B.; Kolkman, A.J.; Ampt, K.A.M.; Commandeur, J.N.M.; Vermeulen, N.P.E.; Kool, J.; Wijmenga, S.S.; Niessen, W.M.A.; Irth, H.; Honing, M.

    2010-01-01

    This paper describes the determination and identification of active and inactive estrogenic compounds produced by biosynthetic methods. A hyphenated screening assay towards the human estrogen receptor ligand binding domain (hER)α and hERβ integrating target–ligand interactions and liquid chromatogra

  3. Development of a microfluidic confocal fluorescence detection system for the hyphenation of nano-LC to on-line biochemical assays

    NARCIS (Netherlands)

    Heus, F.; Giera, M.A.; Kloe, de G.E.; Iperen, van D.; Buijs, J.B.; Nahar, T.T.; Smit, A.B.; Lingeman, H.; Esch, de I.J.P.; Niessen, W.M.A.; Irth, H.; Kool, J.

    2010-01-01

    One way to profile complex mixtures for receptor affinity is to couple liquid chromatography (LC) on-line to biochemical detection (BCD). A drawback of this hyphenated screening approach is the relatively high consumption of sample, receptor protein and (fluorescently labeled) tracer ligand. Here, w

  4. Two-dimensional separation of ionic species by hyphenation of capillary ion chromatography × capillary electrophoresis-mass spectrometry.

    Science.gov (United States)

    Beutner, Andrea; Kochmann, Sven; Mark, Jonas Josef Peter; Matysik, Frank-Michael

    2015-03-17

    The separation of complex mixtures such as biological or environmental samples requires high peak capacities, which cannot be established with a single separation technique. Therefore, multidimensional systems are in demand. In this work, we present the hyphenation of the two most important (orthogonal) techniques in ion analysis, namely, ion chromatography (IC) and capillary electrophoresis (CE), in combination with mass spectrometry. A modulator was developed ensuring a well-controlled coupling of IC and CE separations. Proof-of-concept measurements were performed using a model system consisting of nucleotides and cyclic nucleotides. The data are presented in a multidimensional contour plot. Analyte stacking in the CE separation could be exploited on the basis of the fact that the suppressed IC effluent is pure water.

  5. Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

    Science.gov (United States)

    Campos, Reinaldo C.; Gonçalves, Rodrigo A.; Brandão, Geisamanda P.; Azevedo, Marlo S.; Oliveira, Fabiana; Wasserman, Julio

    2009-06-01

    The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C 18 column was used as stationary phase, and post column treatment was performed by UV irradiation (60 °C, 13 W). The eluate was then merged with 3 mol L - 1 HCl, reduction was performed by a NaBH 4 solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 µg L - 1 were obtained for ionic (Hg 2+) and HgCH 3+, for an injection volume of 200 µL. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sediments.

  6. Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Reinaldo C. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil)], E-mail: rccampos@puc-rio.br; Goncalves, Rodrigo A.; Brandao, Geisamanda P.; Azevedo, Marlo S. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil); Oliveira, Fabiana; Wasserman, Julio [Institut of Geosciences, Fluminense Federal University, Av. Gal. Milton Tavares de Souza, s/n, 24.210-340, Niteroi, Rio de Janeiro (Brazil)

    2009-06-15

    The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C{sub 18} column was used as stationary phase, and post column treatment was performed by UV irradiation (60 deg. C, 13 W). The eluate was then merged with 3 mol L{sup -1} HCl, reduction was performed by a NaBH{sub 4} solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 {mu}g L{sup -1} were obtained for ionic (Hg{sup 2+}) and HgCH{sub 3}{sup +}, for an injection volume of 200 {mu}L. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sedi0011men.

  7. Electrospray-Differential Mobility Hyphenated with Single Particle Inductively Coupled Plasma Mass Spectrometry for Characterization of Nanoparticles and Their Aggregates.

    Science.gov (United States)

    Tan, Jiaojie; Liu, Jingyu; Li, Mingdong; El Hadri, Hind; Hackley, Vincent A; Zachariah, Michael R

    2016-09-01

    The novel hyphenation of electrospray-differential mobility analysis with single particle inductively coupled plasma mass spectrometry (ES-DMA-spICPMS) was demonstrated with the capacity for real-time size, mass, and concentration measurement of nanoparticles (NPs) on a particle-to-particle basis. In this proof-of-concept study, the feasibility of this technique was validated through both concentration and mass calibration using NIST gold NP reference materials. A detection limit of 10(5) NPs mL(-1) was determined under current experimental conditions, which is about 4 orders of magnitude lower in comparison to that of a traditional ES-DMA setup using a condensation particle counter as detector. Furthermore, independent and simultaneous quantification of both size and mass of NPs provides information regarding NP aggregation states. Two demonstrative applications include gold NP mixtures with a broad size range (30-100 nm), and aggregated gold NPs with a primary size of 40 nm. Finally, this technique was shown to be potentially useful for real-world samples with high ionic background due to its ability to remove dissolved ions yielding a cleaner background. Overall, we demonstrate the capacity of this new hyphenated technique for (1) clearly resolving NP populations from a mixture containing a broad size range; (2) accurately measuring a linear relationship, which should inherently exist between mobility size and one-third power of ICPMS mass for spherical NPs; (3) quantifying the early stage propagation of NP aggregation with well-characterized oligomers; and (4) differentiating aggregated NPs and nonaggregated states based on the "apparent density" derived from both DMA size and spICPMS mass.

  8. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters.

    Science.gov (United States)

    Santos, Inês C; Mesquita, Raquel B R; Rangel, António O S S

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60-160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11-21 for the metal ions. A LOD of 0.23 μg L(-1) for cadmium, 2.39 μg L(-1) for zinc, and 0.11 μg L(-1) for copper and a sampling rate of 12, 13, and 15 h(-1) for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples.

  9. Recent developments in automated determinations of trace level concentrations of elements and on-line fractionations schemes exploiting the micro-sequential injection - lab-on-valve approach

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel; Long, Xiangbao;

    2006-01-01

    are presented as based on the exploitation of micro-sequential injection (μSI-LOV) using hydrophobic as well as hydrophilic bead materials. The examples given comprise the presentation of a universal approach for SPE-assays, front-end speciation of Cr(III) and Cr(VI) in a fully automated and enclosed set...

  10. Lab-on-Valve Micro Sequential Injection: A Versatile Approach for Implementing Integrated Sample Pre-preparations and Executing (Bio)Chemical Assays

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    of applications. Particular focus will be placed on its use as a vehicle for pretreatment of complex sample matrices for determination of trace-level concentrations of metal ions by electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) via exploitation...... interfering matrix constituents, or to preconcentrate the analyte material to bring it into the dynamic range of the detector. As will be shown, such pretreatments are advantageously performed in FIA/SIA/LOV manifolds, where all appropriate unit operations can be effected under enclosed and strictly...

  11. Lab-on-Valve Micro Sequential Injection: A Versatile Approach for Implementing Integrated Sample Pre-preparations and Executing (Bio)Chemical Assays

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    will be directed towards its use as a vehicle for on-line pretreatment of complex sample matrices for determination of trace-level concentrations of metal ions by electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) via exploitation of the renewable solid...... and selectivity. Either in order to separate the analyte from potentially interfering matrix constituents, or to preconcentrate the analyte material to bring it into the dynamic range of the detector. As will be shown, such pretreatments are advantageously performed in FIA/SIA/LOV manifolds, where all appropriate...

  12. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Inês C. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Mesquita, Raquel B.R. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto (Portugal); Rangel, António O.S.S., E-mail: arangel@porto.ucp.pt [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal)

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60–160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11–21 for the metal ions. A LOD of 0.23 μg L{sup −1} for cadmium, 2.39 μg L{sup −1} for zinc, and 0.11 μg L{sup −1} for copper and a sampling rate of 12, 13, and 15 h{sup −1} for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples. - Highlights: • Multi-parametric determination of cadmium, zinc, and copper at the μg L{sup −1} level. • In-line metal ions preconcentration using NTA resin. • Minimization of matrix interferences by performing solid phase spectrometry in a SI-LOV platform. • Successful application to metal ions determination in freshwaters.

  13. High performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry for V and Ni quantification as tetrapyrroles

    Energy Technology Data Exchange (ETDEWEB)

    Duyck, Christiane Beatrice, E-mail: cbduyck@vm.uff.br [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), R. Marques de Sao Vicente, 225, Gavea, Rio de Janeiro, RJ, 22451-900 (Brazil); Universidade Federal Fluminense (UFF), Campus do Valonguinho, Outeiro de Sao Joao Batista, s/no, 24020-150, Niteroi, RJ (Brazil); Saint' Pierre, Tatiana Dillenburg; Miekeley, Norbert [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), R. Marques de Sao Vicente, 225, Gavea, Rio de Janeiro, RJ, 22451-900 (Brazil); Oliveira da Fonseca, Teresa Cristina; Szatmari, Peter [Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES), Av. Horacio Macedo, 950, Cidade Universitaria, Rio de Janeiro, RJ, 21941-915 (Brazil)

    2011-05-15

    A method was developed for the determination of V and Ni as tetrapyrroles by High Performance Liquid Chromatography hyphenated to Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS) using reversed phase and elution gradient. Chlorinated solvents and tetrahydrofuran were investigated as regard to separation time and ICP-MS detection efficiencies. The final elution gradient program started from pure methanol to a mixture of 20:80 (v/v) chloroform:methanol. External quantification of V and Ni with inorganic standards by flow injection ICP-MS, used online with HPLC, resulted in 95% of recoveries. The Limits of Detection for V during methanol elution and for Ni during the 20% chloroform gradient elution were evaluated by their minimum detectable concentrations, which were, respectively, 5 {mu}g L{sup -1} and 8 {mu}g L{sup -1}. The methodology was applied to polar and resin fractions separated from a Brazilian crude oil and a sediment extract from an oil-polluted area in the Guanabara Bay, Rio de Janeiro, Brazil. Vanadium as tetrapyrroles represented the totality of V content in the polar fraction, whereas Ni was in different polar forms in the resin and sediment extract.

  14. High performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry for V and Ni quantification as tetrapyrroles

    Science.gov (United States)

    Duyck, Christiane Béatrice; Saint'Pierre, Tatiana Dillenburg; Miekeley, Norbert; da Fonseca, Teresa Cristina Oliveira; Szatmari, Peter

    2011-05-01

    A method was developed for the determination of V and Ni as tetrapyrroles by High Performance Liquid Chromatography hyphenated to Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS) using reversed phase and elution gradient. Chlorinated solvents and tetrahydrofuran were investigated as regard to separation time and ICP-MS detection efficiencies. The final elution gradient program started from pure methanol to a mixture of 20:80 (v/v) chloroform:methanol. External quantification of V and Ni with inorganic standards by flow injection ICP-MS, used online with HPLC, resulted in 95% of recoveries. The Limits of Detection for V during methanol elution and for Ni during the 20% chloroform gradient elution were evaluated by their minimum detectable concentrations, which were, respectively, 5 μg L - 1 and 8 μg L - 1 . The methodology was applied to polar and resin fractions separated from a Brazilian crude oil and a sediment extract from an oil-polluted area in the Guanabara Bay, Rio de Janeiro, Brazil. Vanadium as tetrapyrroles represented the totality of V content in the polar fraction, whereas Ni was in different polar forms in the resin and sediment extract.

  15. Different Ways to On-Line Hyphenate Centrifugal Partition Chromatography and Mass Spectrometry: Application to Prenylated Xanthones from Garcinia mangostana.

    Science.gov (United States)

    Destandau, Emilie; Michel, Thomas; Toribio, Alix; Elfakir, Claire

    2015-11-01

    Centrifugal partition chromatography is a liquid-liquid separation method well adapted for the fractionation or purification of natural compounds from plant extracts. However, following the preparative isolation, the fractions collected must be analysed by high-performance thin-layer chromatography or high-performance liquid chromatography to evaluate their composition and/or their purity. These additional steps are time-consuming and increase the risk of compound degradation. In order to get an instantaneous analysis of fraction content with structural information on the phytochemicals eluted, it is possible to hyphenate on-line centrifugal partition chromatography with mass spectrometry. Depending on the complexity of the extract, two different kinds of centrifugal partition chromatography-mass spectrometry coupling can be performed: centrifugal partition chromatography-mass spectrometry or centrifugal partition chromatography-high-performance liquid chromatography-mass spectrometry coupling. In the first case, one part of the centrifugal partition chromatography effluent is directly introduced in the mass spectrometry ionisation source to identify the eluted compounds, while in the second case, it is directed to a high-performance liquid chromatography-mass spectrometry system where compounds are first separated thanks to high-performance liquid chromatography and then identified using mass spectrometry.

  16. A Hyphenated Technique based on High-Performance Thin Layer Chromatography for Determining Neutral Sphingolipids: A Proof of Concept

    Directory of Open Access Journals (Sweden)

    Andrés Domínguez

    2015-04-01

    Full Text Available Hyphenated HPTLC has been used to analyze several neutral sphingolipids acting as lysosomal storage disease (LSD biomarkers. Automated multiple development (AMD provides separation of lipid peaks, which are detected and quantified using fluorescence detection by intensity changes (FDIC after primuline post-impregnation. A final online transfer to a mass spectrometer by means of an elution-based interface allows their identification using electrospray ionization (ESI and atmospheric pressure chemical ionization (APCI.Given that the increases in fluorescent emission detected by FDIC are produced by non-specific, electrostatic interactions between the primuline and hydrocarbon chains in the ceramide backbones of sphingolipids, it is a non-destructive detection technique, allowing the precise location and transfer of biomarker peaks to a mass spectrometer using an elution interface. By using primuline as a fluorophore, the technique is also compatible with ESI-APCI and does not interfere with the MS of sphingolipids. APCI provides useful and complementary structural information to the ESI for sphingolipid identification. Moreover, FDIC emission can be used for quantitative purposes. Results include the determination of sphingomyelin (SM in human-plasma samples (RSD < 6% by means of a standard addition method with non-linear calibration, and the identification of globotriaosylceramide (Gb3 in the plasma of a Fabry patient. Only one HPTLC plate is needed to perform the analysis.

  17. Hyphenation of a Deoxyribonuclease I immobilized enzyme reactor with liquid chromatography for the online stability evaluation of oligonucleotides.

    Science.gov (United States)

    Álvarez Porebski, Piotr Wiktor; Gyssels, Ellen; Madder, Annemieke; Lynen, Frederic

    2015-11-27

    The stability of antisense oligonucleotides (ONs) toward nucleases is a key aspect for their possible implementation as therapeutic agents. Typically, ON stability studies are performed off-line, where the ONs are incubated with nucleases in solution, followed by their analysis. The problematics of off-line processing render the detailed comparison of relative ON stability quite challenging. Therefore, the development of an online platform based on an immobilized enzyme reactor (IMER) coupled to liquid chromatography (LC) was developed as an alternative for improved ON stability testing. More in detail, Deoxyribonuclease I (DNase I) was immobilized on epoxy-silica particles of different pore sizes and packed into a column for the construction of an IMER. Subsequently, the hyphenation of the IMER with ion-pair chromatography (IPC) and ion-exchange chromatography (IEC) was evaluated, leading to the successful development of two online methodologies: IMER-IPC and IMER-IEC. More specifically, natural and modified DNA and RNA oligonucleotides were used for testing the performance of the methodologies. Both methodologies proved to be simple, automatable, fast and highly reproducible for the quantitative and qualitative evaluation of ON degradation. In addition, the extended IMER life time in combination with a more straightforward control of the reaction kinetics substantiate the applicability of the IMER-LC platform for ON stability tests and its implementation in routine and research laboratories.

  18. Hyphenated and comprehensive liquid chromatography × gas chromatography-mass spectrometry for the identification of Mycobacterium tuberculosis.

    Science.gov (United States)

    Mourão, Marta P B; Denekamp, Ilse; Kuijper, Sjoukje; Kolk, Arend H J; Janssen, Hans-Gerd

    2016-03-25

    Tuberculosis is one of the world's most emerging public health problems, particularly in developing countries. Chromatography based methods have been used to tackle this epidemic by focusing on biomarker detection. Unfortunately, interferences from lipids in the sputum matrix, particularly cholesterol, adversely affect the identification and detection of the marker compounds. The present contribution describes the serial combination of normal phase liquid chromatography (NPLC) with thermally assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) to overcome the difficulties of biomarker evaluation. The in-series combination consists of an LC analysis where fractions are collected and then transferred to the THM-GC-MS system. This was either done with comprehensive coupling, transferring all the fractions, or with hyphenated interfacing, i.e. off-line multi heart-cutting, transferring only selected fractions. Owing to the high sensitivity and selectivity of LC as a sample pre-treatment method, and to the high specificity of the MS as a detector, this analytical approach, NPLC × THM-GC-MS, is extremely sensitive. The results obtained indicate that this analytical set-up is able to detect down to 1 × 10(3) mycobacteria/mL of Mycobacterium tuberculosis strain 124, spiked in blank sputum samples. It is a powerful analytical tool and also has great potential for full automation. If further studies demonstrate its usefulness when applied blind in real sputum specimens, this technique could compete with the current smear microscopy in the early diagnosis of tuberculosis.

  19. Characterization of the Axial Jet Separator with a CO2/Helium Mixture: Toward GC-AMS Hyphenation.

    Science.gov (United States)

    Salazar, G; Agrios, K; Eichler, R; Szidat, S

    2016-02-02

    Development of interfaces for sample introduction from high pressures is important for real-time online hyphenation of chromatographic and other separation devices with mass spectrometry (MS) or accelerator mass spectrometry (AMS). Momentum separators can reduce unwanted low-density gases and introduce the analyte into the vacuum. In this work, the axial jet separator, a new momentum interface, is characterized by theory and empirical optimization. The mathematical model describes the different axial penetration of the components of a jet-gas mixture and explains the empirical results for injections of CO2 in helium into MS and AMS instruments. We show that the performance of the new interface is sensitive to the nozzle size, showing good qualitative agreement with the mathematical model. Smaller nozzle sizes are more preferable due to their higher inflow capacity. The CO2 transmission efficiency of the interface into a MS instrument is ∼ 14% (CO2/helium separation factor of 2.7). The interface receives and delivers flows of ∼ 17.5 mL/min and ∼ 0.9 mL/min, respectively. For the interfaced AMS instrument, the ionization and overall efficiencies are 0.7-3% and 0.1-0.4%, respectively, for CO2 amounts of 4-0.6 μg C, which is only slightly lower compared to conventional systems using intermediate trapping. The ionization efficiency depends on to the carbon mass flow in the injected pulse and is suppressed at high CO2 flows. Relative to a conventional jet separator, the transmission efficiency of the axial jet separator is lower, but its performance is less sensitive to misalignments.

  20. Solvent-resistant sol-gel polydimethyldiphenylsiloxane coating for on-line hyphenation of capillary microextraction with high-performance liquid chromatography.

    Science.gov (United States)

    Segro, Scott S; Malik, Abdul

    2008-09-26

    A sol-gel polydimethyldiphenylsiloxane (PDMDPS) coating was developed for capillary microextraction on-line hyphenated with high-performance liquid chromatography (HPLC). This coating was created using methyltrimethoxysilane (MTMS) as the sol-gel precursor and di-hydroxy-terminated PDMDPS as the sol-gel active polymer. The methyl and phenyl groups on the sol-gel active polymer and the methyl groups on the sol-gel precursor ultimately turned into pendant groups providing the ability to extract non-polar analytes. A 40-cm segment of 0.25 mm I.D. fused silica capillary containing the sol-gel PDMDPS coating was installed as an external sampling loop in an HPLC injection port. Aqueous samples containing polycyclic aromatic hydrocarbons (PAHs), aromatic compounds, ketones, and aldehydes were passed through this capillary wherein the analytes were extracted by the sol-gel coating. The extracted analytes were then transferred to the HPLC column using isocratic or gradient elution with an acetonitrile/water mobile phase. This capillary demonstrated excellent extraction capability for non-polar (e.g., polycyclic aromatic hydrocarbons and aromatic compounds) as well as moderately polar compounds, such as aromatic amines, ketones, and aldehydes. The test results indicate that PDMDPS can be successfully immobilized into a sol-gel network and that the resulting solvent-resistant sol-gel organic-inorganic hybrid coating can be effectively used for on-line hyphenation of capillary microextraction with high-performance liquid chromatography. The test results also indicate that the sol-gel PDMDPS coated capillary is resistant to high-temperature solvents, making it suitable for applications in high-temperature HPLC. To the best of our knowledge, this is the first report on the creation of a silica-based sol-gel PDMDPS coating used in capillary microextraction on-line hyphenated to HPLC.

  1. USAGE OF HYPHEN IN GEOLOGICAL REPORT%地质报告中连接号使用说明与辨析

    Institute of Scientific and Technical Information of China (English)

    刘伯崇

    2011-01-01

    本文阐述了6种形式的连接号的正确使用范围,并对连接号使用时最容易出现的混用和错误进行了辨析,以达到在编制地质报告运用连接号时避免误用混用的目的。%The essay expounded how to use hyphen in geological reports for 6 purposes,and discussed the common errors in using it.

  2. A Novel Combination of Immunoreaction and ICP-MS as a Hyphenated Technique for the Determination of Thyroid-stimulating Hormone (TSH) in Human Serum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The novel coupling method based on the hyphenation of immunoreaction with ICP-MS is developed and applied to the determination of thyroid-stimulating hormone (TSH) in human serum. In this system, TSH is firstly captured by anti-TSH monoclonal antibodies immobilized on a solid support. Biotinylated anti-TSH monoclonal antibodies and Eu3+-labelled streptavidin are then added to form the complex capturing andbody-TSH-biotinylated anti-TSH antibody-Eu3+-labeled streptavidin. After unbound reactants are washed away, Eu3+ bound to the complex is extracted by

  3. High temperature liquid chromatography hyphenated with ESI-MS and ICP-MS detection for the structural characterization and quantification of halogen containing drug metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Vlieger, Jon S.B. de [BioMolecular Analysis Group, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Giezen, Mark J.N. [QPS Netherlands B.V., Petrus Campersingel 123, 9713 AG Groningen (Netherlands); Falck, David [BioMolecular Analysis Group, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Tump, Cornelis; Heuveln, Fred van [QPS Netherlands B.V., Petrus Campersingel 123, 9713 AG Groningen (Netherlands); Giera, Martin; Kool, Jeroen; Lingeman, Henk [BioMolecular Analysis Group, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Wieling, Jaap [QPS Netherlands B.V., Petrus Campersingel 123, 9713 AG Groningen (Netherlands); Honing, Maarten [DSM Resolve, PO Box 18, 6160 MD Geleen (Netherlands); Irth, Hubertus [BioMolecular Analysis Group, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Niessen, Wilfried M.A., E-mail: W.M.A.Niessen@vu.nl [BioMolecular Analysis Group, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands)

    2011-07-18

    Highlights: {yields} Hyphenation of high temperature liquid chromatography to ICP-MS and ESI-MS. {yields} Structural characterization of kinase inhibitor metabolites with high resolution MS{sup n} experiments. {yields} Quantification of drug metabolites with ICP-MS based on Iodine detection. {yields} Significant changes in ESI-MS response after small structural changes. - Abstract: In this paper we describe the hyphenation of high temperature liquid chromatography with ICP-MS and ESI-MS for the characterization of halogen containing drug metabolites. The use of temperature gradients up to 200 deg. C enabled the separation of metabolites with low organic modifier content. This specific property allowed the use of detection methods that suffer from (significant) changes in analyte response factors as a function of the organic modifier content such as ICP-MS. Metabolites of two kinase inhibitors (SB-203580-Iodo and MAPK inhibitor VIII) produced by bacterial cytochrome P450 BM3 mutants and human liver microsomes were identified based on high resolution MS{sup n} data. Quantification was done using their normalized and elemental specific response in the ICP-MS. The importance of these kinds of quantification strategies is stressed by the observation that the difference of the position of one oxygen atom in a structure can greatly affect its response in ESI-MS and UV detection.

  4. Sensitive redox speciation of iron, neptunium, and plutonium by capillary electrophoresis hyphenated to inductively coupled plasma sector field mass spectrometry.

    Science.gov (United States)

    Graser, Carl-Heinrich; Banik, Nidhu Lal; Bender, Kerstin Anne; Lagos, Markus; Marquardt, Christian Michael; Marsac, Rémi; Montoya, Vanessa; Geckeis, Horst

    2015-10-01

    The long-term safety assessment for nuclear waste repositories requires a detailed understanding of actinide (geo)chemistry. Advanced analytical tools are required to gain insight into actinide speciation in a given system. The geochemical conditions in the vicinity of a nuclear repository control the redox state of radionuclides, which in turn has a strong impact on their mobility. Besides the long-lived radionuclides plutonium (Pu) and neptunium (Np), which are key elements in high level nuclear waste, iron (Fe) represents a main component in natural systems controlling redox-related geochemical processes. Measuring the oxidation state distribution for redox sensitive radionuclides and other metal ions is challenging at trace concentrations below the detection limit of most available spectroscopic methods (≥10(-6) M). Consequently, ultrasensitive new analytical techniques are required. Capillary electrophoresis (CE) is a suitable separation method for metal cations. CE hyphenated to inductively coupled plasma sector field mass spectrometry (CE-ICP-SF-MS) was used to measure the redox speciation of Pu (III, IV, V, VI), Np (IV, V, VI), and Fe (II, III) at concentrations lower than 10(-7) M. CE coupling and separation parameters such as sample gas pressure, make up flow rate, capillary position, auxiliary gas flow, as well as the electrolyte system were optimized to obtain the maximum sensitivity. We obtain detection limits of 10(-12) M for Np and Pu. The various oxidation state species of Pu and Np in different samples were separated by application of an acetate-based electrolyte system. The separation of Fe (II) and Fe (III) was investigated using different organic complexing ligands, EDTA, and o-phenanthroline. For the Fe redox system, a limit of detection of 10(-8) M was calculated. By applying this analytical system to sorption studies, we were able to underline previously published results for the sorption behavior of Np in highly diluted concentrations, and

  5. Analysis of the volatile oil from the stem of acanthopanax senticosus(Rupr.et Maxim.)harms with several hyphenated methods of chromatography

    Institute of Scientific and Technical Information of China (English)

    Yu Wanying; Zhang Hua; Huang Weidong; Chen Jiping; Liang Xinmiao

    2006-01-01

    Gas chromatography/quadrupole mass spectrometry (GC/qMS),gas chromatography/Fourier transform infrared spectrometry(CC/FTIR)and gas chromatography/orthogonal acceleration time-of-flight mass spectrometry(GC/oaTOFMS)were applied to analyze the volatile oil from the stem of Acanthopanax Senticosus(Rupr.et Maxim.)Harms.Based on the mass spectra search function of GC/qMS with the aid of the discriminability of the geometrical isomer by GC/FTIR and the ability to determine the accurate mass charge ratio(m/z)by GC/oaTOFMS,68 GC eluants were identified successfully.Compared with the results obtained by GC/qMS only,the analytical results obtained by these hyphenated methods of gas chromatography are more credible.

  6. Sol-gel methyl coating in capillary microextraction hyphenated on-line with high-performance liquid chromatography Counterintuitive extraction behavior for polar analytes.

    Science.gov (United States)

    Segro, Scott S; Malik, Abdul

    2008-07-18

    A sol-gel coating with anchored methyl groups was developed for capillary microextraction hyphenated on-line with high-performance liquid chromatography (HPLC). This was accomplished by using methyltrimethoxysilane as the sol-gel precursor. The methyl group on the sol-gel precursor ultimately turned into a pendant group on the created sol-gel coating and was primarily responsible for the extraction of nonpolar analytes. A 40-cm segment of 0.25mm I.D. fused silica capillary containing the sol-gel methyl coating on the inner surface was installed as a sampling loop in an HPLC injection port. The analytes were extracted by the coating when an aqueous sample containing the analytes was passed through this capillary. The extracted analytes were then transferred to the HPLC column using isocratic elution with an acetonitrile/water mobile phase. This capillary demonstrated excellent extraction capability for polycyclic aromatic hydrocarbons and ketones. Unexpectedly, this coating also provided good extraction for polar analytes, including aromatic phenols, alcohols, and amines. Considering the fact that the methyl group is nonpolar in nature, such an extraction behavior of sol-gel methyl coating toward polar analytes is counterintuitive. Thus, sol-gel sorbents with short alkyl side chains have the potential to offer a polymer-free alternative to traditional sol-gel capillary microextraction (CME) media commonly prepared with the use of polymers in the sol solution. Elimination of polymers from the sol-gel coating solution is conducive to improving thermal stability and solvent tolerance of the created sol-gel extracting phase. This also makes the preparation of sol-gel coatings facile and cost-effective. Possessing excellent solvent stability, such sol-gel coatings offer the opportunity for effective on-line hyphenation of capillary microextraction with HPLC and other liquid-phase separation techniques that employ organo-aqueous mobile phases.

  7. Hyphenation of a carbon analyzer to photo-ionization mass spectrometry to unravel the organic composition of particulate matter on a molecular level.

    Science.gov (United States)

    Grabowsky, Jana; Streibel, Thorsten; Sklorz, Martin; Chow, Judith C; Watson, John G; Mamakos, Athanasios; Zimmermann, Ralf

    2011-12-01

    The carbonaceous fraction of airborne particulate matter (PM) is of increasing interest due to the adverse health effects they are linked to. Its analytical ascertainment on a molecular level is still challenging. Hence, analysis of carbonaceous fractions is often carried out by determining bulk parameters such as the overall content of organic compounds (OC) and elemental carbon (EC) as well as the total carbon content, TC (sum of OC and EC), however, no information about the individual substances or substance classes, of which the single fractions consist can be obtained. In this work, a carbon analyzer and a photo-ionization time-of-flight mass spectrometer (PI-TOF-MS) were hyphenated to investigate individual compounds especially from the OC fractions. The carbon analyzer enables the stepwise heating of particle samples and provides the bulk parameters. With the PI-TOF-MS, it is possible to detect the organic compounds released during the single-temperature steps due to soft ionization and fast detection of the molecular ions. The hyphenation was designed, built up, characterized by standard substances, and applied to several kinds of samples, such as ambient aerosol, gasoline, and diesel emission as well as wood combustion emission samples. The ambient filter sample showed a strong impact of wood combustion markers. This was revealed by comparison to the product pattern of the similar analysis of pure cellulose and lignin and the wood combustion PM. At higher temperatures (450 °C), a shift to smaller molecules occurred due to the thermal decomposition of larger structures of oligomeric or polymeric nature comparable to lignocelluloses and similar oxygenated humic-like substances. Finally, particulate matter from gasoline and diesel containing 10% biodiesel vehicle exhaust has been analyzed. Gasoline-derived PM exhibited large polycyclic aromatic hydrocarbons, whereas diesel PM showed a much higher total organic content. The detected pattern revealed a strong

  8. High-temperature liquid chromatography inductively coupled plasma atomic emission spectrometry hyphenation for the combined organic and inorganic analysis of foodstuffs.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2010-10-01

    The coupling of a High-Temperature Liquid Chromatography system (HTLC) with an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) is reported for the first time. This hyphenation combines the separation efficiency of HTLC with the detection power of a simultaneous ICP-AES system and allows the combined determination of organic compound and metals. The effluents of the column were introduced into the spectrometer and the chromatograms for organic compounds were obtained by plotting the carbon emission signal at a characteristic wavelength versus time. As regards metals, they were determined by injecting a small sample volume between the exit of the column and the spectrometer and taking the emission intensity for each one of the elements simultaneously. Provided that in HTLC the effluents emerged at high temperatures, an aerosol was easily generated at the exit of the column. Therefore, the use of a pneumatic nebulizer as a component of a liquid sample introduction system in the ICP-AES could be avoided, thus reducing the peak dispersion and limits of detection by a factor of two. The fact that a hot liquid stream was nebulized made it necessary to use a thermostated spray chamber so as to avoid the plasma cooling as a cause of the excessive mass of solvent delivered to it. Due to the similarity in sample introduction, an Evaporative Light Scattering Detector (ELSD) was taken as a reference. Comparatively speaking, limits of detection were of the same order for both HTLC-ICP-AES and HTLC-ELSD, although the latter provided better results for some compounds (from 10 to 20 mg L(-1) and 5-10 mg L(-1), respectively). In contrast, the dynamic range for the new hyphenation was about two orders of magnitude wider. More importantly, HTLC-ICP-AES provided information about the content of both organic (glucose, sucrose, maltose and lactose at concentrations from roughly 10 to 400 mg L(-1)) as well as inorganic (magnesium, calcium, sodium, zinc, potassium and

  9. Mass spectrometry hyphenated techniques for the analysis of volatiles and peptides in soft cheese: Useful tools for the shelf life optimization.

    Science.gov (United States)

    Mentana, Annalisa; Natale, Anna; Palermo, Carmen; Nardiello, Donatella; Conte, Amalia; Del Nobile, Matteo Alessandro; Quinto, Maurizio; Centonze, Diego

    2016-07-01

    In order to assess the product quality and shelf life of an Italian soft cream cheese under different storage conditions, the volatile and peptide profiles evolution were tested. Volatiles were sampled directly from the head space of cheese packaging by solid-phase microextraction and analyzed by GC-MS. Peptide profiles were obtained by nanoLC-MS/MS, following a novel bioinformatics approach based on scoring distribution associated to the protein hits originating from the database search. In particular, a refined identification by focusing on selected time segments corresponding to the most intense peaks was carried out. A total of 40 compounds including acids, aldehydes, ketones, lactones, alcohols, esters, hydrocarbons, terpene, sulfur, and aromatic compounds were detected. Significant differences in their abundance during the storage in different packagings were observed, as well as an evolution of peptides mainly belonging to αS1-casein. The results demonstrated the usefulness of the above-mentioned hyphenated techniques for the determination of the soft cheese shelf life under different storage conditions.

  10. 联用色谱完全重叠峰的解析方法%Resolution Methods of Hyphenated Embedded Chromatographic Peaks

    Institute of Scientific and Technical Information of China (English)

    陈迪钊; 毛新平

    2000-01-01

    Based on orthogonal projection technique and constrained peak shape condition, three kind of new methods to resolve completely overalapping chromatographic peaks are proposed in this paper. They are constrained peak shape and curve fitting resolution(CPSCF), iterative orthogonal projection resolution(IOP) and rank annihilation factor analysis(RAFA). If the constrain conditions is satisfied on hyphenated chromatography data matrics, these methods can be proved to be completely possible for them to be used on the resolution of spectra for embedded and concentration profiles for embedding peaks.%基于正交投影技术和约束峰形条件,本文提出了三种完全重叠色谱峰的解析方法,峰形约束曲线拟合解析(CPSCF),交替正交投影(IOP)和秩消失因子分析(RAFA)。对联用色谱数据阵如果约束条件得到满足,这些方法能被证明用于被嵌人组分的光谱和嵌入组分的浓度曲线分辨是完全可能地。

  11. 联用技术在砷形态分析中的研究进展%Research Progress in the Speciation of Arsenic with Hyphenated Techniques

    Institute of Scientific and Technical Information of China (English)

    李林林; 朱英存

    2013-01-01

    Currently the main analysis techniques for arsenic speciation were the combination of chromatograph with atomic spectrum and mass spectrum, especially the combination of HPLC with ICP-OES or ICP-MS. The methods were accurate and reliable and had high sensitivity. But they can not provide the structural information of arsenic compounds. So the combination of chromatograph with ESI-MS was used as the main method for qualitative analysis. The insufficient sensitivity and vulnerability to matrix interference of ESI-MS can be overcome by the complex pretreatment technique. In this article hyphenated techniques were evaluated with particular emphasis on interfaced separation with element-selective detection and identification of the arsenic compounds detected.%  目前用元素砷的形态分析技术主要是色谱与子光谱、质谱等的联用,最常用的是HPLC与ICP-OES、 ICP-MS的联用,方法准确可靠,灵敏度高,但是不能提供砷化合物的分子结构信息。此以色谱-电喷雾质谱(ESI-MS)的联用作为定性分析的主要手段,但是ESI-MS灵敏度低,易受基体干扰,此需要复杂的前处理技术。

  12. Reversed phase liquid chromatography hyphenated to continuous flow-extractive desorption electrospray ionization-mass spectrometry for analysis and charge state manipulation of undigested proteins.

    Science.gov (United States)

    Li, Li; Yang, Samuel H; Vidova, Veronika; Rice, Elisa M; Wijeratne, Aruna B; Havlíček, Vladimír; Schug, Kevin A

    2015-01-01

    The application of continuous flow-extractive desorption electrospray ionization (CF-EDESI), an ambient ionization source demonstrated previously for use with intact protein analysis, is expanded here for the coupling of reversed phase protein separations to mass spectrometry. This configuration allows the introduction of charging additives to enhance detection without affecting the chromatographic separation mechanism. Two demonstrations of the advantages of CF-EDESI are presented in this work. First, a proof-of- principle is presented to demonstrate the applicability of hyphenation of liquid chromatography (LC) to CF- EDESI. LC-CF-EDESI-MS has good sensitivity compared to LC-electrospray ionization (ESI)-mass spectrometry. Second, the supercharging mechanism investigated in CF-EDESI provides an insight into a highly debated supercharging process in ESI. The results indicate that the mechanism of protein charging seen in HPLC-CF-EDESI is different from supercharging phenomena in conventional ESI. The surface tension mechanism and binding mechanism may both contribute to protein supercharging in ESI.

  13. Speciation analysis of mercury by solid-phase microextraction and multicapillary gas chromatography hyphenated to inductively coupled plasma-time-of-flight-mass spectrometry.

    Science.gov (United States)

    Jitaru, Petru; Adams, Freddy C

    2004-11-05

    This paper reports the development of an analytical approach for speciation analysis of mercury at ultra-trace levels on the basis of solid-phase microextraction and multicapillary gas chromatography hyphenated to inductively coupled plasma-time-of-flight mass spectrometry. Headspace solid-phase microextraction with a carboxen/polydimethylsyloxane fiber is used for extraction/preconcentration of mercury species after derivatization with sodium tetraethylborate and subsequent volatilization. Isothermal separation of methylmercury (MeHg), inorganic mercury (Hg2+) and propylmercury (PrHg) used as internal standard is achieved within a chromatographic run below 45 s without the introduction of spectral skew. Method detection limits (3 x standard deviation criteria) calculated for 10 successive injections of the analytical reagent blank are 0.027 pg g(-1) (as metal) for MeHg and 0.27 pg g(-1) for Hg2+. The repeatability (R.S.D., %) is 3.3% for MeHg and 3.8% for Hg2+ for 10 successive injections of a standard mixture of 10pg. The method accuracy for MeHg and total mercury is validated through the analysis of marine and estuarine sediment reference materials. A comparison of the sediment data with those obtained by a purge-and-trap injection (PTI) method is also addressed. The analytical procedure is illustrated with some results for the ultra-trace level analysis of ice from Antarctica for which the accuracy is assessed by spike recovery experiments.

  14. High temperature liquid chromatography hyphenated with ESI-MS and ICP-MS detection for the structural characterization and quantification of halogen containing drug metabolites.

    Science.gov (United States)

    de Vlieger, Jon S B; Giezen, Mark J N; Falck, David; Tump, Cornelis; van Heuveln, Fred; Giera, Martin; Kool, Jeroen; Lingeman, Henk; Wieling, Jaap; Honing, Maarten; Irth, Hubertus; Niessen, Wilfried M A

    2011-07-18

    In this paper we describe the hyphenation of high temperature liquid chromatography with ICP-MS and ESI-MS for the characterization of halogen containing drug metabolites. The use of temperature gradients up to 200°C enabled the separation of metabolites with low organic modifier content. This specific property allowed the use of detection methods that suffer from (significant) changes in analyte response factors as a function of the organic modifier content such as ICP-MS. Metabolites of two kinase inhibitors (SB-203580-Iodo and MAPK inhibitor VIII) produced by bacterial cytochrome P450 BM3 mutants and human liver microsomes were identified based on high resolution MS(n) data. Quantification was done using their normalized and elemental specific response in the ICP-MS. The importance of these kinds of quantification strategies is stressed by the observation that the difference of the position of one oxygen atom in a structure can greatly affect its response in ESI-MS and UV detection.

  15. Determination of sulfur and selected trace elements in metallothionein-like proteins using capillary electrophoresis hyphenated to inductively coupled plasma mass spectrometry with an octopole reaction cell

    Energy Technology Data Exchange (ETDEWEB)

    Proefrock, Daniel; Leonhard, Peter; Prange, Andreas [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max Planck Strasse, 21502, Geesthacht (Germany)

    2003-09-01

    The determination of sulfur in biologically relevant samples such as metalloproteins is described. The analytical methodology used is based on robust on-line coupling between capillary electrophoresis (CE) and octopole reaction cell inductively-coupled plasma mass spectrometry (ORC-ICP-MS). Polyatomic ions that form in the plasma and interfere with the determination of S at mass 32 are minimised by addition of xenon to the collision cell. The method has been applied to the separation and simultaneous element-specific detection of sulfur, cadmium, copper, and zinc in commercially available metallothionein preparations (MT) and metallothionein-like proteins (MLP) extracted from liver samples of bream (Abramis brama L.) caught in the river Elbe, Germany. Instrumental detection limits have been calculated according to the German standard procedure DIN 32645 for the determination of sulfur and some simultaneously measured trace elements in aqueous solution. For sulfur detection limits down to 1.3 {mu}g L{sup -1} ({sup 34}S) and 3.2 {mu}g L{sup -1} ({sup 32}S) were derived. For the other trace elements determined simultaneously detection limits ranging from 300 ng L{sup -1} ({sup 58}Ni) to 500 ng L{sup -1} ({sup 66}Zn, {sup 55}Mn) were achieved. For quantification of sulfur and cadmium in a commercially available MT preparation under hyphenated conditions the use of external calibration is suggested. Finally, the need for proper sample-preparation technique will be discussed. (orig.)

  16. Home-made online hyphenation of pressurized liquid extraction, turbulent flow chromatography, and high performance liquid chromatography, Cistanche deserticola as a case study.

    Science.gov (United States)

    Song, Qingqing; Li, Jun; Liu, Xiao; Zhang, Yuan; Guo, Liping; Jiang, Yong; Song, Yuelin; Tu, Pengfei

    2016-03-18

    Incompatibility between the conventional pressurized liquid extraction (PLE) devices and high performance liquid chromatography (HPLC) extensively hinders direct and green chemical analysis of herbal materials. Herein, a facile PLE module was configured, and then it was online hyphenated with HPLC via a turbulent flow chromatography (TFC) column. Regarding PLE module, a long PEEK tube (0.13 × 1000 mm) was employed to generate desired pressure (approximately 13.0 MPa) when warm acidic water (70 °C) was delivered as extraction solvent at a high flow rate (2.5 mL/min), and a hollow guard column (3.0 × 4.0 mm) was implemented to hold crude materials. Effluent was collected from the outlet of PEEK tube, concentrated, and subjected onto HPLC coupled with hybrid ion trap-time of flight mass spectrometer to assess the extraction efficiency and also to profile the chemical composition of Cistanche deserticola (CD) that is honored as "Ginseng of the desert". Afterwards, a TFC column was introduced to accomplish online transmission of low molecule weight components from PLE module to HPLC coupled with diode array detection, and two electronic 6-port/2-channel valves were in charge of alternating the whole system between extraction (0-3.0 min) and elution (3.0-35.0 min) phases. Quantitative method was developed and validated for simultaneous determination of eight primary phenylethanoid glycosides in CD using online PLE-TFC-HPLC. All findings demonstrated that the home-made platform is advantageous at direct chemical analysis, as well as time-, solvent-, and material-savings, suggesting a robust tool for chemical fingerprinting of herbs.

  17. Speciation of the bio-available iodine and bromine forms in edible seaweed by high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Romaris-Hortas, Vanessa; Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain); Moreda-Pineiro, Jorge [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira, s/n. 15071, A Coruna (Spain); Moreda-Pineiro, Antonio, E-mail: antonio.moreda@usc.es [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Bioavailable iodine and bromine speciation in edible seaweed were developed. Black-Right-Pointing-Pointer In vitro dialyzability was used to assess the bioavailable fractions. Black-Right-Pointing-Pointer AEC hyphenated with inductively coupled plasma-mass spectrometry was used. Black-Right-Pointing-Pointer Iodide, MIT, DIT, bromide and bromate were found in dialyzates from edible seaweed. Black-Right-Pointing-Pointer Positive correlation between bioavailability and protein contents was found. - Abstract: A bioavailability study based on an in vitro dialyzability approach has been applied to assess the bio-available fractions of iodine and bromine species from edible seaweed. Iodide, iodate, 3-iodo-tyrosine (MIT), 3,5-diiodo-tyrosine (DIT), bromide and bromate were separated by anion exchange chromatography under a gradient elution mode (175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase, and flow rates within the 0.5-1.5 mL min{sup -1} range). Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector for iodine ({sup 127}I) and bromine ({sup 79}Br). Low dialyzability ratios (within the 2.0-18% range) were found for iodine species; whereas, moderate dialyzability percentages (from 9.0 to 40%) were obtained for bromine species. Iodide and bromide were the major species found in the dialyzates from seaweed, although MIT and bromate were also found in the dialyzates from most of the seaweed samples analysed. However, DIT was only found in dialyzates from Wakame, Kombu, and NIES 09 (Sargasso) certified reference material; whereas, iodate was not found in any dialyzate. Iodine dialyzability was found to be dependent on the protein content (negative correlation), and on the carbohydrate and dietary fibre levels (positive correlation). However, bromine dialyzability was only dependent on the protein amount in seaweed (negative correlation).

  18. Analysis of tetrodotoxin by hyphenated chromatographic techniques%多种色谱联用技术分析替曲朵辛

    Institute of Scientific and Technical Information of China (English)

    代秀梅; 于风平; 张启明

    2013-01-01

    目的:建立替曲朵辛原料药含量及有关物质的测定方法,并对有关物质的结构进行分析.方法:采用HPLC法测定替曲朵辛原料药含量及有关物质,采用UPLC-UV-MS/MS和LC-NMR联用技术对含量最高的杂质9的结构进行分析.结果:重复性好,替曲朵辛浓度在0.294~44.16 μg· mL-1范围内线性关系良好(r =0.9999),有关物质中最大杂质为4,9,10,11二脱水河豚毒素.结论:本方法操作简便,结果准确,可作为替曲朵辛原料药含量测定和有关物质检查的方法.%Objective:To establish a hyphenated chromatographic method for content determination of tetrodotoxin (TTX) raw medicine and related substances and to analyze the structure of related substances.Methods:HPLC was used to determin the content of tetrodotoxin mw medicine and related substances,and UPLC-UV-MS/MS and LC-NMR were used to study the structure of related substances.Results:There was a good linear relationship for tetrodotoxin in the range of 0.294-44.16 μg · mL-1 (r =0.9999).The impurity of the highest content was 4,9,10,11-dianhydro-TTX.Conclusion:The method is simple,accurate,and well reproducible which can be applied to content determination of Tet rodotoxin raw medicine and related substances.

  19. Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Helsper, Johannes P F G; Peters, Ruud J B; van Bemmel, Margaretha E M; Rivera, Zahira E Herrera; Wagner, Stephan; von der Kammer, Frank; Tromp, Peter C; Hofmann, Thilo; Weigel, Stefan

    2016-09-01

    Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (ICPMS) for chemical characterization. The aF4-ICPMS conditions were optimised and validated for linearity, limit of detection, recovery, repeatability and reproducibility, all indicating good performance. Multi-element detection with aF4-ICPMS showed that some commercial pigments contained zirconium co-eluting with titanium in aF4. The other two TiMs, NM103 and NM104, contained aluminium as integral part of the titanium peak eluting in aF4. The materials were characterised using various size determination techniques: retention time in aF4, aF4 hyphenated with multi-angle laser light spectrometry (MALS), single particle ICPMS (spICPMS), scanning electron microscopy (SEM) and particle tracking analysis (PTA). PTA appeared inappropriate. For the other techniques, size distribution patterns were quite similar, i.e. high polydispersity with diameters from 20 to >700 nm, a modal peak between 200 and 500 nm and a shoulder at 600 nm. Number-based size distribution techniques as spICPMS and SEM showed smaller modal diameters than aF4-UV, from which mass-based diameters are calculated. With aF4-MALS calculated, light-scattering-based "diameters of gyration" (Øg) are similar to hydrodynamic diameters (Øh) from aF4-UV analyses and diameters observed with SEM, but much larger than with spICPMS. A Øg/Øh ratio of about 1 indicates that the TiMs are oblate spheres or fractal aggregates. SEM observations confirm the latter structure. The rationale for differences in modal peak diameter is discussed.

  20. The impact of flow injection on modem chemical analysis: has it fulfilled our expectations? And where are we going?

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    2004-01-01

    Presenting a condensation of the opening lecture of the 12th ICFIA conference, this communication presents a view of the impact that flow injection analysis (FIA) has had on modern analytical chemistry, evaluated both within the academic community and outside it, i.e., in “industry”. The ensuing ...... developments of FIA, encompassing sequential injection analysis (SIA) and bead injection lab-on-valve (BI-LOV), are described and their individual features discussed. Finally some recent results of the activities from the author’s own research group are briefly mentioned.......Presenting a condensation of the opening lecture of the 12th ICFIA conference, this communication presents a view of the impact that flow injection analysis (FIA) has had on modern analytical chemistry, evaluated both within the academic community and outside it, i.e., in “industry”. The ensuing...

  1. Solid reactors in sequential injection analysis: Recent trends in the environmental field

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald

    2006-01-01

    The second generation of flow injection analysis (FIA), so-called sequential injection (SI), has already been consolidated as an attractive flowing-stream approach in several analytical fields, with advantages over the first generation of FIA in terms of automation, miniaturization, and sample...... applications, aiming to facilitate on-line chemical derivatization, chromatographic separation of target species, removal of interfering matrix compounds, or determination of trace levels of analyte via sorptive preconcentration procedures. In this context, the concept of renewable surfaces, so-called SI......-bead injection (SI-BI), used in either the jet-ring or lab-on-valve configurations, is presented as a front-end to many detectors. This article also outlines recent trends focused on exploiting SI as an automated tool for handling solid samples of environmental concern and accommodating dynamic fractionation...

  2. On-line ion exchange preconcentration in a sequential injection lab-on-valve microsystem incorporating a renewable column with ETAAS for the trace-level determination of bismuth in urine and river sediment

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2001-01-01

    A sequential injection system for on-line ion-exchange separation and preconcentration of trace-level amounts of metal ions with ensuing detection by electrothermal atomic absorption spectrometry (ETAAS) is described. Based on the use of a renewable microcolumn incorporated within an integrated l.......3% for the determination of 2.0 mug/l Bi (n = 7). The procedure was validated by determination of bismuth in a certified reference material CRM 320 (river sediment), and by bismuth spike recoveries in two human urine samples....

