The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform

Daryl R. Williams - One of the best experts on this subject based on the ideXlab platform.

  • Novel inverse liquid Chromatography Detector configuration for studying solid-liquid adsorption.
    Journal of Chromatography A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Abstract Inverse liquid Chromatography (ILC) is a physicochemical chromatographic technique for studying solid–liquid interactions and surface properties of unknown solid materials. However, such studies are dependant on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV–vis Detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two Detector system are discussed including the use of both Detectors in the linear concentration regime; with the choice of an optimal Detector wavelength being the most critical factor. The two Detector system was demonstrated to be capable of verifying reversible adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two Detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

  • Novel inverse liquid Chromatography Detector configuration for studying solid-liquid adsorption.
    Journal of chromatography. A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Inverse liquid Chromatography (ILC) is a physicochemical chromatographic technique for studying solid-liquid interactions and surface properties of unknown solid materials. However, such studies are dependent on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV-vis Detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two Detector system are discussed including the use of both Detectors in the linear concentration regime; with the choice of an optimal Detector wavelength being the most critical factor. The two Detector system was demonstrated to be capable of verifying reversible adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two Detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

Pirre P. Ylä-mäihäniemi - One of the best experts on this subject based on the ideXlab platform.

  • Novel inverse liquid Chromatography Detector configuration for studying solid-liquid adsorption.
    Journal of Chromatography A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Abstract Inverse liquid Chromatography (ILC) is a physicochemical chromatographic technique for studying solid–liquid interactions and surface properties of unknown solid materials. However, such studies are dependant on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV–vis Detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two Detector system are discussed including the use of both Detectors in the linear concentration regime; with the choice of an optimal Detector wavelength being the most critical factor. The two Detector system was demonstrated to be capable of verifying reversible adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two Detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

  • Novel inverse liquid Chromatography Detector configuration for studying solid-liquid adsorption.
    Journal of chromatography. A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Inverse liquid Chromatography (ILC) is a physicochemical chromatographic technique for studying solid-liquid interactions and surface properties of unknown solid materials. However, such studies are dependent on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV-vis Detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two Detector system are discussed including the use of both Detectors in the linear concentration regime; with the choice of an optimal Detector wavelength being the most critical factor. The two Detector system was demonstrated to be capable of verifying reversible adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two Detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

Francesco Palmisano - One of the best experts on this subject based on the ideXlab platform.

  • an acetylcholinesterase choline oxidase based amperometric biosensor as a liquid Chromatography Detector for acetylcholine and choline determination in brain tissue homogenates
    Analytical Chemistry, 2001
    Co-Authors: Antonio Guerrieri, Francesco Palmisano
    Abstract:

    A liquid Chromatography (LC) Detector based on a fast response and sensitive bienzyme amperometric biosensor for acetylcholine (ACh) and choline (Ch) is described. The Detector fabrication consisted of glutaraldehyde co-cross-linking of acetylcholinesterase and choline oxidase with bovine serum albumin on the Pt working electrode of a conventional thin-layer electrochemical flow cell. The influence of some experimental parameters (e.g., enzyme loading, thickness of the bienzyme layer, flow rate) on the Detector characteristics has been studied in order to optimize the analyte response while minimizing band-broadening and distortion. A mobile phase consisting of a phosphate buffer (I, 0.1 M; pH, 6.5) containing 5 mM sodium hexane sulfonate and 10 mM tetramethylammonium phosphate was found to give very satisfactory resolution and peak shape in ion-pair, reversed-phase LC. Linear responses were observed over at least four decades and absolute detection limits (at a signal-to-noise ratio of 3) were 12 and 27 ...

Ki-jung Paeng - One of the best experts on this subject based on the ideXlab platform.

  • Ion Chromatography Detector based on solid-state ion-selective electrode array.
    Journal of Chromatography A, 2000
    Co-Authors: Dong Kwon Lee, Geun Sig Cha, Hakhyun Nam, Hyuk Jin Lee, Ki-jung Paeng
    Abstract:

    A variety of neutral carrier type ionophores for monovalent cations were employed to prepare solid-state cation-selective electrodes (SSEs) for use as a Detector in single-column ion Chromatography (IC). The polyurethane-based pseudoreference electrode made it possible to assemble an array type SSE Detector for IC. An SSE-based Detector provides not only the overall chromatogram for the separated ion species (monensin methyl ester-nonactin-based membrane), but also the enhanced chromatogram for specified ions of interest (valinomycin as K+ and nonactin for NH4+). This feature makes it possible to perform highly quantitative analysis with low detection limits even if the separation efficiency of the ion-exchange is not sufficient. Since SSE-based IC Detectors are easily miniaturized and replaceable at low cost, they are an ideal component of a portable IC system