  3. Highly selective micro-sequential injection lab-on-valve (μSI-LOV) method for determination of ultra trace concentrations of nickel in saline matrices using detection by electrothermal atomic absorption spectrometr

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Jensen, Rikard;

    2006-01-01

    by electrothermal atomic absorption spectrometry (ETAAS). Based on the dimethylglyoxime (DMG) gravimetric procedure used for nickel analysis, the sample, as contained in pH 9.0 buffer, is, after on-line merging with the chelating reagent, transported to a reaction coil attached to one of the external ports...

  4. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    DEFF Research Database (Denmark)

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    . The samples are adjusted to pH 5.0 on-line in the system for optimum operation. The target ions are adsorbed by chelation on the surface of the beads, contained in a 20 mul microcolumn within the LOV, and following elution by 50 mul 2M nitric acid, the eluate is, as sandwiched by air segments, introduced...

  5. Hyphenated technique for the extraction and determination of isoflavones in algae: ultrasound-assisted supercritical fluid extraction followed by fast chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Klejdus, B; Lojková, L; Plaza, M; Snóblová, M; Stěrbová, D

    2010-12-17

    New hyphenated technique for the extraction and determination of isoflavones in sea and freshwater algae and cyanobacteria was developed. The method consists of sonication sample pretreatment, extraction by supercritical CO(2) modified by 3% (v/v) of MeOH/H(2)O mixture (9:1, v/v) at 35 MPa and 40°C for 60 min, fast chromatography analysis by the means of Agilent 1200 Series Rapid Resolution and MS/MS determination. Agilent 1200 Series RRLC was used with Zorbax SB-CN chromatographic column (100 mm × 2.1mm, particle size 3.5 μm), 3μl injection volume, mobile phase consisting of 0.2% (v/v) acetic acid in water (solvent A) and acetonitrile (solvent B) and used with linear gradient (30% B at 0 min, from 0 min to 3 min up to 50% B, from 3 to 6 min up to 80% B and from 6 to 10 min down to 30% B). The flow-rate was 0.4 mL/min, column oven temperature 35°C. MS detector Agilent Technologies 6460 Triple quadrupole LC/MS with Agilent Jet Stream was used in a negative ESI mode under following conditions: gas temperature 350°C, gas flow 13 L/min, nebulizer gas pressure 50 psi, sheath gas temperature 400°C, sheath gas flow 12L/min, capillary voltage was 4 kV. Samples were analysed in the multiple reaction monitoring (MRM) mode. Eight isoflavone compounds were found for the first time in seven real samples of sea algae and in three control samples of freshwater algae and cyanobacteria. Usual optimisation study of extraction parameters was performed. Pressure and temperature optima for algae matrix are different from those obtained sooner for other matrices for most of the analytes, but the results of modifier optimisation study are in good accordance with those obtained sooner for spiked samples and red clover matrix. It seems that matrix has very small or no effect on the modifier selection. Two different approaches of sonication pretreatment were tested: sonication bath and the thorn instrument. In longer extraction time experiments, thorn sonication was more efficient

  6. 盐酸法舒地尔有关物质的色谱-质谱结构鉴定%Identification of the related substances in fasudil hydrochloride with hyphenated techniques

    Institute of Scientific and Technical Information of China (English)

    陈月琴; 宋敏; 杭太俊

    2013-01-01

    The study aims to identify the related substances in fasudil hydrochloride by hyphenated techniques. A WondaSil C18 (250 mm × 4.6 mm, 5 μm) column was used for the separation of the related substances with a mixture of methanol and ammonium acetate buffer solution as the mobile phase by gradient elution. The structures of the related substances were speculated by electrospray positive ionization LC-TOF/ MS accurate ion mass and MS/MS determination and elucidation, and verified further through synthesis and spectroscopic analysis. Fasudil hydrochloride and the related substances were separated under the established HPLC condition. Three related substances in fasudil hydrochloride were characterized by hyphenated techniques. The hyphenated LC-MS method is useful for the identification of related substances in fasudil hydrochloride and the results obtained are valuable for its manufacturing process and quality control.%采用WondaSil C18 (250 mm×4.6 mm ID,5 μm)色谱柱,甲醇-醋酸铵缓冲溶液流动相梯度洗脱,对盐酸法舒地尔有关物质进行分离;采用正离子电喷雾-飞行时间质谱法测定准确质量和二级串联质谱分析离子结构特征,并结合合成制备与波谱解析确证主要有关物质结构.结果显示,盐酸法舒地尔与其有关物质分离良好,检测出3个主要有关物质,并综合分析鉴定了有关物质结构.色谱-质谱联用技术能有效地鉴定盐酸法舒地尔有关物质,为其工艺和质量控制提供参考依据.

  7. 中英文破折号、连接号用法异同比较%Similarities and Differences of Usage between Chinese and English Punctuation of Dash/Hyphen

    Institute of Scientific and Technical Information of China (English)

    马奋华; 倪东鸿; 王小曼

    2006-01-01

    针对科技论文中中文破折号、连接号与英文破折号(dash)、连字号(hyphen)用法混乱的现象,参考有关国家标准、文献和国外优秀期刊的编辑规范,指出了4个标点符号的具体表现形式和用法,以及应用中注意的问题,并提出了相应的修改意见,以期引起同行和有关权威部门的重视,达到规范应用这4个标点符号的目的.

  8. 超临界流体分离与NMR联用技术及其应用%Hyphenation of Supercritical Fluid Separation with Nuclear Mag netic Resonance and Their Applications

    Institute of Scientific and Technical Information of China (English)

    陈志伟; 陈忠

    2001-01-01

    The progression,instruments and applications of hyphenation between supercritica l fluid separation (SFC or SFE) and NMR spectrometry were described.The resoluti on of 1H NMR spectra obtained in SFC-NMR and SFE-NMR experiments is compared with that obtained by HPLC-NMR experiments. This review also looks for ward to the future of SFC-NMR and SFE-NMR.%本文重点描述了SFC-NMR和SFE-NMR联用装置的特点及其探头设计,举例说明了它们的几种典型应用,分析比较了超临界流体分离和NMR联用系统与HPLC-NMR联 用系统的特性,并讨论了超临界流体分离与NMR联用技术的发展前景。

  9. Application of microdialysis and its hyphenated techniques in studies of traditional Chinese medicines%微透析及其联用技术在中药研究中的应用

    Institute of Scientific and Technical Information of China (English)

    曹柳; 辛贵忠; 闻晓东; 李萍

    2012-01-01

    微透析技术是用于监测细胞外液中内源性物质及外源性物质的活体取样技术,但由于微透析样品是一种含有高浓度无机盐的复杂混合物,往往需要与色谱分离技术联合使用,才能对微透析样品中目标分析物进行测定.目前,微透析与高分辨率、高灵敏度的分析技术的联用已得到广泛应用,该技术的应用,为现代中药的研究提供了一种新的思路和工具.本文概述了微透析技术的原理及特点,重点介绍了微透析及其联用技术在中药干预下内源性物质的分析、中药药代动力学及相互作用研究中的应用..%Microdialysis (MD) is an in vivo technique used for sampling endogenous and exogenous substances in the extracellular space. However, MD samples are complex mixtures containing high concentrations of inorganic salts that require chromatographic separation to allow for the measurements of interest analytes. Currently, MD combined with high resolution and sensitivity analytical techniques have been used widely. MD and its hyphenated techniques provide new ideas and tools for research of traditional Chinese medicines (TCMs). This review summarized the principles and characteristics of MD techniques, and focused on the applications of MD and its hyphenated techniques in the analysis of endogenous substances, pharmacokinetic study of TCMs and herbs-drug interactions.

  10. 富马酸替诺福韦双特戊酯有关物质的鉴定%Identification of the related substances in tenofovir dipivoxil fumarate with hyphenated techniques

    Institute of Scientific and Technical Information of China (English)

    赵画; 宋敏; 杭太俊

    2012-01-01

    目的:采用色谱-质谱联用技术对富马酸替诺福韦双特戊酯中有关物质进行结构鉴定.方法:采用BDS Hypersil C18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-0.2%醋酸铵溶液,梯度洗脱,对富马酸替诺福韦双特戊酯有关物质进行分离;LC-PDA测定各有关物质的UV吸收,甲醇辅助电喷雾正离子化LC-TOF和LC-MS/MS分别测定各有关物质的精密质量和二级质谱.结果:检测到富马酸替诺福韦双特戊酯中存在多个有关物质,其中仅3个的含量在0.1%以上,并鉴定出4个主要有关物质的结构.结论:色谱-质谱联用技术能够有效地鉴定药物中的有关物质,富马酸替诺福韦双特戊酯有关物质鉴定结果对其质量控制和工艺优化提供了参考依据.%Objective:To identify the related substances in tenofovir dipivoxil fumarate by hyphenated techniques. Methods: An LC-PDA-MS/MS method was established by using acetonitrile-O. 2% ammonium acetate as the mobile phase with gradient elution on a BDS Hypersil C18 (250 mm × 4. 6 mm,5 μm) column with 0. 2 mL-min methanol aided electro-spray positive ionization. The UV spectrum, accurate molecular weight and formula, and product ion MS spectrum of each related substance was obtained by LC-PDA ,LC-TOF and LC-MS/MS,respectively. Results: Several related substances were found in tenofovir dipivoxil fumarate with only 3 of them had the area normalization content over 0. 1% , and 4 of them were identified and elucidated. Conclusion: The hyphenated LC-MS method is useful for the determination and identification of related substances in pharmaceuticals. Identification of the related compounds in tenofovir dipivoxil fumarate is valuable for its manufacturing process optimization and quality control.

  11. Application Progresses on SFE-MD Hyphenated Techniques in the Separation and Purification of Nature Products%SFE-MD联用技术在天然产物分离提纯中的应用进展

    Institute of Scientific and Technical Information of China (English)

    狄崇耀; 李霞; 狄红旗

    2012-01-01

    分子蒸馏技术与超临界萃取技术都是新型的绿色分离技术,二者联用技术也一直备受各国关注。本文介绍了超临界萃取(SFE)与分子蒸馏(MD)技术的原理特点,综合评述了SFE-MD联用技术在天然产物分离提纯中的发展概况及其应用特点,并对该技术在天然产物提纯方面的前景进行了展望。%Technique of molecular distillation and supercritical extraction technology were the new types of green separation technology,and their hyphenated techniques were also concerned in all countries.Characteristics of the supercritical fluid extraction(SFE)and molecular distillation(MD) technique,and the developments and application characteristics of SFE-MD combination technology in the separation and purification of natural products,were introduced and the technology in the purification of natural products was prospected.

  12. Usages of Dashes and Hyphens in English Scientific Papers%英文科技出版物中横线类标点符号用法辨析

    Institute of Scientific and Technical Information of China (English)

    曾晓梅

    2011-01-01

    英语书刊中横线类标点符号,常用的包括em dash(破折号),en dash(连接号),hyphen(连字符)等,出错情况较多.疏误主要表现在不区分各符号间的差异以及与相应中文符号混用.em dash,en dash,hyphen与中文-字线和半字线相混淆的情况很普遍.这几个符号形状不同,语法意义也不-样.根据编辑实践中遇到的问题及相关丈献,对英文横线类标点符号的用法进行了归纳和分析,旨在提醒同行在编辑校对时加以注意.

  13. Design of online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) hyphenated systems for quantitative analysis of small organic compounds in biological matrices.

    Science.gov (United States)

    Kuklenyik, Zsuzsanna; Calafat, Antonia M; Barr, John R; Pirkle, James L

    2011-12-01

    Three online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method examples are presented where two different types of chromatographic columns or solvent systems were coupled to meet specific analytical objectives: (i) SPE of target analytes by restricted access media from high ionic strength urine matrix was coupled with reversed phase LC-MS/MS conditions accommodating high ionization potentials of the analytes (urinary bisphenol A and other phenolic derivatives); (ii) strong cation exchange SPE of analytes of diverse polarity and pK(a) was coupled with reversed phase LC-MS/MS analysis (urinary atrazine metabolites); (iii) pre-concentration of low pg per sample analytes by weak anion exchange SPE was hyphenated with ion pair LC-MS analysis (intracellular nucleotide triphosphate analogs). With these examples we suggest a conductive generic work flow for the development of online SPE-LC-MS methods and show how advanced commercial LC devices and software allow for the design of complex yet highly versatile analytical separation systems suited to the unique physicochemical properties of the target analytes.

  14. Post-polymerization photografting on methacrylate-based monoliths for separation of intact proteins and protein digests with comprehensive two-dimensional liquid chromatography hyphenated with high-resolution mass spectrometry.

    Science.gov (United States)

    Vonk, Rudy J; Wouters, Sam; Barcaru, Andrei; Vivó-Truyols, Gabriel; Eeltink, Sebastiaan; de Koning, Leo J; Schoenmakers, Peter J

    2015-05-01

    Post-polymerization photografting is a versatile tool to alter the surface chemistry of organic-based monoliths so as to obtain desired stationary phase properties. In this study, 2-acrylamido-2-methyl-1-propanesulfonic acid was grafted to a hydrophobic poly(butyl methacrylate-co-ethylene glycol dimethacrylate) monolith to create a strong cation exchange stationary phase. Both single-step and two-step photografting were addressed, and the effects of grafting conditions were assessed. An experimental design has been applied in an attempt to optimize three of the key parameters of the two-step photografting chemistry, i.e. the grafting time of the initiator, the monomer concentration and the monomer irradiation time. The photografted columns were implemented in a comprehensive two-dimensional column liquid chromatography ( (t) LC ×  (t) LC) workflow and applied for the separation of intact proteins and peptides. A baseline separation of 11 intact proteins was obtained within 20 min by implementing a gradient across a limited RP composition window in the second dimension. (t) LC ×  (t) LC with UV detection was used for the separation of cytochrome c digest, bovine serum insulin digest and a digest of a complex protein mixture. A semi-quantitative estimation of the occupation of separation space, the orthogonality, of the (t) LC ×  (t) LC system yielded 75%. The (t) LC ×  (t) LC setup was hyphenated to a high-resolution Fourier transform ion cyclotron resonance mass spectrometer instrument to identify the bovine serum insulin tryptic peptides and to demonstrate the compatibility with MS analysis.

  15. New procedure for multielemental speciation analysis of five toxic species: As(III), As(V), Cr(VI), Sb(III) and Sb(V) in drinking water samples by advanced hyphenated technique HPLC/ICP-DRC-MS.

    Science.gov (United States)

    Marcinkowska, Monika; Komorowicz, Izabela; Barałkiewicz, Danuta

    2016-05-12

    Analytical procedure dedicated for multielemental determination of toxic species: As(III), As(V), Cr(VI), Sb(III) and Sb(V) in drinking water samples using high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC/ICP-DRC-MS) technique was developed. Optimization of the detection and separation conditions was conducted. Dynamic reaction cell (DRC) with oxygen as a reaction gas was involved in the experiments. Obtained analytical signals for species separation were symmetrical, as studied by anion-exchange chromatography. Applied mobile phase consisted of 3 mM of EDTANa2 and 36 mM of ammonium nitrate. Full separation of species in the form of the following forms: H3AsO3, H2AsO4(-), SbO2(-), Sb(OH)6(-), CrO4(2-) was achieved in 15 min with use of gradient elution program. Detailed validation of analytical procedure proved the reliability of analytical measurements. The procedure was characterized by high precision in the range from 1.7% to 2.4%. Detection limits (LD) were 0.067 μg L(-1), 0.068 μg L(-1), 0.098 μg L(-1), 0.083 μg L(-1) and 0.038 μg L(-1) for As(III), As(V), Cr(VI), Sb(III) and Sb(V), respectively. Obtained recoveries confirmed the lack of interferences' influence on analytical signals as their values were in the range of 91%-110%. The applicability of the proposed procedure was tested on drinking water samples characterized by mineralization up to 650 mg L(-1).

  16. Study on multielemental speciation analysis of Cr(VI), As(III) and As(V) in water by advanced hyphenated technique HPLC/ICP-DRC-MS. Fast and reliable procedures.

    Science.gov (United States)

    Marcinkowska, Monika; Komorowicz, Izabela; Barałkiewicz, Danuta

    2015-11-01

    Analytical procedures for multielemental speciation analysis of arsenite - As(III), arsenate - As(V) and hexavalent chromium - Cr(VI) in water using high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC/ICP-DRC-MS) hyphenated technique have been developed. A dynamic reaction cell (DRC) for spectral interferences elimination has been involved in the experiment. Application of oxygen and ammonia as reaction gases in the DRC under various conditions has been verified. Optimization of the following chromatographic conditions: mobile phase composition, concentration of particular components, mobile phase pH and flow rate, injection volume and column temperature, has been conducted. Species separation has been carried out on anion-exchange chromatographic column using isocratic elution with: 22 mM (NH4)2HPO4, 25 mM NH4NO3 (for procedure A) and 22 mM (NH4)2HPO4, 65 mM NH4NO3 (for procedure B) as mobile phases. Detection limits (LD) for procedure A were 0.16 µg L(-1), 0.090 µg L(-1), 0.073 µg L(-1), and for procedure B were 0.14 µg L(-1), 0.062 µg L(-1), 0.15 µg L(-1) for As(III), As(V) and Cr(VI), respectively. Linearity was tested at two concentration ranges of: (0.5-10.0) µg L(-1) for procedure A and (5-50) µg L(-1) for procedure B, and showed correlation coefficients for each of the analytes to be above 0.999. Repeatability values obtained for spiked real water samples were in the range of (4.2-7.6)% and (2.0-2.4)% for procedure A and B respectively. Accuracy was calculated based on the analysis of spiked real water samples at three concentration levels. Obtained recoveries were from 94% to 102%.

  17. Comparison of hydrodynamically closed isotachophoresis-capillary zone electrophoresis with hydrodynamically open capillary zone electrophoresis hyphenated with tandem mass spectrometry in drug analysis: pheniramine, its metabolite and phenylephrine in human urine.

    Science.gov (United States)

    Piešťanský, Juraj; Maráková, Katarína; Kovaľ, Marián; Mikuš, Peter

    2014-09-05

    The advanced two dimensional isotachophoresis (ITP)-capillary zone electrophoresis (CZE) hyphenated with tandem mass spectrometry (MS/MS, here triple quadrupole, QqQ) was developed in this work to demonstrate analytical potentialities of this approach in the analysis of drugs in multicomponent ionic matrices. Pheniramine (PHM), phenylephrine (PHE), paracetamol (PCM) and their potential metabolic products were taken for the analysis by the ITP-CZE-ESI-QqQ technique working in hydrodynamically closed CE separation system and then a comparison with the conventional (hydrodynamically open) CZE-ESI-QqQ technique was made. The ITP-CZE-ESI-QqQ method was favorable in terms of obtainable selectivity (due to highly effective heart-cut analysis), concentration limits of detection (LOD at pgmL(-1) levels due to enhanced sample load capacity and ITP preconcentration), sample handling (on-line sample pretreatment, i.e. clean-up, preconcentration, preseparation), and, by that, possibilities for future automation and miniaturization. On the other hand, this experimental arrangement, in contrast to the CZE-ESI-QqQ arrangement supported by an electroosmotic flow, is principally limited to the analysis of uniformly (i.e. positively or negatively) charged analytes in one run without any possibilities to analyze neutral compounds (here, PCM and neutral or acidic metabolites of the drugs had to be excluded from the analysis). Hence, these general characteristics should be considered when choosing a proper analytical CE-MS approach for a given biomedical application. Here, the analytical potential of the ITP-CZE-ESI-QqQ method was demonstrated showing the real time profiles of excreted targeted drugs and metabolite (PHM, PHE, M-PHM) in human urine after the administration of one dose of Theraflu(®) to the volunteers.

  18. Automatic Screening of 30 Alkaloids by Hyphenation of HPLC with MS%液相色谱-质谱法自动筛选常见30种生物碱

    Institute of Scientific and Technical Information of China (English)

    王学虎; 袁敏; 张前上; 赵武生; 顾月保

    2011-01-01

    HPLC in hyphenation with MS was applied to establish data base of mass spectra and parameters of retention time of 30 common alkaloids. Analytical procedures were carried out under the following conditions: ① chromatographic column: ZORBAX sb-aq. (2.1 mm× 150 mm, 3.5 μm, with precolumn); ② column temp.:30 C; ③ mobile phase: mixture of formic acid+water (0.1 + 99.9) and formic acid+methanol (0.1 + 99.9) in different ratios for gradient elution; ④ flow-rate: 0.4 mL · min-1; ⑤ vol. of sample introduction: 10 μL; ⑥ electrospray ionization source (ESI); ⑦ automatic ternary MS scanning; ⑧ scarming range: 50- 1 000 aum.Automation in operations of screening of alkaloids in drugs was attained by using the software of de-convolution of spectra and locking on retention times. The proposed method has been used instead of the conventional manual operations, in the inspection of substantial cases, displaying its specificity of avoiding missing in detection and decreasing the probability of false-positivity.%应用高效液相色谱与质谱联用建立了30种常见生物碱的质谱图与保留时间参数的数据库.分析时按以下条件进行:①色谱柱:ZORBAX sb-aq.(2.1 mm×150 mm,3.5 μm,带预柱);②柱温:30℃;③流动相:甲酸-水(0.1+99.9)混合溶液与甲酸-甲醇(0.1+99.9)混合溶液以不同比例混合后进行梯度淋洗;④流量:0.4 mL·min-1;⑤进样体积:10μL;⑥用电喷雾离子化电离源;⑦自动3级质谱扫描;⑧扫描范围:50~1 000 aum.用谱图的解卷积和保留时间锁定软件,实现了药物中生物碱筛选的自动化操作.用所提出的方法替代常用方法对几件实际案件进行检验,结果表明:此方法具有避免漏检及降低假阳性报告机率的优点.

  19. 气相色谱与热解吸联用技术在室内环境检测领域的应用及进展%Application and Development of Gas Chromatography Hyphenated with Thermal Desorption in the Field of Indoor Environment Testing

    Institute of Scientific and Technical Information of China (English)

    贾祥焱

    2012-01-01

    It is a brief introduction of gas chromatography and the application and development of gas chromatography hyphenated with thermal desorption in the test benzene and TVOC of indoor environment testing,and puts forward outlook and prospect in it.It provides favorable value in the development of gas chromatographic technique in indoor environment testing.%简要介绍了气相色谱法,及其与热解吸联用在民用建筑工程室内环境检测中检测苯、TVOC的应用和进展。并提出了气相色谱与热解吸联用技术的前景与展望,为气相色谱技术在室内环境检测领域的发展提供有利价值。

  20. Evaluation of a novel PTFE material for use as a means for separation and preconcentration of trace levels of metal ions in sequential injection (SI) and sequential injection lab-on-valve (SI-LOV) systems. Determination of cadmium (II) with detection by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Long, Xiangbao; Chomchoei, Roongrat; Hansen, Elo Harald

    2004-01-01

    The operational characteristics of a novel poly(tetrafluoroethylene) (PTFE) bead material, granular Algoflon®, used for separation and preconcentration of metal ions via adsorption of on-line generated non-charged metal complexes, were evaluated in a sequential injection (SI) system furnished...... material, Aldrich PTFE, which had demonstrated that PTFE was the most promising for solid-state pretreatments. By comparing the two materials, the Algoflon® beads exhibited much higher sensitivity (1.6107 versus 0.2956 μg l-1 per integrated absorbance (s)), and better retention efficiency (82% versus 74...

  1. HPLC-ICP/MS联用同时分析中药材中的多种形态砷%Analysis of arsenic speciation in traditional Chinese medicines by hyphenated technique of high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    郝春莉; 赵丽; 庄峙厦

    2011-01-01

    The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) were applied in the simultaneous determination of six arsenic species including As( Ⅲ ) 、As( Ⅴ ) 、DMA、MMA、AsB and AsC, in traditional Chinese medicines. The arsenic species in Traditional Chinese Medicinal samples were extracted using 1.2 mol/L hydrochloric acid and analyzed by the hyphenated technique of HPLC-ICP-MS with Hamilton PRP-X100 column. The arsenic species were separated well in the 800s,and the detection limits were 0. 2 ~ 0. 6 μg. Arsenate As(Ⅴ) and arsenite As(Ⅲ) were main arsenic species in all samples,and the inorganic arsenic recoveries were 64%. 1% ~91.7%. In addition, a little arsenobetaine (AsB) was found in animal herbs. The method can be applied to the quantitative determination and safety evaluation of inorganic arsenic or six arsenic species in TCMs.%利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)对中药材中的6种砷的形态(三价砷(As(Ⅲ))、五价砷(As(Ⅴ))、二甲基砷酸(DMA)、甲基砷酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC))进行了同时分析.采用1.2mol/,L HCl浸提,Hamilton PRP-X100阴离子交换色谱柱分离后,根据ICP/MS保留时间的差别跟踪检测砷元素的各种形态.6种砷形态在800s内分离良好,检测限在0.2~0.6μg/L之间;中药材中的砷主要以有毒的无机砷(As(Ⅴ)和As(Ⅲ))形态存在,样品中无机砷的回收率在64.1%~91.7%之间,另外动物药材中还存在微量的AsB等有机砷形态.方法可用于中药材中无机砷或各种砷形态的同时分析.

  2. Hyphenated Technique of Anti Asthma Application of Chemical Drugs Added Illegally in Traditional Chinese Medicine in the Identification%色谱联用技术在鉴定抗哮喘中药制剂中非法添加化学药物的应用

    Institute of Scientific and Technical Information of China (English)

    付蔷

    2014-01-01

    Traditional Chinese medicine to medication safety,become a common clinical drug treatment of asthma. In recent years,Chinese medicine clinical treatment of asthma often found il egal y mixed into chemical drug ingredients,pose a serious threat to patient safety.This paper reviews the application of hyphenated chromatographic techniques in the identification of chemical drugs added il egal y anti asthma in Chinese medicine preparation,in order to provide reference for the clinical detection.%中药制剂以其安全可靠的用药特点,成为临床治疗哮喘的常用药物。近年来,临床治疗哮喘的中药制剂中经常发现非法掺入化学类药物成分,给患者的用药安全带来严重威胁。本文分析了色谱联用技术在鉴定抗哮喘中药制剂中非法添加化学药物的应用进展,以期为临床检测提供参考。

  3. 谈谈英文标点dash与hyphen

    Institute of Scientific and Technical Information of China (English)

    黎秋萍; 金丽莉

    2004-01-01

    @@ 现在国人用英文写作(学术著作、论文等)已经比较普遍,涉及英语的报刊、教学材料、阅读辅导书更是不断出版.但是编著者往往不太注意英语书写中标点符号的使用规则.虽然中英文标点符号的功能大同小异,然而这个"小异"却不可忽视.据笔者掌握的情况,误用率最高的当属dash与hyphen了.为了让读者对它们有个感性认识,首先请看下面所列的表.

  4. Electroextraction and electromembrane extraction : Advances in hyphenation to analytical techniques.

    NARCIS (Netherlands)

    Oedit, A.; Ramautar, R.; Hankemeier, T.; Lindenburg, P.W.

    2016-01-01

    Electroextraction (EE) and electromembrane extraction (EME) are sample preparation techniques that both require an electric field that is applied over a liquid-liquid system, which enables the migration of charged analytes. Furthermore, both techniques are often used to pre-concentrate analytes prio

  5. Direct 13C NMR Detection in HPLC Hyphenation Mode

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Johansen, Kenneth; Nyberg, Nils

    2012-01-01

    Solid phase extraction (SPE) was introduced as a crucial step in the HPLC-SPE-NMR technique to enable online analyte enrichment from which proton-detected NMR experiments on submicrogram amounts from complex mixtures were possible. However, the significance of direct-detected (13)C NMR experiments......, and an acquisition time of 13 h resulted in spectra with adequate signal-to-noise ratios to detect all C-13 signals....

  6. Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10).

    Science.gov (United States)

    Beltrán, Blanca; Avivar, Jessica; Mola, Montserrat; Ferrer, Laura; Cerdà, Víctor; Leal, Luz O

    2013-09-03

    A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

  7. Smart thorium and uranium determination exploiting renewable solid-phase extraction applied to environmental samples in a wide concentration range.

    Science.gov (United States)

    Avivar, Jessica; Ferrer, Laura; Casas, Montserrat; Cerdà, Víctor

    2011-07-01

    A smart fully automated system is proposed for determination of thorium and uranium in a wide concentration range, reaching environmental levels. The hyphenation of lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), coupled to a long path length liquid waveguide capillary cell, allows the spectrophotometric determination of thorium and uranium in different types of environmental sample matrices achieving high selectivity and sensitivity levels. Online separation and preconcentration of thorium and uranium is carried out by means of Uranium and TEtraValents Actinides resin. The potential of the LOV-MSFIA makes possible the full automation of the system by the in-line regeneration of the column and its combination with a smart methodology is a step forward in automation. After elution, thorium(IV) and uranium(VI) are spectrophotometrically detected after reaction with arsenazo-III. We propose a rapid, inexpensive, and fully automated method to determine thorium(IV) and uranium(VI) in a wide concentration range (0-1,200 and 0-2,000 μg L(-1) Th and U, respectively). Limits of detection reached are 5.9 ηg L(-1) of uranium and 60 ηg L(-1) of thorium. Different water sample matrices (seawater, well water, freshwater, tap water, and mineral water), and a channel sediment reference material which contained thorium and uranium were satisfactorily analyzed with the proposed method.

  8. Affixial Words with Hyphens%需带连字符的词缀词

    Institute of Scientific and Technical Information of China (English)

    陈春勇

    2009-01-01

    词缀词一般无需使用连字符,但亦有少数例外.本文针对名词、动词和形容词前添加前缀时须使用连字符的几种情形进行了探讨,并附带提及了个别词的后缀前也应使用连字符的问题.

  9. Literature and Social Studies: Reading the Hyphenated Spaces of Canadian Identity.

    Science.gov (United States)

    Johnston, Ingrid

    2000-01-01

    Considers the ideological and imaginative potential of literature for questioning notions of Canadian identity in the social studies classroom. Compares various literary texts and considers how writers attempt to create a unified metanarrative. Contrasts texts from the early twentieth century with contemporary Canadian literature. (CMK)

  10. Pharmacokinetic study of inosiplex tablets in healthy Chinese volunteers by hyphenated HPLC and tandem MS techniques

    Institute of Scientific and Technical Information of China (English)

    Mo Chen; Yuan Zhang; Xiao-Ting Que; Ya Ding; Lin Yang; Ai-Dong Wen; Tai-Jun Hang

    2013-01-01

    Inosiplex is a compound formulation composed of inosine and p-acetaminobenzoic acid (PABA) salt of N,N-dimethylamino-2-propanol (DIP). This study was to investigate the clinical plasma pharmacokinetic properties of DIP and PABA after single and multiple oral doses of inosiplex tablets in healthy Chinese volunteers. The established LC/MS/MS method for plasma DIP determination had a linear range of 0.02-10 mg/mL, and the HPLC method for plasma PABA determination had a linear range of 0.05-40 mg/mL. Linear pharmacokinetic characteristics were found with single oral doses of 0.5, 1.0 and 2.0 g. No obvious accumulation effects were observed for DIP and PABA.

  11. Latin@ Advocacy in the Hyphen: Faculty Identity and Commitment in a Hispanic-Serving Institution

    Science.gov (United States)

    Murakami-Ramalho, Elizabeth; Nunez, Anne-Marie; Cuero, Kimberley K.

    2010-01-01

    This study examines our experiences as female junior scholars with multicultural backgrounds teaching at the same Hispanic-serving institution. As education scholars with mixed-heritage families, we identify with the commitment to serving Latinos and the number of mixed-heritage people in the USA. The election of Barack Obama, whose racial…

  12. NMR-based metabolomics and hyphenated NMR techniques – a perfect match in natural products research

    DEFF Research Database (Denmark)

    Vinther, Joachim Møllesøe; Wubshet, Sileshi Gizachew; Stærk, Dan

    2015-01-01

    Ethnopharmacology is one of the world’s fastest-growing scientific disciplines encompassing a diverse range of subjects. It links natural sciences research on medicinal, aromatic and toxic plants with socio-cultural studies and has often been associated with the development of new drugs....... The Editors of Ethnopharmacology have assembled an international team of renowned contributors to provide a critical synthesis of the substantial body of new knowledge and evidence on the subject that has emerged over the past decade. Divided into three parts, the book begins with an overview of the subject...... including a brief history, ethnopharmacological methods, the role of intellectual property protection, key analytical approaches, the role of ethnopharmacology in primary/secondary education and links to biodiversity and ecological research. Part two looks at ethnopharmacological contributions to modern...

  13. Analysis of xanthines in beverages using a fully automated SPE-SPC-DAD hyphenated system

    Energy Technology Data Exchange (ETDEWEB)

    Medvedovici, A. [Bucarest Univ., Bucarest (Romania). Faculty of Chemistry, Dept. of Analytical Chemistry; David, F.; David, V.; Sandra, P. [Research Institute of Chromatography, Kortrijk (Belgium)

    2000-08-01

    Analysis of some xanthines (caffeine, theophylline and theobromine) in beverages has been achieved by a fully automated on-line Solid Phase Extraction - Supercritical Fluid Chromatography - Diode Array Detection (Spe - Sofc - Dad). Three adsorbents have been tested for the Spe procedure: octadecyl modified silicagel (ODS) and two types of styrene-divinylbenzen copolymer based materials, from which Porapack proved to be the most suitable adsorbent. Optimisation and correlation of both Spe and Sofc operational parameters are also discussed. By this technique, caffeine was determined in ice tea and Coca-Cola in a concentration of 0.15 ppm, theobromine - 1.5 ppb, and theophylline - 0.15 ppb. [Italian] Si e' realizzata l'analis di alcune xantine (caffeina, teofillina e teobromina) mediante un sistema, in linea, completamente automatizzato basato su Estrazione in Fase Solida - Cromatografia in Fase Supercritica - Rivelazione con Diode Array (Spe - Sfc - Dad). Per la procedura Spe sono stati valutati tre substrati: silice ottadecilica (ODS) e due tipi di materiali polimerici a base stirene-divinilbenzene, di cui, quello denominato PRP-1, e' risultato essere il piu' efficiente. Sono discusse sia l'ottimizzazione che la correlazione dei parametri operazionali per la Spe e la Sfc. Con questa tecnica sono state determinate, in te' ghiacciato e Coca-Cola, la caffeina, la teobromina e la teofillina alle concentrazini di 0.15, 1.5 e 0.15 ppm.

  14. Gas chromatography/ion mobility spectrometry as a hyphenated technique for improved explosives detection and analysis

    Science.gov (United States)

    Mercado, AL; Marsden, Paul

    1995-01-01

    Ion Mobility Spectrometry (IMS) is currently being successfully applied to the problem of on-line trace detection of plastic and other explosives in airports and other facilities. The methods of sample retrieval primarily consist of batch sampling for particulate residue on a filter card for introduction into the IMS. The sample is desorbed into the IMS using air as the carrier and negative ions of the explosives are detected, some as an adduct with a reagent ion such as Cl(-). Based on studies and tests conducted by different airport authorities, this method seems to work well for low vapor pressure explosives such as RDX and PETN, as well as TNT that are highly adsorptive and can be found in nanogram quantities on contaminated surfaces. Recently, the changing terrorist threat and the adoption of new marking agents for plastic explosives has meant that the sample introduction and analysis capabilities of the IMS must be enhanced in order to keep up with other detector developments. The IMS has sufficient analytical resolution for a few threat compounds but the IMS Plasmogram becomes increasingly more difficult to interpret when the sample mixture gets more complex.

  15. Neither this nor that: The hyphenated existence of Chinese children growing up in twentieth century North America

    OpenAIRE

    Byrne, Elizabeth

    2005-01-01

    This project takes its evidence from Chinese North American authors who have written about their own lives or those of members of their immigrant community. Authors such as Denise Chong, Wayson Choy, Ben Fong-Torres, Amy Tan, and Yuen-Fong Woon have written autobiographical fictions, fictionalized biographies, and family histories that delve into Chinese communities in Canada and America. These authors have opened windows into the personal worlds of their communities, and this project attempt...

  16. The Hyphen of National Culture : The Paradox of National Distinctiveness in Belgium and the Netherlands, 1860-1918

    NARCIS (Netherlands)

    Tollebeek, Jo

    2010-01-01

    At the turn of the 20th century, intellectuals and artists in Belgium and the Netherlands were keen to define their respective national identities. One of the most striking ways of doing this was based on a paradox: in both Belgium and the Netherlands the idea came into being that their national dis

  17. 连字号复合词的语体分析%Genre Analysis of Hyphenated Compounds

    Institute of Scientific and Technical Information of China (English)

    赵琼

    2009-01-01

    在英语构词法中,复合词占有较大比例.根据拼写规则,复合词可以分为三类: 固定复合词、连字号复合词和开放型复合词.连字号复合词更以形象生动、变化无穷和经济简洁的表现手法著称.文章从语体分析入手,研究连字号复合词的语体色彩、特征和功能.

  18. 分析仪器联用技术的发展动向%Development of Instrument Hyphenated Technology

    Institute of Scientific and Technical Information of China (English)

    赵宏

    2006-01-01

    分析仪器联用技术已在环境样品分析中得到应用,并有广阔的发展前景.本文介绍了色谱-色谱、色谱-原子光谱、离子色谱联用技术、色谱-质谱、色谱-傅立叶变换红外光谱、色谱-核磁共振波谱(NMR)联用技术在分析环境样品方面的应用.

  19. Word Formation with Hyphen and Related Translation%连字符构词探索及其翻译

    Institute of Scientific and Technical Information of China (English)

    李砚霞

    2009-01-01

    连字符构词因其同其他构词之间的特殊联系以及它自身构成的灵活性、广泛性的特点,它的构词规律应该被视为独立的构词法去探索;翻译连字符构词应在掌握其他构词翻译方法和技巧的基础上更加关注连字符构词语义整体性、单一性、简洁性的特点.

  20. Four new degradation products of doxorubicin:An application of forced degradation study and hyphenated chromatographic techniques

    Institute of Scientific and Technical Information of China (English)

    Dheeraj Kaushik; Gulshan Bansal

    2015-01-01

    Forced degradation study on doxorubicin (DOX) was carried out under hydrolytic condition in acidic, alkaline and neutral media at varied temperatures, as well as under peroxide, thermal and photolytic conditions in accordance with International Conference on Harmonization (ICH) guidelines Q1(R2). It was found extremely unstable to alkaline hydrolysis even at room temperature, unstable to acid hy-drolysis at 80 °C, and to oxidation at room temperature. It degraded to four products (O-I-O-IV) in oxidative condition, and to single product (A-I) in acid hydrolytic condition. These products were re-solved on a C8 (150 mm × 4.6 mm, 5μm) column with isocratic elution using mobile phase consisting of HCOONH4 (10 mM, pH 2.5), acetonitrile and methanol (65:15:20, / / ). Liquid chromatography-pho-todiode array (LC-PDA) technique was used to ascertain the purity of the products noted in LC-UV chromatogram. For their characterization, a six stage mass fragmentation (MS6) pattern of DOX was outlined through mass spectral studies in positive mode of electrospray ionization (+ESI) as well as through accurate mass spectral data of DOX and the products generated through liquid chromato-graphy-time of flight mass spectrometry (LC-MS-TOF) on degraded drug solutions. Based on it, O-I-O-IV were characterized as 3-hydroxy-9-desacetyldoxorubicin-9-hydroperoxide, 1-hydroxy-9-desacetyldox-orubicin-9-hydroperoxide, 9-desacetyldoxorubicin-9-hydroperoxide and 9-desacetyldoxorubicin, re-spectively, whereas A-I was characterized as deglucosaminyl doxorubicin. While A-I was found to be a pharmacopoeial impurity, all oxidative products were found to be new degradation impurities. The mechanisms and pathways of degradation of doxorubicin were outlined and discussed.

  1. Effect of the interface on separation in multicapillary gas chromatography-based hyphenated techniques for speciation analysis of organometallic compounds.

    Science.gov (United States)

    Jitaru, Petru; Birzu, Adrian; Mocanu, Raluca; Adams, Freddy C

    2005-08-01

    This paper reports the effect of transfer line (TL) internal diameter (i.d.) on gas chromatographic separation characteristics such as efficiency and speed, when a multicapillary (MC) column is used for speciation analysis of mercury. Five different TL consisting of fused-silica capillaries with 0.15, 0.20, 0.25, 0.32, and 0.53 mm i.d. are compared. The separation efficiency and total chromatographic run time are critically affected by the i.d. of the TL. Narrow capillaries (i.d. or =35 psig) and wide TL (> or =0.25 mm i.d.).

  2. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, Valeria [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Biagi, Simona [National Research Council of Italy, C.N.R., Istituto per i Processi Chimico-Fisici - IPCF-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ghimenti, Silvia [University of Pisa, Department of Chemistry and Industrial Chemistry, Via Risorgimento 35, 56126 Pisa (Italy); Onor, Massimo; D' Ulivo, Alessandro [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Bramanti, Emilia, E-mail: bramanti@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

    2011-11-15

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H{sub 2} miniaturized flame after sodium borohydride reduction to Hg{sup 0}, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H{sub 2} microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10{sup -5} mol L{sup -1}), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L{sup -1} (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 {mu}mol L{sup -1} were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were never less than 91%. Flow injection-chemical vapor generation atomic fluorescence spectrometry method was validated by analyzing the TORT-1 certificate reference material, which contains only monomethylmercury, and obtaining 83 {+-} 5% of monomethylmercury recovered, respectively. This method was also applied to the determination of monomethylmercury in saliva samples. - Highlights: Black-Right-Pointing-Pointer Monomethylmercury and ethylmercury were determined on line using FI-CVG-AFS. Black-Right-Pointing-Pointer No oxidation to Hg{sup II} is required for MeHg and EtHg determination. Black-Right-Pointing-Pointer No complexing agents are needed for their conversion to volatile species detectable by AFS. Black-Right-Pointing-Pointer LOD was about 45 nmol L{sup -1} (as mercury) for all the species considered.

  3. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Science.gov (United States)

    Angeli, Valeria; Biagi, Simona; Ghimenti, Silvia; Onor, Massimo; D'Ulivo, Alessandro; Bramanti, Emilia

    2011-11-01

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H 2 miniaturized flame after sodium borohydride reduction to Hg 0, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H 2 microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10 - 5 mol L - 1 ), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L - 1 (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 μmol L - 1 were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were never less than 91%. Flow injection-chemical vapor generation atomic fluorescence spectrometry method was validated by analyzing the TORT-1 certificate reference material, which contains only monomethylmercury, and obtaining 83 ± 5% of monomethylmercury recovered, respectively. This method was also applied to the determination of monomethylmercury in saliva samples.

  4. Hyphenating the curtius rearrangement with Morita-Baylis-Hillman adducts: synthesis of biologically active acyloins and vicinal aminoalcohols

    Energy Technology Data Exchange (ETDEWEB)

    Amarante, Giovanni W.; Cavallaro, Mayra; Coelho, Fernando, E-mail: coelho@iqm.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Lab. de Sintese de Produtos Naturais e Farmacos

    2011-07-01

    Using Morita-Baylis-Hillman adducts as substrates, the Curtius rearrangement was performed in a sequence that allowed the synthesis of several hydroxy-ketones (acyloins) with great structural diversity and in good overall yields. These acyloins in turn were easily transformed into 1,2-anti aminoalcohols through a highly diastereoselective reductive amination step. The synthetic utility of these approaches was exemplified by performing the syntheses of (+-)-bupropion, a drug used to treat the abstinence syndrome of smoker and (+-)-spisulosine, a potent anti-tumoral compound originally isolated from a marine source. (author)

  5. Determination of Urinary PAH Metabolites Using DLLME Hyphenated to Injector Port Silylation and GC-MS-MS.

    Science.gov (United States)

    Gupta, Manoj Kumar; Jain, Rajeev; Singh, Pratibha; Ch, Ratnasekhar; Mudiam, Mohana Krishna Reddy

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants and well-known carcinogens. Hydroxy derivatives of PAH are considered as biomarkers of PAH exposure, and there is a need to measure these metabolites at low concentrations. So, a precise and eco-friendly analytical method has been developed for rapid determination of PAH metabolites. For the first time, a new analytical method based on coupling of dispersive liquid-liquid microextraction (DLLME) with auto-injector port silylation (auto-IPS) followed by gas chromatography-tandem mass spectrometry (GC-MS-MS) analysis is reported for the analysis of seven urinary PAH metabolites. Factors affecting DLLME and IPS, such as type and volume of extraction and disperser solvent, pH, ionic strength, injector port temperature, volume of N,O-bis(trimethylsilyl)trifluoroacetamide and type of solvent were investigated. Under optimized conditions, the limit of detection and limit of quantification were found to be in the range of 1-9 and 3-29 ng/mL, respectively. Satisfactory recoveries of metabolites in urine samples in the range of 87-95% were found. The developed method has been successfully applied for the determination of PAH metabolites in urine samples of exposed workers. DLLME-auto-IPS-GC-MS-MS method is time, labor, solvent and reagent saving, which can be routinely used for the analysis of urinary PAH metabolites.

  6. Combination of dispersive liquid-liquid microextraction and solid-phase microextraction: An efficient hyphenated sample preparation method.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Mossaddegh, Mehdi

    2016-09-30

    Two well-known microextraction methods, dispersive liquid-liquid microextraction (DLLME) and solid-phase microextraction (SPME), were combined, resulting in as an encouraging method. The method, named DLLME-SPME, was performed based on total vaporization technique. For the DLLME step, 1,1,2,2-tetrachloroethane and acetonitrile were used as extraction and disperser solvents, respectively. Halloysite nanotubes-titanium dioxide was used as the fiber coating in the SPME step. The method was applied for the extraction of diazinon and parathion (as the test compounds) in environmental water samples and fruit juices, and gas chromatography-corona discharge ion mobility spectrometry was used as the determination apparatus. Desorption temperature and time, extraction temperature and time, and the volume of the extracting solvent in the DLLME step were optimized as the effective parameters on the extraction efficiency. The relative standard deviations (RSDs) of intra-day were found to be 4-7% and 6-8% for diazinon and parathion, respectively. Also, the RSDs of inter-day were 7-9% and 8-10% for diazinon and parathion, respectively. The limits of quantification and detection were obtained to be 0.015 and 0.005μgL(-1) for diazinon, and 0.020 and 0.007μgL(-1) for parathion. A good linearity range (r(2)˃0.993) was obtained in the range of 0.015-3.000 and 0.020-3.000μgL(-1) for diazinon and parathion, respectively. The high enrichment factors were obtained as 3150 and 2965 for diazinon and parathion, respectively. This method showed high sensitivity with good recovery values (between 87 and 99%) for the extraction of target analytes in the real samples. Overall, the results revealed that the developed DLLME-SPME method had better extraction efficiency than DLLME and SPME alone.

  7. Symbols of Hyphenated Identity Drawing Maps (IDM) for Arab and Jewish Students at the University of Haifa

    Science.gov (United States)

    Hertz-Lazarowitz, Rachel; Farah, Abeer; Zelniker, Tamar

    2013-01-01

    In 2008, we conducted a large scale study following our methodology developed for the analysis of drawings to assess identity (Hertz-Lazarowitz, Farah & Yosef-Meitav, 2012). We gathered interviews and asked for Identity Drawing Maps (IDM) from 184 students aged from 20-30 years. The symbols in the drawings were grouped in five categories:…

  8. Speciation of gadolinium in surface water samples and plants by hydrophilic interaction chromatography hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lindner, Uwe; Lingott, Jana; Richter, Silke; Jakubowski, Norbert; Panne, Ulrich

    2013-02-01

    Hydrophilic interaction chromatography (HILIC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was optimized for speciation analysis of gadolinium-based contrast agents in environmental samples, in particular surface river waters and plants. Surface water samples from the Teltow channel, near Berlin, were investigated over a distance of 5 km downstream from the influx of a wastewater treatment plant. The total concentration of gadolinium increased significantly from 50 to 990 ng L(-1) due to the influx of the contrast agents. After complete mixing with the river water, the concentration remained constant over a distance of at least 4 km. Two main substances [Dotarem(®) (Gd-DOTA) and Gadovist(®) (Gd-BT-DO3A)] have been identified in the river water using standards. A gadolinium-based contrast agent, possibly Gd-DOTA (Dotarem(®)), was also detected in water plant samples taken from the Teltow channel. Therefore, uptake of contrast agents [Gadovist(®) (Gd-BTDO3A), Magnevist(®) (Gd-DTPA), Omniscan(®) (Gd-DTPA-BMA), Dotarem(®) (Gd-DOTA), and Multihance(®) (Gd-BOPTA)] by plants was investigated in a model experiment using Lepidium sativum (cress plants). HILIC-ICP-MS was used for identification of different contrast agents, and a first approach for quantification using aqueous standard solutions was tested. For speciation analysis, all investigated contrast agents could be extracted from the plant tissues with a recovery of about 54 % for Multihance(®) (Gd-BOPTA) up to 106 % for Gadovist(®) (Gd-BT-DO3A). These experiments demonstrate that all contrast agents investigated are transported from the roots to the leaves where the highest content was measured.

  9. Rapid Identification of Bibenzyls of Stemona sessilifolia using Hyphenated LC-UV-NMR and LC-MS Methods

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As a part of the ongoing search for new constituents of Stemona species in China, chemical investigation of Stemona sessilifolia, a plant used in the traditional Chinese medicine to treat respiratory disorders, was carried out. To identify the chemical components rapidly, a selected sample of S. sessilifolia containing bibenzyls was tested using LC-ESIMS and analyzed further using stop-flow LC-UV-NMR, which was sensitive for the detection of the main constituents. LC microfractions were collected using the LC-UV-NMR technique and HR-EIMS off-line analysis was carried out on the collected fractions. This chemical screening strategy allowed for the on-line identification of the main constituents of S. sessilifolia and provided information that was useful for a further peak-guided isolation procedure.Using these methods, four bibenzyls were isolated: two known compounds, 3,5-dihydroxy-4-methyl bibenzyl(1) and 3,5-dihydroxy-2'-methoxy-4-methyl bibenzyl ( 2 ), and two novel compounds, 3, 3'-dihydroxy-5, 6'-dimethoxy bibenzyl (3) and 3,5-dihydroxy-2' ,5'-dimethoxy bibenzyl (4).

  10. Application of LC and GC hyphenated with mass spectrometry as tool for characterization of unknown derivatives of isoflavonoids.

    Science.gov (United States)

    Maul, Ronald; Schebb, Nils Helge; Kulling, Sabine E

    2008-05-01

    Polyphenols belonging to the class of secondary metabolites of plants and microorganisms play an important role as bioactive food constituents as well as contaminants. Structure elucidation of polyphenols in plant extracts or polyphenol metabolites, especially those arising during biotransformation, still represents a challenge for analytical chemistry. Various approaches have been proposed to utilize fragmentation reactions in connection with mass spectrometry (MS) for structural considerations on polyphenolic targets. We compiled and applied specific liquid chromatography (LC)-electrospray ionization in positive mode [ESI(+)]-tandem MS (MS/MS) and gas chromatography (GC)-(electron impact, EI)-MS/MS fragmentation reactions with a special focus on the analysis of isoflavones, whereby this technique was also found to be extendable to determine further polyphenols. For ESI(+)-MS the basic retro-Diels-Alder (rDA) fragmentation offers information about the substitution pattern in the A- and B-rings of flavonoids and the elimination of a protonated 4-methylenecyclohexa-2,5-dienone (m/z = 107) fragment can be used as a diagnostic tool for many isoflavanones. For GC-(EI)-MS/MS analysis after derivatization of the analytes to their trimethylsilyl ethers, the elimination of methyl radicals, tetramethylsilane groups or the combined loss of two methyl groups can be shown to be specific for certain substitution patterns in polyphenols. The applicability of the fragmentation reactions presented is demonstrated exemplarily for three derivatives of the isoflavone irilone. With the help of these fragmentation reactions of the two MS techniques combined, a reliable identification of polyphenols is possible. Especially in such cases where NMR cannot be utilized owing to low analyte amounts being available or prior to purification, valuable information can be obtained.

  11. Sustainability Study on Heavy Metal Uptake in Neem Biodiesel Using Selective Catalytic Preparation and Hyphenated Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Mirella Elkadi

    2014-04-01

    Full Text Available It is common knowledge that the presence of trace metals in biofuels can be detrimental to the environment and long-term sustainable development. This study provides an insight into selective catalytic preparation of biofuel to compare uptake of trace metals in the biodiesel fraction with preferential base catalysts. The role of specific metal hydroxides in controlling trace metal content in biofuel production is relatively unexplored, and the effect of different homogeneous catalysts (NaOH, KOH on metal retention in biodiesel from commercial neem oil was examined. A detailed study of this nature of catalyst vs. metal uptake is in the interest of sustainable living and could make a significant contribution to biofuels research. Both catalysts displayed variable uptake for certain toxic elements, which was attributed to the behavior of the catalyst in the reaction mixture. A general comparison reflected specific trends in metal retention (ICP-MS with the use of different base catalysts. Challenges encountered by extending the study and using a heterogeneous catalyst (CaO are presented. Our work could play a significant role in influencing catalyzed transesterfication processes to control elemental and toxic metal uptake in biofuels. The impact of our work on sustainable living is presented.

  12. Hyphenated chromatographic techniques for the rapid screening and identification of antioxidants in methanolic extracts of pharmaceutically used plants .

    NARCIS (Netherlands)

    Exarchou, V.; Fiamegos, Y.C.; Beek, van T.A.; Nanos, C.G.; Vervoort, J.J.M.

    2006-01-01

    Phytochemical analysis is an important scientific research area, which normally relies on a number of rather laborious and time-consuming techniques for compound identification. Isolation of the ingredients of plant extracts in adequate quantities for spectral and biological analysis was the basis o

  13. Trends and perspectives of flow injection/sequential injection on-line sample-pretreatment schemes coupled to ETAAS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2005-01-01

    Flow injection (FI) analysis, the first generation of this technique, became in the 1990s supplemented by its second generation, sequential injection (SI), and most recently by the third generation (i.e.,Lab-on-Valve). The dominant role played by FI in automatic, on-line, sample pretreatments...

  14. Tre generationer af Flow Injection Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Chomchoei, Roongrat; Long, Xiangbao

    2004-01-01

    Siden introduktionen af FIA har en række videreudviklinger resulteret i Sequential Injection Analysis (SIA) og senest i Lab-on-Valve (LOV)-metodikken. Her beskrives disse, og der gives eksempler på, hvordan metoderne kan bruges til at bestemme sporstofkoncentrationer af metaller i komplekse...

  15. How Flow Injection Analysis (FIA) over the past 25 years has changed our way of performing chemical analyses

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel

    2007-01-01

    Briefly looking back on the impact of flow injection analysis (FIA), as reflected in the rapid growth of publications in the scientific literature, and touching upon many of the novel and unique analytical chemical possibilities that FIA and its sequels, sequential injection analysis (SIA) and Lab-on-Valve...

  16. Hyphenation of ultra performance liquid chromatography (UPLC) with inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of bromine containing preservatives

    DEFF Research Database (Denmark)

    Bendahl, Lars; Hansen, Steen Honoré; Gammelgaard, Bente

    2006-01-01

    Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material...... at an intermediate and at a high linear velocity. The precision was better than 2.2% R.S.D. and regression analysis showed that a linear response was achieved at both flow rates (R2 > 0.9993, n = 36). The analysis time was less than 4.5 min at a flow rate of 50 microL min(-1) and limits of detection...

  17. Speciation analysis of mercury in sediments, zoobenthos and river water samples by high-performance liquid chromatography hyphenated to atomic fluorescence spectrometry following preconcentration by solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Margetinova, Jana; Houserova-Pelcova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, Brno CZ 613 00 (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, Brno CZ 613 00 (Czech Republic)], E-mail: kuban@mendelu.cz

    2008-05-19

    A high-pressure microwave digestion was applied for microwave-assisted extraction (MAE) of mercury species from sediments and zoobenthos samples. A mixture containing 3 mol L{sup -1} HCl, 50% aqueous methanol and 0.2 mol L{sup -1} citric acid (for masking co-extracted Fe{sup 3+}) was selected as the most suitable extraction agent. The efficiency of proposed extraction method was better than 95% with R.S.D. below 6%. A preconcentration method utilizing a 'homemade' C18 solid phase extraction (SPE) microcolumns was developed to enhance sensitivity of the mercury species determination using on-column complex formation of mercury-2-mercaptophenol complexes. Methanol was chosen for counter-current elution of the retained mercury complexes achieving a preconcentration factor as much as 1000. The preconcentration method was applied for the speciation analysis of mercury in river water samples. The high-performance liquid chromatography-cold vapour atomic fluorescence spectrometric (HPLC/CV-AFS) method was used for the speciation analysis of mercury. The complete separation of four mercury species was achieved by an isocratic elution of aqueous methanol (65%/35%) on a Zorbax SB-C18 column (4.6 mm x 150 mm, 5 {mu}m) using the same complexation reagent (2-mercaptophenol). The limits of detection were 4.3 {mu}g L{sup -1} for methylmercury (MeHg{sup +}), 1.4 {mu}g L{sup -1} for ethylmercury (EtHg{sup +}), 0.8 {mu}g L{sup -1} for inorganic mercury (Hg{sup 2+}), 0.8 {mu}g L{sup -1} for phenylmercury (PhHg{sup +})

  18. Characterizing Environmental Transformation of Multi-walled Carbon Nanotubes and Carbon Nano-Fiber Composites using Thermal Analysis and Related Hyphenated Techniques

    Science.gov (United States)

    Thermogravimetric analysis (TGA) coupled with gas chromatography and mass spectroscopy (TGA/GCMS), for the evolved gas analysis, has given insight to the stability and kinetics of structural changes and determining adsorbed organics to nanomaterials and nanocomposites. TGA is als...

  19. Towards early detection of the hydrolytic degradation of poly(bisphenol A)carbonate by hyphenated liquid chromatography and comprehensive two-dimensional liquid chromatography

    NARCIS (Netherlands)

    Coulier, L.; Kaal, E.R.; Hankemeier, Th.

    2006-01-01

    The hydrolytic degradation of poly(bisphenol A)carbonate (PC) has been characterized by various liquid chromatography techniques. Size exclusion chromatography (SEC) showed a significant decrease in molecular mass as a result of hydrolytic degradation, while 'liquid chromatography at critical condit

  20. Enantioselective column coupled electrophoresis employing large bore capillaries hyphenated with tandem mass spectrometry for ultra-trace determination of chiral compounds in complex real samples.

    Science.gov (United States)

    Piešťanský, Juraj; Maráková, Katarína; Kovaľ, Marián; Havránek, Emil; Mikuš, Peter

    2015-12-01

    A new multidimensional analytical approach for the ultra-trace determination of target chiral compounds in unpretreated complex real samples was developed in this work. The proposed analytical system provided high orthogonality due to on-line combination of three different methods (separation mechanisms), i.e. (1) isotachophoresis (ITP), (2) chiral capillary zone electrophoresis (chiral CZE), and (3) triple quadrupole mass spectrometry (QqQ MS). The ITP step, performed in a large bore capillary (800 μm), was utilized for the effective sample pretreatment (preconcentration and matrix clean-up) in a large injection volume (1-10 μL) enabling to obtain as low as ca. 80 pg/mL limits of detection for the target enantiomers in urine matrices. In the chiral CZE step, the different chiral selectors (neutral, ionizable, and permanently charged cyclodextrins) and buffer systems were tested in terms of enantioselectivity and influence on the MS detection response. The performance parameters of the optimized ITP - chiral CZE-QqQ MS method were evaluated according to the FDA guidance for bioanalytical method validation. Successful validation and application (enantioselective monitoring of renally eliminated pheniramine and its metabolite in human urine) highlighted great potential of this chiral approach in advanced enantioselective biomedical applications.

  1. Multiple heart-cutting and comprehensive two-dimensional liquid chromatography hyphenated to mass spectrometry for the characterization of the antibody-drug conjugate ado-trastuzumab emtansine.

    Science.gov (United States)

    Sandra, Koen; Vanhoenacker, Gerd; Vandenheede, Isabel; Steenbeke, Mieke; Joseph, Maureen; Sandra, Pat

    2016-10-01

    Antibody-drug conjugates might be the magic bullets referred to by Paul Ehrlich over 100 years ago. Together with a huge therapeutic potential, these molecules come with a structural complexity that drives state-of-the-art chromatography and mass spectrometry to its limits. The use of multiple heart-cutting (mLC-LC) and comprehensive (LC×LC) multidimensional LC in combination with high resolution mass spectrometry for the characterization of the lysine conjugated antibody-drug conjugate ado-trastuzumab emtansine, commercialized as Kadcyla, is presented. By combining protein and peptide measurements, attributes such as drug loading, drug distribution and drug conjugation sites can be assessed in an elegant manner.

  2. 核磁共振联用技术在代谢物结构研究中的应用%Application of NMR hyphenation for identification metabolites

    Institute of Scientific and Technical Information of China (English)

    胡增峰; 黄荣清; 肖炳坤; 杨建云

    2008-01-01

    核磁共振联用技术是体内药物代谢产物结构鉴定的强大工具.本文综述固相萃取-核磁共振、液相色谱-核磁共振、液相色谱-核磁共振-质谱等联用技术在研究生物样品中代谢物结构的应用.

  3. 出版物中英语单词移行的技术性细节%Conventional Uses of End-of-Line Hyphenation in Publishing

    Institute of Scientific and Technical Information of China (English)

    王伟

    2014-01-01

    为促使出版物中英语单词的移行规范,按照相关细则,结合示例,归纳了单音节词、专有名词、缩写词、首字母缩略词、缩约词、数字及易产生误解词等不可移行词语;解释了多音节词、带连字符词、带双写辅音字母词、带有前后缀词等可移行词语;提及了行末和行首、网址与电子邮箱、连续移行与隔页移行等应注意的环节.

  4. 英文论文写作中如何正确使用连字符%On Correct Use of Hyphens in Writing English Papers

    Institute of Scientific and Technical Information of China (English)

    宋双明

    2004-01-01

    英文科技论文的特点之一是术语较多,因此经常会遇到连字符的使用问题.本文对正确使用连字符进行了归纳、总结、整理,以期规范使用语言,提高科技论文英文写作与编辑水平.

  5. Dynamic Precoatings for Hyphenated CE Applications%动态预涂层在CE联用技术中的应用

    Institute of Scientific and Technical Information of China (English)

    William W.P.Chang; Christine Hobson; David C.Bomberger; Luke V.Schneider

    2007-01-01

    毛细管电泳与传统分离方法相比,具有分析时间短、分辨率高、样品/缓冲液用量少、易于自动化、功能多样性等优点.尽管如此,毛细管电泳在分析领域仍未能展现出全部的潜力.这是由于在大多数要求比较苛刻的实际应用中,毛细管电泳难以获得较高的重现性.本文对该问题进行了阐述,并提出了一个很有前途的解决方法.

  6. 论英语连合词的形态语义特征%Morphological and semantic features of hyphenated English compounds

    Institute of Scientific and Technical Information of China (English)

    徐宏亮

    2012-01-01

    复合法是英语新词的重要构词手段,是现代英语的一大特征.分析2647个带连字符的英语复合词(连合词),揭示它们的构词形态模式及语义特征,并指出连合词的有效使用是较高语言能力的一个重要标志.

  7. Simultaneous determination of benzene and phenol in heat transfer fluid by head-space gas chromatography hyphenated with ion mobility spectrometry.

    Science.gov (United States)

    Criado-García, L; Garrido-Delgado, R; Arce, L; López, F; Peón, R; Valcárcel, M

    2015-11-01

    The quantitative determination of some compounds such as benzene and phenol in a complex matrix by ion mobility spectrometry (IMS) can be a difficult task, due to the influence of other components present in the matrix and the chemical properties of both compounds, such as their high volatility and low proton affinity. Monitoring of these compounds in a heat transfer fluid (HTF) is essential to check the correct working of a thermosolar plant and for safety and environmental reasons. Benzene and phenol, among other compounds, are produced when HTF is exposed to high temperatures in continuous cycles and their presence can decrease the efficiency of HTF. For the first time, a headspace module coupled to a gas chromatography column in combination with an IMS (with a tritium ionization source) has been optimized and fully validated to simultaneously quantify benzene and phenol in HTF. The limit of detection (LOD) and limit of quantification (LOQ) achieved with the method proposed were 0.011 and 0.038 g L(-1) and 0.004 and 0.014 g L(-1) for benzene and phenol respectively. The precision of the method was evaluated in terms of repeatability and reproducibility with all values lower than 9.2% and 13.3%, respectively. Results demonstrated that benzene and phenol were generated in the HTF heating process, and its concentration increased with heating time (approximately 483 h). The average concentration values for benzene and phenol in degraded HTF samples were not significantly different to values obtained using a gas chromatography-flame ionization detector instrument. Therefore, IMS is a promising technique for in-field quality control of HTF in a thermosolar plant due to its speed, versatility, sensitivity and selectivity to quantify these degradation compounds.

  8. ARSENIC SPECIATION IN CHINESE SEAFOODS BY USING HYPHENATED TECHNIQUES%采用联用技术测定中国海产品中砷的形态

    Institute of Scientific and Technical Information of China (English)

    韦超; 李卫华; 张超; 张新荣; VANHULLEMarijn,CO; CORNELISRita

    2003-01-01

    A study was carried out to determine arsenic species in seafood samples collected from Chinese sea. The information about arsenic species in samples was provided by high performance liquid chromatography-inductively coupled plasma-mass spectrometer (HPLC-ICP-MS) and electrospray tandem mass spectrometry (ES-MS-MS). The arsenic species in thirty Chinese edible seafoods, including algae, fish, crab, shrimp, mussels, oysters, and clams popularly ingested by Chinese people as regular foods, were examined in the present report. Arsenosugars were detected in all of the extracted algae samples (1.5-33.8μg*g-1 dry weight) and some shellfish samples (0.018-0.78μg*g-1 wet weight). Arsenobetaine was detected in all of the extracted fish and shellfish samples (0.025-6.604μg*g-1 wet weight). In contrast, inorganic arsenic was only present in the examined fish and shellfish samples, at levels less than 2% of the total arsenic. The study provides information about a possible distribution pattern of arsenic species in seafood products.

  9. On-line headspace-multicapillary column-ion mobility spectrometry hyphenation as a tool for the determination of off-flavours in foods.

    Science.gov (United States)

    Márquez-Sillero, Isabel; Cárdenas, Soledad; Sielemann, Stefanie; Valcárcel, Miguel

    2014-03-14

    In this work, an ion mobility spectrometer (IMS) with a tritium ionization source on-line coupled to a headspace (HS) autosampler and a multicapillary column (MCC) was evaluated for the monitoring of lipid oxidation products in milk with different flavours (cacao, fruits, cereals and nuts) and linseed oil samples enriched with omega-3 acids. In this combination, the multicapillary column is used as an interface between the HS and the IMS, providing the efficient separation of the volatile compounds. In this way, the proposed method permits the detection of hexanal, 2-butanone, acetone and dimethyl sulfide as representative degradation products. The limits of detection were in the interval 0.3 μg L(-1) (for hexanal in milk) to 3.0 μg L(-1) (for dimethyl sulfide in linseed oil) while the limits of quantification varied between 1.1 μg L(-1) (for hexanal in milk) and 9.6 μg L(-1) (for dimethyl sulfide in linseed oil). The precision of the method was evaluated as relative standard deviation and the values were better than 8% in all cases. The evolution of the volatiles profile during 36 days under different storage conditions (temperature, oxygen and light) demonstrates the capability of the HS-MCC-IMS coupling for the estimation of the degradation of the samples. After the degradation study, it can be concluded that the stability of the milk samples during storage is more affected by the light while temperature was more critical for oil samples.

  10. Characterization of oligosaccharides with capillary high performance anion exchange chromatography hyphenated to pulsed amperometric detection and ion trap mass spectrometry : application to the analysis of human lysosomal disorders

    NARCIS (Netherlands)

    Bruggink, Cornelis

    2013-01-01

    The development of a capillary ion chromatograph is described together with a matching desalter. This desalter made it possible to use on-line a mass spectrometer. The mass spectrometer enables partly to characterize carbohydrates eluting from the anion exchange column. This separation technology is

  11. Elucidation of flavonoids from Carissa congesta, Polyalthia longifolia, and Benincasa hispida plant extracts by hyphenated technique of liquid chromatography-mass spectroscopy

    Directory of Open Access Journals (Sweden)

    Gaurav M Doshi

    2016-01-01

    Full Text Available Background: Carissa congesta (CC, Polyalthia longifolia (PL, and Benincasa hispida (BH are economically important plants. Objective: Current research encompasses identification of quercetin and rutin and their analogues by liquid chromatography-mass spectroscopy (LC-MS from the selected plant species. Materials and Methods: Fresh roots, leaves, and seeds of CC, PL, and BH plants respectively were shade-dried followed by extraction and elucidation of rutin and quercetin by LC-MS. Results: Structural elucidation of CC, PL, and BH extracts revealed the presence of flavonoids such as quercetin (m/z 301 and rutin (m/z 610 as the parent ions along with presence of close analogues such as quercetin-O-hexoside, Vicenin 2, quercetin-3-O-xyloside/arabinoside, and quercetin-3-O-glucoside were identified as fragments. Conclusions: Thus, CC, PL, and BH extracts revealed the presence of flavonoids belonging to the class of flavonols such as rutin and quercetin.

  12. Identification and characterization of the process-related impurities in fasudil hydrochloride by hyphenated techniques using a quality by design approach.

    Science.gov (United States)

    Song, Min; Chen, Yue-Qin; Lu, Ping-Bo; Hang, Tai-Jun

    2014-04-01

    Following the underlying principles of quality by design mentioned in the ICH Q8 guidance, systematic approaches for the control of process-related impurities have been taken in the manufacturing process of fasudil hydrochloride, a potent Rho-kinase inhibitor and vasodilator. Three related impurities were found in fasudil hydrochloride lab samples by a newly developed RP-HPLC with volatile mobile phase gradient elution and UV detection method. The elemental compositions of the impurities were determined by positive ESI high-resolution TOF-MS analysis of their [M + H](+) ions and their structures were identified through the elucidation of the product mass spectra obtained by a triple quadrupole mass spectrometer. The key impurity was further verified through synthesis and organic spectroscopy including NMR and IR spectroscopy. The origins of these impurities were located and the effective approaches to eliminate them were proposed based on the redesign of the synthetic conditions. The results obtained are important for quality control in the manufacture of fasudil hydrochloride bulk drug substance and injection.

  13. Study of extraction procedures for protein analysis in plankton samples by OFFGEL electrophoresis hyphenated with Lab-on-a-chip technology.

    Science.gov (United States)

    García-Otero, Natalia; Barciela-Alonso, Ma Carmen; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2013-10-15

    Extraction procedures for protein analysis from plankton samples were studied. OFFGEL electrophoresis combined with Lab-on-a-chip technology has been applied for protein analysis in plankton samples. BCR-414 (plankton) certified reference material from the European Commission was used to evaluate the protein extraction procedures. Three protein extraction procedures were studied: (1) by using Tris-HCl buffer containing a protease inhibitor cocktail, (2) urea/triton X-100 buffer extraction, and (3) using the phenol/sodium dodecyl sulphate method after different washing steps with 10% trichloroacetic acid/acetone solution and methanol. The pellet of proteins obtained was dried and then dissolved in the OFFGEL buffer. Proteins were separated according to their isoelectric points by OFFGEL electrophoresis. This separation was performed using 24 cm, pH 3-10 IPG Dry Strips. The proteins present in each liquid fraction (24 fractions) were separated according to their molecular weight using a microfluidic Lab-on-a-chip electrophoresis with the Protein 80 LabChip kit. This kit allows for the separation of proteins with a molecular weight ranging from 5 to 80 kDa. Taking into account the intensity and the number of the protein bands obtained, the protein extraction procedure using the phenol/sodium dodecyl sulphate after different wash steps with 10% trichloroacetic acid/acetone solution was selected. The developed method was applied for protein determination in a fresh marine plankton sample. The proteins found in this sample have a molecular weight ranging from 6.4 to 57.3 kDa, and the proteins with highest molecular weight were in the OFFGEL fractions with an isoelectric point ranging from 4.40 to 8.60. The concentration of proteins were calculated using external calibration with Bovine Serum Albumin, and the protein concentrations varied from 50.0 to 925.9 ng µL(-1).

  14. Hyphenated chromatographic analysis of bioactive gallic acid and quercetin in Hygrophila auriculata (K. Schum) Heine growing wildly in marshy places in India by validated HPTLC method

    Institute of Scientific and Technical Information of China (English)

    Md Sarfaraj Hussain; Sheeba Fareed; Mohammad Ali

    2012-01-01

    Objective: A simple, accurate, and rapid high-performance thin-layer chromatographic (HPTLC) method for simultaneous quantification of the two biologically active flavonoidal compounds, gallic acid and quercetin, in Hygrophila auriculata (K. Schum) Heine (HA) has been established and validated. Methods: Chromatography was performed on aluminium foil-backed silica gel 60 F254 HPTLC plates with the binary mobile phase toluene: ethyl acetate: formic acid (5:4:1, v/v/v). Ultraviolet detection was performed densitometrically at the maximum absorbance wavelength, 270nm. The method was validated for precision, recovery, robustness, specificity, and detection and quantification limits, in accordance with ICH guidelines. Results: The system was found to give compact spots for gallic acid (GA) and quercetin (QE) (Rf value of 0.31 and 0.50, respectively). The limit of detection (23 and 41 ng band-1) limit of quantification (69 and 123 ng band-1), recovery (99.4-99.9 and 98.7-99.4%), and precision (i.e ≤1.98 and 1.97) were satisfactory for gallic acid and quercetin respectively. Linearity range for GA and QE were 100-1000 (r 2= 0.9991) and 150-900 ng band-1 (r2= 0.9956) and the contents estimated as 0.28±0.01% and 0.41±0.01% w/w respectively.Conclusions:This simple, precise and accurate method gave good resolution from other constituents present in the extract. The method has been successfully applied in the analysis and routine quality control of herbal material and formulations containing Hygrophila auriculata (K. Schum) Heine.

  15. Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Helsper, J.P.F.G.; Peters, R.J.B.; Bemmel, M.E.M. van; Rivera, Z.E.H.; Wagner, S.; Kammer, F. von der; Tromp, P.C.; Hofmann, T.; Weigel, S.

    2016-01-01

    Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (IC

  16. Development of a triple hyphenated HPLC-radical scavenging detection-DAD-SPE-NMR system for the rapid identification of antioxidants in complex plant extracts

    NARCIS (Netherlands)

    Pukalskas, A.; Beek, van T.A.; Waard, de P.

    2005-01-01

    A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC¿DAD¿SPE¿NMR system. Using this method a commercial rosemary extract was inve

  17. Identification and characterization of alkaloids in mulberry leaf by hyphenated LC-MS techniques%LC-MS法鉴定桑叶中生物碱类成分

    Institute of Scientific and Technical Information of China (English)

    沈小月; 宋敏; 杭太俊

    2016-01-01

    目的:建立LC-MS法对桑叶中生物碱类成分进行结构鉴定.方法:对桑叶中生物碱类成分分别采用9-芴甲氧羰酰氯(FMOC-Cl)衍生化后ODS柱分离或Hypersil SCX色谱柱直接分离,电喷雾正离子化高分辨TOF/MS检测,结合MS/MS法和对照品对照法进行鉴定.结果:在所建立的条件下,共检测并鉴定4个生物碱成分(2-氧-α-D-半乳吡喃糖苷-1-脱氧野尻霉素、1-脱氧野尻霉素、荞麦碱和1,4-二脱氧-l,4-亚胺基-D-阿拉伯糖醇),衍生化法和直接测定法2种分离分析方法的鉴定结果相互验证.此外,9-芴甲氧羰酰氯(FMOC-Cl)柱前衍生化法亦适用于桑叶生物碱成分的准确定量,方法准确可靠.结论:桑叶中生物碱类成分鉴定为相关中药的物质基础研究和质量控制提供依据.

  18. New on-line separation workflow of microbial metabolites via hyphenation of analytical and preparative comprehensive two-dimensional liquid chromatography.

    Science.gov (United States)

    Yan, Xia; Wang, Li-Juan; Wu, Zhen; Wu, Yun-Long; Liu, Xiu-Xiu; Chang, Fang-Rong; Fang, Mei-Juan; Qiu, Ying-Kun

    2016-10-15

    Microbial metabolites represent an important source of bioactive natural products, but always exhibit diverse of chemical structures or complicated chemical composition with low active ingredients content. Traditional separation methods rely mainly on off-line combination of open-column chromatography and preparative high performance liquid chromatography (HPLC). However, the multi-step and prolonged separation procedure might lead to exposure to oxygen and structural transformation of metabolites. In the present work, a new two-dimensional separation workflow for fast isolation and analysis of microbial metabolites from Chaetomium globosum SNSHI-5, a cytotoxic fungus derived from extreme environment. The advantage of this analytical comprehensive two-dimensional liquid chromatography (2D-LC) lies on its ability to analyze the composition of the metabolites, and to optimize the separation conditions for the preparative 2D-LC. Furthermore, gram scale preparative 2D-LC separation of the crude fungus extract could be performed on a medium-pressure liquid chromatograph×preparative high-performance liquid chromatography system, under the optimized condition. Interestingly, 12 cytochalasan derivatives, including two new compounds named cytoglobosin Ab (3) and isochaetoglobosin Db (8), were successfully obtained with high purity in a short period of time. The structures of the isolated metabolites were comprehensively characterized by HR ESI-MS and NMR. To be highlighted, this is the first report on the combination of analytical and preparative 2D-LC for the separation of microbial metabolites. The new workflow exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods.

  19. Antioxidant Properties and Hyphenated HPLC-PDA-MS Profiling of Chilean Pica Mango Fruits (Mangifera indica L. Cv. piqueño

    Directory of Open Access Journals (Sweden)

    Javier E. Ramirez

    2013-12-01

    Full Text Available Antioxidant capacities and polyphenolic contents of two mango cultivars from northern Chile, one of them endemic of an oasis in the Atacama Desert, were compared for the first time. Twenty one phenolic compounds were detected in peel and pulp of mango fruits varieties Pica and Tommy Atkins by HPLC-PDA-MS and tentatively characterized. Eighteen compounds were present in Pica pulp (ppu, 13 in Pica peel (ppe 11 in Tommy Atkins pulp (tpu and 12 in Tommy Atkins peel (tpe. Three procyanidin dimers (peaks 6, 9 and 10, seven acid derivatives (peaks 1–4, 11, 20 and 21 and four xanthones were identified, mainly mangiferin (peak 12 and mangiferin gallate, (peak 7, which were present in both peel and pulp of the two studied species from northern Chile. Homomangiferin (peak 13 was also present in both fruit pulps and dimethylmangiferin (peak 14 was present only in Tommy pulp. Pica fruits showed better antioxidant capacities and higher polyphenolic content (73.76/32.23 µg/mL in the DPPH assay and 32.49/72.01 mg GAE/100 g fresh material in the TPC assay, for edible pulp and peel, respectively than Tommy Atkins fruits (127.22/46.39 µg/mL in the DPPH assay and 25.03/72.01 mg GAE/100 g fresh material in the TPC assay for pulp and peel, respectively. The peel of Pica mangoes showed also the highest content of phenolics (66.02 mg/100 g FW measured by HPLC-PDA. The HPLC generated fingerprint can be used to authenticate Pica mango fruits and Pica mango food products.

  20. Antioxidant properties and hyphenated HPLC-PDA-MS profiling of Chilean Pica mango fruits (Mangifera indica L. Cv. piqueño).

    Science.gov (United States)

    Ramirez, Javier E; Zambrano, Ricardo; Sepúlveda, Beatriz; Simirgiotis, Mario J

    2013-12-31

    Antioxidant capacities and polyphenolic contents of two mango cultivars from northern Chile, one of them endemic of an oasis in the Atacama Desert, were compared for the first time. Twenty one phenolic compounds were detected in peel and pulp of mango fruits varieties Pica and Tommy Atkins by HPLC-PDA-MS and tentatively characterized. Eighteen compounds were present in Pica pulp (ppu), 13 in Pica peel (ppe) 11 in Tommy Atkins pulp (tpu) and 12 in Tommy Atkins peel (tpe). Three procyanidin dimers (peaks 6, 9 and 10), seven acid derivatives (peaks 1-4, 11, 20 and 21) and four xanthones were identified, mainly mangiferin (peak 12) and mangiferin gallate, (peak 7), which were present in both peel and pulp of the two studied species from northern Chile. Homomangiferin (peak 13) was also present in both fruit pulps and dimethylmangiferin (peak 14) was present only in Tommy pulp. Pica fruits showed better antioxidant capacities and higher polyphenolic content (73.76/32.23 µg/mL in the DPPH assay and 32.49/72.01 mg GAE/100 g fresh material in the TPC assay, for edible pulp and peel, respectively) than Tommy Atkins fruits (127.22/46.39 µg/mL in the DPPH assay and 25.03/72.01 mg GAE/100 g fresh material in the TPC assay for pulp and peel, respectively). The peel of Pica mangoes showed also the highest content of phenolics (66.02 mg/100 g FW) measured by HPLC-PDA. The HPLC generated fingerprint can be used to authenticate Pica mango fruits and Pica mango food products.

  1. Introduction

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi; Lecocq, Baz

    2015-01-01

    -abolition, and post-emancipation share the hyphen in common. The hyphen in this context connects the past to the present, the work of the historian to the work of the anthropologist, the slave to the master. But the hyphen also indicates a temporal disruption or discontinuity. We must bridge the historical...

  2. Asymmetric Flow-Field Flow Fractionation Hyphenated ICP-MS as an Alternative to Cloud Point Extraction for Quantification of Silver Nanoparticles and Silver Speciation: Application for Nanoparticles with a Protein Corona.

    Science.gov (United States)

    Mudalige, Thilak K; Qu, Haiou; Linder, Sean W

    2015-07-21

    Production and application of nanoparticles in consumer products is at an all-time high due to the emerging field of nanotechnology. Direct detection and quantification of trace levels of nanoparticles within consumer products is very challenging and problematic. Although multiple methodologies are available for this purpose, each method has its own set of limitations. Herein, we developed an analytical platform consisting of asymmetric flow-field flow fractionation (AF4) coupled with inductively coupled plasma mass spectroscopy (ICP-MS) for the speciation and quantification of silver ions and silver nanoparticles at the ng/kg level (ppt). AF4 is utilized to concentrate the nanoparticles, and ICP-MS acts as the detector. The protein corona that forms upon exposure of nanoparticles to bovine serum albumin was utilized as a nanoparticle stabilization and AF4 recovery enhancement mechanism. Speciation of silver ions and nanoparticles was achieved with the assistance of penicillamine as a complexation ligand. The effect of nanoparticle size, surface coating, and ionization state toward the detection and quantification of the developed methodology was evaluated. The detection limit was found to be 4 ng/kg with the application of a 5 mL sample loop. Further application of this developed methodology on environmentally relevant samples was demonstrated by the analysis of Arkansas River water spiked with silver nanoparticles and nanoparticle spiked into humic acid solution (50 mg/L) at an environmentally relevant level.

  3. Direct comparison of capillary electrophoresis and capillary liquid chromatography hyphenated to collision-cell inductively coupled plasma mass spectrometry for the investigation of Cd-, Cu- and Zn-containing metalloproteins.

    Science.gov (United States)

    Montes-Bayon, Maria; Pröfrock, Daniel; Sanz-Medel, Alfredo; Prange, Andreas

    2006-05-05

    Capillary liquid chromatography (cLC) and capillary electrophoresis (CE) have been critically compared for the separation of metalloproteins when using collision-cell inductively coupled plasma mass spectrometry (ICP-CC-MS) as detection system. For cLC separation, the selected column was a C8 (0.3 mm I.D.) and the separation conditions involved a gradient up to 80% methanol in 10mM ammonium acetate buffer (pH 7.4). The low flow rate used (3 microL min(-1)) permitted the utilization of a high methanol content maintaining the sensitivity along the whole chromatographic run. For this purpose, a new low-flow interface has been developed based on a total consumption nebulizer. Similarly, CE has been studied as separation technique using a 75 microm I.D. fused silica capillary and a running buffer of 20 mM Tris-HNO3 (pH 7.4) and working at 30 kV. Metallothionein (mixture of MT-I and -II) and superoxide dismutase (SOD) have been used as protein models in order to evaluate the separation/detection capabilities using the same injection volumes in both systems (20 nL). For both hybrid systems, separation parameters such as retention factor, numbers of theoretical plates, tailing factor and resolution have been critically compared. Also, the analytical performance characteristics of both hybrid systems have been evaluated and tested by analyzing the Cu-, Zn-species present in red blood cell extracts in order to explore more adequate separation methodology for the analysis of metalloproteins in complex matrices.

  4. 气相色谱-质谱联用法测定川贝母中的挥发性化学成分%HYPHENATED GC-MS DETERMINATION OF VOLATILE CONSTITUENTS IN FRITILLARIA CIRRHOSA D.DON

    Institute of Scientific and Technical Information of China (English)

    李玉美

    2008-01-01

    研究川贝母的挥发性化学成分.川贝母样品经水蒸气蒸馏得挥发油,并用气相色谱一质谱法进行分析,按峰面积归一化法求出挥发性化学成分的相对含量.分离出39个峰,已鉴定了14个化合物,占其挥发油总相对含量的81.92%.已鉴定的化合物主要包括1-十八烯(16.38%),1-十二烯(15.09%),十六烷基一环氧乙烷(11.38%),棕榈醇(10.65%),花生醇(7.95%),9-十八炔酸甲酯(6.94%),n-十六酸(5.41%).

  5. 萃取技术和联用技术在铅的形态分析中的应用%Application of Extraction and Hyphenated Techniques for Lead Speciation in Food and Some other Samples

    Institute of Scientific and Technical Information of China (English)

    陈维; 周耀明; 张倩倩; 杨小弟

    2005-01-01

    铅是环境生物体系和食物中存在的污染元素,其毒性与化学形态密切相关.文章重点概述了国内外近年来萃取技术和联用技术在食品等物质中铅形态分析上的应用进展.

  6. 毛细管电泳-质谱联用技术在环境分析中的应用%Application of Capillary Electrophoresis-mass Spectrometry Hyphenated Technology in Environmental Analysis

    Institute of Scientific and Technical Information of China (English)

    陈祥辉; 付大友; 袁东

    2010-01-01

    毛细管电泳-质谱(CE-MS)联用技术综合了CE的快速、高分离能力与MS强大的鉴定功能等特点,已经成为一种重要的分离分析手段.文章对CE-MS联用的发展、特点及在环境分析领域的应用进展予以综述.

  7. High Performance Liquid Chromatography and Related Hyphenated Techniques for the Speciation Analysis of Mercury%高效液相色谱及其联用技术在汞形态分析中的应用

    Institute of Scientific and Technical Information of China (English)

    梁立娜; 江桂斌

    2002-01-01

    本文对近二十年来高效液相色谱及其联用技术在汞的形态分析中的应用进行了综述.着重讨论了样品的前处理方法,高效液相色谱用于汞化合物的形态分离以及检测器的选择.

  8. On the Use of the Hyphen “-” in The Contemporary Chinese Dictionary%《现代汉语词典》注音中短横“-”的使用问题

    Institute of Scientific and Technical Information of China (English)

    张军; 李战

    2011-01-01

    本文通过全面检视《现代汉语词典》(第5版)的注音拼写情况,发现注音拼写中存在一些与政府政策、法规相抵牾之处,主要表现在两个方面:1.词典内部不一致,自相矛盾;2.应使用短横而未用.

  9. Hyphenated Technique of Spectrum Analyzer and Mass Spectrometer in Environmental Samples Analysis%环境样品分析中的光谱-质谱联用技术

    Institute of Scientific and Technical Information of China (English)

    陈润发; 李康柏; 李惠贤

    2016-01-01

    电感耦合等离子体质谱(ICP-MS)是光谱-质谱联用技术的典型代表.文章介绍ICP-MS的基本特性及用途,归纳ICP-MS联用技术的应用拓展,充分体现光谱-质谱联用技术在环境样品分析中的重要地位.

  10. 联用新技术在元素形态分析领域中的应用进展%Applications of new hyphenated techniques in element speciation analysis

    Institute of Scientific and Technical Information of China (English)

    侯建荣; 黄聪; 彭荣飞; 毛新武; 李铁刚

    2013-01-01

    对联用技术在元素形态分析中的应用进行了综述,重点介绍了HPLC-AFS、HPLC-ICP-MS、GC-ICP-MS、CE-ICP-MS等几种联用技术在形态分析中的应用,并对元素形态分析的前景进行了展望.

  11. Recent Progress of Application of FIA in Hyphenation with Instrumental Analysis%流动注射分析法与多种仪器分析联用的进展

    Institute of Scientific and Technical Information of China (English)

    金绍祥

    2009-01-01

    对流动注射分析法(FIA)与多种仪器分析方法,包括分光光度法、电感耦合等离子体原子发射光谱法(ICP-AES)、原子吸收光谱法(AAS)、化学发光法(CL)、荧光光度法、电化学分析法、生物传感器、毛细管电泳、免疫分析法等联用在最近两年中的新进展作了评述,引述文献42篇.

  12. 《现代汉语词典》注音拼写的连写分写问题%Hyphenation of notational phonetic alphabets in The Modern Chinese Dictionary

    Institute of Scientific and Technical Information of China (English)

    张军

    2000-01-01

    @@ 《现代汉语词典》(以下简称《现汉》)1996年出版修订本,“修订工作主要从词语增删、推行规范、增补修正释义、增补用例、完善体例等几个方面进行”.在“推行规范”方面,《现汉》“编写的目……

  13. 联用技术在生物体系化合物分析中的应用进展%APPLICATION ADVANCE OF THE HYPHENATED TECHNIQUE ON BIOSYSTEM COMPOUNDANALYSIS

    Institute of Scientific and Technical Information of China (English)

    汤广宇; 张曦

    2009-01-01

    介绍了目前分离分析生物体系化合物的一般步骤和注意事项.综述了联用技术在生物体系化合物分析中的应用进展情况.展望了联用技术在生物体系化合物分析中的发展方向和应用前景.

  14. 从《现代汉语词典》(第5版)谈成语拼音分连写标准%On Hyphenation of Phonetic Letters of Chinese Idioms in Modern Chinese Dictionary (5th Edition)

    Institute of Scientific and Technical Information of China (English)

    王飙

    2009-01-01

    本文考察了第5版成语拼音标注的修订情况,指出其仍没有妥善解决成语拼音分连写方面的疏漏争矛盾,根源在于编者在古今汉语确定词的两种标准间游移不定、顾此失彼,进而指出应该以古代汉语标准为主给成语分词,并给出了分词标准.

  15. My opinion on hyphen usage prescribed in national standard GB /T 15834-1995%关于GB/T 15834-1995中连接号应用问题之我见

    Institute of Scientific and Technical Information of China (English)

    杨小萍

    2005-01-01

    通过对GB/T15834-1995中关于连接号应用标准的制定及在实际应用中存在问题的分析,提出有关连接号应用的分类原则,进而对其应用类型和应用标准提出修改意见,以达到易学易用、表意明确、避免误用混用的目的.

  16. 在线离子交换-ICP-OES测定水中微量六价铬%The Determination of Trace Chromium (Ⅵ) in Tanning Wasterwater by ICP-OES Hyphenated with On-Line Ion-Exchange

    Institute of Scientific and Technical Information of China (English)

    陈斌; 韩双来

    2014-01-01

    建立了流动注射离子交换预富集与电感耦合等离子体原子发射光谱法(FIA-IE-ICP-OES)测定制革废水中微量六价铬的分析方法,确定了最佳的分析条件,其准确度和精密度较国标方法明显提高,检出限为0.003 mg/L.

  17. Mastering analytical challenges for the characterization of pentacyclic triterpene mono- and diesters of Calendula officinalis flowers by non-aqueous C30 HPLC and hyphenation with APCI-QTOF-MS.

    Science.gov (United States)

    Nicolaus, Christoph; Sievers-Engler, Adrian; Murillo, Renato; D'Ambrosio, Michele; Lämmerhofer, Michael; Merfort, Irmgard

    2016-01-25

    Pentacyclic triterpene mono- and diesters have been isolated from Calendula officinalis flowers. GC-MS, APCI-Exactive Orbitrap HR-MS and NMR allowed to identify the triterpene skeleton in various samples (different triterpene mixtures from Calendula n-hexane extract). NMR provided evidence that triterpene diesters are present in the samples as well. However, the corresponding quasi-molecular ions could not be detected by APCI-Exactive Orbitrap HR-MS. Instability of triterpene diesters and loss of a fatty acid residue, respectively, in the ion-source made their MS detection challenging. Thus, a set of new APCI-QTOF-MS methods (using the TripleTOF 5600+ mass spectrometer) were developed which made it eventually possible to solve this problem and confirm the diester structures by MS via quasi-molecular ion [M+H](+) detection. Direct infusion APCI-QTOF MS experiments in MS/MS high sensitivity scan mode with low collision energy and multi-channel averaging acquisition (MCA) allowed the detection of quasi-molecular ions of triterpene diesters for the first time and unequivocally confirmed the presence of faradiol 3,16-dimyristate and -dipalmitate, as well as the corresponding mixed diesters faradiol 3-myristate,16-palmitate and faradiol 3-palmitate,16-myristate. Preferential loss of the fatty acid in 16-position made it possible to distinguish the mixed diesters by MS/MS spectra. Their chromatographic separations turned out to be challenging due to their bulkiness and extended molecular dimensions. However, separation could be achieved by an uncommon non-aqueous RPLC mode with an in-house synthesized C30 phase. Finally, two (U)HPLC-APCI-QTOF-MS methods with C18- and C30-based non-aqueous RPLC provided suitable, sensitive assays to monitor the presence of monoesters and diesters of various triterpenes (faradiol, maniladiol, arnidiol, arnitriol A and lupane-3β,16β,20-triol esters) in the n-hexane extract of C. officinalis with high mass resolution and good mass accuracy.

  18. Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques

    DEFF Research Database (Denmark)

    Mardal, Marie; Kinyua, Juliet; Ramin, Pedram

    2017-01-01

    chromatography – mass spectrometry / mass spectrometry (HILIC-MS/MS) method of quantifying urinary targets of identified drugs in wastewater; and (3) to conduct a 24 h stability study, using PU and US to better reflect the chemical environment for targets in wastewater. Cocaine (COC) and ecstasy-like compounds...

  19. Methodology for monitoring gold nanoparticles and dissolved gold species in culture medium and cells used for nanotoxicity tests by liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    López-Sanz, Sara; Fariñas, Nuria Rodríguez; Vargas, Rosario Serrano; Martín-Doimeadios, Rosa Del Carmen Rodríguez; Ríos, Ángel

    2017-03-01

    An analytical methodology based on coupling reversed-phase liquid chromatography (HPLC) to an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the characterization and identification of gold nanoparticles (AuNPs) and gold dissolved species (Au(3+)) in culture medium (Dulbecco's Modified Eagle Medium, DMEM) and HeLa cells (a human cervical adenocarcinoma cell line) used in nanotoxicity tests. The influence of the culture medium was also studied and the method applied for nanotoxicity tests. It was also observed that AuNPs can undergo an oxidation process in the supernatants and only a small amount of AuNPs and dissolved Au(3+) was associated with cells. To evaluate the biological impact of AuNPs, a classical viability assay onto HeLa cells was performed using cellular media DMEM in the presence of increasing dosage of 10nm AuNPs. The results showed that 10nm AuNPs exhibit a slight toxic effect.

  20. A novel ultra-performance liquid chromatography hyphenated with quadrupole time of flight mass spectrometry method for rapid estimation of total toxic retronecine-type of pyrrolizidine alkaloids in herbs without requiring corresponding standards.

    Science.gov (United States)

    Zhu, Lin; Ruan, Jian-Qing; Li, Na; Fu, Peter P; Ye, Yang; Lin, Ge

    2016-03-01

    Nearly 50% of naturally-occurring pyrrolizidine alkaloids (PAs) are hepatotoxic, and the majority of hepatotoxic PAs are retronecine-type PAs (RET-PAs). However, quantitative measurement of PAs in herbs/foodstuffs is often difficult because most of reference PAs are unavailable. In this study, a rapid, selective, and sensitive UHPLC-QTOF-MS method was developed for the estimation of RET-PAs in herbs without requiring corresponding standards. This method is based on our previously established characteristic and diagnostic mass fragmentation patterns and the use of retrorsine for calibration. The use of a single RET-PA (i.e. retrorsine) for construction of calibration was based on high similarities with no significant differences demonstrated by the calibration curves constructed by peak areas of extract ion chromatograms of fragment ion at m/z 120.0813 or 138.0919 versus concentrations of five representative RET-PAs. The developed method was successfully applied to measure a total content of toxic RET-PAs of diversified structures in fifteen potential PA-containing herbs.

  1. Fully Automatic In-Syringe Magnetic Stirring-Assisted Dispersive Liquid-Liquid Microextraction Hyphenated to High-Temperature Torch Integrated Sample Introduction System-Inductively Coupled Plasma Spectrometer with Direct Injection of the Organic Phase.

    Science.gov (United States)

    Sánchez, Raquel; Horstkotte, Burkhard; Fikarová, Kateřina; Sklenářová, Hana; Maestre, Salvador; Miró, Manuel; Todolí, Jose-Luis

    2017-03-21

    A proof of concept study involving the online coupling of automatic dispersive liquid-liquid microextraction (DLLME) to inductively coupled plasma optical emission spectrometry (ICP OES) with direct introduction and analysis of the organic extract is herein reported for the first time. The flow-based analyzer features a lab-in-syringe (LIS) setup with an integrated stirring system, a Meinhard nebulizer in combination with a heated single-pass spray chamber, and a rotary injection valve, used as an online interface between the microextraction system and the detection instrument. Air-segmented flow was used for delivery of a fraction of the nonwater miscible extraction phase, 12 μL of xylene, to the nebulizer. All sample preparative steps including magnetic stirring assisted DLLME were carried out inside the syringe void volume as a size-adaptable yet sealed mixing and extraction chamber. Determination of trace level concentrations of cadmium, copper, lead, and silver as model analytes has been demonstrated by microextraction as diethyldithiophosphate (DDTP) complexes. The automatic LIS-DLLME method features quantitative metal extraction, even in troublesome sample matrixes, such as seawater, salt, and fruit juices, with relative recoveries within the range of 94-103%, 93-100%, and 92-99%, respectively. Furthermore, no statistically significant differences at the 0.05 significance level were found between concentration values experimentally obtained and the certified values of two serum standard reference materials.

  2. Inductively Coupled Plasma(ICP) Mass Spectrometry(MS) Hyphenated with Atomic Emission Spectrometry(AES) for Simultaneous Determination of Major, Minor and Micro Amounts of Elements in Geochemical Samples

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhen-yu; ZHANG Qin; HU Ke; WU Jian-ling; YANG Peng-yuan

    2005-01-01

    @@ Introduction Geological resource survey demands for determining various constituents including major, minor, micro, trace and ultra-trace levels of elements for preparing the map of resource distribution of our country. As a powerful and popularly used technique for multi-element analysis, inductively coupled plasma(ICP) atomic emission spectrometry (AES) has been applied to this field for a period of time[1-3]. However, ICP spectrometric determination of those micro, trace and ultratrace elements needs enrichment procedures for improving the detection limit, which is unacceptable in case a great mass of samples should be analyzed as that in the task of geological resource survey. On the other hand, although ICP mass spectrometry(MS) is considered the most powerful method for trace elements determination[4,5], it is difficult for ICP-MS to be used to determine the trace and major analytes simultaneously in a spectrum.

  3. 盐酸特拉唑嗪有关物质的色谱-质谱结构鉴定%Identification of related substances in terazosin hydrochloride with hyphenated techniques

    Institute of Scientific and Technical Information of China (English)

    金婵; 王敏; 娜琴; 卢萍; 孙晶; 宋敏; 杭太俊

    2014-01-01

    目的:采用色谱-质谱联用技术对盐酸特拉唑嗪有关物质进行结构鉴定.方法:采用Sepax GP-C8 (250 mm×4.6 mm,5 μm)色谱柱,以醋酸铵缓冲液(1L中含醋酸铵4.0g,以甲酸调pH至3.2)-乙腈(1685∶ 315)流动相等度洗脱,对盐酸特拉唑嗪有关物质进行分离;采用电喷雾正离子化的四极杆飞行时间质谱(LC-Q-TOF/MS)方法测定离子准确质量并分析子离子特征,结合对照品对照确证有关物质结构.质谱电喷雾正离子化的喷雾电压3 kV、雾化氮气压力150 kPa、气流量6L·min-1、温度180℃.结果:在所建立的条件下,盐酸特拉唑嗪与其有关物质分离良好,检测出14个有关物质,并综合分析鉴定了有关物质结构,它们大都具有4-氨基-6,7-二甲氧基喹唑啉母核结构,制剂中有关物质状态与原料药中的相似.结论:色谱-质谱联用技术能有效地鉴定盐酸特拉唑嗪有关物质,为其工艺和质量控制提供参考依据.

  4. Application of the Solid-Phase Microextraction Chromatography Hyphenated with Mass Spectrometry to the Analysis of Petroluem Content in Water%固相微萃取-色谱/质谱技术分析水中汽油成分

    Institute of Scientific and Technical Information of China (English)

    陈旭东; 周红

    2000-01-01

    @@ 对于样品中有机物的分离,传统的前处理技术有液-液萃取、顶空富集(ACS)、超临界萃取(SPE)和吹扫-捕集法等.这些方法所需样品量较多、耗时长,有些试剂有碍人体健康,并造成环境污染等.

  5. 气相色谱-离子阱二级质谱测定食品中丙烯酰胺残留%Determination of Residual Acrylamide in Foodstuffs by Hyphenation of Gas Chromatography and Tandem Secondary Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    邓晓军; 胡国华; 朱坚; 李波; 郭德华

    2007-01-01

    建立了一种基于气相色谱-离子阱二级质谱(GC-MS/MS)检测食品(薯条,薯片,咖啡,饼干和膨化食品)中丙烯酰胺残留量的方法.样品中丙烯酰胺采用去离子水提取,正己烷脱脂后石墨化碳黑小柱净化,溴水衍生后GC-MS/MS进行分析.方法在10~1 000 μg·L-1浓度范围内呈线性关系,相关系数为0.999,检出限为4.02μg·kg-1,在10,100,1 000 μg·kg-1三个水平的相对标准偏差为8%~12%,回收率为68.3%~105.2%.结果表明,相对于GC-MS方法,GC-MS/MS分析时间短、无杂质峰干扰、灵敏度高,可以满足食品的丙烯酰胺检测大批量筛选要求.

  6. On-line sample-pre-treatment schemes for trace-level determinations of metals by coupling flow injection or sequential injection with ICP-MS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2003-01-01

    a polytetrafluoroethylene (PTFE) knotted reactor (KR), solvent extraction-back extraction and hydride/vapor generation. It also addresses a novel, robust approach, whereby the protocol of SI-LOV-bead injection (BI) on-line separation and pre-concentration of ultra-trace levels of metals by a renewable microcolumn...

  7. The Impact of Flow Injection on Modern Chemical Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    There is no doubt that Flow Injection Analysis (FIA) has had a profound impact on the ways and means that modern analytical chemical procedures are performed. This is amply reflected in the voluminous scientific literature, which by the middle of 2004 passed more than 14,500 FIA-publications in i......There is no doubt that Flow Injection Analysis (FIA) has had a profound impact on the ways and means that modern analytical chemical procedures are performed. This is amply reflected in the voluminous scientific literature, which by the middle of 2004 passed more than 14,500 FIA...... and preconcentration procedures. In recent years, FIA has been supplemented by Sequential Injection Analysis (SIA) and the Lab-on-Valve (LOV) approach. Following a brief historic introduction and an account of the impact of FIA in academia, the lecture will describe these two new generations of FIA, accompanied...

  8. Use of flow injection and sequential injection analysis schemes for the determination of trace-level concentrations of metals in complex matrices by ETAAS and ICPMS

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    2005-01-01

    Despite their excellent analytical chemical capacities for determination of low levels of metal species, electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry often require suitable pretreatment (separation and preconcentration) of the sample material....../preconcentration procedures are feasible, such as liquid-liquid extraction (possibly including back extraction), (co)precipitation with collection in knotted coils, adsorption on hydrophilic or hydrophobic reactors, hydride generation, or the use of ionexchange/chelating packed columns. After describing the particulars...... and characteristics of FI and SI, we present, via selected examples, various separation/preconcentration FI/Sl schemes for the determination of trace levels of metals, with particular emphasis on the use of the novel extension of FI/SI, that is, the so-called lab-on-valve concept....

  9. Structural changes that accompany the self-assembly of hydrophobins

    NARCIS (Netherlands)

    Vocht, Marcel Leo de

    2001-01-01

    De meeste schimmels groeien in lange draadvormige structuren die schimmeldraden of hyphen genoemd worden. Deze hyphen scheiden aan hun uiteinden zogenaamde hydrofobines uit. Deze klasse eiwitten speelt een belangrijke rol in de groei en ontwikkeling van schimmels. De belangrijkste eigenschap van hyd

  10. Hyphenated techniques in speciation analysis of polyoxometalates: identification of individual [PMo12-xVxO40](-3-x) (x = 1-3) in the reaction mixtures by high performance liquid chromatography and atomic emission spectrometry with inductively coupled plasma.

    Science.gov (United States)

    Shuvaeva, O V; Zhdanov, A A; Romanova, T E; Abramov, P A; Sokolov, M N

    2017-03-14

    Unambiguous identification of polyoxometalate (POM) species generated in self-assembly reactions in solution is rather problematic due to close similarity of their properties such as solubility and spectral characteristics. The situation is made more complex by protonation equilibria (which can change their analytical signals) and the lack of individual compounds to serve as standards for individual members of these mixtures. In the present work a new approach to the study of such POMs has been suggested, taking molybdovanadates [PMo12-xVxO40](-3-x) as a model. The key feature of this approach consists of generation of so-called "conditional model systems" that include most of the expected components of a mixture formed by self-assembly, tracked down by reliable detection techniques, e.g., (51)V NMR-spectroscopy in this particular case. Then the proposed composition of the mixture is verified and corrected by means of high-performance liquid chromatography coupled with inductively coupled plasma atomic emission spectrometry (HPLC-ICP-AES).

  11. Distress and Fury: The Governor-General Award Winner Fred Wah and the Strategy of Ethnic Hyphenation%困惑和愤怒——评加拿大总督奖作家Fred Wah和少数族裔作家的连接号策略

    Institute of Scientific and Technical Information of China (English)

    赵庆庆

    2006-01-01

    本文探讨了加拿大总督奖作家弗雷德·华(Fred Wah)的获奖传记小说(Diamond Grill),并结合其文论,探讨了自名的困惑、文本的愤怒和少数族裔作家的连接号策略这三大相关论题,得出少数族裔作家必须把多元文化和强势文化的冲突化为自身价值才可生存的结论.

  12. 气相色谱-附加氯的化学电离与低分辨质谱法联用测定短链氯化石蜡含量%Determination of Short Chain Chlorinated Paraffins by GC-Chioridine Attchment Chemical Ionization in Hyphenation with Low Resolution MS

    Institute of Scientific and Technical Information of China (English)

    袁从慧; 阮毅; 谈金辉; 方正; 叶典贤

    2015-01-01

    以己烷-二氯甲烷混合溶剂上气体经石英毛细管柱直接导入离子源为反应气,建立了气相色谱-附加氯的化学电离-低分辨质谱法检测短链氯化石蜡.加标回收率在84.9%~95.4%之间,测定值的相对标准偏差在15%~18%之间.本法应用于实际样品测试,并和碳骨架法进行了对比.结果表明:对于中链(MCCP)与短链的氯化石蜡(SCCP)质量比(mMCCP/mSCCP)比值较低样品,相对误差在3.67%~7.69%之间;对于mMCCP/mSCCP比值较高样品,相对误差为77.9%.

  13. Application of Hyphenation of HPLC and ICP-MS to Water Analysis%高效液相色谱-电感耦合等离子体质谱联用技术在水质分析中的应用

    Institute of Scientific and Technical Information of China (English)

    苏宇亮

    2009-01-01

    对高效液相色谱-电感耦合等离子体质谱联用技术在水质分析中的应用作了评述,对高效液相色谱-电感耦合等离子体质谱联用技术的发展前景作了展望.引用文献48篇.

  14. Perspectives on Norwegian-Russian energy cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Bourmistrov, Anatoli; Mellemvik, Frode; Vasiliev, Sergey Vasiliev (eds.)

    2011-07-01

    Review from publisher: Perspectives on Norwegian#Hyphen#Russian Energy Cooperation, September 2011 NAREC : Norwegian#Hyphen# Russian Education and Research Consortium for International Business Development in the field of Energy The book illustrates the kind of knowledge and competence possessed by the NAREC partner academic institutions: Part I highlights and discusses opportunities and barriers for the Norwegian#Hyphen#Russian energy cooperation in the High North. Part II considers and exemplifies the High North as an arena for increasing modernization and innovations. Part III devoted to advanced technologies for developing the High North.(Author)

  15. Anthropometric and functional characteristics of phisically active individuals Características antropométricas y funcionales de individuos físicamente activos

    OpenAIRE

    Liliana Constanza Marmolejo; Róbinson Ramírez Vélez; César Enrique Sánchez Gallardo; Carlos Alejandro López Albán

    2008-01-01

  1. A Morphofunctional Study on the Effect of Cytochalasin B on Intestinal Water Transport.

    Science.gov (United States)

    1986-05-10

    filaments. Studies from a number of laboratories suggest that these cytokinins in- hibit the rate of actin filament polymerisation and disrupt actin...misspellings, poor hyphenations and deviations ny sde wgornbod quality BAC rbon.) (Afrom good usage will be glaringly apparent in the published may smudge; a

  2. 76 FR 18706 - Fisheries in the Eastern Pacific Ocean; Pelagic Fisheries; Vessel Identification Requirements

    Science.gov (United States)

    2011-04-05

    ... Endorsement would be required to display its IRCS on the port and starboard sides of the hull or... hyphen (i.e., ``USA--''). Only these markings would be allowed on the hull or superstructure, apart from.... Dated: March 31, 2011. John Oliver, Deputy Assistant Administrator for Operations, National...

  3. 75 FR 54271 - Wassenaar Arrangement 2009 Plenary Agreements Implementation: Categories 1, 2, 3, 4, 5 Part I, 6...

    Science.gov (United States)

    2010-09-07

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the... indication parameter. Category 3--Electronics ECCN 3A001 is amended by: --Adding a hyphen in the word ``space... Trade Controls. See 22 CFR part 121.'' --Adding a List of Items Controlled section to harmonize...

  4. Ovarian Cancer Stage II

    Science.gov (United States)

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage II Add to My Pictures View /Download : ... 1650x675 View Download Large: 3300x1350 View Download Title: Ovarian Cancer Stage II Description: Three-panel drawing of stage ...

  5. Ovarian Cancer Stage IIIC

    Science.gov (United States)

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage IIIC Add to My Pictures View /Download : ... 1530x1350 View Download Large: 3060x2700 View Download Title: Ovarian Cancer Stage IIIC Description: Drawing of stage IIIC shows ...

  6. Ovarian Cancer Stage I

    Science.gov (United States)

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage I Add to My Pictures View /Download : ... 1650x675 View Download Large: 3300x1350 View Download Title: Ovarian Cancer Stage I Description: Three-panel drawing of stage ...

  7. Design and implementation of an automated liquid-phase microextraction-chip system coupled on-line with high performance liquid chromatography

    DEFF Research Database (Denmark)

    Li, Bin; Petersen, Nickolaj J.; Payán, María D Ramos

    2014-01-01

    An automated liquid-phase microextraction (LPME) device in a chip format has been developed and coupled directly to high performance liquid chromatography (HPLC). A 10-port 2-position switching valve was used to hyphenate the LPME-chip with the HPLC autosampler, and to collect the extracted...

  8. Volatile compound fingerprinting of mixed cultutre fermentations

    NARCIS (Netherlands)

    Bok, de F.A.M.; Janssen, P.W.M.; Bayjanov, J.R.; Sieuwerts, S.; Lommen, A.; Hylckama, van J.; Molenaar, D.

    2011-01-01

    With the advent of the -omics era, classical technology platforms, such as hyphenated mass spectrometry, are currently undergoing a transformation toward high-throughput application. These novel platforms yield highly detailed metabolite profiles in large numbers of samples. Such profiles can be use

  9. Volatile compound fingerprinting of mixed-culture fermentations.

    NARCIS (Netherlands)

    Bok, F.A. de; Janssen, P.W.; Bayjanov, J.; Sieuwerts, S.; Lommen, A.; Hylckama Vlieg, J.E. van; Molenaar, D.

    2011-01-01

    With the advent of the -omics era, classical technology platforms, such as hyphenated mass spectrometry, are currently undergoing a transformation toward high-throughput application. These novel platforms yield highly detailed metabolite profiles in large numbers of samples. Such profiles can be use

  10. [Software development of multi-element transient signal acquisition and processing with multi-channel ICP-AES].

    Science.gov (United States)

    Zhang, Y; Zhuang, Z; Wang, X; Zhu, E; Liu, J

    2000-02-01

    A software for multi-channel ICP-AES multi-element transient signal acquisition and processing were developed in this paper. It has been successfully applied to signal acquisition and processing in many transient introduction techniques on-line hyphenated with multi-channel ICP-AES.

  11. Eletroforese capilar acoplada à espectrometria com plasma: uma ferramenta eficiente para a especiação Capillary electrophoresis coupled to plasma spectrometry: an efficient tool for speciation

    Directory of Open Access Journals (Sweden)

    Ana Paula G. Gervasio

    2003-01-01

    Full Text Available The most important features of the CE-ICP hyphenation, as well as its advantages and drawbacks as a tool for speciation are discussed. The fundamental principles of capillary electrophoresis and inductively coupled plasma mass spectrometry are also presented. Some applications involving different designs proposed in the literature to couple CE and ICP system for elemental speciation are reviewed.

  12. Identification of Radical Scavenging Compounds in Rhaponticum carthamoides by Means of LC-DAD-SPE-NMR

    NARCIS (Netherlands)

    Miliauskas, G.; Beek, van T.A.; Waard, de P.; Venskutonis, R.P.; Sudhölter, E.J.R.

    2005-01-01

    A hyphenated LC-DAD-SPE-NMR setup in combination with on-line radical scavenging detection has been applied for the identification of radical scavenging compounds in extracts of Rhaponticum carthamoides. After NMR measurements, the pure compounds were infused into a mass spectrometer. The technique

  13. On-line liquid phase micro-extraction based on drop-in-plug sequential injection lab-at-valve platform for metal determination

    Energy Technology Data Exchange (ETDEWEB)

    Mitani, Constantina [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece); Anthemidis, Aristidis N., E-mail: anthemid@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece)

    2013-04-10

    Highlights: ► Drop-in-plug micro-extraction based on SI-LAV platform for metal preconcentration. ► Automatic liquid phase micro-extraction coupled with FAAS. ► Organic solvents with density higher than water are used. ► Lead determination in environmental water and urine samples. -- Abstract: A novel automatic on-line liquid phase micro-extraction method based on drop-in-plug sequential injection lab-at-valve (LAV) platform was proposed for metal preconcentration and determination. A flow-through micro-extraction chamber mounted at the selection valve was adopted without the need of sophisticated lab-on-valve components. Coupled to flame atomic absorption spectrometry (FAAS), the potential of this lab-at-valve scheme is demonstrated for trace lead determination in environmental and biological water samples. A hydrophobic complex of lead with ammonium pyrrolidine dithiocarbamate (APDC) was formed on-line and subsequently extracted into an 80 μL plug of chloroform. The extraction procedure was performed by forming micro-droplets of aqueous phase into the plug of the extractant. All critical parameters that affect the efficiency of the system were studied and optimized. The proposed method offered good performance characteristics and high preconcentration ratios. For 10 mL sample consumption an enhancement factor of 125 was obtained. The detection limit was 1.8 μg L{sup −1} and the precision expressed as relative standard deviation (RSD) at 50.0 μg L{sup −1} of lead was 2.9%. The proposed method was evaluated by analyzing certified reference materials and applied for lead determination in natural waters and urine samples.

  14. MSFIA-LOV system for (226)Ra isolation and pre-concentration from water samples previous radiometric detection.

    Science.gov (United States)

    Rodríguez, Rogelio; Borràs, Antoni; Leal, Luz; Cerdà, Víctor; Ferrer, Laura

    2016-03-10

    An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of (226)Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO2 deposited on macroporous of bead cellulose. Then, it is eluted with hydroxylamine to transform insoluble MnO2 to soluble Mn(II) thus freeing Ra, which is then coprecipitated with BaSO4. The (226)Ra can be directly detected in off-line mode using a low background proportional counter (LBPC) or through a liquid scintillation counter (LSC), after performing an on-line coprecipitate dissolution. Thus, the versatility of the proposed system allows the selection of the radiometric detection technique depending on the detector availability or the required response efficiency (sample number vs. response time and limit of detection). The MSFIA-LOV system improves the precision (1.7% RSD), and the extraction frequency (up to 3 h(-1)). Besides, it has been satisfactorily applied to different types of water matrices (tap, mineral, well and sea water). The (226)Ra minimum detectable activities (LSC: 0.004 Bq L(-1); LBPC: 0.02 Bq L(-1)) attained by this system allow to reach the guidance values proposed by the relevant international agencies e.g. WHO, EPA and EC.

  15. High performance liquid chromatography coupled to atomic fluorescence spectrometry for the speciation of the hydride and chemical vapour-forming elements As, Se, Sb and Hg: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yuwei [Department of Chemistry and Biochemistry, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada)

    2010-06-25

    We present the most recent applications of high performance liquid chromatography (HPLC) hyphenated to hydride generation or chemical vapour generation and atomic fluorescence spectrometry (HG/CVG-AFS), for the determination and speciation of the selected hydride-forming elements arsenic (As), selenium (Se) and antimony (Sb) and the chemical vapour-forming metal Hg. The review focuses on sample preparation, post-column treatments and on the applications of this technique to various liquid and solid samples. This review also intends to discuss some limitations associated to HPLC-HG/CVG-AFS due to the necessity on post-column treatments, including the oxidation of organo-element compounds and the pre-reduction to a suitable valence. Nevertheless, the hyphenated technique HPLC-HG/CVG-AFS remains an efficient, sensitive and affordable approach to perform speciation of the four studied elements as shown by the variety of applications presented and discussed in this review.

  16. From retrospective assessment to prospective decisions in natural product isolation

    DEFF Research Database (Denmark)

    Johansen, Kenneth T; Wubshet, Sileshi G; Nyberg, Nils T;

    2011-01-01

    An extract of Carthamus oxyacantha (wild safflower) was investigated using two approaches: a traditional, nontarget fractionation by VLC and HPLC, and the hyphenated technique HPLC-PDA-HRMS-SPE-NMR followed by targeted isolation of selected constituents for inclusion in a screening library of pure...... natural products. While the nontarget fractionation involved considerable time spent on pursuing fractions containing well-known or undesired compounds, the hyphenated analysis was considerably faster and required less solvent and other consumables. The results were used to design and execute an optimized......, HPLC-HRMS-guided, targeted isolation scheme aiming exclusively at a series of identified spiro compounds. Thus, HPLC-PDA-HRMS-SPE-NMR is a dereplication technique of choice, allowing economical acquisition of comprehensive data about compounds in crude extracts, which can be used for rational...

  17. 色谱联用技术的研究进展%Research Progress of Hypenated Chromatographic Techniques

    Institute of Scientific and Technical Information of China (English)

    杨洁; 索习东

    2012-01-01

    综述了色谱联用技术的发展概况及其在各种研究中的应用和薪进展,同时指出随着色谱联用技术的不断发展,各种新型色谱技术在现代研究中将有更大的发展空间与应用前景。%This article summarized the development of hyphenated Chromatography would techniques and its applications and new developments in various studies. Meanwhile it indicated that there would be greater room and application prospects for new types of chromatographic techniques in modern researches with the continuous development of hyphenated Chromatographic techniques.

  18. Intersubjective relation: change alternative for the human health professions

    Directory of Open Access Journals (Sweden)

    Maria C. Chapela M

    2009-05-01

    Full Text Available Objectives: 1. To exemplify the relationships between changes in the body inscriptions of people exposed to professional health services and the inter-subjective hyphens occurring in those relationships. 2. To identify in those relationships some components of subordination and autonomy. Methodology: here I present one aspect of a critical qualitative case study of a health promotion intervention. Results: the examples provided show changes in the body inscriptions as a product of capital recuperation processes that took part during the intervention. Conclusions: in the particular characteristics of the inter-subjective hyphen unavoidable in the health profession practice, there are subordination and autonomy possibilities. A critical qualitative inquiry perspective can not just improve the understanding of the social determinants of health and subjects’ body inscriptions, but also may help to search for new health concepts and to transform practices which are undermining the capacity of subject to produce their spaces and develop their ethic capacity.

  19. Chemometrics tools used in analytical chemistry: an overview.

    Science.gov (United States)

    Kumar, Naveen; Bansal, Ankit; Sarma, G S; Rawal, Ravindra K

    2014-06-01

    This article presents various important tools of chemometrics utilized as data evaluation tools generated by various hyphenated analytical techniques including their application since its advent to today. The work has been divided into various sections, which include various multivariate regression methods and multivariate resolution methods. Finally the last section deals with the applicability of chemometric tools in analytical chemistry. The main objective of this article is to review the chemometric methods used in analytical chemistry (qualitative/quantitative), to determine the elution sequence, classify various data sets, assess peak purity and estimate the number of chemical components. These reviewed methods further can be used for treating n-way data obtained by hyphenation of LC with multi-channel detectors. We prefer to provide a detailed view of various important methods developed with their algorithm in favor of employing and understanding them by researchers not very familiar with chemometrics.

  20. Development of a simple extraction cell with bi-directional continuous flow coupled on-line to ICP-MS for assessment of elemental associations in solid samples

    DEFF Research Database (Denmark)

    Buanuam, Janya; Tiptanasup, Kasipa; Shiowatana, Juwadee

    2006-01-01

    A continuous-flow system comprising a novel, custom-built extraction module and hyphenated with inductively coupled plasma-mass spectrometric (ICP-MS) detection is proposed for assessing metal mobilities and geochemical associations in soil compartments as based on using the three step BCR (now...... to discretely introduce appropriate extract volumes to the detector at a given time and with a given dilution factor. The proposed hyphenated method demonstrates excellent performance for on-line monitoring of major and trace elements (Ca, Mn, Fe, Ni, Pb, Zn and Cd) released when applying the various extracting...... the extraction time. Thus, the intimate elemental association between Cd and Zn in contaminated soils could be assessed....

  1. New Oxford style manual

    CERN Document Server

    2012-01-01

    The New Oxford Style Manual brings together two essential reference works in a single volume: New Hart's Rules and the New Oxford Dictionary for Writers and Editors. New Hart's Rules, Oxford's definitive guide to style, consists of 20 chapters that provide authoritative and expert advice on how to prepare copy for publication. Topics covered include how to use italic, roman, and other type treatments, numbers and dates, law and legal references, illustrations, notes and references, and bibliographies. The guidelines are complemented by the New Oxford Dictionary for Writers and Editors, which features 25,000 alphabetically arranged entries giving authoritative advice on those words and names which raise questions time and time again because of spelling, capitalization, hyphenation, or cultural and historical context. Entries give full coverage of recommended spellings, variant forms, confusable words, hyphenation, capitalization, foreign and specialist terms, proper names, and abbreviations. The dictionary a...

  2. Erotic(izing Cubans

    Directory of Open Access Journals (Sweden)

    Virginia R. Domínguez

    1996-07-01

    Full Text Available [First paragraph] Sugar's Secrets: Race and the Erotics of Cuban Nationalism. VERA M. KUTZINSKI. Charlottesville: University Press of Virginia, 1993. xvii + 287 pp. (Cloth US$ 40.00, Paper US$ 17.95 Life on the Hyphen: The Cuban-American Way. GUSTAVO PÉREZ FlRMAT. Austin: University of Texas Press, 1994. xii + 217 pp. (Cloth US$ 30.00, Paper US$ 12.95 When a country is subjected to as much external political and ideological scrutiny as Cuba in the post-Batista years, scholarly explorations of something other than its foreign policy, its political economy, and its human rights abuses provide a breath of fresh air. But I am struck by the other things Sugar's Secrets and Life on the Hyphen have in common and how suspicious I am of their commonalities.

  3. Bayesian networks for omics data analysis

    OpenAIRE

    Gavai, A.K.

    2009-01-01

    This thesis focuses on two aspects of high throughput technologies, i.e. data storage and data analysis, in particular in transcriptomics and metabolomics. Both technologies are part of a research field that is generally called ‘omics’ (or ‘-omics’, with a leading hyphen), which refers to genomics, transcriptomics, proteomics, or metabolomics. Although these techniques study different entities (genes, gene expression, proteins, or metabolites), they all have in common that they use high-throu...

  4. Aspects of recent developments in analytical chemometrics

    Institute of Scientific and Technical Information of China (English)

    LIANG; Yizeng; WU; Hailong; SHEN; Guoli; JIANG; Jianhui; LIANG; Sheng

    2006-01-01

    Some aspects of recent developments in analytical chemometrics are discussed, in particular the developments viewed from the angle of the research efforts undertaken in authors' laboratories. The topics concerned include resolution of high-order chemical data, morphological theory and methodology for chemical signal processing, multivariate calibration and chemical pattern recognition for solving complex chemical problems, and resolution of two-way chemical data from hyphenated chromatographic instruments.

  5. Egg White Protein-Bonded Columns and Their Applications%蛋清蛋白质键合柱及其应用

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Egg white protein-bonded columns were developed for HPLC. These columns can be used under aqueous mobile phase and separate various kinds of drug enantiomers. Hyphenated techniques using protein-bonded columns with LC/MS and/or column switching have been recognized as integral methods in pharmaceutical research to analyze drug enantiomers. Therefore, these methods are very useful for research fields of pharmacokinetics and pharmacology.

  6. Molecular-level investigation on electrochemical interfaces by Raman spectroscopy

    Institute of Scientific and Technical Information of China (English)

    TIAN, Zhong-Qun; REN, Bin

    2000-01-01

    The structure and dynamics of electrode/liquid interfaces play an increasingly important role in electrochemistry. Raman spectroscopy is capable of providing detailed structural information at molecular level and new insight into the interfacial structure, adsorption, reaction, electrocatalysis and corrosion. In this account we will summarize some progresses of surface Raman spectroscopy in the study of electrochemical interfaces, mainly based on our group's work, laying emphasis on the detection sensitivity, spectral resolution, time resolution and spatial resolution as well as the hyphenated technique.

  7. Raman spectroscopy in pharmaceutical product design

    DEFF Research Database (Denmark)

    Paudel, Amrit; Raijada, Dhara; Rantanen, Jukka

    2015-01-01

    molecular-based drug discovery, design of innovative drug delivery systems and quality control of finished products. This review presents concise accounts of various conventional and emerging Raman instrumentations including associated hyphenated tools of pharmaceutical interest. Moreover, relevant...... application cases of Raman spectroscopy in early and late phase pharmaceutical development, process analysis and micro-structural analysis of drug delivery systems are introduced. Finally, potential areas of future advancement and application of Raman spectroscopic techniques are discussed....

  8. Are Flow Injection-based Approaches Suitable for Automated Handling of Solid Samples?

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald; Cerdà, Victor

    with the potential hyphenation with modern analytical instrumentation for automated monitoring of the content of targeted species in the on-line generated extracts [3,4]. [1] Z.-L. Zhi, A. Ríos, M. Valcárcel, Crit. Rev. Anal. Chem., 26 (1996) 239. [2] M. Miró, E.H. Hansen, R. Chomchoei, W. Frenzel, TRAC-Trends Anal...

  9. Research Progress in Coupled Process of Fenton Oxidation Technology with Other Technologys to Treat Wastewater%Fenton氧化技术与其他方法联用在废水处理方面的研究进展

    Institute of Scientific and Technical Information of China (English)

    王鹏

    2011-01-01

    The hyphenated methods between Fenton oxidation technology and other technologys are reviewed. The characteristics and present state of applications of the adsorption - Fenton oxidation technology,coagulation- Fenton oxidation technology,microwave- Fenton oxidation technology, biological methods -Fenton oxidation technology are explored the places of the hyphenated methods which we can improve are point out. In addition, the prospect of hyphenated methods is predicted.%综述了近些年Fenton氧化技术与其他方法联用在处理难降解有机废水方面的研究进展,探讨了吸附-Fenton氧化技术、混凝-Fenton氧化技术、微波-Fenton氧化技术、生物方法-Fenton氧化技术的特点及其应用研究现状,指出了这些联用技术可改进的地方。此外,展望了联用方法的发展趋势。

  10. Direct analysis in real time - high resolution mass spectrometry (DART-HRMS): a high throughput strategy for identification and quantification of anabolic steroid esters.

    Science.gov (United States)

    Doué, Mickael; Dervilly-Pinel, Gaud; Pouponneau, Karinne; Monteau, Fabrice; Le Bizec, Bruno

    2015-07-01

    High throughput screening is essential for doping, forensic, and food safety laboratories. While hyphenated chromatography-mass spectrometry (MS) remains the approach of choice, recent ambient MS techniques, such as direct analysis in real time (DART), offer more rapid and more versatile strategies and thus gain in popularity. In this study, the potential of DART hyphenated with Orbitrap-MS for fast identification and quantification of 21 anabolic steroid esters has been evaluated. Direct analysis in high resolution scan mode allowed steroid esters screening by accurate mass measurement (Resolution = 60 000 and mass error  0.99), dynamic range (from 1 to 1000 ng mL(-1) ), bias (<10%), sensitivity (1 ng mL(-1) ), repeatability and reproducibility (RSD < 20%) were evaluated as similar to those obtained with hyphenated chromatography-mass spectrometry techniques. This innovative high throughput approach was successfully applied for the characterization of oily commercial preparations, and thus fits the needs of the competent authorities in the fight against forbidden or counterfeited substances.

  11. Truth Telling, Companionship, and Witness: An Agenda for Narrative Ethics.

    Science.gov (United States)

    Frank, Arthur W

    2016-05-01

    Narrative ethics holds that if you ask someone what goodness is, as a basis of action, most people will first appeal to various abstractions, each of which can be defined only by other abstractions that in turn require further definition. If you persist in asking what each of these abstractions actually means, eventually that person will have to tell you a story and expect you to recognize goodness in the story. Goodness and badness need stories to make them thinkable and to translate them into individual and collective actions. Yet after more than two decades of considering the issue, I do not believe that a collection of stories can by itself guide actions in ways that are sufficient to respond to ethical troubles in institutional settings. The question will always remain open for me, but my present belief is that narrative bioethics is always hyphenated, in the sense that guidance from stories needs to be allied with other ethical guidance. Each side of the hyphen qualifies the other side. The hyphenation I will argue for in this essay is "narrative-deontology."

  12. MSFIA-LOV system for {sup 226}Ra isolation and pre-concentration from water samples previous radiometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Rogelio [Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma (Spain); Environment and Energy Department, Advanced Materials Research Center (CIMAV) S.C., Miguel de Cervantes 120, Chihuahua, Chih. 31136 (Mexico); Borràs, Antoni [Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma (Spain); Leal, Luz [Environment and Energy Department, Advanced Materials Research Center (CIMAV) S.C., Miguel de Cervantes 120, Chihuahua, Chih. 31136 (Mexico); Cerdà, Víctor [Department of Chemistry, University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma (Spain); Ferrer, Laura, E-mail: laura.ferrer@uib.es [Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma (Spain)

    2016-03-10

    An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of {sup 226}Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO{sub 2} and the BaSO{sub 4} co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO{sub 2} deposited on macroporous of bead cellulose. Then, it is eluted with hydroxylamine to transform insoluble MnO{sub 2} to soluble Mn(II) thus freeing Ra, which is then coprecipitated with BaSO{sub 4}. The {sup 226}Ra can be directly detected in off-line mode using a low background proportional counter (LBPC) or through a liquid scintillation counter (LSC), after performing an on-line coprecipitate dissolution. Thus, the versatility of the proposed system allows the selection of the radiometric detection technique depending on the detector availability or the required response efficiency (sample number vs. response time and limit of detection). The MSFIA-LOV system improves the precision (1.7% RSD), and the extraction frequency (up to 3 h{sup −1}). Besides, it has been satisfactorily applied to different types of water matrices (tap, mineral, well and sea water). The {sup 226}Ra minimum detectable activities (LSC: 0.004 Bq L{sup −1}; LBPC: 0.02 Bq L{sup −1}) attained by this system allow to reach the guidance values proposed by the relevant international agencies e.g. WHO, EPA and EC. - Highlights: • Automatic, rapid and selective method for {sup 226}Ra extraction/pre-concentration from water. • MSFIA-LOV system performs a sample clean-up prior to {sup 226}Ra radiometric detection. • {sup 226}Ra sample preparation allows using two radiometric detectors (LBPC and LSC). • Environmental levels of {sup 226}Ra are easily quantified. • High sensitivity and selectivity are achieved, reaching the

  13. Bead-Based Microfluidic Sediment Analogues: Fabrication and Colloid Transport.

    Science.gov (United States)

    Guo, Yang; Huang, Jingwei; Xiao, Feng; Yin, Xiaolong; Chun, Jaehun; Um, Wooyong; Neeves, Keith B; Wu, Ning

    2016-09-13

    Mobile colloids can act as carriers for low-solubility contaminants in the environment. However, the dominant mechanism for this colloid-facilitated transport of chemicals is unclear. Therefore, we developed a bead-based microfluidic platform of sediment analogues and measured both single and population transport of model colloids. The porous medium is assembled through a bead-by-bead injection method. This approach has the versatility to build both electrostatically homogeneous and heterogeneous media at the pore scale. A T-junction at the exit also allowed for encapsulation and enumeration of colloids effluent at single particle resolution to give population dynamics. Tortuosity calculated from pore-scale trajectory analysis and its comparison with lattice Boltzmann simulations revealed that transport of colloids was influenced by the size exclusion effect. The porous media packed by positively and negatively charged beads into two layers showed distinctive colloidal particle retention and significant remobilization and re-adsorption of particles during water flushing. We demonstrated the potential of our method to fabricate porous media with surface heterogeneities at the pore scale. With both single and population dynamics measurement, our platform has the potential to connect pore-scale and macroscale colloid transport on a lab scale and to quantify the impact of grain surface heterogeneities that are natural in the subsurface environment.

  14. Ndel1-derived peptides modulate bidirectional transport of injected beads in the squid giant axon

    Directory of Open Access Journals (Sweden)

    Michal Segal

    2012-01-01

    Bidirectional transport is a key issue in cellular biology. It requires coordination between microtubule-associated molecular motors that work in opposing directions. The major retrograde and anterograde motors involved in bidirectional transport are cytoplasmic dynein and conventional kinesin, respectively. It is clear that failures in molecular motor activity bear severe consequences, especially in the nervous system. Neuronal migration may be impaired during brain development, and impaired molecular motor activity in the adult is one of the hallmarks of neurodegenerative diseases leading to neuronal cell death. The mechanisms that regulate or coordinate kinesin and dynein activity to generate bidirectional transport of the same cargo are of utmost importance. We examined how Ndel1, a cytoplasmic dynein binding protein, may regulate non-vesicular bidirectional transport. Soluble Ndel1 protein, Ndel1-derived peptides or control proteins were mixed with fluorescent beads, injected into the squid giant axon, and the bead movements were recorded using time-lapse microscopy. Automated tracking allowed for extraction and unbiased analysis of a large data set. Beads moved in both directions with a clear bias to the anterograde direction. Velocities were distributed over a broad range and were typically slower than those associated with fast vesicle transport. Ironically, the main effect of Ndel1 and its derived peptides was an enhancement of anterograde motion. We propose that they may function primarily by inhibition of dynein-dependent resistance, which suggests that both dynein and kinesin motors may remain engaged with microtubules during bidirectional transport.

  15. Size exclusion and anion exchange high performance liquid chromatography for characterizing metals bound to marine dissolved organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Otero, Natalia; Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela (Spain); Moreda-Pineiro, Antonio, E-mail: antonio.moreda@usc.es [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela (Spain)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer Fractionation methods for assessing metals bound to marine DOM were developed. Black-Right-Pointing-Pointer SEC and AEC with UV detection and hyphenated with inductively coupled plasma-mass spectrometry were used. Black-Right-Pointing-Pointer SEC-UV showed marine DOM of molecular weights from 16 to 1 kDa. Black-Right-Pointing-Pointer Cobalt, manganese, strontium and zinc are bound to marine DOM. - Abstract: Size exclusion chromatography (SEC) followed by anion exchange chromatography (AEC) hyphenated with inductively coupled plasma-mass spectrometry (ICP-MS) was applied for fractionating metals bound to marine dissolved organic matter (DOM). Surface seawater samples (100 L) were subjected to tangential flow ultrafiltration (10,000 Da cut off) for isolating and pre-concentrating dissolved large molecules. The isolated fraction (retentate) consisted of 1 L, which was further freeze-dried and re-dissolved to 250 mL with ultrapure water. After HI Trap desalting of the re-dissolved retentate, SEC with UV detection showed marine DOM ranging from 6.5 kDa (lower than the permeable volume of the SEC column) to 16 kDa. A further characterization of this fraction by AEC with UV detection revealed the existence of four groups of macromolecules exhibiting retention times of 2.3, 2.8, 4.5 and 14.0 min. AEC hyphenated with ICP-MS showed the presence of strontium and zinc in the first AE fraction isolated from the SEC fraction; while manganese was found to be bound to the second AE fraction. Cobalt was found to be bound to molecules comprising the third AE fraction.

  16. Analysis of Phytomedicines%植物药分析

    Institute of Scientific and Technical Information of China (English)

    余海燕; 吴香玉; 张利民; 唐惠儒

    2012-01-01

    As widely used medicines in the world, phytomedicines played important roles in human health. The analysis of herbal medicines is important for the development of new drugs and functional food. Such analysis includes traditional methods, including metabolite extraction, component isolation and structure elucidation, and the hyphenated techniques with the combination of chromatographic and spectroscopic techniques. Here, we review the general procedures of traditional methods and hyphenated techniques for phytomedicine analysis with emphasis on the hyphenated HPLC-DAD-SPE-NMR-MS techniques.%植物药在世界范围内已经得到了广泛使用,对人类的健康发挥着重要作用.植物药分析是新药、保健食品研发的重要途径.目前,植物药分析方法主要包括传统分析法和联用技术分析法.传统分析法的步骤包括植物药成分提取、分离和结构鉴定.联用技术分析法主要是色谱、质谱、核磁共振等技术的联用.该文对植物药分析的方法尤其是联用技术在植物药分析中的应用进行了综述,重点介绍了HPLC-DAD-SPE-NMR-MS联用技术.

  17. 砷形态分析技术研究进展%ADVANCES ON THE ANALYTICAL TECHNIQUE OF ARSENIC SPECIATION

    Institute of Scientific and Technical Information of China (English)

    田靖; 陈昌云

    2011-01-01

    The research advance of separation, detection and hyphenated techniques on arsenic speciation analysis in recent years was summarized. The main issues to be concerned about arsenic speciation analysis in future were put forward.%总结了近年来砷形态分析的分离、检测以及联用技术的研究进展,提出了今后在砷形态分析工作中应关注的主要问题.

  18. 紫外可见分光光度技术的应用进展%Recent Progress of Application of UV-Vis Spectrophotometric Technique

    Institute of Scientific and Technical Information of China (English)

    王海军; 宁新霞

    2012-01-01

    介绍了近几年来紫外可见分光光度技术在仪器部件、多组分体系的测定,新技术应用进展以及与其他技术联用等方面的情况(引用文献33篇)。%An introduction on the recent progress of application of UVVis spectrophotometric technique was presented covering mainly the last several years, relating especially to parts of instrument, determination of multi- component systems, application of new technology and it's hyphenation with other technologies (33 ref. cited).

  19. 花样跑鞋百变秘笈

    Institute of Scientific and Technical Information of China (English)

    凹凹; 花花(设计); 黄剑锋(摄影); JOJO(化妆); Natasha(模特)

    2013-01-01

    Natasha碎花连体裙裤/E hyphen world gallery亮黄色功能跑步鞋/PUMA花花条纹蕾丝连身裙,earthmusic&ecology高帮印花帆布鞋/converse亮粉色短袜/tutuanna PART3 NIKE CLASSIC CORTEZ NYLON 此款鞋履可以说是跑鞋界的元老之物,薄荷绿配色与荧光黄运动衫呼应整身色彩,对热爱运动风的女孩而言势必是个不错的选择。

  20. Targeted natural product isolation guided by HPLC-SPE-NMR: Constituents of Hubertia species

    DEFF Research Database (Denmark)

    Sprogoe, K.; Staek, D.; Jager, A.K.;

    2007-01-01

    full or partial identification of all major extract constituents and demonstrated the presence of unusual quinic acid derivatives containing the (1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl residue that exhibit strongly coupled ABXY patterns, the parameters of which were obtained by spin simulations......The hyphenated technique, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-SPE-NMR), has been applied for rapid identification of novel natural products in crude extracts of Hubertia ambavilla and Hubertia tomentosa. The technique allowed...

  1. SFC/FTIR, SFC/APCI-MS and MALDI-TOF-MS for the analysis of siloxane-ethylene oxide copolymers.

    Science.gov (United States)

    Just, U; Jones, D J; Auerbach, R H; Davidson, G; Käppler, K

    2000-07-05

    Polydimethylsiloxanes (PDMSs) modified by introducing ethylene oxide units with the aim of forming sufficiently water-soluble siloxane compounds were characterized using supercritical fluid chromatography (SFC) coupled with Fourier transform infrared (FTIR) spectroscopy and atmospheric pressure chemical ionization mass spectrometry (APCI-MS), and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS). SFC has a domain in analyzing oligomers. Hyphenated techniques enable elucidation of the components. Remarkable is the resolution and short analysis time of MALDI-TOF-MS. SFC also allows quantification of the basic and reaction products.

  2. Format Guide for Scientific and Technical Reports.

    Science.gov (United States)

    1984-01-01

    Beta B / Kappa K K Sigma I (r Gamma r , Lambda A X Tau T 7 S Delta a 8 Mu M p Upsilon Y v Epsilon E E Nu N v Phi 4 Zeta Z C Xi f Chi X X Eta H 71...crytallographic centrifugal cumulant Cerenkov, Cherenkov cumulus cesium cure-all chain -reacting pile cut (use cap. letter and no hyphen for Charpy V-notch...one word) • lifetime minelayer lighter-than-air craft minesweeper lightweight minimum, minima light -year mismatch .. like (combines to form one mockup

  3. Occurrence, biological activities and {sup 13}C NMR data of amides from Piper (Piperaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jeferson C. do; Paula, Vanderlucia F. de [Universidade Estadual do Sudoeste da Bahia, Jequie, BA (Brazil). Dept. de Quimica e Exatas; David, Jorge M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; David, Juceni P., E-mail: jmdavid@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Fac. de Farmacia

    2012-07-01

    This manuscript describes an update review with up to 285 references concerning the occurrence of amides from a variety of species of the genus Piper (Piperaceae). Besides addressing occurrence, this review also describes the biological activities attributed to extracts and pure compounds, a compiled {sup 13}C NMR data set, the main correlations between structural and NMR spectroscopic data of these compounds, and employment of hyphened techniques such as LC-MS, GC-MS and NMR for analysis of amides from biological samples and crude Piper extracts. (author)

  4. Metabolomic applications in nutritional research: a perspective.

    Science.gov (United States)

    O'Gorman, Aoife; Brennan, Lorraine

    2015-10-01

    Metabolomics focuses on the global study of metabolites in cells, tissues and biofluids. Analytical technologies such as nuclear magnetic resonance (NMR) spectroscopy and hyphenated mass spectrometry (MS) combined with advanced multivariate statistical methods allow us to study perturbations in metabolism. The close link between metabolism and nutrition has seen the application of metabolomics in nutritional research increase in recent times. Such applications can be divided into three main categories, namely (1) the area of dietary biomarker identification, (2) diet-related diseases and (3) nutritional interventions. The present perspective gives an overview of these applications and an outlook to the future.

  5. Rheo-Raman microscope: Tracking molecular structures as a function of deformation and temperature

    Science.gov (United States)

    Plog, Jan P.; Meyer, Matt; De Vito, Francesca; Soergel, Fritz; Kotula, Anthony

    2016-05-01

    The Rheo-Raman Microscope combines rheology, Raman spectroscopy and polarization light microscopy and provides comprehensive insight into a material's bulk as well as micro structural properties under well defined and reproducible conditions such as temperature or shear profiles. The simultaneous acquisition with three independent analytical methods is advantageous for investigation of structural changes occurring for example in gelation, melting or crystallization. Details of this hyphenated instrumentation as well as selected results including temperature induced melting of a polymer emulsion and crystallization of a polymer melt are presented in this contribution.

  6. On-line sample processing methods in flow analysis

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald

    2008-01-01

    In this chapter, the state of the art of flow injection and related approaches thereof for automation and miniaturization of sample processing regardless of the aggregate state of the sample medium is overviewed. The potential of the various generation of flow injection for implementation of in......-line dilution, derivatization, separation and preconcentration methods encompassing solid reactors, solvent extraction, sorbent extraction, precipitation/coprecipitation, hydride/vapor generation and digestion/leaching protocols as hyphenated to a plethora of detection devices is discussed in detail...

  7. Combining asymmetrical flow field-flow fractionation with light-scattering and inductively coupled plasma mass spectrometric detection for characterization of nanoclay used in biopolymer nanocomposites

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Petersen, Jens Højslev; Koch, C. Bender

    2009-01-01

    of polylactide (PLA) with 5% Cloisite®30B (a derivatized montmorillonite clay) as a filler. Based on AF4-MALS analyses, we found that particles ranging from 50 to 800 nm in radius indeed migrated into the 95% ethanol used as a food simulant. The full hyphenated AF4-MALS-ICP-MS system showed, however, that none...... of clay nanoparticulates, an analytical system combining asymmetrical flow field-flow fractionation (AF4) with multi-angle light-scattering detection (MALS) and inductively coupled plasma mass spectrometry (ICP-MS) is presented. In a migration study, we tested a biopolymer nanocomposite consisting...

  8. Determination of cadmium and lead species and phytochelatins in pea (Pisum sativum) by HPLC-ICP-MS and HPLC-ESI-MSn.

    Science.gov (United States)

    Barałkiewicz, Danuta; Kózka, Małgorzata; Piechalak, Aneta; Tomaszewska, Barbara; Sobczak, Paweł

    2009-07-15

    An analytical approach based on hyphenated techniques was used for studying the speciation of cadmium and lead in Pisum sativum. Proper preservation conditions were employed to avoid the oxidation of -SH groups and corresponding decomposition of metal-binding complexes. SEC column was washed with 5 mM beta-mercaptoethanol and then samples were analysed using ICP-MS as a detector. Results showed that cadmium is the inhibitor of lead uptake. HPLC-ESI-MS(n) assays revealed fragmentation pathways of phytochelatins.

  9. Grammatically Correct The Essential Guide to Spelling, Style, Usage, Grammar, and Punctuation

    CERN Document Server

    Stilman, Anne

    2010-01-01

    How does good writing stand out? If its purpose is to convey facts, findings, or instructions, it need be read only once for its content to be clear. If its purpose is to entertain or to provoke thought, it makes readers want to come back for more. Revised and updated, this guide covers four essential aspects of good writing:Individual words - spelling variations, hyphenation, frequently confused homonyms, frequently misused words and phrases, irregular plurals and negatives, and uses of capitalization and type style to add special meaningsPunctuation - the role of each mark in achieving clar

  10. Methyl mercury in nail clippings in relation to fish consumption analysis with gas chromatography coupled to inductively coupled plasma mass spectrometry: a first orientation.

    Science.gov (United States)

    Krystek, Petra; Favaro, Paulo; Bode, Peter; Ritsema, Rob

    2012-08-15

    For the identification of human exposure to one of the most toxic compounds, which is methyl mercury (MeHg(+)), fingernail clippings were selected as the matrix of interest. Within this pilot study, six samples from different origins and from people with different food consumption patterns were chosen. Species-analysis of MeHg(+) was performed according to the following procedure: dissolution of the sample material in tetramethylammonium hydroxide (TMAH), derivatisation of MeHg(+) with sodium tetraethylborate (NaBEt(4)), extraction into iso-octane and measurement with gas chromatography hyphenated to inductively coupled plasma mass spectrometry (GC-ICPMS) for the quantification MeHg(+).

  11. Ibuprofen metabolite profiling using a combination of SPE/column-trapping and HPLC-micro-coil NMR.

    Science.gov (United States)

    Djukovic, Danijel; Appiah-Amponsah, Emmanuel; Shanaiah, Narasimhamurthy; Gowda, G A Nagana; Henry, Ian; Everly, Mike; Tobias, Brian; Raftery, Daniel

    2008-06-09

    Solid-phase extraction and column-trapping preconcentration are combined to enhance HPLC-nuclear magnetic resonance (HPLC-NMR) and applied to metabolite profiling in biological samples. Combining the two signal enhancement techniques improved the NMR signal substantially such that we were able to identify 2-hydroxyibuprofen, carboxyibuprofen, and unmetabolized ibuprofen molecules from a small urine sample after a therapeutic dose of ibuprofen. The hyphenated SPE/column-trapping method resulted in an excellent overall signal enhancement of up to 90-fold.

  12. Recent advances and new strategies in the NMR-based identification of natural products.

    Science.gov (United States)

    Halabalaki, Maria; Vougogiannopoulou, Konstantina; Mikros, Emmanuel; Skaltsounis, Alexios Leandros

    2014-02-01

    Nature comprises an untapped pool of unique compounds with high structural uniqueness and exceptional properties. At the core of natural products (NPs) discovery is the identification procedure and NMR remains the most efficient method. Technical improvements such as miniaturized and crycogenic NMR probes along with hyphenation capabilities and computational support are at the center of evolution. Concepts such as dereplication and metabolomics are increasingly adopted in NPs using the power of databases, currently fragmented. The introduction and utilization of these technical and computational implements could lead NPs research to more comprehensive structure identification and new holistic perspectives.

  13. Occurrence, biological activities and 13C NMR data of amides from Piper (Piperaceae

    Directory of Open Access Journals (Sweden)

    Jeferson C. do Nascimento

    2012-01-01

    Full Text Available This manuscript describes an update review with up to 285 references concerning the occurrence of amides from a variety of species of the genus Piper (Piperaceae. Besides addressing occurrence, this review also describes the biological activities attributed to extracts and pure compounds, a compiled 13C NMR data set, the main correlations between structural and NMR spectroscopic data of these compounds, and employment of hyphened techniques such as LC-MS, GC-MS and NMR for analysis of amides from biological samples and crude Piper extracts.

  14. Information meeting CETAMA; Journees d'information CETAMA

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, C.; Denauwer, C.; Schlegel, M.; Moisy, P.; Gouget, B.; Carriere, M.; Baglan, N.; Reiller, P.; Hanssens, A.; Boullis, B.; Leguay, J.J.; Vercouter, T.; Guilbaud, P.; Taran, F.; Bion, L.; Chaix, P.; Madic, C.; Lecomte, M.; Moulin, C.; Lobinski, R.; Fourest, B.; Hagege, A.; Mercier, F.; Billard, I.; Denecke, M.; Neu, M.; Bernhard, G.; Duffield, J.; Gilbin, R.; Grenthe, I.; Hummel, W.; Turq, P.; Van Der Lee, J

    2004-07-01

    This seminar devoted to the speciation was presented in four main sessions: analytical speciation (actinides and lanthanides speciation, methodology developments, the XPS contribution of hyphenated CE-IPS/MS in metal/protein interaction, spectroscopy...), the applications to the biological and environmental systems (plutonium and neptunium speciation, uranium in plants, radionuclides speciation and interaction with living organisms...), the data bases (advances in chemical thermodynamic database, theoretical chemistry calculation, discovery of powerful uranyl ligands, simulation...) and projects bound to databases and analytical speciation ( BASSIST-GT32, Actinet network, EUROSPART, Gdr Paris, Common Thermodynamic Database Project, ToxNuc-E). (A.L.B.)

  15. Mass Spectrometry Applications for Toxicology

    Science.gov (United States)

    Mbughuni, Michael M.; Jannetto, Paul J.

    2016-01-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MSn) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  16. Mass Spectrometry Applications for Toxicology.

    Science.gov (United States)

    Mbughuni, Michael M; Jannetto, Paul J; Langman, Loralie J

    2016-12-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MS(n)) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  17. 双周至潮事件无码解密

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    演绎趣味更浓的自在摩登 留学巴黎的E hyphen girl,将自在、趣味、摩登与巴黎艺术与时尚完美结合,不论打球、上课,还是逛展览,都能演绎出自己独特的穿搭法则。E hyphen world gallery 2015年春季系列便是留学巴黎的摩登女性的趣味艺术之旅,设计师将年轻女性的个性诉求与别样心机融入巴黎时尚之中,开启舂日女生自我发现的新鲜之旅。网球图案、波普水果印花、条纹格纹等元素让这一季增添不少运动与艺术气患,春意盎然的明快色调让春目的活力与张扬尽情释放。

  18. Multidrug analysis of pharmaceutical and urine matrices by on-line coupled capillary electrophoresis and triple quadrupole mass spectrometry.

    Science.gov (United States)

    Maráková, Katarína; Piešt'anský, Juraj; Veizerová, Lucia; Galba, Jaroslav; Dokupilová, Svetlana; Havránek, Emil; Mikuš, Peter

    2013-06-01

    The present work illustrates potentialities of CE hyphenated with MS/MS for the simultaneous determination and identification of a mixture of simultaneously acting drugs in pharmaceutical and biological matrices. Here, the hyphenation was provided by ESI interface, while the MS/MS technique was based on the triple quadrupole configuration. Three drugs, namely pheniramine, phenylephrine, and paracetamol were determined and identified with high reliability due to their characterization in three different dimensions, i.e. electrophoresis and MS/MS, that prevented practically any interference. Appropriately selected transitions of the analytes (parent ion-quantifier product ion-qualifier product ion) provided their selective determination at maximum S/N. The proposed CE-MS/MS method was validated (LOD/LOQ, linearity, precision, recovery, accuracy) and applied for (i) the multidrug composition pharmaceuticals, namely Theraflu®, and (ii) human urine taken after per-oral administration of the same pharmaceutical preparation. The method was applied also for the investigation of potential weak associates of the drugs and monitoring of predicted (bio)degradation products of the drugs. Successful validation and application of the proposed method suggest its routine use in highly effective and reliable advanced drug control and biomedical research.

  19. Comparison of high-performance liquid chromatography and supercritical fluid chromatography using evaporative light scattering detection for the determination of plasticizers in medical devices.

    Science.gov (United States)

    Lecoeur, Marie; Decaudin, Bertrand; Guillotin, Yoann; Sautou, Valérie; Vaccher, Claude

    2015-10-23

    Recently, interest in supercritical fluid chromatography (SFC) has increased due to its high throughput and the development of new system improving chromatographic performances. However, most papers dealt with fundamental studies and chiral applications and only few works described validation process of SFC method. Likewise, evaporative light scattering detection (ELSD) has been widely employed in liquid chromatography but only a few recent works presented its quantitative performances hyphenated with SFC apparatus. The present paper discusses about the quantitative performances of SFC-ELSD compared to HPLC-ELSD, for the determination of plasticizers (ATBC, DEHA, DEHT and TOTM) in PVC tubing used as medical devices. After the development of HPLC-ELSD, both methods were evaluated based on the total error approach using accuracy profile. The results show that HPLC-ELSD was more precise than SFC-ELSD but lower limits of quantitation were obtained by SFC. Hence, HPLC was validated in the ± 10% acceptance limits whereas SFC lacks of accuracy to quantify plasticizers. Finally, both methods were used to determine the composition of plasticized-PVC medical devices. Results demonstrated that SFC and HPLC both hyphenated with ELSD provided similar results.

  20. Inductively coupled plasma-MS in drug development: bioanalytical aspects and applications.

    Science.gov (United States)

    van Heuveln, Fred; Meijering, Henri; Wieling, Jaap

    2012-08-01

    The vast majority of today's modern bioanalytical methods for pharmacokinetic, pharmacodynamic and immunogenicity purposes are based on LC-MS/MS and immunoanalytical approaches. Indeed, these methodologies are suitable for a wide range of molecules from small to large. For a smaller but not insignificant group of compounds, LC-MS/MS is not suitable - or in some cases much less suitable - as a reliable bioanalytical methodology, and inductively coupled plasma (ICP)-MS is a more appropriate methodology. ICP-MS is one of these less widely used techniques in drug development. This methodology is predominantly used for elemental bioanalysis for pharmacokinetics, for imaging purposes, for mass-balance, food-effect and biomarker studies. In addition, in the last couple of years an increasing number of applications has been published, where ICP-MS and its various hyphenations (LC-ICP-MS, CE-ICP-MS) have been used for speciation/metabolism and proteomics studies. Here, the analytical potential, the quantitative bioanalytical aspects, the various modes of operation and the challenges of the application of ICP-MS in life sciences applications are given. This includes an overview of recent applications in this area in scientific literature, the various hyphenation possibilities and their application areas and the analysis of the various sample matrices applicable to these fields. It also provides a brief outlook of where the potential of this technique lies in the future of regulated bioanalysis and drug development.

  1. Elemental ratios for characterization of quantum-dots populations in complex mixtures by asymmetrical flow field-flow fractionation on-line coupled to fluorescence and inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Menendez-Miranda, Mario; Fernandez-Arguelles, Maria T.; Costa-Fernandez, Jose M., E-mail: jcostafe@uniovi.es; Encinar, Jorge Ruiz; Sanz-Medel, Alfredo, E-mail: asm@uniovi.es

    2014-08-11

    Highlights: • The hyphenated system allows unequivocal identification of nanoparticle populations. • AF4 separation permitted detection of unexpected nanosized species in a sample. • ICP-QQQ provides elemental ratios with adequate accuracy in every nanoparticle. • Purity and chemical composition of different quantum dot samples were assessed. - Abstract: Separation and identification of nanoparticles of different composition, with similar particle diameter, coexisting in heterogeneous suspensions of polymer-coated CdSe/ZnS quantum dots (QDs) have been thoroughly assessed by asymmetric flow field-flow fractionation (AF4) coupled on-line to fluorescence and inductively coupled plasma mass spectrometry (ICPMS) detectors. Chemical characterization of any previously on-line separated nanosized species was achieved by the measurement of the elemental molar ratios of every element involved in the synthesis of the QDs, using inorganic standards and external calibration by flow injection analysis (FIA). Such elemental molar ratios, strongly limited so far to pure single nanoparticles suspensions, have been achieved with adequate accuracy by coupling for the first time an ICP-QQQ instrument to an AF4 system. This hyphenation turned out to be instrumental to assess the chemical composition of the different populations of nanoparticles coexisting in the relatively complex mixtures, due to its capabilities to detect the hardly detectable elements involved in the synthesis. Interestingly such information, complementary to that obtained by fluorescence, was very valuable to detect and identify unexpected nanosized species, present at significant level, produced during QDs synthesis and hardly detectable by standard approaches.

  2. Combining field-amplified sample stacking with moving reaction boundary electrophoresis on a paper chip for the preconcentration and separation of metal ions.

    Science.gov (United States)

    Ouyang, Liangfei; Liu, Qian; Liang, Heng

    2017-02-01

    A common drawback of paper-based separation devices is their poor detection limit. In this study, we combined field-amplified sample stacking with moving reaction boundary electrophoresis on a paper chip with six array channels for the parallel separation and concentration of multiple samples. With a new hyphenated technique, the brown I2 from the Fe(3+) /I(-) oxidation-reduction reaction emerged near the boundary between the dilute ethylene diamine tetraacetic acid and potassium iodide and highly concentrated KCl solutions. For the separation and concentration of three components, Cr(3+) , Cu(2+) , and Fe(3+) , the Fe(3+) detection limit was improved at least 266-fold by comparing the hyphenated technique with moving reaction boundary electrophoresis. The detection limit of Fe(3+) was found to be as low as 0.34 ng (20 μM) on the paper chip. We also demonstrated the analysis of a real sample of four metal ions, with detection limits as follows: 0.16 μg Cr(3+) , 1.5 μg Ni(2+) , 0.64 μg Cu(2+) , and 1.5 μg Co(2+) . The synergy of field-amplified sample stacking and moving reaction boundary electrophoresis in the micron paper-based array channels dramatically improved the detection limit and throughput of paper-based electrophoresis.

  3. Tandem mass spectrometry in metallomics and the involving role of ICP-MS detection: a review.

    Science.gov (United States)

    Vogiatzis, C G; Zachariadis, G A

    2014-03-28

    Metallomics is a relatively new branch of omics with a growing interest. The study of metallomes is becoming more focused in certain metabolites and the screening of various categories of analytes using a robust analytical methodology is more than appealing. In this context, when dealing with the challenge of identifying a certain species or specify a particular molecular structure, tandem mass spectrometry (MS/MS) is a reliable tool. Moreover, MS/MS instrumentation is recommended in hyphenated chromatographic techniques with MS detection such as LC-MS, where primary molecular species suffer minor fragmentation (soft-ionization techniques). ICP-MS is widely used in metallomics with its main advantages being the provided high sensitivity and selectivity. Usually, analyzes utilize ICP-MS as the main detection. Its role in proteomics is significant as an alternating choice for protein and peptide quantifications. In this review, we discuss modern trends and applications of MS/MS in the important and growing field of metallomics. These reports concern the identification, characterization and determination of various metal species such as metalloproteins, metallo-DNA adducts, metal-labeled molecules and other metal binding biomolecules. Such assays also present new and interesting hyphenated instrumentation and novel sophisticated apparatus. In addition, we designate the role of ICP-MS in the mentioned contributions and in the same scope we highlight some general analytical strategies.

  4. A dupla face de Janus da China

    Directory of Open Access Journals (Sweden)

    Henrique Rattner

    2010-06-01

    Full Text Available Na mitologia romana, Janus é o rei mais antigo do Latium. Por ter acolhido a Saturno, expulso do Olimpo, este lhe brindou com uma visão em que tanto o futuro quanto o passado estivessem presentes, ficando assim conhecido como dono de duas faces. Essa duplicidade de personagem aplica-se perfeitamente ao papel da política chinesa, neste início de século XXI.

  5. Arsenic, Antimony, Chromium, and Thallium Speciation in Water and Sediment Samples with the LC-ICP-MS Technique

    Directory of Open Access Journals (Sweden)

    Magdalena Jabłońska-Czapla

    2015-01-01

    Full Text Available Chemical speciation is a very important subject in the environmental protection, toxicology, and chemical analytics due to the fact that toxicity, availability, and reactivity of trace elements depend on the chemical forms in which these elements occur. Research on low analyte levels, particularly in complex matrix samples, requires more and more advanced and sophisticated analytical methods and techniques. The latest trends in this field concern the so-called hyphenated techniques. Arsenic, antimony, chromium, and (underestimated thallium attract the closest attention of toxicologists and analysts. The properties of those elements depend on the oxidation state in which they occur. The aim of the following paper is to answer the question why the speciation analytics is so important. The paper also provides numerous examples of the hyphenated technique usage (e.g., the LC-ICP-MS application in the speciation analysis of chromium, antimony, arsenic, or thallium in water and bottom sediment samples. An important issue addressed is the preparation of environmental samples for speciation analysis.

  6. Susceptibility to glaucoma damage related to age and connective tissue mutations in mice.

    Science.gov (United States)

    Steinhart, Matthew R; Cone-Kimball, Elizabeth; Nguyen, Cathy; Nguyen, Thao D; Pease, Mary E; Chakravarti, Shukti; Oglesby, Ericka N; Quigley, Harry A

    2014-02-01

    The purpose of this research was to study the effects of age and genetic alterations in key connective tissue proteins on susceptibility to experimental glaucoma in mice. We used mice haploinsufficient in the elastin gene (EH) and mice without both alleles of the fibromodulin gene (FM KO) and their wild type (WT) littermates of B6 and CD1 strains, respectively. FM KO mice were tested at two ages: 2 months and 12 months. Intraocular pressure (IOP) was measured by Tonolab tonometer, axial lengths and widths measured by digital caliper post-enucleation, and chronic glaucoma damage was measured using a bead injection model and optic nerve axon counts. IOP in EH mice was not significantly different from WT, but FM KO were slightly lower than their controls (p = 0.04). Loss of retinal ganglion cell (RGC) axons was somewhat, but not significantly greater in young EH and younger or older FM KO strains than in age-matched controls (p = 0.48, 0.34, 0.20, respectively, multivariable regression adjusting for IOP exposure). Older CD1 mice lost significantly more RGC axons than younger CD1 (p = 0.01, multivariable regression). The CD1 mouse strain showed age-dependence of experimental glaucoma damage to RGC in the opposite, and more expected, direction than in B6 mice in which older mice are more resistant to damage. Genetic alteration in two genes that are constituents of sclera, fibromodulin and elastin do not significantly affect RGC loss.

  7. Characteristic patterns of dendritic remodeling in early-stage glaucoma: evidence from genetically identified retinal ganglion cell types.

    Science.gov (United States)

    El-Danaf, Rana N; Huberman, Andrew D

    2015-02-11

    Retinal ganglion cell (RGC) loss is a hallmark of glaucoma and the second leading cause of blindness worldwide. The type and timing of cellular changes leading to RGC loss in glaucoma remain incompletely understood, including whether specific RGC subtypes are preferentially impacted at early stages of this disease. Here we applied the microbead occlusion model of glaucoma to different transgenic mouse lines, each expressing green fluorescent protein in 1-2 specific RGC subtypes. Targeted filling, reconstruction, and subsequent comparison of the genetically identified RGCs in control and bead-injected eyes revealed that some subtypes undergo significant dendritic rearrangements as early as 7 d following induction of elevated intraocular pressure (IOP). By comparing specific On-type, On-Off-type and Off-type RGCs, we found that RGCs that target the majority of their dendritic arbors to the scleral half or "Off" sublamina of the inner plexiform layer (IPL) undergo the greatest changes, whereas RGCs with the majority of their dendrites in the On sublamina did not alter their structure at this time point. Moreover, M1 intrinsically photosensitive RGCs, which functionally are On RGCs but structurally stratify their dendrites in the Off sublamina of the IPL, also underwent significant changes in dendritic structure 1 week after elevated IOP. Thus, our findings reveal that certain RGC subtypes manifest significant changes in dendritic structure after very brief exposure to elevated IOP. The observation that RGCs stratifying most of their dendrites in the Off sublamina are first to alter their structure may inform the development of new strategies to detect, monitor, and treat glaucoma in humans.

  8. Fractionation analysis of manganese in Turkish hazelnuts (Corylus avellana L.) by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Erdemir, Umran Seven; Gucer, Seref

    2014-11-05

    In this study, an analytical fractionation scheme based on water, diethyl ether, n-hexane, and methanol extractions has been developed to identify manganese-bound fractions. Additionally, in vitro simulated gastric and intestinal digestion, n-octanol extraction, and activated carbon adsorption were used to interpret the manganese-bound structures in hazelnuts in terms of bioaccessibility. The total content of manganese in the samples was determined by inductively coupled plasma-mass spectrometry after microwave-assisted digestion, and additional validation was performed using atomic absorption spectroscopy. Water fractions were further evaluated by high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry for the identification of water-soluble manganese fractions in hazelnut samples. The limits of detection and quantification were 3.6 and 12.0 μg L(-1), respectively, based on peak height.

  9. Alkaloid analysis by high-performance liquid chromatography-solid phase extraction-nuclear magnetic resonance

    DEFF Research Database (Denmark)

    Johansen, Kenneth; Ebild, S.J.; Christensen, S.B.

    2012-01-01

    The hyphenated technique HPLC-SPE-NMR is an important tool for rapid dereplication of complex mixtures of in particular small molecules and has been successfully employed in natural product research. However, positively charged alkaloids at low pH are often poorly trapped on the generally used SPE...... cartridge limiting the general application of the procedure. In this work, two new approaches for efficient SPE trapping of alkaloids and elution efficiencies were evaluated using 24 model alkaloids. Use of a 0.1M NaOH solution as the post-column dilution greatly enhanced trapping of alkaloids...... on the commonly used cartridge containing divinylbenzene polymer (GP resin). This procedure, however, was unsuitable for trapping phenolic alkaloids. Severe line broadening and immiscibility with water made chloroform-d unsuited as eluent. None of these problems occurred when methanol-d was used as eluent...

  10. Advanced analytical techniques for the extraction and characterization of plant-derived essential oils by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Waseem, Rabia; Low, Kah Hin

    2015-02-01

    In recent years, essential oils have received a growing interest because of the positive health effects of their novel characteristics such as antibacterial, antifungal, and antioxidant activities. For the extraction of plant-derived essential oils, there is the need of advanced analytical techniques and innovative methodologies. An exhaustive study of hydrodistillation, supercritical fluid extraction, ultrasound- and microwave-assisted extraction, solid-phase microextraction, pressurized liquid extraction, pressurized hot water extraction, liquid-liquid extraction, liquid-phase microextraction, matrix solid-phase dispersion, and gas chromatography (one- and two-dimensional) hyphenated with mass spectrometry for the extraction through various plant species and analysis of essential oils has been provided in this review. Essential oils are composed of mainly terpenes and terpenoids with low-molecular-weight aromatic and aliphatic constituents that are particularly important for public health.

  11. Microfluidic chip for stacking, separation and extraction of multiple DNA fragments.

    Science.gov (United States)

    Wu, Ruige; Seah, Y P; Wang, Zhiping

    2016-03-11

    A disposable integrated microfluidic device was developed for rapid sample stacking, separation and extraction of multiple DNA fragments from a relatively large amount of sample. Isotachophoresis hyphenated gel electrophoresis (ITP-GE) was used to pre-concentrate and separate DNA fragments, followed by extraction of pure DNA fragments with electroelution on-chip. DNA fragments of 200bp, 500bp and 1kbp were successfully separated and collected in the extraction chamber within 25min. The extraction efficiency obtained from the chip was 49.9%, 52.1% and 53.7% for 200bp, 500bp and 1kbp DNA fragments, respectively. The extracted DNA fragments exhibited compatibility with downstream enzymatic reactions, for example PCR. The chip was also used to extract DNA fragments with specific size range from sheared genomic DNA and demonstrated similar performance to that using traditional gel cutting method. The whole assay can finish in 32min, 6 times faster than traditional method.

  12. Chlorococcalean microalgae Ankistrodesmus convolutes biodiesel characterization with Fourier transform-infrared spectroscopy and gas chromatography mass spectroscopy techniques

    Directory of Open Access Journals (Sweden)

    Swati SONAWANE

    2015-12-01

    Full Text Available The Chlorococcalean microalgae Ankistrodesmus convolutes was found in fresh water Godawari reservoir, Ahmednagar district of Maharashtra State, India. Microalgae are modern biomass for the production of liquid biofuel due to its high solar cultivation efficiency. The collection, harvesting and drying processes were play vital role in converting algal biomass into energy liquid fuel. The oil extraction was the important step for the biodiesel synthesis. The fatty acid methyl ester (FAME synthesis was carried through base catalyzed transesterification method. The product was analyzed by using the hyphened techniques like Fourier Transform-Infrared spectroscopy (FT-IR and Gas Chromatography Mass Spectroscopy (GCMS. FT-IR Spectroscopy was results the ester as functional group of obtained product while the Gas Chromatography Mass Spectroscopy was results the six type of fatty acid methyl ester with different concentration. Ankistrodesmus convolutes biodiesel consist of 46.5% saturated and 49.14% unsaturated FAME.

  13. Automotive Painting Technology A Monozukuri-Hitozukuri Perspective

    CERN Document Server

    Salazar, Abraham; Saito, Kozo

    2013-01-01

    This book offers unique and valuable contributions to the field. It offers breadth and inclusiveness. Most existing works on automotive painting cover only a single aspect of this complex topic, such as the chemistry of paint or paint booth technology. Monozukuri and Hitozukuri are Japanese terms that can be translated as “making things” and “developing people” but their implications in Japanese are richer and more complex than this minimal translation would indicate. The Monozukuri-Hitozukuri perspective is drawn from essential principles on which the Toyota approach to problem-solving and continuous improvement is based. From this perspective, neither painting technology R&D nor painting technology use in manufacturing can be done successfully without integrating technological and human concerns involved with making and learning in the broadest sense, as the hyphen is meant to indicate. The editors provide case studies and examples -- drawn from Mr. Toda’s 33 years of experience with automotiv...

  14. 毛细管电泳-电致化学发光联用技术应用进展%Recent Progress of Application of CE-ECL

    Institute of Scientific and Technical Information of China (English)

    胡月芳; 李建平; 刘蓉; 郝再彬

    2011-01-01

    A review on the application of capillary electrophoresis hyphenated with electrochemiluminescence (CE-ECL) was presented, relating especially to its principle and application to analysis of pharmaceutical, biological, environmental, food and agricultural samples during the years from 1983-2010. (66 ref. Cited).%介绍了毛细管电泳-电致化学发光联用技术(CE-ECL)的检测原理,重点评述了1983-2010年间CE-ECL在药物制品、生物样品、环境和食品、农产品分析中的应用(引用文献66篇)。

  15. 汞结合金属硫蛋白的色谱-质谱表征方法%Characterization of Mercurial-bound Metallothioneins in Tissues of Rat Kidney by Chromatography Coupled With ICP-MS and ESI-MS

    Institute of Scientific and Technical Information of China (English)

    黄志勇; 沈金灿; 庄峙厦; 王小如; 黎先春

    2004-01-01

    Mercurial-bound metallothioneins (MTs) induced in kidney of rat after oral intake of HgCl2 were characterized with the developed hyphenated techniques including reverse phase chromatography (RPC) coupled with inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization mass spectrometry(ESIMS). After being purified with size-exclusion column (Sephadex G-75) and dialysis (M<1000 Da), the extracts was separated with a narrow-bore reverse phase column and eluted by increasing methanol at gradient mode. The MT polymorphism with different binding-metal (including Hg, Cu and Zn) species was interpreted by the measured masses at the vicinity of apexes in total ion current (TIC) of ESIMS and the reference data of apo-MTs reported.The results indicated that many Hg-binding MT species existed in the polluted rat kidney.

  16. 膜分离在中药制药中的应用进展%Application progress on the production of traditional Chinese medicine using membrane separation

    Institute of Scientific and Technical Information of China (English)

    樊君; 代宏哲; 高续春

    2011-01-01

    This article reviews recent developments of membrane technology such as microfiltration, ultra-filtration, nanofiltration, reverse osmosis, molecularly imprinted membrane, membrane distillation and hyphenated techniques in the membrane separation. Then, the field and the status quo of membrane separation in the production of traditional Chinese medicine are given and the applications of membrane separation in future are prospected.%对膜分离技术在中药生产过程中的应用领域以及常用的微滤、超滤、纳滤、反渗透、分子印迹膜、膜蒸馏和膜集成联用技术等的应用现状进行了综述,并对膜分离技术的应用前景进行了展望.

  17. Ribeiro ou Miranda-Ribeiro? Nota biográfica sobre Alípio de Miranda Ribeiro (1874-1939 Ribeiro or Miranda-Ribeiro? A biographical note on Alípio de Miranda Ribeiro (1874-1939

    Directory of Open Access Journals (Sweden)

    José P Pombal Jr

    2002-09-01

    Full Text Available Alípio de Miranda Ribeiro was one of the foremost Brazilian naturalists of his era and published extensively on all vertebrate groups. His son, Paulo de Miranda Ribeiro (1901-1965, was an ichthyologist, and, as his father, worked at the Museu Nacional, in Rio de Janeiro. Brazil. Although the papers of Alípio and Paulo de Miranda Ribeiro are commonly cited, two distinct forms are found: Ribeiro and Miranda-Ribeiro. The use a hyphen between Miranda and Ribeiro (spo-radically, and verified names of ancestor and descendants suggest that the better form for citation is Miranda-Ribeiro. A short biographical note on Alípio de Miranda-Ribeiro is provided.

  18. 汞结合金属硫蛋白的色谱-质谱表征方法

    Institute of Scientific and Technical Information of China (English)

    黄志勇; 沈金灿; 庄峙厦; 王小如; 黎先春

    2004-01-01

    Mercurial-bound metallothioneins (MTs) induced in kidney of rat after oral intake of HgCl2 were characterized with the developed hyphenated techniques including reverse phase chromatography (RPC) coupled with inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization mass spectrometry(ESIMS). After being purified with size-exclusion column (Sephadex G-75) and dialysis (M<1000 Da), the extracts was separated with a narrow-bore reverse phase column and eluted by increasing methanol at gradient mode. The MT polymorphism with different binding-metal (including Hg, Cu and Zn) species was interpreted by the measured masses at the vicinity of apexes in total ion current (TIC) of ESIMS and the reference data of apo-MTs reported.The results indicated that many Hg-binding MT species existed in the polluted rat kidney.

  19. 高铁氧化技术在环境污染治理中的应用及研究进展%The Application and Advances of Potassium Ferrate in Removal of Pollutents

    Institute of Scientific and Technical Information of China (English)

    马超

    2012-01-01

    Potassium ferrate technology has been paied more and more attention with advantage of itself.The article introduces the preparation of potassium ferrate and the mechanism of pollutants processing,discusses the main influence factors in the pollutants processing.It states the advances in hypHenated techniques.by combination of potassium ferrate and other treatment techniques.%高铁氧化技术在环境污染治理中因其自身所具有的优势而得到越来越多的重视,文章介绍了高铁盐在污染物处理的作用机理,讨论了高铁盐在处理污染物过程中主要影响因素。简述高铁氧化技术与其他处理技术协同作用的研究进展。

  20. Direct coupling of a flow-flow electromembrane extraction probe to LC-MS

    DEFF Research Database (Denmark)

    Fuchs, David; Gabel-Jensen, Charlotte; Jensen, Henrik

    2016-01-01

    extraction/analysis position the setup allowed simultaneous analysis of previously loaded analytes while extracting a new sample. Performance of the system was characterized with respect to precision and linearity (RSD metabolism...... of methadone by rat liver microsomes. As the metabolic reaction proceeded, methadone and its metabolites were extracted and analyzed in parallel by LC-MS using either isocratic or gradient elution. Compared to a conventional in-vitro metabolism analysis based on protein precipitation followed by LC-MS analysis......A fully integrated and automated electromembrane extraction LC-MS (EME-LC-MS) system has been developed and characterized. Hyphenation of a flow-flow EME probe to LC-MS was accomplished by using an in-built 10-port switching valve of the LC-MS system. The 10-port switching valve decoupled the high...

  1. Extraction and detection of Ionophores in the Aquatic Environment

    DEFF Research Database (Denmark)

    Bak, Søren Alex; Hansen, Martin; Krogh, Kristine Andersen;

    with resistance in the treatment of coccidiosis. Several reports have revealed that ionophores are emerging environmental contaminants in agricultural run-off waters, surface waters, sediments, and ground waters, due to their continuously increased and constant application as feed additives in modern livestock...... compounds on the soil bacterial community (Halling-Sørensen et al. 2002; Hansen et al. 2009c). The focus of the present study is on the recent advances of a new analytical method for sampling, extraction and detection of ionophores in liquid matrices. The hyphenated method consists of an integrated clean......-up with solid phase extraction followed by high-performance liquid chromatography tandem in space mass spectrometry. Preliminary results for the HPLC-MS/MS method determine the limit of detection (LOD) for five ionophores in the range of 10 - 25 ng kg-1 and limit of quantification (LOQ) in the range of 25 – 100...

  2. Você está brincando?

    Directory of Open Access Journals (Sweden)

    Rosanna Lauriola

    2010-04-01

    Full Text Available A presença de uma imagem tal como a que aparece na página (http://farm4.static.flickr.com/3252/2843406747_3c135d63d9.jpg

  3. LC-MS metabolomics from study design to data-analysis - using a versatile pathogen as a test case.

    Science.gov (United States)

    Berg, Maya; Vanaerschot, Manu; Jankevics, Andris; Cuypers, Bart; Breitling, Rainer; Dujardin, Jean-Claude

    2013-01-01

    Thanks to significant improvements in LC-MS technology, metabolomics is increasingly used as a tool to discriminate the responses of organisms to various stimuli or drugs. In this minireview we discuss all aspects of the LC-MS metabolomics pipeline, using a complex and versatile model organism, Leishmania donovani, as an illustrative example. The benefits of a hyphenated mass spectrometry platform and a detailed overview of the entire experimental pipeline from sampling, sample storage and sample list set-up to LC-MS measurements and the generation of meaningful results with state-of-the-art data-analysis software will be thoroughly discussed. Finally, we also highlight important pitfalls in the processing of LC-MS data and comment on the benefits of implementing metabolomics in a systems biology approach.

  4. Structural elucidation of biologically active neomycin N-octyl derivatives in a regioisomeric mixture by means of liquid chromatography/ion trap time-of-flight mass spectrometry.

    Science.gov (United States)

    Giera, Martin; de Vlieger, Jon S B; Lingeman, Henk; Irth, Hubertus; Niessen, Wilfried M A

    2010-05-30

    Structural elucidation of six regioisomers of mono-N-octyl derivatized neomycin is achieved using MS(n) (up to n = 4) on an ion trap time-of-flight (IT-TOF) instrument equipped with electrospray ionization. The mixture of six derivatized neomycin analogues was generated by reductive amination in a shotgun synthetic approach. In parallel to the liquid chromatography/mass spectrometry (LC/MS) detection, the antibacterial activity of the neomycin regioisomers was tested by post-column addition of buffer and bacterial inocula, subsequent microfractionation of the resulting mixture, incubation, and finally a chemiluminescence-based bioactivity measurement based on the production of bacterial ATP. The MS-based high-resolution screening approach described can be applied in medicinal chemistry to help in designing and producing new antibiotic substances, which is particularly challenging due to the high functionality of most antibiotic substances, therefore requiring advanced (hyphenated) separation and detection techniques for compound mixtures.

  5. The role of visual acuity and segmentation cues in compound word identification

    Directory of Open Access Journals (Sweden)

    Jukka eHyönä

    2012-06-01

    Full Text Available Studies are reviewed that demonstrate how the foveal area of the eye constrains how compound words are identified during reading. When compound words are short, their letters can be identified during a single fixation, leading to the whole-word route dominating word recognition from early on. Hence, visually marking morpheme boundaries by hyphens slows down processing by encouraging morphological decomposition when holistic processing is a feasible option. In contrast, the decomposition route dominates the early stages of identifying long compound words. Thus, visual marking of morpheme boundaries facilitates processing of long compound words, unless the initial fixation made on the word lands very close to the morpheme boundary. The reviewed pattern of results is explained by the visual acuity principle (Bertram & Hyönä, 2003 and the dual-route framework of morphological processing.

  6. Method optimization and quality assurance in speciation analysis using high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt

    1998-01-01

    operating characteristics of the entire hyphenated system. An isocratic HPLC system, which employs an aqueous mobile phase with organic buffer constituents, is well suited for introduction into the ICP-MS because of the stability of the detector response and high degree of analyte sensitivity attained......Achievement of optimum selectivity, sensitivity and robustness in speciation analysis using high performance liquid chromatography (HPLC) with inductively coupled mass spectrometry (ICP-MS) detection requires that each instrumental component is selected and optimized with a view to the ideal....... Anion and cation exchange HPLC systems, which meet these requirements, were used for the separation of selenium and arsenic species in crude extracts of biological samples. Furthermore, the signal-to-noise ratios obtained for these incompletely ionized elements in the argon ICP were further enhanced...

  7. Secoiridoids in olive seed: characterization of nuzhenide and 11-methyl oleosides by liquid chromatography with diode array and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S.; Gomes, L.; Leitao, F.; Bronze, M.; Coelho, A. V.; Vilas Boas, L.

    2010-07-01

    The seed extracts of olive tree cultivars were analyzed by reverse phase HPLC with diode array detection and mass spectrometry. HPLC hyphenation with mass spectrometry (Ei source) in both polarity modes enabled the identification in olive seeds of nuzhenide and nuzhenide 11-methyl oleoside, among other 11-methyl oleosides, by means of MSn. The methods used allowed us to obtain olive seed profiles of phenolic components and to conclude that they are mainly secoiridoids. The quantification of detected phenolic secoiridoids was also achieved using ultraviolet detection ({lambda}= 240 nm) which enabled comparison of the samples. Nuzhenide and nuzhenide 11-methyl oleoside were the major components detected in olive seeds of all the cultivars studied, but variations in individual components of olive seeds were verified among the cultivars. The results also support the existence of di and tri(11-methyl oleosides) of nuzhenide. (Author)

  8. Speciation analysis by gas chromatography with plasma source spectrometric detection

    Science.gov (United States)

    Łobiński, Ryszard; Adams, Freddy C.

    State-of-the-art species-selective analysis by gas chromatography (GC) with plasma source spectrometric detection is discussed for organometal and organometalloid compounds. Various plasmas, inductively coupled plasma, microwave induced plasma, capacitatively coupled plasma, direct current plasma and alternating current plasma, are characterized and critically compared as sources of radiation for atomic emission spectrometry and sources of ions for mass spectrometry. Interfaces between gas chromatography (packed, wide-bore, capillary and multicapillary) and plasma source spectrometry are characterized. Particular emphasis is given to applications of GC with plasma source detection to real-world analytical problems, which are comprehensively reviewed. The use of plasmas for the acquisition of auxiliary molecular information such as empirical formulae and structural information is discussed. Recent developments relating to sample preparation and presentation to the hyphenated system are addressed. The most significant trends in speciation analysis are highlighted.

  9. Evaluation of extraction procedures for the ion chromatographic determination of arsenic species in plant materials.

    Science.gov (United States)

    Schmidt, A C; Reisser, W; Mattusch, J; Popp, P; Wennrich, R

    2000-08-11

    The determination of arsenic species in plants grown on contaminated sediments and soils is important in order to understand the uptake, transfer and accumulation processes of arsenic. For the separation and detection of arsenic species, hyphenated techniques can be applied successfully in many cases. A lack of investigations exists in the handling (e.g., sampling, pre-treatment and extraction) of redox- and chemically labile arsenic species prior to analysis. This paper presents an application of pressurized liquid extraction (PLE) using water as the solvent for the effective extraction of arsenic species from freshly harvested plants. The method was optimized with respect to extraction time, number of extraction steps and temperature. The thermal stability of the inorganic and organic arsenic species under PLE conditions (60-180 degrees C) was tested. The adaptation of the proposed extraction method to freeze-dried, fine-grained material was limited because of the insufficient reproducibility in some cases.

  10. Validated HPLC-RI method for the determination of lactulose and its process related impurities in syrup

    Directory of Open Access Journals (Sweden)

    Nelofar A

    2010-01-01

    Full Text Available A simple, swift with good sensitivity and reproducibility, HPLC-RI method has been developed for the quantification of lactulose and related compounds (fructose, galactose, epilactose and lactose in oral suspension formulation. The analysis was carried out by using mobile phase (water and acetonitrile 75:25 at the flow rate of 1.0 ml/min. on isocratic HPLC-RI system. After manipulating mobile phase composition and mobile phase flow rate a good separation of five components was achieved within 15 minutes of run time. This study is beneficial to determine the active ingredient as well as related compounds simultaneously, without using buffer in mobile phase which causes bad resolution and has limitation to analyze on other hyphenated techniques such as LC-MS.

  11. Development of a micro flow-through cell for high field NMR spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Todd Michael; McIntyre, Sarah K.

    2011-05-01

    A highly transportable micro flow-through detection cell for nuclear magnetic resonance (NMR) spectroscopy has been designed, fabricated and tested. This flow-through cell allows for the direct coupling between liquid chromatography (LC) and gel permeation chromatography (GPC) resulting in the possibility of hyphenated LC-NMR and GPC-NMR. The advantage of the present flow cell design is that it is independent and unconnected to the detection probe electronics, is compatible with existing commercial high resolution NMR probes, and as such can be easily implemented at any NMR facility. Two different volumes were fabricated corresponding to between {approx}3.8 and 10 {micro}L detection volume. Examples of the performance of the cell on different NMR instruments, and using different NMR detection probes were demonstrated.

  12. Novel applications of high performance ion chromatography-inductively coupled plasma mass spectrometry (HPIC-ICP-MS)

    CERN Document Server

    Hann, S

    2001-01-01

    This work demonstrates the development of highly sensitive and selective analytical methods, which make use of the hyphenation of high performance ion chromatography (HPIC) to inductively coupled plasma sector field mass spectrometry (ICP-SFMS). On-line coupling a chromatographic separation method with an elemental detection method provides two advantages: (1) the components of a possibly interfering matrix can be separated allowing accurate and precise ultra trace analysis of the element of interest and (2) elemental species of an element can be separated and quantified. In this work, matrix separation methods for interference free determination of 232Th, 234U, 235U and 238U in geological matrices were developed and employed. Furthermore HPIC-ICP-SFMS was applied for ultra trace analysis of Pd in environmental and geological matrices. The usefulness of HPIC-ICP-SFMS for speciation studies was demonstrated by investigating the interaction of an anti-cancer drug (cisplatin) with guanosine monophosphates.

  13. Capillary electrophoretic methods in the development of metal-based therapeutics and diagnostics: new methodology and applications.

    Science.gov (United States)

    Bytzek, Anna K; Hartinger, Christian G

    2012-02-01

    In recent years, capillary electrophoresis (CE) has matured to a standard method in medicinal inorganic chemistry. More and more steps of the drug discovery process are followed by CE. However, not only the number of applications has steadily increased but also the variety of used methodology has significantly broadened and, as compared to a few years ago, a wider scope of separation modes and hyphenated systems has been used. Herein, a summary of the newly utilized CE methods and their applications in metallodrug research in the timeframe 2006-2011 is presented, following related reviews from 2003 and 2007 (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis 2007, 28, 3436-3446). Areas covered include impurity profiling, quality control of pharmaceutical formulations, lipophilicity estimation, interactions between metallodrugs and proteins or nucleotides, and characterization and also quantification of metabolites in biological matrices and real-world samples.

  14. Extraction and detection of Ionophores in the Aquatic Environment

    DEFF Research Database (Denmark)

    Bak, Søren Alex; Hansen, Martin; Krogh, Kristine Andersen;

    . 2002; Hansen et al. 2009c). The focus of the present study is on the recent advances of a new analytical method for sampling, extraction and detection of ionophores in liquid matrices. The hyphenated method consists of an integrated clean-up with solid phase extraction followed by high......-performance liquid chromatography tandem in space mass spectrometry. Halling-Sørensen B, Sengelov G, Tjørnelund J (2002) Arch Environ Contam Toxicol, 42: 3, pp. 263-271 Dolliver H, Gupta S (2008) J. Environ. Qual. 37: 2 pp. 1227-1237. Hansen M, Björklund E, Krogh KA, Halling-Sørensen B (2009a) TrAC 28:5 pp521...

  15. Recent trends in rapid dereplication of natural product extracts:an update

    Institute of Scientific and Technical Information of China (English)

    Fikre Mammo; Milkyas Endale

    2015-01-01

    Natural products are the prominent sources of drugs to combat various infectious diseases. The rapid progress of multi-resistance and pan-resistant pathogens to various medicines represents today a major challenge. The search for novel natural products requires a quick and efficient approach to distinguish novel compounds from the known ones, a process called dereplication. Dereplication strategy is generic and time-saving, avoids isolation/purification of known compounds, enables an efficient liquid chromatography peak annotation of most of the studied compounds and can be well adapted for plant chemotaxonomy, phytochemical screening and metabolite profiling. In this review, recent developments of hyphenated techniques towards dereplication of active compounds, chemotaxonomy, metabolite profiling and rapid detection of novel compounds in medicinal plant extracts are presented.

  16. Recent trends in rapid dereplication of natural product extracts: an update

    Directory of Open Access Journals (Sweden)

    Fikre Mammo

    2015-03-01

    Full Text Available Natural products are the prominent sources of drugs to combat various infectious diseases. The rapid progress of multi-resistance and pan-resistant pathogens to various medicines represents today a major challenge. The search for novel natural products requires a quick and efficient approach to distinguish novel compounds from the known ones, a process called dereplication. Dereplication strategy is generic and time-saving, avoids isolation/purification of known compounds, enables an efficient liquid chromatography peak annotation of most of the studied compounds and can be well adapted for plant chemotaxonomy, phytochemical screening and metabolite profiling. In this review, recent developments of hyphenated techniques towards dereplication of active compounds, chemotaxonomy, metabolite profiling and rapid detection of novel compounds in medicinal plant extracts are presented.

  17. Application of LC-MS/MS for quantitative analysis of glucocorticoids and stimulants in biological fluids

    Institute of Scientific and Technical Information of China (English)

    Jamshed Haneef; Mohammad Shaharyar; Asif Husaina; Mohd Rashid; Ravinesh Mishra; Shama Parveen; Niyaz Ahmed; Manoj Pal; Deepak Kumar

    2013-01-01

    Liquid chromatography tandem mass chromatography (LC-MS/MS) is an important hyphenated technique for quantitative analysis of drugs in biological fluids. Because of high sensitivity and selectivity, LC-MS/MS has been used for pharmacokinetic studies, metabolites identification in the plasma and urine. This manuscript gives comprehensive analytical review, focusing on chromatographic separation approaches (column packing materials, column length and mobile phase) as well as different acquisition modes (SIM, MRM) for quantitative analysis of glucocorticoids and stimulants. This review is not meant to be exhaustive but rather to provide a general overview for detection and confirmation of target drugs using LC-MS/MS and thus useful in the doping analysis, toxicological studies as well as in pharmaceutical analysis.

  18. DART-MS:A New Research Tool for Herbal Medicine Analysis

    Institute of Scientific and Technical Information of China (English)

    Yao Shen; Wan-Ying Wu; De-An Guo

    2016-01-01

    Direct analysis in real time (DART) possesses the merits of analyzing sample in its native status with minimal or even no sample pretreatment. In this review, we summarized the recent applications of DART in the field of herbal medicine analysis such as compound detection, species identification, metabolites profiling and initial quantification. DART with the characters of hyper-rapid, easy-hyphenated offers a new research tool for herbal medicines to complete the experimental process in a very simple but still reliable way. It is anticipated that more wide and deep applications of DART in herbal medicine analysis, as rapid quantification, high-throughput active compounds screening, rapid species identification, and fast illegal additives screening will be promising and foreseeable in the near future.

  19. [The participation of pharmacists in the activities of the Society of Health of the town of Nancy (1796-1806)].

    Science.gov (United States)

    Labrude, Pierre

    2007-07-01

    Revolution having suppressed the universities and constitution of year III having authorized citizens to form free societies, a "Society of health of the town of Nancy" was formed in 1795-1796. Its aims were the teaching of medicine and pharmacy students, the diffusion of knowledges, the help to poors and the protection of health. Two pharmacists, Willemet and Mandel, were among the founders; they were joined by Nicolas, formerly professor at the faculty of médicine. All three became professors at the society. Mandel was the author of numerous studies and Willemet remained some years as a member of the board of the society which disappeared in 1806-1807. The Society was a hyphen between old and new structures, and the presence and activity of our fellows were significative.

  20. Human sports drug testing by mass spectrometry.

    Science.gov (United States)

    Schänzer, Wilhelm; Thevis, Mario

    2017-01-01

    Since the installation of anti-doping rules and regulations and their international enforcement in the mid-1960s, mass spectrometry has been an integral part of doping control procedures. Although its utility was limited in the first decade, instrumental improvements and method optimizations have made mass spectrometry, in all its facets, an indispensable tool in modern sports drug testing. In this review, milestones in doping control analysis accomplished in Germany and reaching from the early developments to the current use of hyphenated mass spectrometric techniques concerning low- and high molecular mass analytes are presented. The considered drug classes include anabolic agents, peptidic drugs, nucleotide-derived therapeutics, approved and non-approved organic as well as inorganic analytes, and particular focus is put on drug class- and instrument-driven strategies. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:16-46, 2017.

  1. A Review on Inductively Coupled Plasma Mass Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ramyalakshmi G

    2012-12-01

    Full Text Available Inductively coupled plasma mass spectroscopy is routinely used in many diverse research fields such as earth, environmental, life and forensic sciences and in food, material, chemical, semiconductor and nuclear industries. The high ion density and the high temperature in a plasma provide an ideal atomizer and element ionizer for all types of samples and materials introduced by a specialised devices .outstanding properties such as high sensitivity, relative salt tolerance, compound-independent element response and highest quantitation accuracy lead to the unchallenged performance of ICPMS in efficiently detecting, identifying and reliably quantifying trace element. The increasing availability of relevant reference compounds and high separation selectively extend the molecular identification capability of ICPMS hyphenated to species – specific separation techniques

  2. Prosecuting the Leaders: Promises, Politics and Practicalities

    Directory of Open Access Journals (Sweden)

    Robert Cryer

    2009-02-01

    Full Text Available Given recent developments in relation to the prosecution of international crimes,  it might be thought that one of the last bastions of sovereignty has been breached, and international criminal law has not only entrenched itself in international law. Indeed further to this, it has assumed a supranational position that stands entirely above States, promising justice for all and as a trump card over depredations committed in the name of State sovereignty. After all, Charles Taylor from Liberia is standing trial before the Special Court for Sierra Leone, Slobodan Milošević only escaped judgment by the International Criminal Tribunal for the former

  3. Metallomics: the concept and methodology.

    Science.gov (United States)

    Mounicou, Sandra; Szpunar, Joanna; Lobinski, Ryszard

    2009-04-01

    The emerging field of metallomics refers to the entirety of research activities aimed at the understanding of the molecular mechanisms of metal-dependent life processes. This critical review discusses the concept of metallomics with a focus on analytical techniques and methods for the probing of interactions between metal ions and the organism's genome and the derived -omes: proteome and metabolome. Particular attention is paid to the in vivo screening for the native metal-protein and metal-metabolite complexes by hyphenated techniques that combine a high-resolution separation technique (gel electrophoresis, chromatography or capillary electrophoresis) with sensitive elemental (inductively coupled plasma, ICP) or molecular (electrospray or MALDI) mass spectrometric detection. The contribution of bioinformatics to the prediction of metal-binding sequences in proteins and the role of molecular biology approaches for the detection of metal-dependent genes, proteins and metabolites are highlighted (115 references).

  4. [Development of metallomics research on environmental toxicology].

    Science.gov (United States)

    Ogra, Yasumitsu

    2015-01-01

    Metallomics is newly coined terms and defined as a comprehensive analysis of the entirety of metal and metalloid species within a cell or tissue type. Then, metallome is defined as the entire category of metalloproteins and any other metal-containing biomolecules. Metallomics and research on metallome require analytical techniques that can provide information on the identification and quantification of metal/metalloid-containing biomolecules. This concept has been called speciation, and the acquisition of data according to the concept is performed using hyphenated techniques involving both separation and detection methods. In this review, the author intends to present several applications of complementary use of HPLC-inductively coupled plasma mass spectrometry (ICP-MS) and HPLC-electrospray ionization tandem mass spectrometry for identification of unknown selenium-containing metabolites, and also to present a newly developed technique, capillary LC-ICP-MS to be used for the analysis of metal-binding proteins.

  5. Separation and identification of phenolic compounds of extra virgin olive oil from Olea europaea L. by HPLC-DAD-SPE-NMR/MS. Identification of a new diastereoisomer of the aldehydic form of oleuropein aglycone.

    Science.gov (United States)

    Pérez-Trujillo, Míriam; Gómez-Caravaca, Ana María; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Parella, Teodor

    2010-08-25

    The phenolic fraction of a monovarietal extra virgin olive oil (EVOO) from Olea europaea L. var. Cornezuelo was studied by the hyphenated HPLC-DAD-SPE-NMR/MS techniques. This survey led to the identification of 25 main compounds. One was identified as a new diastereoisomer of the aldehydic form of oleuropein aglycone (AOA) and characterized by 1D and 2D NMR techniques. The relative configuration of this new AOA was determined as 5R*,8S*,9S* on the basis of the results obtained from the combination of NOE experiments and Monte Carlo conformational search calculations. Assuming, as for the described diastereoisomers, that the new AOA comes from the natural oleuropein aglycone (OA), the absolute configuration was proposed as 5S,8R,9R.

  6. Synchrotron radiation for direct analysis of metalloproteins on electrophoresis gels.

    Science.gov (United States)

    Ortega, Richard

    2009-03-01

    Metalloproteomics requires analytical techniques able to assess and quantify the inorganic species in metalloproteins. The most widely used methods are hyphenated techniques, based on the coupling of a high resolution chromatographic method with a high sensitivity method for metal analysis in solution. An alternative approach is the use of methods for solid sample analysis, combining metalloprotein separation by gel electrophoresis and direct analysis of the gels. Direct methods are based on beam analysis, such as lasers, ion beams or synchrotron radiation beams. The aim of this review article is to present the main features of synchrotron radiation based methods and their applications for metalloprotein analysis directly on electrophoresis gels. Synchrotron radiation X-ray fluorescence has been successfully employed for sensitive metal identification, and X-ray absorption spectroscopy for metal local structure speciation in proteins. Synchrotron based methods will be compared to ion beam and mass spectrometry for direct analysis of metalloproteins in electrophoresis gels.

  7. A novel sensitive sheathless CE-MS device for peptide and protein analysis

    DEFF Research Database (Denmark)

    Nguyen, Tam T. T. N.; Petersen, Nickolaj J.; Rand, Kasper Dyrberg

    Introduction CE-MS has shown considerable potential in protein research and pharmaceutical development, however, technical challenges of hyphenation of CE with MS have limited its use. Here, we have developed a sensitive CE-MS setup for peptide and protein analysis, that employs a novel and low......-cost sheathless CE-MS interface and a poly(ethyleneglycol)-coated capillary. Using the CE-MS setup, we have achieved fast and efficient separation and sensitive mass analysis of individual components of a complex sample of pharmaceutically relevant human proteins including insulin, tissue factor, α......-synuclein and a tryptic digest of bovine serum albumin. We have furthermore compared the performance of the CE-MS technique to UPLC-MS and demonstrate significant advantages of the CE-MS setup in terms of analysis time, sample consumption and separation capacity. Methods The sheathless CE-MS interface is based...

  8. Morphological Analysis as Classification an Inductive-Learning Approach

    CERN Document Server

    Van den Bosch, A; Weijters, T; Bosch, Antal van den; Daelemans, Walter; Weijters, Ton

    1996-01-01

    Morphological analysis is an important subtask in text-to-speech conversion, hyphenation, and other language engineering tasks. The traditional approach to performing morphological analysis is to combine a morpheme lexicon, sets of (linguistic) rules, and heuristics to find a most probable analysis. In contrast we present an inductive learning approach in which morphological analysis is reformulated as a segmentation task. We report on a number of experiments in which five inductive learning algorithms are applied to three variations of the task of morphological analysis. Results show (i) that the generalisation performance of the algorithms is good, and (ii) that the lazy learning algorithm IB1-IG performs best on all three tasks. We conclude that lazy learning of morphological analysis as a classification task is indeed a viable approach; moreover, it has the strong advantages over the traditional approach of avoiding the knowledge-acquisition bottleneck, being fast and deterministic in learning and process...

  9. An Enhanced Static Data Compression Scheme Of Bengali Short Message

    CERN Document Server

    Arif, Abu Shamim Mohammod; Islam, Rashedul

    2009-01-01

    This paper concerns a modified approach of compressing Short Bengali Text Message for small devices. The prime objective of this research technique is to establish a low complexity compression scheme suitable for small devices having small memory and relatively lower processing speed. The basic aim is not to compress text of any size up to its maximum level without having any constraint on space and time, rather than the main target is to compress short messages up to an optimal level which needs minimum space, consume less time and the processor requirement is lower. We have implemented Character Masking, Dictionary Matching, Associative rule of data mining and Hyphenation algorithm for syllable based compression in hierarchical steps to achieve low complexity lossless compression of text message for any mobile devices. The scheme to choose the diagrams are performed on the basis of extensive statistical model and the static Huffman coding is done through the same context.

  10. Direct Detection of Pharmaceuticals and Personal Care Products from Aqueous Samples with Thermally-Assisted Desorption Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Campbell, Ian S.; Ton, Alain T.; Mulligan, Christopher C.

    2011-07-01

    An ambient mass spectrometric method based on desorption electrospray ionization (DESI) has been developed to allow rapid, direct analysis of contaminated water samples, and the technique was evaluated through analysis of a wide array of pharmaceutical and personal care product (PPCP) contaminants. Incorporating direct infusion of aqueous sample and thermal assistance into the source design has allowed low ppt detection limits for the target analytes in drinking water matrices. With this methodology, mass spectral information can be collected in less than 1 min, consuming ~100 μL of total sample. Quantitative ability was also demonstrated without the use of an internal standard, yielding decent linearity and reproducibility. Initial results suggest that this source configuration is resistant to carryover effects and robust towards multi-component samples. The rapid, continuous analysis afforded by this method offers advantages in terms of sample analysis time and throughput over traditional hyphenated mass spectrometric techniques.

  11. Apolar Compounds in Seaweeds from Fernando de Noronha Archipelago (Northeastern Coast of Brazil)

    Science.gov (United States)

    Ferreira, Leandro De Santis; Turatti, Izabel Cristina Casanova; Lopes, Norberto Peporine; Guaratini, Thais; Colepicolo, Pio; Oliveira Filho, Eurico Cabral; Garla, Ricardo Clapis

    2012-01-01

    Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n9; 18 : 2 Δ9,12; 20 : 4; 20 : 5. These fatty acids are commonly found in seaweeds present in warm regions. Thus, we found no specificity in the presence of a particular set of fatty acids and the studied species indicating that they are not useful as taxonomic indicators. However, they could be used in a comparative study with algae found in polluted area because many of the studied seaweeds are widespread and Fernando de Noronha has low human influence. PMID:22272200

  12. Highly selective and sensitive analysis of dopamine by molecularly imprinted stir bar sorptive extraction technique coupled with complementary molecularly imprinted polymer sensor.

    Science.gov (United States)

    Prasad, Bhim Bali; Srivastava, Amrita; Tiwari, Mahavir Prasad

    2013-04-15

    This paper reports a combination of molecularly imprinted stir bar sorptive extraction and complementary molecularly imprinted polymer-sensor for the analysis of dopamine as a biomarker of several neurodegenerative diseases occurred at ultra trace level. This exploited iniferter initiated polymerization via "surface grafting-from" approach onto magnetic stir bar (for sorptive extraction) and multiwalled carbon nanotubes-ceramic electrode (for detection). Such hyphenation helped dual pre-concentration of dopamine in aqueous, biological and pharmaceutical samples. This enabled high sensitivity to achieve the stringent limit [limit of detection: 4.9ngL(-1), RSD=2.4%, S/N=3, cerebrospinal fluid] of clinical detection, without any problems of non-specific contributions and cross-reactivity.

  13. Mental illness in the nursing workplace: a collective autoethnography.

    Science.gov (United States)

    Kidd, Jacquie Dianne; Finlayson, Mary P

    2010-01-01

    Many nurses are burned out, exhausted and have a high intent to leave their jobs. These factors, when experienced over a period of time, are consistent with the development of mental illness. This study takes a collective autoethnographical approach to mental illness in the nursing workplace by focusing on the stories of nurses who have experienced mental illness in clinical practice. It highlights three ways in which nursing and mental illness are connected; the nurse who is vulnerable to mental illness prior to entering the profession, the nurse who develops mental illness that is independent of her work but is nevertheless impacted by it, and the nurse who develops mental illness as a result of her work and/or role. This paper explores the hyphenated lives and bullying these nurses experience, and recommends strategies that the profession, employing organisations, and individuals can adopt to reduce nurses' progression from stress to distress and mental illness.

  14. Vigo, vulgo Almereyda e Jean Vigo: Paulo Emílio Salles Gomes e a interlocução entre anarquismo e cinema

    Directory of Open Access Journals (Sweden)

    Julierme Sebastião Morais

    2009-11-01

    Full Text Available

    Resenha:

  1. Study on Retention in Liquid Chromatography%关于液相色谱保留的研究

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    After joining the faculty at Toyohashi University of Technology (TUT) in 1978, the author has found two areas in separation sciences where microcolumn liquid chromatography (micro-LC) can be beneficial. One is the hyphenated techniques between many spectroscopic methods such as mass (MS), infrared (FT-IR) and atomic emission (ICP), and micro-LC. The other one is rather difficult, but basic and theoretical approach which deals with retention mechanism in LC. The latter project has especially been giving him a lot of scientific funs and honors in the last 20 years. On the occasion of being awarded by The Society for Chromatographic Sciences the author would like to summarize his contributions to this topic which asks us "What Is Chromatographic Retention".

  2. Recent trends in analytical methods and separation techniques for drugs of abuse in hair.

    Science.gov (United States)

    Baciu, T; Borrull, F; Aguilar, C; Calull, M

    2015-01-26

    Hair analysis of drugs of abuse has been a subject of growing interest from a clinical, social and forensic perspective for years because of the broad time detection window after intake in comparison to urine and blood analysis. Over the last few years, hair analysis has gained increasing attention and recognition for the retrospective investigation of drug abuse in a wide variety of contexts, shown by the large number of applications developed. This review aims to provide an overview of the state of the art and the latest trends used in the literature from 2005 to the present in the analysis of drugs of abuse in hair, with a special focus on separation analytical techniques and their hyphenation with mass spectrometry detection. The most recently introduced sample preparation techniques are also addressed in this paper. The main strengths and weaknesses of all of these approaches are critically discussed by means of relevant applications.

  3. Notas sobre a liberdade e a tirania da maioria em Stuart Mill

    Directory of Open Access Journals (Sweden)

    Antonio Ozaí da Silva

    2009-10-01

    Full Text Available O liberalismo é uma doutrina política que, em suas origens, tem como alicerce vários autores clássicos do pensamento político: Locke, Montesquieu, Kant, Adam Smith, Humboldt, Benjamin Constant, Alexis de Tocqueville, Stuart Mil e outros. Portanto, a exemplo do socialismo, cabe perfeitamente a pergunta: Qual liberalismo? Como o(s marxismo(s, o pensamento liberal não é homogêneo. Da mesma forma, o conceito de liberdade no pensamento liberal tem mais de uma conotação, como também a sua crítica. Estes apontamentos se limitam a expor o pensamento político de John Stuart Mill, mais precisamente sobre a sua argumentação em defesa da liberdade individual e a crítica à tirania da maioria no ensaio “Sobre a Liberdade” (MILL, 1991.

  4. O desafio social do saber universitário

    Directory of Open Access Journals (Sweden)

    Moisés dos Santos Viana

    2009-08-01

    Full Text Available O artigo é uma reflexão sobre o saber universitário e o desafio social de gerar conhecimento técnico-científico. Desse modo, há muitas implicações e divergências em meio ao conhecimento e seu aspecto emancipador. Uma crítica ao utilitarismo universitário, mercadológico, que se manifesta como práxis conservadora do status quo. Assim, propõem-se um novo modo de refletir, sentir, dialogar, agir para provocar, alterar e superar o desafio social do saber universitário.    

  5. Articles with short titles describing the results are cited more often

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Paiva

    2012-01-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate some features of article titles from open access journals and to assess the possible impact of these titles on predicting the number of article views and citations. METHODS: Research articles (n = 423, published in October 2008 from all Public Library of Science (PLoS journals and from 12 Biomed Central (BMC journals were evaluated. Publication metrics (views and citations were analyzed in December 2011. The titles were classified according to their contents, namely methods-describing titles and results-describing titles. The number of title characters, title typology, the use of a question mark, reference to a specific geographical region, and the use of a colon or a hyphen separating different ideas within a sentence were analyzed to identify predictors of views and citations. A logistic regression model was used to identify independent title characteristics that could predict citation rates. RESULTS: Short-titled articles had higher viewing and citation rates than those with longer titles. Titles containing a question mark, containing a reference to a specific geographical region, and that used a colon or a hyphen were associated with a lower number of citations. Articles with results-describing titles were cited more often than those with methods-describing titles. After multivariate analysis, only a low number of characters and title typology remained as predictors of the number of citations. CONCLUSIONS: Some features of article titles can help predict the number of article views and citation counts. Short titles presenting results or conclusions were independently associated with higher citation counts. The findings presented here could be used by authors, reviewers, and editors to maximize the impact of articles in the scientific community.

  6. Steam Methane Reforming System for Hydrogen Production: Advanced Exergetic Analysis

    Directory of Open Access Journals (Sweden)

    Tatiana Morosuk

    2012-02-01

    Full Text Available Steam methane reforming (SMR is one of the most promising processes for the production of hydrogen. Therefore, the overall thermodynamic efficiency of this process is of particular importance. The thermodynamic inefficiencies in a thermal system are related to exergy destruction and exergy loss. However, a conventional exergetic analysis cannot evaluate the mutual interdependencies among the system components nor the real potential for improving the energy conversion system being considered. One of the tools under development for the improvement of energy conversion systems from the thermodynamic viewpoint is the advanced exergetic analysis. In this paper, the avoidable part of the exergy destruction is estimated and the interactions among components of the overall system are evaluated in terms of endogenous and exogenous exergy destruction. The assumptions required for these calculations are discussed in detail, especially for those components that are typically used in chemical processes. Results of this paper suggest options for increasing the thermodynamic efficiency of hydrogen production by steam-methane reforming.

  7. Recent advances and trends in the liquid-chromatography-mass spectrometry analysis of flavonoids.

    Science.gov (United States)

    de Villiers, André; Venter, Pieter; Pasch, Harald

    2016-01-22

    Flavonoids have elicited significant attention as a result of their importance in plants, their influence on the properties of natural-product derived commodities and especially as a consequence of their purported health benefits. Research in all of these fields relies heavily on accurate analytical data, and in this LC-MS has come to play an influential role by allowing relatively fast tentative identification and accurate quantification of low levels of flavonoids in a variety of matrices. The field has undergone rapid expansion in the last decade due to important developments in both HPLC and MS instrumentation, which nowadays allow much faster and more accurate analysis of flavonoids. This contribution aims to provide an overview of these developments and their application in flavonoid analysis since 2009. The discussion is focussed first on methodologies which provide improved LC separation of flavonoids in terms of speed and/or resolution, including ultra high pressure LC (UHPLC), monolithic and superficially porous phases, high temperature LC (HTLC) and comprehensive two-dimensional LC (LC×LC). The fundamental background relevant to each of these will be briefly outlined, as well as the implications and promise of their hyphenation to MS. Secondly, the possibilities and limitations of a range of the latest MS instruments available in combination with advanced LC analysis will be discussed, including ion trap, triple quadrupole, time-of-flight, Orbitrap, ion mobility and various hybrid instruments. Examples from the latest literature will be used to illustrate the performance gains achievable in flavonoid analysis by the hyphenation of advanced LC separation and high-end MS instrumentation.

  8. Um gramsciano a serviço da união dos povos

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Nogueira

    2010-02-01

    Full Text Available Quarta-feira, 20 de janeiro, soube da morte de Giorgio Baratta. Poucos brasileiros sabem quem foi ele. Era conhecido e admirado por marxistas gramscianos, com quem mantinha relações estreitas, aqui no Brasil e em diversas partes do mundo. A todos encantava com sua ironia fina, seu conhecimento enciclopédico, sua admiração incondicional por Gramsci – uma admiração que não o cegava nem o fechava em tolos dogmatismos.

  9. As bregafestas de fim de ano (apenas uma reflexão pessoal

    Directory of Open Access Journals (Sweden)

    Raymundo de Lima

    2010-01-01

    Full Text Available Peço perdão aos festeiros de fim de ano, pela minha irritação com o mesmismo dessa época. Acho horrorosas as musiquinhas com arpa, os anúncios televisivos, os enfeites bregaluminosos nas árvores urbanas, as filas, a obrigação de desejar feliz Natal e Próspero Ano Novo, receber-enviar mensagens etc. Na verdade, me irrito com o consumismo e a profanação do significado do nascimento de Jesus. Incomodo-me especialmente com as mulheres que entram em frenesi com as compras de roupas pra si, para parentes e crianças exigentes com presentes de griffes, a ansiedade dos preparativos para a ceia de Natal, seleção dos convidados. Por que ceia? Por que “tem que ter” peru? No Rio “tem que ter” rabanada gordurosa?

  10. O Muro, dois Estados, dois Mundos

    Directory of Open Access Journals (Sweden)

    Luis Edmundo de Souza Moraes

    2009-11-01

    Full Text Available

    O  artigo trata do problema das fronteiras sociais e políticas na Berlim do pós-II Guerra Mundial relacionadas à divisão da cidade em zonas de ocupação e, posteriormente, à construção do Muro. Ele reflete sobre o fato de que o muro, que dividiu uma cidade de forma artificial, produziu divisões e diferenças concretas pela ação do tempo, criando descontinuidades onde haviam continuidades. O artigo ainda aponta para uma forma de pensar o encontro não planejado entre as duas partes da cidade naquilo que foi chamada de reunificação.

  11. User Experience – Essencial para Usabilidade de Produtos

    Directory of Open Access Journals (Sweden)

    Antonio Mendes Silva Filho

    2011-07-01

    Full Text Available Usabilidade tem sido um dos fatores utilizados por empresas para conquistar novos usuários (consumidores. De acordo com a Norma 9241-11 da ISO (International Organization for Standardization, a usabilidade é definida como “The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use”. Esses objetivos compreendem a base do que é denominado “user experience”. Mas, o que é user experience? Trata-se da experiência do usuário quando interage com produtos ou serviços. Um produto pode ser qualquer coisa como, por exemplo, um notebook, um aparelho celular ou smartphone, um painel de automóvel ou software. Qualquer desses produtos ou até serviços (como oferecidos em web sites, têm a usabilidade como atributo determinante da qualidade perceptível aos usuários. Nesse sentido, o objetivo deste artigo é discutir e explorar experiência e percepção do usuário no uso e adoção de novas tecnologias. O artigo destaca como a Apple tem inovado em seus produtos provendo usabilidade levando em consideração a experiência do usuário.

  12. Ministério do Turismo e sua Festa de Babette

    Directory of Open Access Journals (Sweden)

    João dos Santos Filho

    2010-05-01

    Full Text Available Não sei por que! Mas quando estava pensando na Política Nacional de Turismo, visualizei um banquete, onde a prática gastronômica explicitava inexistir a plena felicidade sem o pecado, que pode ser o da gula em razão da comida e do dinheiro pela existência das emendas parlamentares. O Ministério do Turismo seria madame Babette em seu banquete articulado por um maquiamento marqueteiro, buscando contrapor a noção do pecado com a idéia da felicidade.

  13. Redes Sociais na Era da Conectividade (“The good, the bad and the Ugly”

    Directory of Open Access Journals (Sweden)

    Antonio Mendes Silva Filho

    2010-12-01

    Full Text Available O mundo caminha para uma população que deverá atingir a população de 7 bilhões de pessoas. Entretanto, muito antes disso, a impressionante marca de 2 bilhões de usuários da Internet será alcançada. E, nada mais encanta mais o ser humano que a comunicação. Por natureza, o ser humano precisa viver em sociedade. Trata-se de uma característica intrínseca do homem. Ao longo de sua história, a humanidade tem sido marcada por tragédias e avanços e, especificamente, o século XX foi rico no avanço científico. A década de 90 foi marcada pela popularização da Internet, a qual foi intensificada nesta última década, destacando-se o crescente número de usuários e tempo de permanência nas redes sociais. O que isso indica? Um novo brinquedo? Necessidade de comunicação ? Um novo vício? Este artigo parte desses questionamentos e dados estatísticos para explorar como novas tecnologias impactam sobre o cotidiano humano e corporativo.

  14. Sobre o Classicismo de Goethe (Caracter

    Directory of Open Access Journals (Sweden)

    Júlio César Mioto

    2009-10-01

    Full Text Available Este artigo mostra certo descompasso entre as orientações positivas da estética de Goethe, como aparecem nos seus Escritos sobre arte, e a realização efetiva de sua obra artística, tomando o caso exemplar de Ifigênia em Táuris. Tal ocorre, conforme sustentamos, por uma exigência interna à obra, que de algum modo já era compreendida por sua estética anterior. Pelo tratamento do problema clássico do “caracter”, veremos como se realiza sua concepção do procedimento maneira. Também como se dá uma superação em relação às prescrições clássicas por meio de uma particular resolução do drama.

  15. Étude préliminaire sur les stucs trouvés dans le "Bâtiment à Péristyle" du quartier sud-ouest de Palmyre (PAL.M.A.I.S. - Fouilles 2008-2009 A preliminary study on the stuccos found in the "Peristyle Building" of Palmyra's south-west quarter (PAL.M.A.I.S. - Excavations 2008-2009

    Directory of Open Access Journals (Sweden)

    Lilia Palmieri

    2011-03-01

    Full Text Available

    The Italian-Syrian joint Mission of the Università degli Studi of Milan at Palmyra (Pal.M.A.I.S. = Palmira. Missione Archeologica Italo-Siriana is focus on the exploration of the south-west quarter of the ancient city. Since 2008 the stratigraphic excavation of the "Peristyle Building" has begun. Many fragments of stucco which are part of a frieze decorated by an Anthemion have been found in one room of the building - the room A -. These fragments belong to the decoration of a luxury complex which was damaged (or destroyed? before the 6th century AD, and they are very important elements in order to define the chronological horizon of the first phase of development of the area.

    Les travaux archéologiques de la Mission conjointe italienne-syrienne de l'Università degli Studi de Milan à Palmyre (Pal.M.A.I.S.= Palmira. Missione Archeologica Italo-Siriana sont dédiés à l’exploration du quartier sud-ouest de la ville antique. Depuis 2008 a été entreprise la fouille stratigraphique du "Bâtiment à Péristyle", et dans une

  16. BIOCHEMICAL ATTRIBUTES OF TWO SAVANNAH SOILS UNDER DIFFERENT MANAGEMENT SYSTEMS AND USE ATRIBUTOS BIOQUÍMICOS EM DOIS SOLOS DE CERRADO SOB DIFERENTES SISTEMAS DE MANEJO E USO

    Directory of Open Access Journals (Sweden)

    Américo Nunes da Silveira Neto

    2008-11-01

    Full Text Available

    Soil biochemical attributes can be used as sensitive indicators of alterations promoted by the agricultural use, being a tool to guide tillage practices planning and evaluation to maintain soil sustainability. The objective of this study was to evaluate alterations in the soil organic carbon, biomass and microbial activity, urease and acid phosphatase activity, in two savannah soils, as affected by soil management systems. The study consisted of five soil management systems in a Typic Quartzipsamment, four in an Oxisol, and reference areas without alterations in the two soil types. The management systems changed the biochemical attributes of both soils. The Typic Quartzipsamment area under the soybean/Brachiaria decumbens sequence decreased the soil organic carbon and the microbial biomass carbon, and increased the respiration and qCO2, while the Oxisol, in all the areas, except for pasture, promoted reductions in the biochemical attributes. Among the management systems studied,  the pasture provided improvements in the evaluated attributes, in both soils.

    KEY-WORDS: Soil quality; microbial biomass; soil enzymatic activity.

    Para a filosofia clássica chinesa, quando uma pessoa chega aos 60 anos chega um sinal que indica maturidade na vida terrena. Neste sentido, são altamente pertinentes a busca por respostas menos superficiais e capazes de ajudar-nos em algo que também buscamos ao trilhar o caminho brasileiro de transição ao socialismo. Serenidade, visão de processo histórico e o tato político como marca registrada daqueles que enxergam no movimento político imediato algo passivo de tratamento científico.
    Neste sentido, tendo a transição como uma categoria filosófica a ser cada vez mais degustada e trabalhada, tentarei – nestas curtas linhas – mapear o caminho do sucesso inerente ao

  17. Picturing the Other: Targets of Delegitimization across Time

    Directory of Open Access Journals (Sweden)

    Luca Andrighetto

    2010-12-01

    Full Text Available

     

    Italian Fascist propaganda was compared with contemporary right-wing material to explore how political propaganda depicts specific target groups in different historical periods. Taking the theory of delegitimization as the theoretical framework, we analyzed visual images concerning despised social groups used by the Fascist regime and current images of contemporary targets of social resentment used by Lega Nord (currently part of the governing coalition. Images of Jewish and Black people published in the Fascist magazine La Difesa della Razza were classified according to eight delegitimizing strategies, as were images of immigrants used on Lega Nord propaganda posters. Although the target group has changed, six of the eight strategies of delegitimization were used in both periods. In most cases, overlap was found in the way target groups were portrayed in the past and in the present.

     

    This is a historical and sociological overview of violence and violence research in and on North Africa, West Asia, and South Asia, considering only studies for a global audience. The main focus is on political violence, with a brief look at religious and communal violence, youth violence, and domestic and gendered violence. These regions have been consistently affected by political violence for many decades, the main source of which seems to be the ongoing state formation process, as well as social transformation in general. The literature on violence is dominated by international debates, at

  1. The dangers of Utopia

    Directory of Open Access Journals (Sweden)

    Larry Hufford

    2009-06-01

    Full Text Available

    Utopia can have an uplifting and a dark side, but usually the dark side ends up trumping the initial idealism. The reason for this is that utopians inevitably adopt a messianic image of the world. The three messianic revolutions in history—the American, French and Bolshevik—were led by men who thought their ideas were universal. This essay examines the writings of French existentialist Albert Camus, who argues that there are no transcendental values, at the same time he does not accept nihilism. Camus makes a distinction between a rebel and a revolutionary, and concludes that a rebellion will try to end the specific oppression, whereas the revolution will try to create a “new man,” with common values throughout the world.

  2. Afinidades eletivas: EZLN e MST na contramão da história do progresso dos vencedores

    Directory of Open Access Journals (Sweden)

    Fabio Querido

    2011-04-01

    Full Text Available

    Inspirando-se em algumas reflexões de Walter Benjamin e, em menor medida, de José Carlos Mariátegui, o objetivo deste pequeno artigo é esboçar algumas afinidades eletivas entre o Exército Zapatista de Libertação Nacional e o Movimento dos Trabalhadores Sem Terra, particularmente no que se refere à importância que eles conferem ao resgate e rememoração das lutas sociais do passado – transformadas em fonte de inspiração das lutas do presente.

  3. NatureDNS:一种自然语言式域名寻址系统%NATUREDNS: AN ADDRESSING SYSTEM FOR DOMAIN NAMES USING NATURAL LANGUAGES

    Institute of Scientific and Technical Information of China (English)

    刘振兴

    2013-01-01

    探讨一种使用自然语言进行域名注册登记、解析和寻址的方法.现行的域名系统DNS(Domain Name System)采用层级式的命名空间,点分多段表达式,域名与IP的对应关系维护在一个分布式的数据库系统中.随着网络发展这种体系面临:(1)越来越多的人们被迫接受一种点分字符串作为访问对象的标记;(2)随着新顶级域名的增多和国际化域名的启用,点分字符串的域名变得进一步复杂多变.在深入分析这一体系及其他相关改进型探索的基础上,提出一种以“-”(hyphen)为起始和分级标记使用自然语言式字符串进行网络寻址的新方法(“-XXXX”),取名为NatureDNS,即“自然语言式DNS系统”.%We propose an approach for registration, resolution and addressing of the domain names using natural languages. Current DNS is a hierarchical namespace where the dotted multi-segment expression, the correlated relationship of domain name and its IP addresses are maintained in a distributed database system. With the development of the networks, such system is encountering: 1) more and more people are compelled to accept the dotted strings as the tags for the accessing objects; 2) along with the increasing of new gTLD and the enabling of the IDN, the domain names with dotted strings become more complicated and changeable than ever. Based on a thorough investigation on this system and other related improvement exploration, we present in the article a new method ( "-xxxx" ) , which uses "-" ( hyphen) as the tags of starting and hierarchical separation, and uses natural languages string for networks addressing, and give its name as "NatureDNS" , i. e. , "to express the domain names in natural languages".

  4. Ciência, pseudociência e o fascínio popular

    Directory of Open Access Journals (Sweden)

    Raymundo de Lima

    2010-03-01

    Full Text Available

    Rádio, televisão e internet divulgam fórmulas milagrosas para tratar calvície, emagrecer, até para aumentar o tamanho do pênis. Técnicas bizarras ensinam a aplicar o próprio sangue [hemoterapia?], tomar a própria unina [urinoterapia?], viver apenas tomando luz [helioterapia?] etc.

  5. Países pobres e aquecimento global: tempos sombrios para o desenvolvimento

    Directory of Open Access Journals (Sweden)

    Henrique Rattner

    2009-11-01

    Full Text Available

    O crescimento dos países pobres está contribuindo para as mudanças climáticas. Entretanto, eles já estão entre suas maiores vítimas, sofrendo imensas devastações, ora por secas prolongadas, ora por chuvas torrenciais, ciclones e tsunamis.

  6. O Ensino do Sistema de Escrita Alfabética: PCN de Língua Portuguesa e Livro Didático

    Directory of Open Access Journals (Sweden)

    Leticia Fraga

    2009-07-01

    Full Text Available

    Esse artigo busca identificar os papéis da lingüística no ensino de língua, identificação essa que tem como objetivo central a compreensão de como se deu a correlação entre o desenvolvimento da pesquisa e sua aplicação ao ensino. Em geral, quando se tem um tema como este, se pensa em Lingüística Aplicada e, em particular, no Ensino de Língua Estrangeira ou Língua Materna. No entanto, a perspectiva do trabalho procura relacionar a Lingüística ao desenvolvimento das bases teóricas do ensino, refletindo sobre alguns aspectos atuais da Lingüística e seu potencial, sobretudo na aplicação que dela vem sendo feita. Dessa forma, analisar-se-á nesse trabalho de que forma a proposta de ensino do sistema de escrita alfabética de um livro didático se relaciona à proposta dos Parâmetros Curriculares Nacionais em Língua Portuguesa, uma vez que esses documentos evidenciam de que forma a teoria lingüística pode influenciar o ensino de língua materna.

  7. A abordagem de Morin frente à construção do todo

    Directory of Open Access Journals (Sweden)

    Paloma Maria Santos

    2009-08-01

    Full Text Available

    O objetivo deste artigo é apresentar uma reflexão sobre a abordagem de Edgar Morin frente a construção do conhecimento. Partindo das transformações que podem ocorrer dentro de um sistema complexo, Morin discorre sobre três pressupostos relacionados a interação entre partes e todo, que irão conduzir o desenvolvimento deste trabalho.

  8. A História do Ensino do Espanhol na década de 1980-1990 no Estado do Paraná

    Directory of Open Access Journals (Sweden)

    Jonathas de Paula Chaguri

    2011-04-01

    Full Text Available

    Este trabalho tem como objetivo apresentar os (des caminhos que levaram o estado do Paraná a um momento de reformulação em sua grade curricular, levando a saída do Espanhol como componente curricular do Colégio Estadual em Curitiba na década de 1980 e voltando a sua oferta no final da mesma década com a criação do CELEM em todo estado. Por conseguinte, o espanhol vem se solidificando em todo estado do Paraná, após a criação da Lei nº. 11.161 sancionado pelo Presidente Luiz Inácio Lula da Silva, que dispõe sobre o ensino do espanhol como componente curricular obrigatório nas escolas de ensino médio de todo o país.

  9. O primeiro ano de governo de Barack Obama: tempestades à toda volta

    Directory of Open Access Journals (Sweden)

    Eva Paulino Bueno

    2010-02-01

    Full Text Available O primeiro ano de Barak Obama à frente do governo americano foi um ano de grandes dificuldades, não só para ele, mas também para o seu partido democrata. Não só para os democratas, mas também para o povo americano. Não só para o povo americano, mas também para o povo iraquiano, e o povo do Afeganistão. E, por extensão, para todas as pessoas do mundo que ouviram seu discurso de aceitação do cargo, no dia 20 de janeiro de 2009. Os únicos que não sofreram, pelo que pude averiguar ouvindo rádio, lendo jornais e assistindo as notícias, foram os comentaristas republicanos, especialmente os ligados à tropa da cadeia de televisão Fox. Para eles, foi um ano de exultação.  Só não foi melhor porque o país não sofreu um ataque terrorista de

  10. Simultaneous 19F-1H medium resolution NMR spectroscopy for online reaction monitoring

    Science.gov (United States)

    Zientek, Nicolai; Laurain, Clément; Meyer, Klas; Kraume, Matthias; Guthausen, Gisela; Maiwald, Michael

    2014-12-01

    Medium resolution nuclear magnetic resonance (MR-NMR) spectroscopy is currently a fast developing field, which has an enormous potential to become an important analytical tool for reaction monitoring, in hyphenated techniques, and for systematic investigations of complex mixtures. The recent developments of innovative MR-NMR spectrometers are therefore remarkable due to their possible applications in quality control, education, and process monitoring. MR-NMR spectroscopy can beneficially be applied for fast, non-invasive, and volume integrating analyses under rough environmental conditions. Within this study, a simple 1/16″ fluorinated ethylene propylene (FEP) tube with an ID of 0.04″ (1.02 mm) was used as a flow cell in combination with a 5 mm glass Dewar tube inserted into a benchtop MR-NMR spectrometer with a 1H Larmor frequency of 43.32 MHz and 40.68 MHz for 19F. For the first time, quasi-simultaneous proton and fluorine NMR spectra were recorded with a series of alternating 19F and 1H single scan spectra along the reaction time coordinate of a homogeneously catalysed esterification model reaction containing fluorinated compounds. The results were compared to quantitative NMR spectra from a hyphenated 500 MHz online NMR instrument for validation. Automation of handling, pre-processing, and analysis of NMR data becomes increasingly important for process monitoring applications of online NMR spectroscopy and for its technical and practical acceptance. Thus, NMR spectra were automatically baseline corrected and phased using the minimum entropy method. Data analysis schemes were designed such that they are based on simple direct integration or first principle line fitting, with the aim that the analysis directly revealed molar concentrations from the spectra. Finally, the performance of 1/16″ FEP tube set-up with an ID of 1.02 mm was characterised regarding the limit of detection (LOQ (1H) = 0.335 mol L-1 and LOQ (19F) = 0.130 mol L-1 for trifluoroethanol in

  11. O Programa Bolsa Família: lições da experiência alemã

    Directory of Open Access Journals (Sweden)

    Clóvis Roberto Zimmermann

    2009-07-01

    Full Text Available

    Esse artigo tece uma comparação do Bolsa Família com a experiência internacional, argumentando que os programas de transferência de renda brasileiros jamais podem ser visto como “barbaridade”, e de forma alguma “assombram o Brasil”, assim como também não contribuem para manter e tornar operativa a “pobreza brasileira”. Conforme demonstramos no artigo, programas de transferência de renda similares ao Bolsa Família, porém mais justos e generosos, existem em muitos países da Europa, não sendo encarados como “barbaridade”. Além disso, não existe a intenção política de se extinguir tais programas, pois contribuem para reduzir a fome e diminuir consideravelmente os níveis de

  12. Conventional Exergetic and Exergoeconomic Analyses of a Power Plant with Chemical Looping Combustion for CO2 Capture

    Directory of Open Access Journals (Sweden)

    Tatiana Morosuk

    2010-09-01

    Full Text Available

    Exergy-based methods can be used as a tool for examining, comparing and assessing thermodynamic systems. In this paper, an exergoeconomic analysis is used to evaluate a power plant with chemical looping combustion (CLC for CO2 capture. This oxy-fuel plant is compared, from an exergetic and an economic perspective, to a conventional, reference power plant without CO2 capture. The exergetic analysis shows decreased exergy destruction in the CLC reactors, compared to the exergy destruction in the conventional combustion chamber of the reference case; thus, the irreversibilities caused by combustion in the CLC are reduced. However, due to the addition of the CO2 compression unit, the overall exergetic efficiency of the plant with CLC is lower than that of the reference plant by approximately 5 percentage points. The economic analysis confirms a significant increase in the investment cost of the CO2 capture plant, due to the addition of the units for CO2 compression and CLC. Thus, the cost of electricity is 24% higher for this plant in comparison to that of the reference case. Nevertheless, when compared to the reference plant with CO2 capture with monoethanolamine, the plant with CLC was found to be a more economical option. Since CO2 abatement must be realized in the future, given expected environmental or tax measures, CLC provides relatively low cost carbon dioxide capture and it, therefore, appears to be a promising option for

  13. Os perigos da utopia

    Directory of Open Access Journals (Sweden)

    Larry Hufford

    2009-06-01

    Full Text Available

    A utopia pode ter um lado que eleva e um lado sinistro, mas geralmente o lado sinistro acaba destruindo o idealismo inicial. A razão para isto é que os utópicos inevitavelmente adotam uma imagem messiânica do mundo. As três revoluções messiânicas na história—a americana, a francesa e a bolchevique—foram lideradas por homens que pensavem que suas idéias eram universais. Este ensaio examina os escritos do existencialista francês Albert Camus, que argumenta que não existem valores transcendentais, ao mesmo tempo que ele não aceita o niilismo. Camus faz uma distinção entre um rebelde e um revolucionário, e conclui que uma rebelião tentará terminar com uma opressão espedífica, enquanto que uma revolução tentará criar “um novo

  14. Online coupling of pure O{sub 2} thermo-optical methods – {sup 14}C AMS for source apportionment of carbonaceous aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Agrios, Konstantinos [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Salazar, Gary [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Zhang, Yan-Lin; Uglietti, Chiara [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Battaglia, Michael [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Luginbühl, Marc [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Ciobanu, Viorela Gabriela [Paul Scherrer Institute, Villigen (Switzerland); Vonwiller, Matthias [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Szidat, Sönke, E-mail: szidat@dcb.unibe.ch [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland)

    2015-10-15

    This paper reports on novel separation methods developed for the direct determination of {sup 14}C in organic carbon (OC) and elemental carbon (EC), two sub-fractions of total carbon (TC) of atmospheric air particulate matter. Until recently, separation of OC and EC has been performed off-line by manual and time-consuming techniques that relied on the collection of massive CO{sub 2} fractions. We present here two on-line hyphenated techniques between a Sunset OC/EC analyzer and a MICADAS (MIni radioCArbon DAting System) accelerator mass spectrometer (AMS) equipped with a gas ion source. The first implementation facilitates the direct measurement in the low sample size range (<10 μg C) with high throughput on a routine basis, while the second explores the potential for a continuous-flow real-time CO{sub 2} gas feed into the ion source. The performance achieved with reference materials and real atmospheric samples will be discussed to draw conclusions on the improvement offered in the field of {sup 14}C aerosol source apportionment.

  15. Capillary electrophoresis and column chromatography in biomedical chiral amino acid analysis.

    Science.gov (United States)

    Waldhier, Magdalena C; Gruber, Michael A; Dettmer, Katja; Oefner, Peter J

    2009-06-01

    Free amino acids are typically quantified as the sum of their enantiomers, because in terrestrial organisms they mainly exist in the left-handed form. However, with increasing understanding of the biological significance of right-handed amino acids interest in enantioselective quantification of amino acids has steadily increased. Initially, electrophoretic and chromatographic methods using chiral (pseudo)-stationary phases or chiral eluents were applied to the separation of amino acid enantiomers. Later, derivatization of amino acids prior to chromatography with chiral reagents gained in popularity, because the diastereomers formed can be resolved on conventional reversed-phase columns. Novel multi-interaction chiral columns turned attention back to direct chiral chromatographic methods. Hyphenation to mass spectrometry has increasingly replaced optical detection because of superior selectivity, although this has not obviated the need for baseline resolution of amino acid enantiomers. Despite the progress made, enantioselective separation and quantification of amino acids remains an analytical challenge owing to frequently incomplete resolution of all naturally occurring enantiomers and insufficient sensitivity for the determination of the trace amounts of D-amino acids typically found in biological fluids and tissues.

  16. Method for the quantification of vanadyl porphyrins in fractions of crude oils by High Performance Liquid Chromatography-Flow Injection-Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Wandekoken, Flávia G.; Duyck, Christiane B.; Fonseca, Teresa C. O.; Saint'Pierre, Tatiana D.

    2016-05-01

    High performance liquid chromatography hyphenated by flow injection to inductively coupled plasma mass spectrometry (HPLC-FI-ICP-MS) was used to investigate V linked to porphyrins present in fractions of crude oil. First, the crude oil sample was submitted to fractionation by preparative liquid chromatography with UV detection, at the porphyrin Soret band wavelength (400 nm). The obtained porphyrin fractions were then separated in a 250 mm single column, in the HPLC, and eluted with different mobile phases (methanol or methanol:toluene (80:20; v:v)). The quantification of V-porphyrins in the fractions eluted from HPLC was carried out by online measuring the 51V isotope in the ICP-MS, against vanadyl octaethylporphine standard solutions (VO-OEP), prepared in the same solvent as the mobile phase, and injected post-column directly into the plasma. A 20 μg L- 1 Ge in methanol was used as internal standard for minimizing non-spectral interference, such as short-term variations due to injection. The mathematical treatment of the signal based on Fast Fourier Transform smoothing algorithm was employed to improve the precision. The concentrations of V as V-porphyrins were between 2.7 and 11 mg kg- 1 in the fractions, which were close to the total concentration of V in the porphyrin fractions of the studied crude oil.

  17. Automated dispersive liquid-liquid microextraction coupled to high performance liquid chromatography - cold vapour atomic fluorescence spectroscopy for the determination of mercury species in natural water samples.

    Science.gov (United States)

    Liu, Yao-Min; Zhang, Feng-Ping; Jiao, Bao-Yu; Rao, Jin-Yu; Leng, Geng

    2017-04-14

    An automated, home-constructed, and low cost dispersive liquid-liquid microextraction (DLLME) device that directly coupled to a high performance liquid chromatography (HPLC) - cold vapour atomic fluorescence spectroscopy (CVAFS) system was designed and developed for the determination of trace concentrations of methylmercury (MeHg(+)), ethylmercury (EtHg(+)) and inorganic mercury (Hg(2+)) in natural waters. With a simple, miniaturized and efficient automated DLLME system, nanogram amounts of these mercury species were extracted from natural water samples and injected into a hyphenated HPLC-CVAFS for quantification. The complete analytical procedure, including chelation, extraction, phase separation, collection and injection of the extracts, as well as HPLC-CVAFS quantification, was automated. Key parameters, such as the type and volume of the chelation, extraction and dispersive solvent, aspiration speed, sample pH, salt effect and matrix effect, were thoroughly investigated. Under the optimum conditions, linear range was 10-1200ngL(-1) for EtHg(+) and 5-450ngL(-1) for MeHg(+) and Hg(2+). Limits of detection were 3.0ngL(-1) for EtHg(+) and 1.5ngL(-1) for MeHg(+) and Hg(2+). Reproducibility and recoveries were assessed by spiking three natural water samples with different Hg concentrations, giving recoveries from 88.4-96.1%, and relative standard deviations <5.1%.

  18. 2,4-D的毒性与残留检测方法研究进展%A Review on the Toxicity and Residues Determination of 2,4-Dichlorophenoxy

    Institute of Scientific and Technical Information of China (English)

    龚芳; 席俊; 职爱民; 胡骁飞; 邓瑞广; 陆启玉

    2011-01-01

    2,4-二氯苯氧乙酸(2,4 - D)是常用的除草剂和植物生长调节剂,并被广泛应用于提高水果品质和延长保鲜时间,但其毒性和残留问题日益受到人们的重视.为了给2,4-D的检测提供方便,从免疫毒性、生殖毒性及其他毒性方面综述了其毒副作用,简要叙述了其检测方法,如高效液相色谱法、气象色谱法、联用技术、免疫学检测方法等.%2,4-dichlorophenoxy (2,4-D) is a commonly used herbicide and plant growth regulator, widely employed to improve the quality of fruit and prolong their preservation time. But its toxicity and residue problem has attracted increasing attention. In this paper,the side effects of 2,4-D in terms of immunotoxicity,reproductive toxicity and other toxicity were reviewed. Several detection methods of 2,4-D,such as high performance liquid chromatography (HPLC) ,gas chromatography (GO .hyphenated techniques,and immunoassay,are also discussed.

  19. Technologies in quantification of plant polyphenols and its research progress%植物膳食多酚及其定量分析方法的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐维盛; 杨月欣

    2013-01-01

      Plant polyphenols, with complex structures and multiple functions, are a class of plant second-ary metabolites and have been widely used in food because of its activities. This paper reviewed the kinds of plant polyphenols such as tea polyphenol, grape polyphenol, apple polyphenol, pomegranate polyphenol, and algae polyphenols, and the detection methods such as high pressure liquid chromatography, gas chromatogra-phy, high performance capillary electrophoresis, infrared spectroscopy, nuclear magnetic resonance spectros-copy, and some hyphenated techniques to provide a reference for the further study.%  植物多酚是一种植物次生代谢物,其结构多样,具有多种生物活性。本文对近年来研究较多的植物多酚(茶多酚、葡萄多酚、苹果多酚、石榴多酚、海藻多酚)及其定量分析方法(高压液相色谱法、气相色谱法、毛细管电泳法,红外光谱法、核磁共振波谱法及各种联用技术)进行了综述,以期为植物多酚的后续研究提供参考。

  20. Simultaneous analysis of six aristolochic acids and five aristolactams in herbal plants and their preparations by high-performance liquid chromatography-diode array detection-fluorescence detection.

    Science.gov (United States)

    Yuan, Jinbin; Liu, Qian; Zhu, Weifeng; Ding, Li; Tang, Fei; Yao, Shouzhuo

    2008-02-22

    Aristolochic acid analogues, including aristolochic acids (AAs) and aristolactams (ALs), are known to be nephrotoxic, carcinogenic and mutagenic. In this paper, a high-performance liquid chromatography-diode array detection-fluorescence detection (HPLC-DAD-FLD) method was developed for the simultaneous determination of six AAs together with five ALs. Baseline separation was obtained on an ODS C18 analytical column with 0.2% HAc/methanol gradient elution. The hyphenation of DAD and FLD allows the method to directly meet the analysis requirements of most herbal plants with high sensitivity and selectivity. For trace analysis, aristolochic acids were reduced to their corresponding aritstolactams in acidic solution containing iron powder, and then high sensitive detection and quantification were carried out. The method was successfully validated in the matrices of various Aristolochiaceae plants and their preparations. Linearities of around 3-4 orders of magnitude were obtained with correlation coefficients exceeding 0.9970. The detection limits were decreased to 0.2ng/ml. Satisfactory intra-day and inter-day precisions were achieved with RSDs less than 5.74%, and the average recovery factors were in the range of 94.5-99.2%.

  1. Biotransformation and Incorporation into Proteins along a Simulated Terrestrial Food Chain

    Energy Technology Data Exchange (ETDEWEB)

    Unrine, J.M., B.P. Jackson and W.A. Hopkins

    2007-01-01

    Selenium is an essential trace element in vertebrates, but there is a narrow concentration range between dietary requirement and toxicity threshold. Although a great deal is known about the biochemistry of Se from a nutritional perspective, considerably less attention has been focused on the specific biochemistry of Se as an environmental toxicant. Recent advances in hyphenated analytical techniques have provided the capability of quantifying specific chemical forms of Se in biological tissues as well as the distribution of Se among macromolecules. We applied liquid chromatography coupled to inductively coupled plasma mass spectrometry to investigate biotransformations of selenomethionine along a simulated terrestrial food chain consisting of selenomethionine exposed crickets (Acheta domesticus) fed to western fence lizards (Sceloporus occidentalis). Evidence was obtained for selenomethionine biotransformation as well as for sex-specific differences in the metabolism of Se compounds and their subsequent incorporation into proteins in the lizard. The results demonstrate the complexities involved in trophic transfer of Se due to the potential for extensive biotransformation and the species- and even sex-specific nature of these biotransformations.

  2. Immunoaffinity purification of peptide hormones prior to liquid chromatography-mass spectrometry in doping controls.

    Science.gov (United States)

    Thomas, Andreas; Schänzer, Wilhelm; Delahaut, Philippe; Thevis, Mario

    2012-02-01

    For most peptide hormones prohibited in elite sports the concentrations in plasma or urine are very low (pg/mL). Accordingly, hyphenated purification and enrichment steps prior to mass spectrometric detection are required to obtain sufficient doping control assays. Immunoaffinity purification in combination with nano-scale liquid chromatography coupled to high resolution/high accuracy mass spectrometry was found to have the potential of providing the necessary sensitivity and unambiguous specificity to produce reliable results. With the presented methodology 12 prohibited peptides (porcine insulin, Novolog, Apidra, Lantus DesB30-32 metabolite, Humalog and human insulin, Synacthen (synthetic ACTH analogue), luteinizing hormone-releasing hormone (LH-RH), growth hormone releasing hormone (GH-RH(1-29)) and CJC-1295 (GH-RH analogue), LongR(3)-IGF-1 and IFG-1) were simultaneously purified from plasma/serum or urine. With limits of detection for each target compound ranging in the low pg/mL level (urine), the method enables the determination of urinary peptides at physiologically relevant concentrations. For each class of peptides an appropriate antibody and a respective internal standard was implemented ensuring robust analysis conditions. Due to the fast and simple sample preparation procedure (∼25 samples per day) and the fact that all materials are commercial available, the implementation of the methodology to laboratories from other analytical fields (forensics, pharmacokinetic sciences, etc.) is enabled.

  3. Metallomics:An integrated biometal science

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Metallomics is an emerging scientific area integrating the research fields related to the understanding of the molecular mechanisms of metal-associated life processes and the entirety of metal and metalloid species within a cell or tissue type. In metallomics,metalloproteins,metalloenzymes and other metal-containing biomolecules in a biological system are referred to as metallomes,similar to genomes and proteomes in genomics and proteomics,respectively. This review discusses the concept of metallomics with a focus on analytical techniques and methods,particularly the so-called hyphenated techniques which combine a high-resolution separation technique (gel electrophoresis/laser ablation,chromatography or capillary electrophoresis) with a highly sensitive detection method such as elemental (inductively coupled plasma,ICP) or molecular (electron spray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI)) mass spectrometry,or nuclear X-ray fluorescence/absorption spectrometry. The applications of these advanced analytical methods in the identification of metallo-/phospho-/seleno-proteins,probing of relationships between structure and function of metal-loproteins,and study of clinically used metallodrugs will be selectively outlined,along with their advantages and limitations.

  4. 4-hydroxyphenylacetic acid derivatives of inositol from dandelion (Taraxacum officinale) root characterised using LC-SPE-NMR and LC-MS techniques.

    Science.gov (United States)

    Kenny, O; Smyth, T J; Hewage, C M; Brunton, N P; McLoughlin, P

    2014-02-01

    The combination of hyphenated techniques, LC-SPE-NMR and LC-MS, to isolate and identify minor isomeric compounds from an ethyl acetate fraction of Taraxacum officinale root was employed in this study. Two distinct fractions of 4-hydroxyphenylacetic acid derivatives of inositol were isolated and characterised by spectroscopic methods. The (1)H NMR spectra and MS data revealed two groups of compounds, one of which were derivatives of the di-4-hydroxyphenylacetic acid derivative of the inositol compound tetrahydroxy-5-[2-(4-hydroxyphenyl)acetyl] oxycyclohexyl-2-(4-hydroxyphenyl) acetate, while the other group consisted of similar tri-substituted inositol derivatives. For both fractions the derivatives of inositols vary in the number of 4-hydroxyphenylacetic acid groups present and their position and geometry on the inositol ring. In total, three di-substituted and three tri-substituted 4-hydroxyphenylacetic acid inositol derivates were identified for the first time along with a further two previously reported di-substituted inositol derivatives.

  5. Sulfur analysis by inductively coupled plasma-mass spectrometry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Giner Martínez-Sierra, J.; Galilea San Blas, O.; Marchante Gayón, J.M.; García Alonso, J.I., E-mail: jiga@uniovi.es

    2015-06-01

    In recent years the number of applications of sulfur (S) analysis using inductively coupled plasma mass spectrometry (ICP-MS) as detector has increased significantly. In this article we describe in some depth the application of ICP-MS for S analysis with emphasis placed on the sulfur-specific detection by hyphenated techniques such as LC, GC, CE and LA coupled on-line to ICP-MS. The different approaches available for sulfur isotope ratio measurements by ICP-MS are also detailed. Particular attention has been paid to the quantification of peptides/proteins and the analysis of metallopeptides/metalloproteins via sulfur by LC–ICP-MS. Likewise, the speciation analysis of metal-based pharmaceuticals and metallodrugs and non-metal selective detection of pharmaceuticals via S are highlighted. Labeling procedures for metabolic applications are also included. Finally, the measurement of natural variations in S isotope composition with multicollector ICP-MS instruments is also covered in this review. - Highlights: • Emphasis placed on the sulfur-specific detection by chromatographic techniques coupled on-line to ICP-MS. • Different instrumental approaches available for sulfur measurements by ICP-MS. • Quantification of proteins and the analysis of metalloproteins via sulfur by LC-ICP-MS. • Labelling procedures for metabolic applications are also included. • The measurement of natural variations in S isotope composition with multicollector ICP-MS.

  6. Sol-gel microextraction phases for sample preconcentration in chromatographic analysis.

    Science.gov (United States)

    Segro, Scott S; Tran, Minh Phuong; Kesani, Sheshanka; Alhendal, Abdullah; Turner, Erica B

    2010-10-01

    Sol-gel technology provides a simple and reliable method for solid-phase microextraction (SPME) fiber preparation through in situ creation of surface-bonded organic-inorganic hybrid coatings characterized by enhanced thermal stability and solvent-resistance properties that are important for the coupling of SPME with GC and HPLC, respectively. The sol-gel coating technology has led to the development of an extensive array of sol-gel sorbent coatings for SPME. In this article, sol-gel microextraction coatings are reviewed, with particular attention on their synthesis, characterization, and applications in conjunction with GC and HPLC analyses. In addition, the development of sol-gel-coated stir bars, their inherent advantages, and applications are discussed. Next, the development and applications of sol-gel capillary microextraction (CME) in hyphenation with GC and HPLC is extensively reviewed. The newly emerging germania- and titania-based sol-gel microextraction phases look promising, especially in terms of pH and hot solvent stability. Finally, sol-gel monolithic beds for CME are reviewed. Such monolithic beds are in a position to greatly improve the extracting capabilities and enhanced sensitivity in CME.

  7. Using sheath-liquid reagents for capillary electrophoresis-mass spectrometry: application to the analysis of phenolic plant extracts.

    Science.gov (United States)

    Maringer, Leila; Ibáñez, Elena; Buchberger, Wolfgang; Klampfl, Christian W; Causon, Tim J

    2015-01-01

    The combination of CE and MS is now a widely used tool that can provide a combination of high resolution separations with detailed structural information. Recently, we highlighted the benefits of an approach to add further functionality to this well-established hyphenated technique, namely the possibility to perform chemical reactions within the sheath-liquid of the CE-MS interface . Apart from using hydrogen/deuterium exchange for online determination of numbers of exchangeable protons, the addition of DPPH• (2,2-diphenyl-1-picrylhydrazyl) to the sheath-liquid can be used as a fast screening tool for studying antioxidant characteristics of individual components. Such a CE-MS methodology allows rapid and information-rich analysis with minimal reagent and sample consumption to be performed. In the present work, we demonstrate the applicability of this approach for the characterization of phenolic plant extracts from the Labiatae family, namely Rosmarinus officinalis and Melissa officinalis. Using the described approach, a wide range of compounds (15 and 13 phenolic compounds, respectively) could be confidently identified using a combination of high resolution CE-MS separations with implementation of online deuterium exchange and DPPH• reactions. These compounds included polyphenols, phenolic acids, and triterpene acids. In conjunction with online MS/MS experiments, extensive structural information for aglyconic and glycosylated antioxidants present in the extracts could be obtained using simple experimental changes, which can be carried out prior to the purchasing of expensive chemical standards or the time-consuming preparative isolation of individual compounds.

  8. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  9. Chemical analysis applied to the radiation sterilization of solid ketoprofen

    Science.gov (United States)

    Colak, S.; Maquille, A.; Tilquin, B.

    2006-01-01

    The aim of this work is to investigate the feasibility of radiation sterilization of ketoprofen from a chemical point of view. Although irradiated ketoprofen has already been studied in the literature [Katusin-Razem et al., Radiat. Phys. Chem. 73 111-116 (2005)], new results, on the basis of electron spin resonance (ESR) measurements and the use of hyphenated techniques (GC-MS and LC-MS), are obtained. The ESR spectra of irradiated ketoprofen consists of four unresolved resonance peaks and the mean G-value of ketoprofen is found to be 4 +/- 0.9 nmoles/J, which is very small. HPLC-UV analyses indicate that no significant loss of ketoprofen is detected after irradiation. LC-MS-MS analyses show that the structures of the non-volatile final products are similar to ketoprofen. Benzaldehyde is detected in the irradiated samples after dynamic-extraction GC-MS. The analyses show that ketoprofen is radioresistant and therefore might be radiosterilized.

  10. Current and Future Perspectives on the Structural Identification of Small Molecules in Biological Systems

    Directory of Open Access Journals (Sweden)

    Daniel A. Dias

    2016-12-01

    Full Text Available Although significant advances have been made in recent years, the structural elucidation of small molecules continues to remain a challenging issue for metabolite profiling. Many metabolomic studies feature unknown compounds; sometimes even in the list of features identified as “statistically significant” in the study. Such metabolic “dark matter” means that much of the potential information collected by metabolomics studies is lost. Accurate structure elucidation allows researchers to identify these compounds. This in turn, facilitates downstream metabolite pathway analysis, and a better understanding of the underlying biology of the system under investigation. This review covers a range of methods for the structural elucidation of individual compounds, including those based on gas and liquid chromatography hyphenated to mass spectrometry, single and multi-dimensional nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry and includes discussion of data standardization. Future perspectives in structure elucidation are also discussed; with a focus on the potential development of instruments and techniques, in both nuclear magnetic resonance spectroscopy and mass spectrometry that, may help solve some of the current issues that are hampering the complete identification of metabolite structure and function.

  11. Field-flow fractionation: An efficient approach for matrix removal of soil extract for inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    Sangsawong, Supharart; Waiyawat, Weerawan; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2011-06-01

    An on-line coupling between a continuous-flow sequential extraction (CFSE) unit and flow field-flow fractionation with cross flow matrix removal (FlFFF/CFM) with ICP-OES detection was developed for determination of metal leachability from soil. The use of high concentration of Mg(NO 3) 2 in exchangeable phase can cause undesirable matrix effects by shifting ionization equilibrium in the plasma, etc., resulting in a clear need for matrix removal. Therefore, the capability of FlFFF/CFM to remove Mg matrix ion from soil extract was evaluated. Poly(ethylene imine) (PEI) having molecular weight of 25,000 Da was added to form complexes with analyte elements (Cu, Mn, Pb, and Zn) but not the matrix element (Mg). The free Mg matrix ions were then removed by filtering off through the ultrafiltration membrane, having a 1000-Da molecular weight cut-off, inside the FlFFF channel. With the use of FlFFF/CFM, matrix removal efficiency was approximately 83.5%, which was equivalent to approximately 6-fold dilution of the matrix ion. The proposed hyphenated system of CFSE and FlFFF/CFM with ICP-OES detection was examined for its reliability by checking with SRM 2710 (a highly contaminated soil from Montana). The metal contents determined by the proposed method were not significantly different (at 95% confidence) from the certified values.

  12. Recent trends in the impurity profile of pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Kavita Pilaniya

    2010-01-01

    Full Text Available Various regulatory authorities such as the International Conference on Harmonization (ICH, the United States Food and Drug administration (FDA, and the Canadian Drug and Health Agency (CDHA are emphasizing on the purity requirements and the identification of impurities in Active Pharmaceutical Ingredients (APIs. The various sources of impurity in pharmaceutical products are - reagents, heavy metals, ligands, catalysts, other materials like filter aids, charcoal, and the like, degraded end products obtained during \\ after manufacturing of bulk drugs from hydrolysis, photolytic cleavage, oxidative degradation, decarboxylation, enantiomeric impurity, and so on. The different pharmacopoeias such as the British Pharmacopoeia, United State Pharmacopoeia, and Indian Pharmacopoeia are slowly incorporating limits to allowable levels of impurities present in APIs or formulations. Various methods are used to isolate and characterize impurities in pharmaceuticals, such as, capillary electrophoresis, electron paramagnetic resonance, gas-liquid chromatography, gravimetric analysis, high performance liquid chromatography, solid-phase extraction methods, liquid-liquid extraction method, Ultraviolet Spectrometry, infrared spectroscopy, supercritical fluid extraction column chromatography, mass spectrometry, Nuclear magnetic resonance (NMR spectroscopy, and RAMAN spectroscopy. Among all hyphenated techniques, the most exploited techniques for impurity profiling of drugs are Liquid Chromatography (LC-Mass Spectroscopy (MS, LC-NMR, LC-NMR-MS, GC-MS, and LC-MS. This reveals the need and scope of impurity profiling of drugs in pharmaceutical research.

  13. Gas Chromatography Coupled to Atmospheric Pressure Chemical Ionization FT-ICR Mass Spectrometry for Improvement of Data Reliability.

    Science.gov (United States)

    Schwemer, Theo; Rüger, Christopher P; Sklorz, Martin; Zimmermann, Ralf

    2015-12-15

    Atmospheric pressure chemical ionization (APCI) offers the advantage of molecular ion information with low fragmentation. Hyphenating APCI to gas chromatography (GC) and ultrahigh resolution mass spectrometry (FT-ICR MS) enables an improved characterization of complex mixtures. Data amounts acquired by this system are very huge, and existing peak picking algorithms are usually extremely time-consuming, if both gas chromatographic and ultrahigh resolution mass spectrometric data are concerned. Therefore, automatic routines are developed that are capable of handling these data sets and further allow the identification and removal of known ionization artifacts (e.g., water- and oxygen-adducts, demethylation, dehydrogenation, and decarboxylation). Furthermore, the data quality is enhanced by the prediction of an estimated retention index, which is calculated simply from exact mass data combined with a double bond equivalent correction. This retention index is used to identify mismatched elemental compositions. The approach was successfully tested for analysis of semivolatile components in heavy fuel oil and diesel fuel as well as primary combustion particles emitted by a ship diesel research engine. As a result, 10-28% of the detected compounds, mainly low abundant species, classically assigned by using only the mass spectrometric information, were identified as not valid and removed. Although GC separation is limited by the slow acquisition rate of the FT-ICR MS (information.

  14. Some guidelines for the analysis of genomic DNA by PCR-LC-ESI-MS.

    Science.gov (United States)

    Oberacher, Herbert; Niederstätter, Harald; Casetta, Bruno; Parson, Walther

    2006-02-01

    Ion-pair reversed-phase high-performance liquid chromatography online hyphenated to electrospray ionization mass spectrometry (ICEMS) represents an efficient method for the characterization of nucleic acids amplified by polymerase chain reaction (PCR). Since sample preparation is limited to PCR, the optimization of its solution conditions is of utmost importance for efficient mass spectrometric detection. The compatibility of a number of different commercially available PCR components including DNA polymerases, deoxynucleotide triphosphates, bovine serum albumin, enhancer, and ionic buffers was evaluated. These experiments revealed that higher concentration of enhancer and detergents such as Tween-20 or Nonidet P-40 impairs the mass spectrometric detection of nucleic acids and should be avoided within the PCR mixture. The optimized analytical platform was applied to the characterization of PCR products covering parts of the first hypervariable region of the noncoding mitochondrial control region. Truncated amplicons were detected attributable to the use of low quality primers. Furthermore, due to the proofreading activity of the applied polymerase system, mismatches between the primer and the target sequence located at the last or the second last base at the 3'-end of primers were corrected and detected within the corresponding amplicons.

  15. In-time and in-space tandem mass spectrometry to determine the metabolic profiling of flavonoids in a typical sweet cherry (Prunus avium L.) cultivar from Southern Italy.

    Science.gov (United States)

    Crupi, Pasquale; Genghi, Rosalinda; Antonacci, Donato

    2014-10-01

    This paper presents a comprehensive analytical methodology, based on 'in-time' and 'in-space' tandem mass spectrometry (MS) techniques, to identify and quantify flavonoid compounds in a typical Italian sweet cherry cultivar (cv. Ferrovia). Five anthocyanins, four flavan-3-ols and nine flavonols were determined by means of hyphenated high-performance liquid chromatography - multi-stage MS (HPLC-MS(n)) analyses (MS(n) up to MS(4)), among which quercetin-3-O-rutinoside-7-O-glucoside, kaempferol-3-O-rutinoside-7-O-glucoside, quercetin-3-O-galactosyl-rhamnoside and quercetin-3-O-coumaroylglucoside were tentatively identified in sweet cherries for the first time. Ultrafast HPLC and tandem MS (UHPLC-MS/MS) analyses through multiple reaction monitoring experiments showed that cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside were the main anthocyanins of cv. Ferrovia at maturity. Moreover, consistent levels of catechin and epicatechin as well as quercetin-3-O-rutinoside and kaempferol-3-O-rutinoside were also found. Because flavonoids have been ascribed as potential health-promoting compounds, gathered findings provide new insight into the knowledge of the quali-quantitative profile of these phytochemicals into a widespread fruit such as sweet cherry.

  16. Identification and determination of phase II nabumetone metabolites by high-performance liquid chromatography with photodiode array and mass spectrometric detection.

    Science.gov (United States)

    Nobilis, M; Holcapek, M; Kolárová, L; Kopecký, J; Kunes, M; Svoboda, Z; Kvetina, J

    2004-03-26

    Chromatographic analyses play an important role in the identification and determination of phase I and phase II drug metabolites. While the chemical standards of phase I metabolites are usually available from commercial sources or by various synthetic, degradation or isolation methods, the phase II drug metabolites have usually more complicated structures, their standards are in general inaccessible and their identification and determination require a comprehensive analytical approach involving the use of xenobiochemical methods and the employment of hyphenated analytical techniques. In this work, various high-performance liquid chromatography (HPLC) methods were employed in the evaluation of xenobiochemical experiments leading to the identification and determination of phase II nabumetone metabolites. Optimal conditions for the quantitative enzymatic deconjugation of phase II metabolites were found for the samples of minipig bile, small intestine contents and urine. Comparative HPLC analyses of the samples of above-mentioned biomatrices and of the same biomatrices after their enzymatic treatment using beta-glucuronidase and arylsulfatase afforded the qualitative and quantitative information about phase II nabumetone metabolites. Hereby, three principal phase II nabumetone metabolites (ether glucuronides) were discovered in minipig's body fluids and their structures were confirmed using liquid chromatography (LC)-electrospray ionization mass spectrometric (MS) analyses.

  17. On-line two-dimensional capillary electrophoresis with mass spectrometric detection using a fully electric isolated mechanical valve.

    Science.gov (United States)

    Kohl, Felix J; Montealegre, Cristina; Neusüß, Christian

    2016-04-01

    CE is becoming more and more important in many fields of bioanalytical chemistry. Besides optical detection, hyphenation to ESI-MS detection is increasingly applied for sensitive identification purposes. Unfortunately, many CE techniques and methods established in research and industry are not compatible to ESI-MS since essential components of the background electrolyte interfere in ES ionization. In order to identify unknown peaks in established CE methods, here, a heart-cut 2D-CE separation system is introduced using a fully isolated mechanical valve with an internal loop of only 20 nL. In this system, the sample is separated using potentially any non-ESI compatible method in the first separation dimension. Subsequently, the portion of interest is cut by the internal sample loop of the valve and reintroduced to the second dimension where the interfering compounds are removed, followed by ESI-MS detection. When comparing the separation efficiency of the system with the valve to a system using a continuous capillary only a slight increase in peak width is observed. Ultraviolet/visible detection is integrated in the first dimension for switching time determination, enabling reproducible cutting of peaks of interest. The feasibility of the system is successfully demonstrated by a 2D analysis of a BSA tryptic digest sample using a nonvolatile (phosphate based) background electrolyte in the first dimension.

  18. Atmospheric pressure gas chromatography coupled to quadrupole-time of flight mass spectrometry as a tool for identification of volatile migrants from autoadhesive labels used for direct food contact.

    Science.gov (United States)

    Canellas, Elena; Vera, Paula; Nerín, Cristina

    2014-11-01

    Pressure-sensitive adhesives (PSA) are used to manufacture labels that are applied directly on the food. These adhesives could contain not only intentionally added compounds (IAS) to the adhesive formula but also non-intentionally added substances (NIAS), due to the impurities from the raw materials used, decomposition of the initial components or from chemical interactions between them. These compounds could migrate to the food and contaminate it. In this study, gas chromatography coupled with mass spectrometry (GC-MS/Q) and atmospheric pressure gas chromatography coupled to a quadrupole hyphenated to a time of flight mass spectrometer (APGC-MS/Q-TOF) have been used for identification of unknown compounds and NIAS coming from a PSA. Seven compounds were identified by GC-MS/Q, and other eight compounds remained initially unknown. The structure of these eight new compounds was elucidated by working with the spectra obtained by APGC-MS/Q-TOF. Finally, two different migration studies were carried out. The first one with Tenax as solid food simulant in contact with the paper label containing the adhesive and the second one with isooctane filled in a natural pork intestine where the label containing the adhesive was applied on the external side. The results are shown and discussed.

  19. Sb(V reactivity with human blood components: redox effects.

    Directory of Open Access Journals (Sweden)

    Silvana López

    Full Text Available We assessed the reactivity of Sb(V in human blood. Sb(V reactivity was determined using an HPLC-HG-AFS hyphenated system. Sb(V was partially reduced to Sb(III in blood incubation experiments; however, Sb(III was a highly unstable species. The addition of 0.1 mol L(-1 EDTA prevented Sb(III oxidation, thus enabling the detection of the reduction of Sb(V to Sb(III. The transformation of Sb(V to Sb(III in human whole blood was assessed because the reduction of Sb(V in human blood may likely generate redox side effects. Our results indicate that glutathione was the reducing agent in this reaction and that Sb(V significantly decreased the GSH/GSSG ratio from 0.32 ± 0.09 to 0.07 ± 0.03. Moreover, the presence of 200 ng mL(-1 of Sb(V increased the activity of superoxide dismutase from 4.4 ± 0.1 to 7.0 ± 0.4 U mL(-1 and decreased the activity of glutathione peroxidase from 62 ± 1 to 34 ± 2 nmol min(-1 mL(-1.

  20. A educação cooperativa numa perspectiva marxista

    Directory of Open Access Journals (Sweden)

    Antonio Inacio Andrioli

    2009-12-01

    Full Text Available

  1. Tracing gadolinium-based contrast agents from surface water to drinking water by means of speciation analysis.

    Science.gov (United States)

    Birka, Marvin; Wehe, Christoph A; Hachmöller, Oliver; Sperling, Michael; Karst, Uwe

    2016-04-01

    In recent decades, a significant amount of anthropogenic gadolinium has been released into the environment as a result of the broad application of contrast agents for magnetic resonance imaging (MRI). Since this anthropogenic gadolinium anomaly has also been detected in drinking water, it has become necessary to investigate the possible effect of drinking water purification on these highly polar microcontaminats. Therefore, a novel highly sensitive method for speciation analysis of gadolinium is presented. For that purpose, the hyphenation of hydrophilic interaction liquid chromatography (HILIC) and inductively coupled plasma-mass spectrometry (ICP-MS) was employed. In order to enhance the detection power, sample introduction was carried out by ultrasonic nebulization. In combination with a novel HILIC method using a diol-based stationary phase, it was possible to achieve superior limits of detection for frequently applied gadolinium-based contrast agents below 20pmol/L. With this method, the contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A were determined in concentrations up to 159pmol/L in samples from several waterworks in a densely populated region of Germany alongside the river Ruhr as well as from a waterworks near a catchment lake. Thereby, the direct impact of anthropogenic gadolinium species being present in the surface water on the amount of anthropogenic gadolinium in drinking water was shown. There was no evidence for the degradation of contrast agents, the release of Gd(3+) or the presence of further Gd species.

  2. Elemental speciation of neptunium in ultra trace amount ranges; Elementspeziation von Neptunium im Ultraspurenbereich

    Energy Technology Data Exchange (ETDEWEB)

    Stoebener, Nils

    2013-06-25

    In the presented work, the detection of the isotope Np-237 with resonance ionization mass spectrometry (RIMS) was developed and optimized. In RIMS, sample atoms are excited and ionized with laser radiation in several, resonant steps and are subsequently detected by a mass spectrometer. Energy levels suitable for the excitation and ionization of Np-237 were identified using resonance ionization spectroscopy (RIS). With RIS, more than 300 previously unknown electronic states and autoionizing resonances of Np-237 were identified. Using in-source-RIMS, a limit of detection of 9E+5 atoms was demonstrated for the isotope. The mobility of Np in the environment strongly depends on its elemental speciation. Therefore, safety assessments of proposed nuclear waste repositories require analytical methods for the detection of Np species. CE (capillary electrophoresis) was hyphenated to ICP-MS (inductively coupled plasma mass spectrometry) to examine the distribution of the Np redox species Np(IV) and Np(V), which was possible at Np concentrations as low as 1E-9 mol/L. The method was used to study the interaction of the element with Opalinus Clay at varying conditions. CE-ICP-MS revealed, that under the presence of Fe(II), Np(V) is reduced to Np(IV), which is sorbed onto the clay. This leads to a higher overall Np sorption.

  3. In-capillary approach to eliminate SDS interferences in antibody analysis by capillary electrophoresis coupled to mass spectrometry.

    Science.gov (United States)

    Sánchez-Hernández, Laura; Montealegre, Cristina; Kiessig, Steffen; Moritz, Bernd; Neusüß, Christian

    2016-12-23

    Capillary electrophoresis is an important technique for the characterization of monoclonal antibodies (mAbs), especially in the pharmaceutical context. However, identification is difficult as upscaling and hyphenation of used methods directly to mass spectrometry is often not possible due to separation medium components that are incompatible with MS detection. Here a CE-MS method for the analysis of mAbs is presented analyzing SDS-complexed samples. To obtain narrow and intensive peaks of SDS-treated antibodies, an in-capillary strategy was developed based on the co-injection of positively charged surfactants and methanol as organic solvent. For samples containing 0.2% (v/v) of SDS, recovered MS peak intensities up to 97 and 95% were achieved using cetyltrimethylammonium bromide or benzalkonium chloride, respectively. Successful removal of SDS was shown in neutral coated capillaries but also in a capillary with a positively charged coating applying reversed polarity. The usefulness of this in-capillary strategy was demonstrated also for other proteins and for antibodies dissolved in up to 10% v/v SDS solution, and in other SDS-containing matrices, including the sieving matrix used in a standard CE-SDS method and gel-buffers applied in SDS-PAGE methods. The developed CE-MS approaches enable fast and reproducible characterization of SDS-complexed antibodies.

  4. Trace Elements Analysis of Geological Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes recent work applying a taser ablation system (LSX-200) hyphenated with POEMS Ⅲ inductively coupled plasma mass spectrometry (LA-ICP-MS) for the in situ analysis of 22 trace elements of solid geological materials. It demonstrates the potential of LA-ICP-MS for the determination of geochemically important trace and ultra-trace elements following XRF routine sample preparation. Signal drift, difference in transport efficiency and sampling yield are well corrected with NIST SRM 612 as external calibration standard and Ca as internal standard. The obtained results agree to the recommended values with relative error better than 15 % and RSD less than 15 % for most determined trace elemems. LOD ranges from 0.021 × 10-6 to 0. 23 × 10-6 and less than 0.10 × 10-6 for majority trace elements determined. In addition, home-made macro functions including filter and calculator compiled by VBA language under Excel software greatly enhanced off-line data reduction efficiency.``

  5. Introduction to engineering electromagnetics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeon Ho [Sungkyunkwan Univ., Kyongkido (Korea, Republic of). School of Information and Communication Engineering

    2013-11-01

    This book provides students with the missing link that can help them master the basic principles of electromagnetics. The concept of vector fields is introduced by starting with clear definitions of position, distance, and base vectors. The symmetries of typical configurations are discussed in detail, including cylindrical, spherical, translational, and two-fold rotational symmetries. To avoid serious confusion between symbols with two indices, the text adopts a new notation: a letter with subscript 1-2 for the work done in moving a unit charge from point 2 to point 1, in which the subscript 1-2 mimics the difference in potentials, while the hyphen implies a sense of backward direction, from 2 to 1. This book includes 300 figures in which real data are drawn to scale. Many figures provide a three-dimensional view. Each subsection includes a number of examples that are solved by examining rigorous approaches in steps. Each subsection ends with straightforward exercises and answers through which students can check if they correctly understood the concepts. A total 350 of examples and exercises are provided. At the end of each section, review questions are inserted to point out key concepts and relations discussed in the section. They are given with hints referring to the related equations and figures. The book contains a total of 280 end-of-chapter problems.

  6. XPS和TOF-SIMS在硬盘驱动器(HDD)磁头表面微污染分析中的应用%XPS AND TOF-SIMS ANALYSIS OF MICRO-CONTAMINATION ON THE SURFACE OF MAGNETIC HEAD

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    XPS和TOF-SIMS表面分析仪器联用分析磁头臂焊接位表面有机微污染物成分,找出 污染物的来源;XPS能够提供污染物中元素组成及价态信息,而TOF-SIMS能够提供其分子信息。试验证明两者联用是分析表面有机微污染物强有力的手段。%The analysis of micro organic contamination on the surface of magnetic head by XPS and TOFSIMS is described in this paper. The informations of the composing elements and their valency states are obtained by XPS, and of the molecular structures by TOF-SIMS. The analytical results obtained proved that the hyphenation of XPS and TOF-SIMS is a very effective method for the surface ro-contamination analysis and searching for the sources of the contamination in the data storage industry.

  7. 新型水处理剂高铁酸钾的制备及应用研究%Progress of Preparation and Application of Potassium Ferrate in Water Treatment

    Institute of Scientific and Technical Information of China (English)

    李元昊; 丁忠浩

    2011-01-01

    Potassium ferrate is a efficient multipurpose water treatment agent with the novel properties of the oxidation, oxidation, adsorption, flocculation, coagulation, disinfection, and deodorization. This paper describes the preparation, features of potassium ferrateand, and the application in water treatment,its reaction mechanism was also discussed. Also, the suggestions and prospects are proposed for study on the practial and hyphenated techniques.%指出了高铁酸钾是一种集氧化、吸附、絮凝、助凝、杀菌、除臭为一体的新型高效多功能水处理剂,阐述了高铁酸钾的制备、特性以及在污水处理中的应用特点,对其反应机理进行了探讨,展望了研究其高效、低耗、联用技术的十分广阔的开发前景。

  8. 科技名词汉语拼音难点探析--以《两岸科技常用词典》为例%The Exploration on Difficulties in the Chinese Phonetic Alphabet of Scientific Terms:Case Study of The Cross-straits Common Dictionary on Science & Technology

    Institute of Scientific and Technical Information of China (English)

    杜翔; 李志江

    2015-01-01

    According to Basic Rules of Chinese Pinyin Orthography, about 19 500 terms of proper nouns are listed in The Cross-straits Common Dictionary on Science & Technology. The paper explores the difficult points when giving the Pinyin form, such as integrity of concept, combining or not, hyphen use, etc. , explains how to tackle these problems, and shows thinking and evidence of the approach.%《两岸科技常用词典》根据《汉语拼音正词法基本规则》,给出了19500条科技名词的拼写形式。重点探析了科技名词拼写中概念整体性、分连写、连接号使用等方面的难点,交代了处理这些难点的具体方法,并阐明之所以这样处理的思路和依据。

  9. Application of Modern Instrumental Analyses in Glass Fiber Industry%现代仪器分析在玻璃纤维检测中的应用

    Institute of Scientific and Technical Information of China (English)

    王玲

    2014-01-01

    Modern instrumental analyses have advantages of high sensitivity,good selectivity,low detection limit and good accuracy,which provide important means for the qualitative,quantitative and morphological analyses of glass fi-ber raw materials and products. The types,characteristics and functions of commonly-used modern instrumental ana-lyses,as well as the analyses of glass compositions,element valence forms and trace elements in complex samples, are discussed in this paper. Finally,the prospects of hyphenating technology and automation of modern instrumental analyses are predicted.%现代仪器分析灵敏度高,选择性好,检出限低,准确性好,为玻璃纤维原料及制品的定性、定量及形态分析提供了重要的测试手段。作者阐述了常用的现代仪器分析的种类、特性、作用,分析讨论了成分分析、元素价态形态分析、复杂样品的痕量分析在玻璃纤维检测中的应用,最后介绍了现代分析仪器在仪器联用、自动化方面的前景。

  10. Construction of a new interface for comprehensive supercritical fluid chromatography x reversed phase liquid chromatography (SFC x RPLC).

    Science.gov (United States)

    François, Isabelle; Pereira, Alberto dos Santos; Lynen, Frédéric; Sandra, Pat

    2008-10-01

    The design of a new interface to hyphen high efficiency supercritical fluid chromatography (SFC) and fast RPLC in a comprehensive configuration is described. SFC x RPLC is a viable alternative to normal phase (NP) LC x RPLC and is characterized by high orthogonality. Compared to NPLC x RPLC an additional advantage is the expansion of supercritical carbon dioxide (CO(2)) when exposed to atmospheric pressure leading to fractions consisting of solvents that are miscible with the second dimension RPLC mobile phase. The interface consists of a two-position/ten-port switching valve equipped with two packed octadecyl silica (C(18)) loops for effective trapping and focusing of the analytes after elution from the SFC dimension. The addition of a water make-up flow to the SFC effluent prior to entering the loops is of fundamental importance to efficiently focus the solutes on the C(18) material and to reduce interferences of expanded CO(2) gas on the second dimension separation. The features of the system are illustrated with the analysis of a lemon oil sample.

  11. Characterization and Quantification of Compounds in the Hydroalcoholic Extract of the Leaves from Terminalia catappa Linn. (Combretaceae) and Their Mutagenic Activity.

    Science.gov (United States)

    Mininel, Francisco José; Leonardo Junior, Carlos Sérgio; Espanha, Lívia Greghi; Resende, Flávia Aparecida; Varanda, Eliana Aparecida; Leite, Clarice Queico Fujimura; Vilegas, Wagner; Dos Santos, Lourdes Campaner

    2014-01-01

    Terminalia is a genus of Combretaceous plants widely distributed in tropical and subtropical regions. Thus, the aim of this study was to quantify the majority compounds of the hydroalcoholic extract (7 : 3, v/v) of the leaves from T. catappa by HPLC-PDA, chemically characterize by hyphenated techniques (HPLC-ESI-IT-MS(n)) and NMR, and evaluate its mutagenic activity by the Salmonella/microsome assay on S. typhimurium strains TA98, TA97a, TA100, and TA102. The quantification of analytes was performed using an external calibration standard. Punicalagin is the most abundant polyphenol found in the leaves. The presence of this compound as a mixture of anomers was confirmed using HPLC-PDA and (1)H and (13)C NMR. Mutagenic activity was observed in strains TA100 and TA97a. As the extract is a complex mixture of punicalagin, its derivatives, and several other compounds, the observed mutagenicity may be explained in part by possible synergistic interaction between the compounds present in the extract. These studies show that mutagenic activity of T. catappa in the Ames test can only be observed when measured at high concentrations. However, considering the mutagenic effects observed for T. catappa, this plant should be used cautiously for medicinal purposes.

  12. Identification of marker compounds in herbal drugs on TLC with DART-MS.

    Science.gov (United States)

    Kim, Hye Jin; Jee, Eun Hye; Ahn, Kwang Sung; Choi, Hyo Sook; Jang, Young Pyo

    2010-09-01

    This study was conducted to provide a more versatile and specific information on Thin Layer Chromatographic (TLC) analysis of medicinal plants. TLC plates developed with the extract of herbal medicines were analyzed with direct analysis in real time (DART) ion source. Three well known herbal drugs were extracted and developed on a silica-coated TLC plate with the conditions pre-established in Korean Pharmacopoeia IX. The developed plate was placed between the DART ion source and TOF-MS analyzer to get real time mass spectra from the bands on the TLC plate directly. The marker coumarin compounds, decursin and decursinol were successfully identified from the TLC plate developed with Angelicae gigantis radix, along with alkaloid compounds of rutaecarpine and evodiamine from Evodiae fructus, and lignan molecules of gomisin A, N, and schisandrin from Schisandrae fructus. This hyphenation system of TLC and DART-MS could provide unique and specific information on the major constituents of crude plant drug on TLC through uncovering high resolution mass number of each band on the TLC plate directly in real time.

  13. Analytical methods for the endocrine disruptor compounds determination in environmental water samples.

    Science.gov (United States)

    Locatelli, Marcello; Sciascia, Francesco; Cifelli, Roberta; Malatesta, Luciano; Bruni, Pantaleone; Croce, Fausto

    2016-02-19

    The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples.

  14. Highly efficient peptide separations in proteomics Part 1. Unidimensional high performance liquid chromatography.

    Science.gov (United States)

    Sandra, Koen; Moshir, Mahan; D'hondt, Filip; Verleysen, Katleen; Kas, Koen; Sandra, Pat

    2008-04-15

    Sample complexity and dynamic range constitute enormous challenges in proteome analysis. The back-end technology in typical proteomics platforms, namely mass spectrometry (MS), can only tolerate a certain complexity, has a limited dynamic range per spectrum and is very sensitive towards ion suppression. Therefore, component overlap has to be minimized for successful mass spectrometric analysis and subsequent protein identification and quantification. The present review describes the advances that have been made in liquid-based separation techniques with focus on the recent developments to boost the resolving power. The review is divided in two parts; the first part deals with unidimensional liquid chromatography and the second part with bi- and multidimensional liquid-based separation techniques. Part 1 mainly focuses on reversed-phase HPLC due to the fact that it is and will, in the near future, remain the technique of choice to be hyphenated with MS. The impact of increasing the column length, decreasing the particle diameter, replacing the traditional packed beds by monolithics, amongst others, is described. The review is complemented with data obtained in the laboratories of the authors.

  15. Biogenic nanoparticles bearing antibacterial activity and their synergistic effect with broad spectrum antibiotics: Emerging strategy to combat drug

    Directory of Open Access Journals (Sweden)

    Syed Baker

    2017-01-01

    Full Text Available The present study emphasizes on synthesis of bimetallic silver–gold nanoparticles from cell free supernatant of Pseudomonas veronii strain AS41G inhabiting Annona squamosa L. The synthesized nanoparticles were characterized using hyphenated techniques with UV–Visible spectra ascertained absorbance peak between 400 and 800 nm. Possible interaction of biomolecules in mediating and stabilization of nanoparticles was depicted with Fourier transform infrared spectroscopy (FTIR. X-ray diffraction (XRD displayed Bragg’s peak conferring the 100, 111, 200, and 220 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Size and shape of the nanoparticles were determined using Transmission electron microscopy (TEM microgram with size ranging from 5 to 50 nm forming myriad shapes. Antibacterial activity of nanoparticles against significant human pathogens was conferred with well diffusion assay and its synergistic effect with standard antibiotics revealed 87.5% fold increased activity with antibiotic “bacitracin” against bacitracin resistant strains Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae followed by kanamycin with 18.5%, gentamicin with 11.15%, streptomycin with 10%, erythromycin with 9.7% and chloramphenicol with 9.4%. Thus the study concludes with biogenic and ecofriendly route for synthesizing nanoparticles with antibacterial activity against drug resistant pathogens and attributes growing interest on endophytes as an emerging source for synthesis of nanoparticles.

  16. Field cryofocussing hydride generation applied to the simultaneous multi-elemental determination of alkyl-metal(loid) species in natural waters using ICP-MS detection.

    Science.gov (United States)

    Tseng, C M; Amouroux, D; Brindle, I D; Donard, O F

    2000-12-01

    Two hydride generation manifold systems, utilizing flow injection and cryotrapping techniques for alkyl-metal(loid) speciation analysis in natural waters, are described in this paper. They provide shipboard capacity for simultaneous derivatization of analytes with NaBH4 and cryotrapping of the generated products in a field packed column at -196 degrees C. The first system is a large-volume hydride generator, using a reagent-injection flow technique as a flow batch type, that has been fully optimized and applied to the simultaneous detection of alkylated species in estuarine waters. The technique permits the analysis of a large volume sample (0.5-11) at a sampling rate of 3 h-1. The second is an online continuous flow hydride generator. A sampling rate of 3-12 h-1 can be achieved with samples of 0.1-0.51. In addition, shipboard operation eliminates major problems related to sample pretreatment, transport and storage. Ultra-trace multi-element determination is finally performed in the laboratory by cryogenic GC hyphenated with ICP-MS. Routine detection limits of 0.5-10 pg (as metal) for 0.51 water samples were achieved for the selected alkyl-metal(loid) species of arsenic, germanium, mercury and tin. Concentrations of various species, obtained from water samples taken from the Rhine estuary, are also presented. These species include alkylated arsenic compounds, other than methyl derivatives, that have been tentatively identified and are reported here for the first time.

  17. Optimized synthesis of L-sorbose by C(5)-dehydrogenation of D-sorbitol with Gluconobacter oxydans.

    Science.gov (United States)

    De Wulf, P; Soetaert, W; Vandamme, E J

    2000-08-01

    The optimization of L-sorbose synthesis by regiospecific dehydrogenation of D-sorbitol using Gluconobacter oxydans is reported. The current L-sorbose production processes that are based on G. oxydans and other bacterial strains are suboptimal as to yield and rate of L-sorbose synthesis. One reason for these problems is the toxicity that is induced by the substrate D-sorbitol when used in concentrations of >10% (w/v). This phenomenon significantly limits the potentials of L-sorbose production from an industrial point of view. The goal of this study was to develop a fast production process that yields L-sorbose in stoichiometric amounts starting from D-sorbitol concentrations that exceed 10% (w/v). A gradual improvement of the inoculum build-up procedure, culture medium composition, and process parameters ultimately led to a theoretically maximal L-sorbose productivity (200 g L(-1) of L-sorbose from 200 g L(-1) of D-sorbitol in 28 h of fermentation) using a Gluconobacter oxydans mutant strain that was selected under conditions of substrate inhibition. Because the D-sorbitol/L&HYPHEN;sorbose bioconversion is used to mass-produce vitamin C, the procedure reported here will contribute to a more efficient and more economic synthesis of vitamin C.

  18. Do interoperable national information systems enhance availability of data to assess the effect of scale-up of HIV services on health workforce deployment in resource-limited countries?

    Science.gov (United States)

    Oluoch, Tom; Muturi, David; Kiriinya, Rose; Waruru, Anthony; Lanyo, Kevin; Nguni, Robert; Ojwang, James; Waters, Keith P; Richards, Janise

    2015-01-01

    Sub-Saharan Africa (SSA) bears the heaviest burden of the HIV epidemic. Health workers play a critical role in the scale-up of HIV programs. SSA also has the weakest information and communication technology (ICT) infrastructure globally. Implementing interoperable national health information systems (HIS) is a challenge, even in developed countries. Countries in resource-limited settings have yet to demonstrate that interoperable systems can be achieved, and can improve quality of healthcare through enhanced data availability and use in the deployment of the health workforce. We established interoperable HIS integrating a Master Facility List (MFL), District Health Information Software (DHIS2), and Human Resources Information Systems (HRIS) through application programmers interfaces (API). We abstracted data on HIV care, health workers deployment, and health facilities geo-coordinates. Over 95% of data elements were exchanged between the MFL-DHIS and HRIS-DHIS. The correlation between the number of HIV-positive clients and nurses and clinical officers in 2013 was R2=0.251 and R2=0.261 respectively. Wrong MFL codes, data type mis-match and hyphens in legacy data were key causes of data transmission errors. Lack of information exchange standards for aggregate data made programming time-consuming.

  19. Square-Toed Boots and Felt Hats: Irish Revolutionaries and the Invasion of Canada (1848-1871

    Directory of Open Access Journals (Sweden)

    Marta Ramón-García

    2010-03-01

    Full Text Available The Fenian movement was born in 1858 as an alliance between the Irish Republican Brotherhood, a revolutionary secret society, and the Fenian Brotherhood, an Irish-American organisation intended to supply this society with funds and trained officers. This was not the first time that Irish nationalists on both sides of the Atlantic had tried to cooperate, but it was the first time that there was a steady arrangement in place. The Fenian partnership was extremely successful on the surface, but it was undermined by fundamental differences in customs, political attitudes and ultimate goals between Irish and American Fenians. The clearest evidence of these differences was afforded by the Fenian Brotherhood’s successive attempts to invade Canada between 1866 and 1871. As military episodes the Canadian raids were negligible; as Irish revolutionary attempts they seem absurd. However, they were a perfectly coherent manifestation of the Irish-American “hyphenated identity”. The present article traces the parallel evolution of the Irish Republican Brotherhood and the Fenian Brotherhood up to 1866, and reconstructs the cultural and political reasons for the revival of the Canadian scheme, the ensuing split in the Fenian Brotherhood, and the final collapse of the Fenian alliance.

  20. Rapid and sensitive determination of carbohydrates in foods using high temperature liquid chromatography with evaporative light scattering detection.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2012-04-01

    In the present work, an evaporative light scattering detector was used as a high-temperature liquid chromatography detector for the determination of carbohydrates. The compounds studied were glucose, fructose, galactose, sucrose, maltose, and lactose. The effect of column temperature on the retention times and detectability of these compounds was investigated. Column heating temperatures ranged from 25 to 175°C. The optimum temperature in terms of peak resolution and detectability with pure water as mobile phase and a liquid flow rate of 1 mL/min was 150°C as it allowed the separation of glucose and the three disaccharides here considered in less than 3 min. These conditions were employed for lactose determination in milk samples. Limits of quantification were between 2 and 4.7 mg/L. On the other hand, a temperature gradient was developed for the simultaneous determination of glucose, fructose, and sucrose in orange juices, due to coelution of monosaccharides at temperatures higher than 70°C, being limits of quantifications between 8.5 and 12 mg/L. The proposed hyphenation was successfully applied to different types of milk and different varieties of oranges and mandarins. Recoveries for spiked samples were close to 100% for all the studied analytes.

  1. Performance evaluation of a versatile multidimensional chromatographic preparative system based on three-dimensional gas chromatography and liquid chromatography-two-dimensional gas chromatography for the collection of volatile constituents.

    Science.gov (United States)

    Pantò, Sebastiano; Sciarrone, Danilo; Maimone, Mariarosa; Ragonese, Carla; Giofrè, Salvatore; Donato, Paola; Farnetti, Sara; Mondello, Luigi

    2015-10-23

    The present research deals with the multi-collection of the most important sesquiterpene alcohols belonging to sandalwood essential oil, as reported by the international regulations: (Z)-α-santalol, (Z)-α-trans bergamotol, (Z)-β-santalol, epi-(Z)-β-santalol, α-bisabolol, (Z)-lanceol, and (Z)-nuciferol. A versatile multidimensional preparative system, based on the hyphenation of liquid and gas chromatography techniques, was operated in the LC-GC-GC-prep or GC-GC-GC-prep configuration, depending on the concentration to be collected from the sample, without any hardware or software modification. The system was equipped with a silica LC column in combination with polyethylene glycol-poly(5% diphenyl/95% dimethylsiloxane)-medium polarity ionic liquid or β-cyclodextrin based GC stationary phases. The GC-GC-GC-prep configuration was exploited for the collection of four components, by using a conventional split/splitless injector, while the LC-GC-GC-prep approach was applied for three low abundant components (87%).

  2. Separation of maleic anhydride grafted polypropylene using multidimensional high-temperature liquid chromatography.

    Science.gov (United States)

    Prabhu, K N; Macko, T; Brüll, R; Remerie, K; Tacx, J; Garg, P; Ginzburg, A

    2016-04-01

    Functionalization addresses a property gap of polyolefins and opens new perspectives due to improved surface properties in applications like composites (e.g., glass fiber reinforced polypropylene) and anti-corrosive coatings for metals. Various techniques have been developed to characterize functionalized polyolefins, yet no analytical approach addressing their chemical heterogeneity exists. Using High Temperature Size Exclusion Chromatography (HT-SEC) coupled to infrared spectroscopy we could show for two model samples of polypropylene grafted maleic anhydride (PP-g-MA), differing in their nominal MA content, that the grafting density increases with decreasing molar mass. Crystallization Analysis Fractionation (CRYSTAF) does not enable to separate these samples according to their composition to the extent required. Yet, when using High Temperature High Performance Liquid Chromatography (HT-HPLC), with either silica gel or Mica as stationary phase and a gradient mobile phase, a deformulation into a grafted and a non-grafted fraction could be achieved. This was confirmed by analyzing the eluted fractions by infrared spectroscopy. Hyphenating the separation according to composition with a separation according to molar mass (HT-HPLC x HT-SEC) enabled for the first time to reveal the bivariate distribution of PP-g-MA with regard to the molar mass and composition. Using on-line infrared detection quantitative information on the compositional and molar mass parameters of the individual fractions could be obtained.

  3. Dual ultrasonic-assisted dispersive liquid-liquid microextraction coupled with microwave-assisted derivatization for simultaneous determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhao, Xian-En; Lv, Tao; Zhu, Shuyun; Qu, Fei; Chen, Guang; He, Yongrui; Wei, Na; Li, Guoliang; Xia, Lian; Sun, Zhiwei; Zhang, Shijuan; You, Jinmao; Liu, Shu; Liu, Zhiqiang; Sun, Jing; Liu, Shuying

    2016-03-11

    This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid-liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4'-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma.

  4. Long-term high-temperature and pH stability assessment of modern commercially available stationary phases by using retention factor analysis.

    Science.gov (United States)

    Haun, Jakob; Oeste, Katja; Teutenberg, Thorsten; Schmidt, Torsten C

    2012-11-09

    High-temperature liquid chromatography provides several advantages concerning HPLC method development and is needed to realize special hyphenation techniques. However, hardware limitations and stationary phase degradation can prevent the successful application of this technique. Therefore, column stability is of major importance. The presented study contains results of long-term high-temperature stability tests for eight modern commercially available HPLC stationary phases. Six of them were silica-based reversed-phase C18 columns tested according to an earlier reported procedure (Teutenberg, 2009 [12]). On the basis of the extended data set that covers a wide range of column technologies, a comparative approach using retention factor analysis was evaluated in order to categorize the columns according to their long-term high-temperature stability at 150 °C and changing pH value. This approach offers a more objective alternative to conventional listings in which temperature maxima are compared for columns tested under different conditions. Additionally, customized tests are presented for one promising polymer-based C18 stationary phase and an amide column for hydrophilic interaction liquid chromatography.

  5. On-line coupling of supercritical fluid extraction and chromatographic techniques.

    Science.gov (United States)

    Sánchez-Camargo, Andrea Del Pilar; Parada-Alfonso, Fabián; Ibáñez, Elena; Cifuentes, Alejandro

    2017-01-01

    This review summarizes and discusses recent advances and applications of on-line supercritical fluid extraction coupled to liquid chromatography, gas chromatography, and supercritical fluid chromatographic techniques. Supercritical fluids, due to their exceptional physical properties, provide unique opportunities not only during the extraction step but also in the separation process. Although supercritical fluid extraction is especially suitable for recovery of non-polar organic compounds, this technique can also be successfully applied to the extraction of polar analytes by the aid of modifiers. Supercritical fluid extraction process can be performed following "off-line" or "on-line" approaches and their main features are contrasted herein. Besides, the parameters affecting the supercritical fluid extraction process are explained and a "decision tree" is for the first time presented in this review work as a guide tool for method development. The general principles (instrumental and methodological) of the different on-line couplings of supercritical fluid extraction with chromatographic techniques are described. Advantages and shortcomings of supercritical fluid extraction as hyphenated technique are discussed. Besides, an update of the most recent applications (from 2005 up to now) of the mentioned couplings is also presented in this review.

  6. Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents.

    Science.gov (United States)

    Müller, David; Cattaneo, Stefano; Meier, Florian; Welz, Roland; de Vries, Tjerk; Portugal-Cohen, Meital; Antonio, Diana C; Cascio, Claudia; Calzolai, Luigi; Gilliland, Douglas; de Mello, Andrew

    2016-04-01

    We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel method of sample preparation for the analysis of complex nanoparticle-containing samples, in our case a model sunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplified process using a lab scale supercritical fluid extraction system. The residual material was easily dispersed in an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenated with UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguous determination of the presence of nanoparticles within the sample, with almost no background from the matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained. These results are especially relevant in view of recently introduced regulatory requirements concerning the labeling of nanoparticle-containing products. The novel sample preparation method is potentially applicable to commercial sunscreens or other emulsion-based cosmetic products and has important ecological advantages over currently used sample preparation techniques involving organic solvents.

  7. Phenolic Compounds in Chilean Mistletoe (Quintral, Tristerix tetrandus Analyzed by UHPLC–Q/Orbitrap/MS/MS and Its Antioxidant Properties

    Directory of Open Access Journals (Sweden)

    Mario J. Simirgiotis

    2016-02-01

    Full Text Available Mass spectrometry has become a method of choice to characterize bioactive compounds in biological samples because of its sensitivity and selectivity. Hybrid ultra-HPLC hyphenated with Orbitrap mass analyzer is an innovative state of the art technology that allows fast and accurate metabolomic analyses. In this work the metabolites of a Chilean mistletoe endemic to the VIII region of Chile were investigated for the first time using UHPLC mass analysis (UHPLC-PDA-HESI-Orbitrap MSn. The anthocyanins, together with the non-pigmented phenolics were fingerprinted and correlated with the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP, the superoxide anion scavenging activity assay (SA, and total content of phenolics, flavonoids and anthocyanins measured by spectroscopic methods. Six anthocyanins were identified, and among them, the 3-O-glycosides of delphinidin and cyanidin were the major ones. In addition, several phenolic acids (including feruloylquinic acid, feruloyl glucose, chlorogenic acid and several flavonols (luteolin, quercetin, apigenin, isorhamnetin and glycoside derivatives were also identified. The mistletoe leaves showed the highest antioxidant activity as measured by the DPPH radical bleaching, ferric reducing antioxidant power and superoxide anion scavenging activity tests (13.38 ± 0.47 µg/mL, 125.32 ± 5.96 µmolTE/g DW and 84.06 ± 4.59 at 100 µg/mL, respectively.

  8. Mercury speciation by high-performance liquid chromatography atomic fluorescence spectrometry using an integrated microwave/UV interface. Optimization of a single step procedure for the simultaneous photo-oxidation of mercury species and photo-generation of Hg0

    Science.gov (United States)

    de Quadros, Daiane P. C.; Campanella, Beatrice; Onor, Massimo; Bramanti, Emilia; Borges, Daniel L. G.; D'Ulivo, Alessandro

    2014-11-01

    We described the hyphenation of photo-induced chemical vapor generation with high performance liquid chromatography-atomic fluorescence spectrometry (HPLC-AFS) for the quantification of inorganic mercury, methylmercury (MeHg) and ethylmercury (EtHg). In the developed procedure, formic acid in mobile phase was used for the photodecomposition of organomercury compounds and reduction of Hg2 + to mercury vapor under microwave/ultraviolet (MW/UV) irradiation. We optimized the proposed method studying the influence of several operating parameters, including the type of organic acid and its concentration, MW power, composition of HPLC mobile phase and catalytic action of TiO2 nanoparticles. Under the optimized conditions, the limits of detection were 0.15, 0.15 and 0.35 μg L- 1 for inorganic mercury, MeHg and EtHg, respectively. The developed method was validated by determination of the main analytical figures of merit and applied to the analysis of three certified reference materials. The online interfacing of liquid chromatography with photochemical-vapor generation-atomic fluorescence for mercury determination is simple, environmentally friendly, and represents an attractive alternative to the conventional tetrahydroborate (THB) system.

  9. On-line coupling of flow field-flow fractionation and multiangle laser light scattering for the characterization of macromolecules in aqueous solution as illustrated by sulfonated polystyrene samples.

    Science.gov (United States)

    Thielking, H; Kulicke, W M

    1996-04-01

    Seven sulfonated polystyrene standards (18 000-3 000 000 g/mol), taken as model substances for macromolecular polyelectrolytes, were dissolved in aqueous 0.1 M sodium nitrate solution and characterized by multiangle laser light scattering coupled on-line to flow field-flow fractionation. The distributions of molar mass and root mean square radius and the diffusion coefficients were obtained for each sample using a constant field of force for separation. Relationships between molar mass and root mean square radius [〈R(G)(2)〉(z)(0.5) = (2.71 × 10(-)(2))M(w)(0.56)] or diffusion coefficient [D = (7.10 × 10(-)(8))M(w)(-)(0.68)] were calculated. To investigate the static analytical range of this novel hyphenated technique a mixture of all seven samples was fractionated applying a programmed field. The relationship obtained between root mean square radius and molar mass was used to calculate a Mark-Houwink equation [[η]calcd = (2.99 × 10(-)(2))M(w)(0.68)]. To verify this result, the intrinsic viscosities for all samples were measured at low shear rate and found to be in good agreement [[η]calcd = (2.77 × 10(-)(2))M(w)(0.67)].

  10. Quantitative mass spectrometry of unconventional human biological matrices

    Science.gov (United States)

    Dutkiewicz, Ewelina P.; Urban, Pawel L.

    2016-10-01

    The development of sensitive and versatile mass spectrometric methodology has fuelled interest in the analysis of metabolites and drugs in unconventional biological specimens. Here, we discuss the analysis of eight human matrices-hair, nail, breath, saliva, tears, meibum, nasal mucus and skin excretions (including sweat)-by mass spectrometry (MS). The use of such specimens brings a number of advantages, the most important being non-invasive sampling, the limited risk of adulteration and the ability to obtain information that complements blood and urine tests. The most often studied matrices are hair, breath and saliva. This review primarily focuses on endogenous (e.g. potential biomarkers, hormones) and exogenous (e.g. drugs, environmental contaminants) small molecules. The majority of analytical methods used chromatographic separation prior to MS; however, such a hyphenated methodology greatly limits analytical throughput. On the other hand, the mass spectrometric methods that exclude chromatographic separation are fast but suffer from matrix interferences. To enable development of quantitative assays for unconventional matrices, it is desirable to standardize the protocols for the analysis of each specimen and create appropriate certified reference materials. Overcoming these challenges will make analysis of unconventional human biological matrices more common in a clinical setting. This article is part of the themed issue 'Quantitative mass spectrometry'.

  11. Capillary Electrophoresis-Mass Spectrometry for the Analysis of Heparin Oligosaccharides and Low Molecular Weight Heparin.

    Science.gov (United States)

    Sun, Xiaojun; Lin, Lei; Liu, Xinyue; Zhang, Fuming; Chi, Lianli; Xia, Qiangwei; Linhardt, Robert J

    2016-02-01

    Heparins, highly sulfated, linear polysaccharides also known as glycosaminoglycans, are among the most challenging biopolymers to analyze. Hyphenated techniques in conjunction with mass spectrometry (MS) offer rapid analysis of complex glycosaminoglycan mixtures, providing detailed structural and quantitative data. Previous analytical approaches have often relied on liquid chromatography (LC)-MS, and some have limitations including long separation times, low resolution of oligosaccharide mixtures, incompatibility of eluents, and often require oligosaccharide derivatization. This study examines the analysis of glycosaminoglycan oligosaccharides using a novel electrokinetic pump-based capillary electrophoresis (CE)-MS interface. CE separation and electrospray were optimized using a volatile ammonium bicarbonate electrolyte and a methanol-formic acid sheath fluid. The online analyses of highly sulfated heparin oligosaccharides, ranging from disaccharides to low molecular weight heparins, were performed within a 10 min time frame, offering an opportunity for higher-throughput analysis. Disaccharide compositional analysis as well as top-down analysis of low molecular weight heparin was demonstrated. Using normal polarity CE separation and positive-ion electrospray ionization MS, excellent run-to-run reproducibility (relative standard deviation of 3.6-5.1% for peak area and 0.2-0.4% for peak migration time) and sensitivity (limit of quantification of 2.0-5.9 ng/mL and limit of detection of 0.6-1.8 ng/mL) could be achieved.

  12. Evaluation and prevention of the negative matrix effect of terpenoids on pesticides in apples quantification by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Giacinti, Géraldine; Raynaud, Christine; Capblancq, Sophie; Simon, Valérie

    2017-02-03

    The sample matrix can enhance the gas chromatography signal of pesticide residues relative to that obtained with the same concentration of pesticide in solvent. This paper is related to negative matrix effects observed in coupled gas chromatography-mass spectrometry ion trap (GC/MS(2)) quantification of pesticides in concentrated extracts of apple peel prepared by the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method. It is focused on the pesticides most frequently used on the apple varieties studied, throughout the crop cycle, right up to harvest, to combat pests and diseases and to improve fruit storage properties. Extracts from the fleshy receptacle (flesh), the epiderm (peel) and fruit of three apple varieties were studied by high-performance thin-layer chromatography hyphenated with UV-vis light detection (HPTLC/UV visible). The peel extracts had high concentrations of triterpenic acids (oleanolic and ursolic acids), reaching 25mgkg(-1), whereas these compounds were not detected in the flesh extracts (<0.05mgkg(-1)). A significant relationship has been found between the levels of these molecules and negative matrix effects in GC/MS(2). The differences in the behavior of pesticides with respect to matrix effects can be accounted for by the physicochemical characteristics of the molecules (lone pairs, labile hydrogen, conjugation). The HPTLC/UV visible method developed here for the characterization of QuEChERS extracts acts as a complementary clean-up method, aimed to decrease the negative matrix effects of such extracts.

  13. Aspectos toxicológicos e inmunológicos del veneno del escorpión Tityus pachyurus

    Directory of Open Access Journals (Sweden)

    Rafael Valderrama

    2001-04-01

    Full Text Available

  1. Benefits of high resolution IC-ICP-MS for the routine analysis of inorganic and organic arsenic species in food products of marine and terrestrial origin.

    Science.gov (United States)

    Kohlmeyer, Ute; Jantzen, Eckard; Kuballa, Jürgen; Jakubik, Sandra

    2003-09-01

    A recently developed and validated method for simultaneous determination of 17 inorganic and organic arsenic compounds in marine biota has been successfully applied to routine analysis of different food products, including fish, shellfish, edible algae, rice, and other types of grain. During one year, approximately 250 food samples were analyzed, mostly fish and rice. Long-term stability and robustness of the system was observed and reproducible results for certified reference materials were ensured by means of control charts. The separation was performed by ion-pair chromatography on an anion-exchange column to separate anionic, neutral, and cationic arsenic species in one chromatographic run. Hyphenation to ICP-MS allowed element-specific and sensitive detection of the different arsenic species with a detection limit as low as 8 ng As L(-1 )in the sample extract, which is equivalent to 2 ng As g(-1) in the original sample. Special emphasis was laid on the analysis of marine algae and rice samples. These food types can contain elevated levels of the very toxic inorganic arsenic species (up to 90% in rice) and therefore are the focus of interest in the food industry. In marine algae, inorganic arsenic was mainly present as arsenate whereas in rice arsenite predominated.

  2. Determination of biogenic amines in wines by pre-column derivatization and high-performance liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    García-Villar, Natividad; Hernández-Cassou, Santiago; Saurina, Javier

    2009-09-01

    A new HPLC method for determining biogenic amines in wines is developed. This method is based on pre-column amine derivatization, further separation of derivatives and on-line hyphenation of HPLC to atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Biogenic amines have been derivatized with 1,2-naphthoquinone-4-sulfonate at 65 degrees C and pH 9.2 for 5 min. The separation of derivatives has been accomplished in a C(18) analytical column using an elution gradient based on increasing the percentage of methanol. Derivatives have been ionized in positive mode and detected by selected ion monitoring. The operating conditions of the APCI-MS system (voltages, temperatures and gases) have been thoroughly optimized to obtain the maximum sensitivity for all analytes. In the selected conditions, APCI-MS spectra display little fragmentation and good signal-to-noise ratio. Depending on the amine characteristics, the main spectral peaks are due to mono- and di-derivative products. Figures of merit of the method have been established under the selected conditions using red wine samples. Recoveries ranging from 94% to 106% have been obtained which prove excellent accuracy of the method in the determination of histamine, putrescine, cadaverine, tryptamine, phenylethylamine, tyramine and serotonin in red wines. The proposed method has been applied to the analysis of commercial wines from different Spanish regions.

  3. THEORETICAL FOUNDATIONS OF COMPOSING A REFERENCE BOOK OF REGIONAL TOPONYMS

    Directory of Open Access Journals (Sweden)

    Ilyin Dmitriy Yuryevich

    2014-09-01

    Full Text Available The article deals with the linguistic issues of composing a reference book of regional toponyms – a genre that requires special consideration in national lexicography. The assortment of these issues gave the possibility to carry out complex description of regional toponyms on the basis of semantic, functional, and orpthologuos criteria that let unify the names of Volgograd region settlements that are registered in various documents. The significance of the composed reference book is determined by several factors – the presence of local subsystems of geographical names in Russian toponymy; the inconsistency of current orthography norms on using capital letter in compound proprius names and fused-with-hyphen spelling of toponyms and off-toponym derivations; the lack of linguistically justified explanation of peculiarities of grammatical norms in the field of proper names use. The reference book of regional toponyms is based on the object description (toponymic vocabulary, principles of lexical units selection (description of spelling and grammatical properties of toponyms, encyclopedic information, the glossary (full list of toponyms of Volgograd region, typical article. The articles in the reference book are arranged in lexicographical zones with grammatical and semantic markers, lexicographical illustrations, other lexicographical labels, word etymology including. The reference book on Volgograd region toponymy is addressed to executive and administration authorities, journalists, regional ethnographers.

  4. Simultaneous determination of quinolones for veterinary use by high-performance liquid chromatography with electrochemical detection.

    Science.gov (United States)

    Rodríguez Cáceres, M I; Guiberteau Cabanillas, A; Galeano Díaz, T; Martínez Cañas, M A

    2010-02-01

    A selective method based on high-performance liquid chromatography with electrochemical detection (HPLC-ECD) has been developed to enable simultaneous determination of three fluoroquinolones (FQs), namely danofloxacin (DANO), difloxacin (DIFLO) and sarafloxacin (SARA). The fluoroquinolones are separated on a Novapack C-18 column and detected in a high sensitivity amperometric cell at a potential of +0.8 V. Solid-phase extraction was used for the extraction of the analytes in real samples. The range of concentration examined varied from 10 to 150 ng g(-1) for danofloxacin, from 25 to 100 ng g(-1) for sarafloxacin and from 50 to 315 ng g(-1) for difloxacin, respectively. The method presents detection limits under 10 ng g(-1) and recoveries around 90% for the three analytes have been obtained in the experiments with fortified samples. This HPLC-ECD approach can be useful in the routine analysis of antibacterial residues being less expensive and less complicated than other more powerful tools as hyphenated techniques.

  5. Sb(V) reactivity with human blood components: redox effects.

    Science.gov (United States)

    López, Silvana; Aguilar, Luis; Mercado, Luis; Bravo, Manuel; Quiroz, Waldo

    2015-01-01

    We assessed the reactivity of Sb(V) in human blood. Sb(V) reactivity was determined using an HPLC-HG-AFS hyphenated system. Sb(V) was partially reduced to Sb(III) in blood incubation experiments; however, Sb(III) was a highly unstable species. The addition of 0.1 mol L(-1) EDTA prevented Sb(III) oxidation, thus enabling the detection of the reduction of Sb(V) to Sb(III). The transformation of Sb(V) to Sb(III) in human whole blood was assessed because the reduction of Sb(V) in human blood may likely generate redox side effects. Our results indicate that glutathione was the reducing agent in this reaction and that Sb(V) significantly decreased the GSH/GSSG ratio from 0.32 ± 0.09 to 0.07 ± 0.03. Moreover, the presence of 200 ng mL(-1) of Sb(V) increased the activity of superoxide dismutase from 4.4 ± 0.1 to 7.0 ± 0.4 U mL(-1) and decreased the activity of glutathione peroxidase from 62 ± 1 to 34 ± 2 nmol min(-1) mL(-1).

  6. Chemometrics: A new scenario in herbal drug standardization

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    Ankit Bansal

    2014-08-01

    Full Text Available Chromatography and spectroscopy techniques are the most commonly used methods in standardization of herbal medicines but the herbal system is not easy to analyze because of their complexity of chemical composition. Many cutting-edge analytical technologies have been introduced to evaluate the quality of medicinal plants and significant amount of measurement data has been produced. Chemometric techniques provide a good opportunity for mining more useful chemical information from the original data. Then, the application of chemometrics in the field of medicinal plants is spontaneous and necessary. Comprehensive methods and hyphenated techniques associated with chemometrics used for extracting useful information and supplying various methods of data processing are now more and more widely used in medicinal plants, among which chemometrics resolution methods and principal component analysis (PCA are most commonly used techniques. This review focuses on the recent various important analytical techniques, important chemometrics tools and interpretation of results by PCA, and applications of chemometrics in quality evaluation of medicinal plants in the authenticity, efficacy and consistency.

  7. Characterization of petroleum distillates by GC-AED (coupling with gas chromatography and atomic emission detection); Caracterisation des distillats petroliers par couplage chromatographie en phase gazeuse et detection par emission atomique

    Energy Technology Data Exchange (ETDEWEB)

    Baco, F.

    1997-05-21

    This thesis describes the characterization of atmospheric petroleum distillates (kerosenes and gas-oils) and vacuum distillates by hyphenated technic of Gas Chromatography and Atomic Emission Detector (GC-AED). A gas chromatographic simulated distillation, which gives the weight % of sample as a function of the petroleum cut temperature, was adapted to the GC-AED to obtain an original information about the elemental composition profile. After generalities, historic of the development of the instrument and the first petroleum applications are described. In the experimental part, analytical conditions used, different technics of characterisation of distillates and the base of samples analyzed are exposed. After a study of the GC-AED`s performances for the target elements (C, H, S, N), a quantitative method for the elemental analysis of distillates was developed and validated at three levels: total elemental analysis, simulated distillation and elemental composition as a function of the distillation profile. Finally, different ways for the applications of the GC-AED in order to characterize the distillates were explored, in particular to classify products and predict some petroleum properties (cetane number, density,...). The more interesting outlook seems to be the prediction of some properties as a function of the distillation profile. (author) 155 refs.

  8. Rapid determination of baicalin and total baicalein content in Scutellariae radix by ATR-IR and NIR spectroscopy.

    Science.gov (United States)

    Navarro Escamilla, M; Rodenas Sanz, F; Li, H; Schönbichler, S A; Yang, B; Bonn, G K; Huck, C W

    2013-09-30

    In this study methods for the quantification of baicalin and total baicalein in Scutellariae radix with near infrared (NIR) spectroscopy and attenuated-total-reflectance mid-infrared (ATR-IR) spectroscopy in hyphenation with multivariate analysis were developed and compared. The reference analysis was performed by high performance liquid chromatography coupled to diode array detection (HPLC-DAD). Different pretreatments like standard normal variate (SNV), multiplicative scatter correction (MSC), first and second derivative Savitzky-Golay were applied on the spectra to optimize the calibrations. A principal component analysis was performed with both spectroscopic methods to distinguish wild and cultivated samples. Quality parameters obtained for test-set calibration models of ATR-IR spectroscopy (baicalin: standard error of prediction (SEP)=1.31, ratio performance to deviation (RPD)=2.91 and R(2)=0.88; total baicalein: SEP=1.02, RPD=3.24 and R(2)=0.89) and NIR spectroscopy (baicalin: SEP=1.50, RPD=2.54 and R(2)=0.88; total baicalein: SEP=1.19, RPD=2.76 and R(2)=0.84) demonstrate that both spectroscopic techniques in combination with multivariate analysis are successful tools for the quantification of baicalin and total baicalein in Scutellariae radix, but it was found that ATR-IR spectroscopy provides higher accuracy in the given application. Furthermore it was proved that wild and cultivated samples can be distinguished by ATR-IR.

  9. Prueba de esfuerzo cardiopulmonar (PEC en el síndrome de falla cardíaca. Una propuesta basada en la evidencia Cardiopulmonary exercise testing in congestive heart failure. a proposal based on evidence

    Directory of Open Access Journals (Sweden)

    Juan Manuel Sénior Sánchez

    2008-06-01

    Full Text Available

    El objetivo de este artículo es presentar recomendaciones para la utilización clínica de la prueba de esfuerzo cardiopulmonar en el síndrome de falla cardíaca con énfasis en la medicina basada en la evidencia mediante una búsqueda sistemática de la

  10. Electrospun nanofiber layers with incorporated photoluminescence indicator for chromatography and detection of ultraviolet-active compounds.

    Science.gov (United States)

    Kampalanonwat, Pimolpun; Supaphol, Pitt; Morlock, Gertrud E

    2013-07-19

    For the first time, electrospun nanofiber phases were fabricated with manganese-activated zinc silicate as photoluminescent indicator (UV254) to transfer and enlarge its application to the field of UV-active compounds. By integration of such an indicator, UV-active compounds got visible on the chromatogram. The separation of 7 preservatives and a beverage sample were studied on the novel luminescent polyacrylonitrile layers. The mat thickness and mean fiber diameters were calculated for additions of different UV254 indicator concentrations. The separation efficiency on the photoluminescent layers was characterized by comparison to HPTLC layers and calculation of the plate numbers and resolutions. Some benefits were the reduction in migration distance (3cm), migration time (12min), analyte (10-nL volumes) and mobile phase volumes (1mL). As ultrathin stationary phase, such layers are suited for their integration into the Office Chromatography concept. For the first time, electrospun nanofiber layers were hyphenated with mass spectrometry and the confirmation of compounds was successfully performed using the elution-head based TLC-MS Interface.

  11. On the frontiers of knowledge: the enlargement of experience and the new forms of rationality doi:10.5007/1807-1384.2010v7n2p1

    Directory of Open Access Journals (Sweden)

    Ivan Domingues

    2010-12-01

    Full Text Available The article discusses the panorama of knowledge today, focusing on the inflation of knowledge, the fragmentation of disciplines and the density loss of cognitive processes as well as the search for alternatives through multi-, inter- and transdisciplinary experiments. Other points emphasized: the emergence of the hyphenated disciplines (bio-chemistry, ethno-music, etc.; the approach of science, technology, art and philosophy; the end of the generalist and the specialist. The sense of the analyses is epistemological and the goal is to demonstrate, in contrast, two real approaches that define cognitive strategies in different fields of knowledge: the reductionist and the non-reductionist. The stress falls on the non-reductionist approaches, highlighting the following topics or aspects: the dilatation of the experience and the expansion of reason, the conquest of different levels of reality, new perspectives for the humanities and social sciences. Finally, after emphasizing the importance of discipline, its centrality anchor is placed in context, through the recognition of themes and issues as important challenges and opportunities acquis, enabling the advancement of knowledge.

  12. Determination of atractylon in rat plasma by a GC-MS method and its application to a pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Han Yan; Yuanyuan Sun; Yuying Ma; Bin Ji; Xiaohong Hou; Zhiguo Yu; Yunli Zhao

    2015-01-01

    A sensitive and selective method based on gas chromatography hyphenated to mass spectrometry (GC-MS) was developed and validated for the determination of atractylon in rat plasma. Plasma samples were processed by liquid-liquid extraction with ethyl acetate-n-hexane (1:1, v/v) using acetophenone as an internal standard (IS). Analytes were determined in selective ion monitoring (SIM) mode using target ions at m/z 108.1 for atractylon and m/z 105.1 for acetophenone. The calibration curve was linear over the concentration range of 10-1000 ng/mL with lower limit of quantification of 10 ng/mL. The intra- and inter-day precision variations were not more than 10.4% and 9.6%, respectively, whilst accuracy values ranged from -6.5% to 4.9%. Extraction recovery of the assay was satisfactory. This method was suc-cessfully applied to quantification and pharmacokinetic study of atractylon in rat plasma after in-tragastric administration of Atractylodis extract.

  13. Determination of atractylon in rat plasma by a GC–MS method and its application to a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Han Yan

    2015-10-01

    Full Text Available A sensitive and selective method based on gas chromatography hyphenated to mass spectrometry (GC–MS was developed and validated for the determination of atractylon in rat plasma. Plasma samples were processed by liquid–liquid extraction with ethyl acetate-n-hexane (1:1, v/v using acetophenone as an internal standard (IS. Analytes were determined in selective ion monitoring (SIM mode using target ions at m/z 108.1 for atractylon and m/z 105.1 for acetophenone. The calibration curve was linear over the concentration range of 10–1000 ng/mL with lower limit of quantification of 10 ng/mL. The intra- and inter-day precision variations were not more than 10.4% and 9.6%, respectively, whilst accuracy values ranged from −6.5% to 4.9%. Extraction recovery of the assay was satisfactory. This method was successfully applied to quantification and pharmacokinetic study of atractylon in rat plasma after intragastric administration of Atractylodis extract.

  14. A special reactor design for investigations of mixing time effects in a scaled-down industrial L-lysine fed-batch fermentation process

    Science.gov (United States)

    Schilling; Pfefferle; Bachmann; Leuchtenberger; Deckwer

    1999-09-01

    A specially designed model reactor based on a 42-L laboratory fermentor was equipped with six stirrers (Rushton turbines) and five cylindrical disks. In this model reactor, the mixing time, Theta(90), turned out to be 13 times longer compared with the 42-L standard laboratory fermentor fitted with two Rushton turbines and four wall-fixed longitudinal baffles. To prove the suitability of the model reactor for scaledown studies of mixing-time-dependent processes, parallel exponential fed-batch cultivations were carried out with the leucine-auxotrophic strain, Corynebacterium glutamicum DSM 5715, serving as a microbial test system. L&HYPHEN;Leucine, the process-limiting substrate, was fed onto the liquid surface of both reactors. Cultivations were conducted using the same inoculum material and equal oxygen supply. The model reactor showed reduced sugar consumption (-14%), reduced ammonium consumption (-19%), and reduced biomass formation (-7%), which resulted in a decrease in L-lysine formation (-12%). These findings were reflected in less specific enzyme activity, which was determined for citrate synthase (CS), phosphoenolpyruvate carboxylase (PEP-C), and aspartate kinase (AK). The reduced specific activity of CS correlated with lower CO(2) evolution (-36%) during cultivation. The model reactor represents a valuable tool to simulate the conditions of poor mixing and inhomogeneous substrate distribution in bioreactors of industrial scale. Copyright 1999 John Wiley & Sons, Inc.

  15. A single sorbent for tetracycline enrichment and subsequent solid-matrix time-resolved luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Liu Linshu [Eastern Regional Research Center, Agriculture Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)]. E-mail: lsliu@errc.ars.usda.gov; Chen Guoying [Eastern Regional Research Center, Agriculture Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States); Fishman, Marshall L. [Eastern Regional Research Center, Agriculture Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)

    2005-01-10

    The aim of this study was to search for a sorbent that could act as an extraction phase and as a support for solid-matrix time-resolved luminescence (SMTRL). Four potential sorbents were investigated for this purpose using tetracycline (TC) as a model analyte. Sorbents prepared from C18 silica gel or calcium cross-linked pectin gel were able to extract TC from dilute solutions. Europium(III)-TC complex adsorbed on the surface of C18 generated the most intense TRL signal when measured at {lambda}{sub ex} = 388 nm and {lambda}{sub em} = 615 nm. This method achieved a 1 ng/ml limit of detection (LOD) with a 100 {mu}l sample solution in a repeated spotting mode. Hyphenation of sorbent extraction and SMTRL was demonstrated using C18. This method is suitable for screening of TC in foods or aqueous solutions and can be extended to other luminescent lanthanide-chelating analytes in physiological or environmental samples.

  16. Selenium metabolism in cancer cells: the combined application of XAS and XFM techniques to the problem of selenium speciation in biological systems.

    Science.gov (United States)

    Weekley, Claire M; Aitken, Jade B; Finney, Lydia; Vogt, Stefan; Witting, Paul K; Harris, Hugh H

    2013-05-21

    Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (XFM). The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  17. Mercury speciation by CE: an update.

    Science.gov (United States)

    Kubán, Petr; Pelcová, Pavlína; Margetínová, Jana; Kubán, Vlastimil

    2009-01-01

    This review provides an update on mercury speciation by CE. It includes a brief discussion on physicochemical properties, toxicity and transformation pathways of mercury species (i.e. methyl-, ethyl-, phenyl- and inorganic mercury) and outlines recent trends in Hg speciation by CE. CE is presented as a complementary technique to chromatographic separation techniques, especially in cases when speed, high efficiency and low sample volumes are required. The development of suitable sample preconcentration/isolation (sample stacking, ion exchange, liquid-liquid-liquid extraction, dual-cloud point extraction) to achieve low LODs for analysis of trace concentrations of mercury species in real samples is emphasized. Hyphenation of CE to element specific detectors (i.e. electrothermal atomic absorption spectrometry, atomic fluorescence spectrometry, inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry) is discussed as well as a potential of CE in interaction studies that may provide useful information on interaction of various Hg species with selected bio-macromolecules.

  18. Chemical Characterization and in Vitro Antibacterial Activity of Myrcianthes hallii (O. Berg McVaugh (Myrtaceae, a Traditional Plant Growing in Ecuador

    Directory of Open Access Journals (Sweden)

    Patricia Chavez Carvajal

    2016-06-01

    Full Text Available Myrcianthes hallii (O. Berg McVaugh (Myrtaceae is a plant native to Ecuador, traditionally used for its antiseptic properties. The composition of the hydro-methanolic extract of this plant was determined by submitting it to ultra-high performance liquid chromatography (UHPLC hyphenated to heated-electrospray ionization mass spectrometry and UV detection. The presence of antimicrobial components prompted us to test the extract against methicillin-resistant and methicillin-susceptible Staphylococcus aureus, multidrug-resistant and susceptible Escherichia coli, Pseudomonas aeruginosa, Enterococcus spp. and Streptococcus pyogenes strains. The chromatographic analysis led to the identification of 38 compounds, including polyphenols and organic acids, and represents the first chemical characterization of this plant. The extract showed modest antibacterial activity against all tested bacteria, with the exception of E. coli which was found to be less sensitive. Whilst methicillin-resistant strains usually display resistance to several drugs, no relevant differences were observed between methicillin-susceptible and resistant strains. Considering its long-standing use in folk medicine, which suggests the relative safety of the plant, and the presence of many known antibacterial polyphenolic compounds responsible for its antibacterial activity, the results show that M. hallii extract could be used as a potential new antiseptic agent. Moreover, new anti-infective biomaterials and nanomaterials could be designed through the incorporation of M. hallii polyphenols. This prospective biomedical application is also discussed.

  19. Electrochemical methods in conjunction with capillary and microchip electrophoresis.

    Science.gov (United States)

    Mark, Jonas J P; Scholz, Rebekka; Matysik, Frank-Michael

    2012-12-01

    Electromigrative techniques such as capillary and microchip electrophoresis (CE and MCE) are inherently associated with various electrochemical phenomena. The electrolytic processes occurring in the buffer reservoirs have to be considered for a proper design of miniaturized electrophoretic systems and a suitable selection of buffer composition. In addition, the control of the electroosmotic flow plays a crucial role for the optimization of CE/MCE separations. Electroanalytical methods have significant importance in the field of detection in conjunction with CE/MCE. At present, amperometric detection and contactless conductivity detection are the predominating electrochemical detection methods for CE/MCE. This paper reviews the most recent trends in the field of electrochemical detection coupled to CE/MCE. The emphasis is on methodical developments and new applications that have been published over the past five years. A rather new way for the implementation of electrochemical methods into CE systems is the concept of electrochemically assisted injection which involves the electrochemical conversions of analytes during the injection step. This approach is particularly attractive in hyphenation to mass spectrometry (MS) as it widens the range of CE-MS applications. An overview of recent developments of electrochemically assisted injection coupled to CE is presented.

  20. Identification of Polish cochineal (Porphyrophora polonica L.) in historical textiles by high-performance liquid chromatography coupled with spectrophotometric and tandem mass spectrometric detection.

    Science.gov (United States)

    Lech, Katarzyna; Jarosz, Maciej

    2016-05-01

    The present work reports a method for identification of Polish cochineal (Porphyrophora polonica L.) in historical fabrics by the use of high-performance liquid chromatography coupled with diode array and tandem mass spectrometric detection with electrospray ionization (HPLC-DAD-ESI MS/MS). This hyphened technique allows detection and identification of 16 new minor colorants present in the discussed scale insect (including two previously observed by Wouters and Verhecken (Ann Soc Entomol Fr. 1989;25:393-410), but specified only as compounds of unknown structures) that do not occur (e.g., in American cochineal). The MS/MS experiments, complemented with UV-VIS data, enable identification of mono- and di-, C- and O-hexosides of kermesic and flavokermesic acids or their derivatives. The present paper introduces a fingerprint of color compounds present in Polish cochineal and defines them, particularly pp6 (ppI, O-hexoside of flavokermesic acid), as its markers allow distinguishing of Polish-cochineal reds from the American ones. Usefulness of the selected set of markers for identification of Polish cochineal has been demonstrated in the examination of textiles from the collection of the National Museum in Warsaw using the multiple reaction monitoring (MRM) method, originally elaborated on the basis of this study.

  1. Anionic metabolite profiling by capillary electrophoresis-mass spectrometry using a noncovalent polymeric coating. Orange juice and wine as case studies.

    Science.gov (United States)

    Acunha, Tanize; Simó, Carolina; Ibáñez, Clara; Gallardo, Alberto; Cifuentes, Alejandro

    2016-01-01

    In several metabolomic studies, it has already been demonstrated that capillary electrophoresis hyphenated to mass spectrometry (CE-MS) can detect an important group of highly polar and ionized metabolites that are overseen by techniques such as NMR, LC-MS and GC-MS, providing complementary information. In this work, we present a strategy for anionic metabolite profiling by CE-MS using a cationic capillary coating. The polymer, abbreviated as PTH, is composed of a poly-(N,N,N',N'-tetraethyldiethylenetriamine, N-(2-hydroxypropyl) methacrylamide, TEDETAMA-co-HPMA (50:50) copolymer. A CE-MS method based on PTH-coating was optimized for the analysis of a group of 16 standard anionic metabolites. Separation was achieved within 12min, with high separation efficiency (up to 92,000 theoretical plates per meter), and good repeatability, namely, relative standard deviation values for migration times and peak areas were below 0.2 and 2.1%, respectively. The optimized method allowed the detection of 87 metabolites in orange juice and 142 metabolites in red wine, demonstrating the good possibilities of this strategy for metabolomic applications.

  2. Headspace-solid phase microextraction approach for dimethylsulphoniopropionate quantification in Solanum lycopersicum plants subjected to water stress

    Directory of Open Access Journals (Sweden)

    Stefano Catola

    2016-08-01

    Full Text Available Dimethylsulphoniopropionate (DMSP and dimethyl sulphide (DMS are compounds found mainly in marine phytoplankton and in some halophytic plants. DMS is a globally important biogenic volatile in regulating of global sulphur cycle and planetary albedo, whereas DMSP is involved in the maintenance of plant-environment homeostasis. Plants emit minute amounts of DMS compared to marine phytoplankton and there is a need for hypersensitive analytic techniques to enable its quantification in plants. Solid Phase Micro Extraction from Head Space (HS-SPME is a simple, rapid, solvent-free and cost-effective extraction mode, which can be easily hyphenated with GC-MS for the analysis of volatile organic compounds (VOCs. Using tomato (Solanum lycopersicum plants subjected to water stress as a model system, we standardized a sensitive and accurate protocol for detecting and quantifying DMSP pool sizes, and potential DMS emissions, in cryoextracted leaves. The method relies on the determination of DMS free and from DMSP pools before and after the alkaline hydrolysis via HS-SPME-GC-MS. We found a significant (2.5 time increase of DMSP content in water-stressed leaves reflecting clear stress to the photosynthetic apparatus. We hypothesize that increased DMSP, and in turn DMS, in water-stressed leaves are produced by carbon sources other than direct photosynthesis, and function to protect plants either osmotically or as antioxidants. Finally, our results suggest that SPME is a powerful and suitable technique for the detection and quantification of biogenic gases in trace amounts.

  3. An Integrated Strategy for Global Qualitative and Quantitative Profiling of Traditional Chinese Medicine Formulas: Baoyuan Decoction as a Case.

    Science.gov (United States)

    Ma, Xiaoli; Guo, Xiaoyu; Song, Yuelin; Qiao, Lirui; Wang, Wenguang; Zhao, Mingbo; Tu, Pengfei; Jiang, Yong

    2016-12-07

    Clarification of the chemical composition of traditional Chinese medicine formulas (TCMFs) is a challenge due to the variety of structures and the complexity of plant matrices. Herein, an integrated strategy was developed by hyphenating ultra-performance liquid chromatography (UPLC), quadrupole time-of-flight (Q-TOF), hybrid triple quadrupole-linear ion trap mass spectrometry (Qtrap-MS), and the novel post-acquisition data processing software UNIFI to achieve automatic, rapid, accurate, and comprehensive qualitative and quantitative analysis of the chemical components in TCMFs. As a proof-of-concept, the chemical profiling of Baoyuan decoction (BYD), which is an ancient TCMF that is clinically used for the treatment of coronary heart disease that consists of Ginseng Radix et Rhizoma, Astragali Radix, Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle, and Cinnamomi Cortex, was performed. As many as 236 compounds were plausibly or unambiguously identified, and 175 compounds were quantified or relatively quantified by the scheduled multiple reaction monitoring (sMRM) method. The findings demonstrate that the strategy integrating the rapidity of UNIFI software, the efficiency of UPLC, the accuracy of Q-TOF-MS, and the sensitivity and quantitation ability of Qtrap-MS provides a method for the efficient and comprehensive chemome characterization and quality control of complex TCMFs.

  4. [E]motion in the Nineteenth Century: A Culture of Fidgets

    Directory of Open Access Journals (Sweden)

    Karen Chase

    2014-10-01

    Full Text Available I see the fidget as a neglected aspect of the sense of touch, which collects a range of suggestive imaginative movements and which opens towards a rereading of Dickens's construal of character, its relation to the self, and its social world. An affective swamping of personality repeatedly overwhelms the barriers of personality. A tic, a flick, an insult, a plea, a joke, a contortion, a wink, a tickle, a prod - such fidgets lead an active life in the novels. They often reflect the friction of inter-subjectivity, but also the abrasions between character and the universe of objects. The twittering of a Miss Flite in 'Bleak House', Bradley Headstone's physical eruptions of rage, Mr F's Aunt's proleptic warnings and Flora Finching's galloping tale-telling in 'Little Dorrit', the handiwork of Uriah Heep in 'David Copperfield', the insuppressible hyphenated speech of Jingle in 'Pickwick Papers' - these are radiant instances. My article looks to give the fidget its due and to initiate more scholarly conversation on the circle of issues that it generates: mind and body, subjects and objects, textual continuity and its disruptions.

  5. Characterization of the molecularly cloned murine alpha-globin transcription factor CP2.

    Science.gov (United States)

    Lim, L C; Fang, L; Swendeman, S L; Sheffery, M

    1993-08-25

    We recently cloned human and murine cDNAs that encode CP2, a transcription factor that interacts with the murine alpha-globin promoter. In this report, we exploited our ability to express CP2 in bacteria and eukaryotic cells to further investigate factor activities in vitro and in vivo. CP2 expressed in bacteria was significantly enriched and used in a series of DNase I footprinting and electrophoretic gel shift assays. The results suggest that CP2 binds a hyphenated recognition sequence motif that spans one DNA helix turn. In addition, the enriched bacterial protein activated transcription of alpha-globin promoter templates approximately 3- to 4-fold in vitro. We then tested the effect of elevating CP2 levels 2.5- to 5.5-fold in vivo using both transient and stable transformation assays. When a reporter construct comprised of the intact murine alpha-globin promoter driving the bacterial chloramphenicol acetyltransferase (CAT) gene was introduced into these overexpressing cells, we observed a 3- to 6-fold increase in CAT activity when compared to cells expressing normal levels of CP2. These results define the CP2 factor binding site in more detail and help characterize the activities of the factor in vivo.

  6. Bioanalytical Applications of Fluorescence Line-Narrowing and Non-Line-Narrowing Spectroscopy Interfaced with Capillary Electrophoresis and High-Performance Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Kenneth Paul [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) are widely used analytical separation techniques with many applications in chemical, biochemical, and biomedical sciences. Conventional analyte identification in these techniques is based on retention/migration times of standards; requiring a high degree of reproducibility, availability of reliable standards, and absence of coelution. From this, several new information-rich detection methods (also known as hyphenated techniques) are being explored that would be capable of providing unambiguous on-line identification of separating analytes in CE and HPLC. As further discussed, a number of such on-line detection methods have shown considerable success, including Raman, nuclear magnetic resonance (NMR), mass spectrometry (MS), and fluorescence line-narrowing spectroscopy (FLNS). In this thesis, the feasibility and potential of combining the highly sensitive and selective laser-based detection method of FLNS with analytical separation techniques are discussed and presented. A summary of previously demonstrated FLNS detection interfaced with chromatography and electrophoresis is given, and recent results from on-line FLNS detection in CE (CE-FLNS), and the new combination of HPLC-FLNS, are shown.

  7. Off-line integration of CE and MALDI-MS using a closed-open-closed microchannel system.

    Science.gov (United States)

    Jacksén, Johan; Frisk, Thomas; Redeby, Theres; Parmar, Varun; van der Wijngaart, Wouter; Stemme, Göran; Emmer, Asa

    2007-07-01

    In this work, a new technique for off-line hyphenation between CE and MALDI-MS is presented. Two closed fused-silica capillaries were connected via a silicon chip comprising an open microcanal. The EOF in the system was evaluated using mesityloxide or leucine-enkephalin as a sample and with a running buffer that rendered the analyte neutrally charged. Comparison was made between the EOF in a closed system (first capillary solely included in the electrical circuit) and in a closed-open system (first capillary and microcanal included in the electrical circuit). It was concluded that the experimental values of the EOF agreed with the theory. The influence of the capillary outer diameter on the peak dispersion was investigated using a closed-open-closed system (first capillary, microcanal and second capillary included in the electrical circuit). It was clearly seen that a capillary with 375 microm od induced considerably higher peak dispersion than a 150 microm od capillary, due to a larger liquid dead volume in the connection between the first capillary outlet and the microcanal. Mass spectrometric analysis has also been performed following CE separation runs in a closed-open-closed system with cytochrome c and lysozyme as model proteins. It was demonstrated that a signal distribution profile of the separated analytes could be recorded over a 30 mm long microcanal.

  8. Medición de la calidad percibida en organización de servicio: utilizando o Índice de Potencial de Aumento de la Satisfacción del consumidor (PASC y Modelo dos 5 GAPS

    Directory of Open Access Journals (Sweden)

    Nara Medianeira Stefano

    2010-09-01

    Full Text Available

  1. Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

    Science.gov (United States)

    Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko

    2016-04-01

    Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort.

  2. Monitoring compliance to therapy during addiction treatments by means of hair analysis for drugs and drug metabolites using capillary zone electrophoresis coupled to time-of-flight mass spectrometry.

    Science.gov (United States)

    Gottardo, Rossella; Fanigliulo, Ameriga; Sorio, Daniela; Liotta, Eloisa; Bortolotti, Federica; Tagliaro, Franco

    2012-03-10

    Capillary electrophoresis coupled to time-of-flight mass spectrometry was used in the present work for the determination of therapeutic and abused drugs and their metabolites in the hair of subjects undergoing addiction treatments, in order to monitor their compliance to therapy. For this purpose a rapid, qualitative drug screening method was adopted based on capillary electrophoresis hyphenated with time-of-flight mass spectrometry, which had earlier been developed and validated for the forensic-toxicological analysis of hair, limitedly to illicit/abused drugs [1]. Sampling of hair was carried out in order to refer to a time window of about two months from the date of sampling (i.e. 2cm ca. from cortex). A single extraction procedure was applied, allowing the determination in the hair matrix of "drugs of abuse" referred to the past abuses, and therapeutic drugs prescribed in the detoxification program as well as their metabolites. Analyte identification was based on accurate mass measurements and comparison of isotope patterns, providing the most likely matching between accurate mass value and elemental formula. Small molecules (forensic and toxicological interest could be identified unambiguously using mass spectrometric conditions tailored to meet a mass accuracy ≤5ppm. In the present study, the proposed approach proved suitable for the rapid broad spectrum screening of hair samples, although needing further confirmation of results by using fragmentation mass spectrometry.

  3. Development of a fast and selective UHPLC-DAD-QTOF-MS/MS method for the qualitative and quantitative assessment of destruxin profiles.

    Science.gov (United States)

    Taibon, Judith; Sturm, Sonja; Seger, Christoph; Parth, Martin; Strasser, Hermann; Stuppner, Hermann

    2014-11-01

    A fast and selective ultrahigh-performance liquid chromatography diode array detector (UHPLC-DAD) method combined with an off-line solid phase extraction (SPE) protocol was established to monitor destruxins (dtxs), a secondary metabolite class of highly bioactive cyclic depsipeptides. Sample purification via SPE was tailored to remove both more polar and apolar matrix constituents by applying analyte class-selective washing and elution conditions. To separate and detect destruxin congeners an UHPLC-DAD system hyphenated to a quadrupole-time-of-flight (Q-TOF) hybrid mass spectrometer was utilized. Analyses were performed on a sub-2-μm-particle-size RP-18 column with an acidified (0.02% acetic acid) 12 min water/acetonitrile solvent gradient. In the dtx congener elution zone 22 chromatographic peaks were separated. Four of these were identified by comparison with reference materials as dtx A, dtx B, dtx E, and dtx E-diol; 16 were tentatively assigned as known or novel dtx congeners by the analysis of high resolution UHPLC-DAD-QTOF-MS/MS data recorded in the positive electrospray ionization (ESI) mode. The applicability of the UHPLC-DAD assay to investigate biological materials in a qualitative and quantitative manner was proven by the application of the platform to monitor the dtx production profile of three Metarhizium brunneum strain fungal culture broths.

  4. Extracting numeric measurements and temporal coordinates from Japanese radiological reports

    Science.gov (United States)

    Imai, Takeshi; Onogi, Yuzo

    2004-04-01

    Medical records are written mainly, in natural language. The focus of this study is narrative radiological reports written in natural Japanese. These reports cannot be used for advanced retrieval, data mining, and so on, unless they are stored, using a structured format such as DICOM-SR. The goal is to structure narrative reports progressively, using natural language processing (NLP). Structure has many different levels, for example, DICOM-SR has three established levels -- basic text, enhanced and comprehensive. At the enhanced level, it is necessary to use numerical measurements and spatial & temporal coordinates. In this study, the wording used in the reports was first standardized, dictionaries were organized, and morphological analysis performed. Next, numerical measurements and temporal coordinates were extracted, and the objects to which they referred, analyzed. 10,000 CT and MR reports were separated into 82,122 sentences, and 34,269 of the 36,444 numerical descriptions were tagged. Periods, slashes, hyphens, and parentheses are ambiguously used in the description of enumerated lists, dates, image numbers, and anatomical names, as well as at the end of sentences; to resolve this ambiguity, descriptions were processed, according to the order -- date, size, unit, enumerated list, and abbreviation -- then, the tagged reports were separated into sentences.

  5. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  6. Dynamic vapor sorption as a tool for characterization and quantification of amorphous content in predominantly crystalline materials.

    Science.gov (United States)

    Sheokand, Sneha; Modi, Sameer R; Bansal, Arvind K

    2014-11-01

    It is well established that pharmaceutical processing can cause disruption of the crystal structure, leading to generation of amorphous content in crystalline materials. The presence of even a small amount of amorphous form, especially on the surface of crystalline material, can affect processing, performance, and stability of a drug product. This necessitates the need to quantify, monitor, and control the amorphous form. Numerous analytical techniques have been reported for the quantification of amorphous phase, but issues of sensitivity, suitability, limit of detection, and quantitation pose significant challenges. The present review focuses on use of dynamic vapor sorption (DVS) for quantification of amorphous content in predominantly crystalline materials. The article discusses (1) theoretical and experimental considerations important for developing a quantification method, (2) methods used for quantification of amorphous content, (3) basis for selecting a suitable methodology depending on the properties of a material, and (4) role of various instrument and sample-related parameters in designing a protocol for quantification of amorphous content. Finally, DVS-based hyphenated techniques have been discussed as they can offer higher sensitivity for quantification of amorphous content.

  7. Optimization of chemical and instrumental parameters in hydride generation laser-induced breakdown spectrometry for the determination of arsenic, antimony, lead and germanium in aqueous samples.

    Science.gov (United States)

    Yeşiller, Semira Unal; Yalçın, Serife

    2013-04-03

    A laser induced breakdown spectrometry hyphenated with on-line continuous flow hydride generation sample introduction system, HG-LIBS, has been used for the determination of arsenic, antimony, lead and germanium in aqueous environments. Optimum chemical and instrumental parameters governing chemical hydride generation, laser plasma formation and detection were investigated for each element under argon and nitrogen atmosphere. Arsenic, antimony and germanium have presented strong enhancement in signal strength under argon atmosphere while lead has shown no sensitivity to ambient gas type. Detection limits of 1.1 mg L(-1), 1.0 mg L(-1), 1.3 mg L(-1) and 0.2 mg L(-1) were obtained for As, Sb, Pb and Ge, respectively. Up to 77 times enhancement in detection limit of Pb were obtained, compared to the result obtained from the direct analysis of liquids by LIBS. Applicability of the technique to real water samples was tested through spiking experiments and recoveries higher than 80% were obtained. Results demonstrate that, HG-LIBS approach is suitable for quantitative analysis of toxic elements and sufficiently fast for real time continuous monitoring in aqueous environments.

  8. Chemical Characterization of Fruit Wine Made from Oblačinska Sour Cherry

    Directory of Open Access Journals (Sweden)

    Milica Pantelić

    2014-01-01

    Full Text Available This paper was aimed at characterizing the wine obtained from Oblačinska, a native sour cherry cultivar. To the best of our knowledge, this is the first paper with the most comprehensive information on chemical characterization of Oblačinska sour cherry wine. The chemical composition was characterized by hyphenated chromatographic methods and traditional analytical techniques. A total of 24 compounds were quantified using the available standards and another 22 phenolic compounds were identified based on the accurate mass spectrographic search. Values of total phenolics content, total anthocyanin content, and radical scavenging activity for cherry wine sample were 1.938 mg gallic acid eqv L−1, 0.113 mg cyanidin-3-glucoside L−1, and 34.56%, respectively. In general, cherry wine polyphenolics in terms of nonanthocyanins and anthocyanins were shown to be distinctive when compared to grape wines. Naringenin and apigenin were characteristic only for cherry wine, and seven anthocyanins were distinctive for cherry wine.

  9. Modification of chemical and conformational properties of natural organic matter by click chemistry as revealed by ESI-Orbitrap mass spectrometry.

    Science.gov (United States)

    Nebbioso, Antonio; Piccolo, Alessandro

    2015-11-01

    A click reaction is reported here for the first time as a useful technique to control the conformational stability of natural organic matter (NOM) suprastructures. Click conjugates were successfully formed between a previously butynylated NOM hydrophobic fraction and a hydrophilic polyethylene glycol (PEG)-amino chain. The click products were shown by size exclusion chromatography (HPSEC) hyphenated with Orbitrap mass spectrometry (MS) in electrospray ionization (ESI) (+), while precursors were visible in ESI (-). Despite their increase in molecular weight, HPSEC elution of click conjugates occurred after that of precursors, thus showing their departure from the NOM supramolecular association. This indicates that the click-conjugated NOM molecules were varied in their hydrophilic and cationic character and lost the capacity to accommodate in the original hydrophobic suprastructures. The most abundant product had the C16H30O5N4 formula, a click conjugate of butanoic acid, while other products were short-chained (C4-C8) linear unsaturated and hydroxylated carboxylic acids. Tandem MS revealed formation of triazole rings in clicked conjugates and their two fragmentations at the ester and the C-N alkyl-aryl bonds. The behavior of NOM molecules modified by click chemistry confirms that hydrophobicity and ionic charge of humic molecules play a pivotal role in stabilizing intermolecular forces in NOM. Moreover, the versatility of the click reaction may become useful to decorate NOM molecules with a variety of substrates, in order to alter NOM conformational and chemical properties and diversify its applications in the environment.

  10. FAMILY FARMERS AND FRUIT PRODUCTION SYSTEMS IN ITAPURANGA, GOIÁS, BRAZIL AGRICULTORES FAMILIARES E SISTEMAS DE PRODUÇÃO DE FRUTAS EM ITAPURANGA, GOIÁS

    Directory of Open Access Journals (Sweden)

    Glays Rodrigues Matos

    2009-09-01

    ="font-size: small;">Itapuranga, município do Estado de Goiás, tem uma representação significativa da agricultura familiar, com o desenvolvimento de sistemas de produção de frutas, especialmente maracujá, mamão e banana. O objetivo da pesquisa é analisar a organização do sistema de produção dos agricultores familiares fruticultores de Itapuranga. A metodologia utilizada está fundamentada no estudo dos sistemas agrários, sendo que as técnicas de pesquisa para o levantamento de dados de campo foram: pesquisa documental, entrevistas e observação. Inicialmente, os sistemas de produção dos agricultores familiares de Itapuranga estavam organizados em torno de lavouras diversificadas, orientados ao consumo da família e à comercialização dos excedentes. A partir da década de 1990, os agricultores familiares passaram a desenvolver sistemas de produção especializados na fruticultura, integrados a outros sistemas de cultivo e ao sistema de criação de bovinos de leite. A pesquisa conclui que, apesar das limitações, a fruticultura desenvolvida em Itapuranga representa um potencial de sustentabilidade da agricultura familiar.

    PALAVRAS-CHAVE: Agricultura familiar; sistemas agrários; sistemas de produção; fruticultura.

    This work aimed to study the interaction between genotypes and environments, using the BLUP/REML procedure for evaluation of precocious cashew clones. The purpose of this work was to identify genotypes that simultaneously aggregate high productivity and

  11. Reanimación del paciente quemado Resuscitation of burned patients

    Directory of Open Access Journals (Sweden)

    Marco Antonio Hoyos Franco

    2008-06-01

    Full Text Available

    Tetanus is an immune-preventable disease which still causes ravages in nations without protective vaccination coverage. Its lethality rate is almost 50%. It is necessary that health personnel are familiarized with its prevention, diagnosis, treatment and

  12. Anthropometric and functional characteristics of phisically active individuals Características antropométricas y funcionales de individuos físicamente activos

    Directory of Open Access Journals (Sweden)

    Liliana Constanza Marmolejo

    2008-06-01

    Full Text Available

    In order to determine their health status and physical fitness, studies were carried out in 57 women and 60 men

  13. Prevalence of sleep disorders in school children from Sabaneta, Colombia 2005 Prevalencia de los trastornos del sueño en niños escolares de Sabaneta, Colombia, 2005

    Directory of Open Access Journals (Sweden)

    José William Cornejo Ochoa

    2008-06-01

    Full Text Available

    Sleep is one of the basic needs in a child’s life and it is essential for day time alert state. Any sleep

  14. Um Caderno Digital nos laptops educacionais: proposta conceitual e ferramenta

    Directory of Open Access Journals (Sweden)

    Diego Soares Cardoso

    2009-10-01

    Full Text Available

  15. DIAGNOSIS OF “CACHAÇA” PRODUCTION IN THE ORIZONA REGION, GOIÁS STATE, BRAZIL DIAGNÓSTICO DA PRODUÇÃO DE CACHAÇA NA REGIÃO DE ORIZONA, ESTADO DE GOIÁS, BRASIL

    Directory of Open Access Journals (Sweden)

    Márcio Caliari

    2009-01-01

    Full Text Available

    The aim of this work was to diagnose relevant aspects of the “cachaça” production

  16. THE PHONOLOGICAL SYSTEM OF SPANISH

    Directory of Open Access Journals (Sweden)

    Claudia S. Salcedo

    2010-10-01

    Full Text Available Spanish articulatory phonetics, the classification of sounds and the physiological mechanism used in the production of phonemes are discussed in this article. The process of learning a language consists of classifying sounds within the target language. Since the learner may be hearing the utterance in a different way than the native speaker some objective criteria are needed to classify sounds. If these distinctions are not mastered, he may be perceived as sounding awkward. Other phonological processes are applied in informal situations due to socio-linguistic factors such as age, social class, and education. Sound deletion in particular phonological environments are not done randomly by the speaker, but by necessity to retain semantic comprehension. Allophonic choices within phonemes make up the dialect for a particular area.

    En varios trabajos se ha publicado la existencia de asociación estadística entre polimorfismos del HLA y el pronóstico de individuos seropositivos al virus de la hepatitis C (VHC pero no existen estudios que demuestren asociación entre genes y ser infectado por VHC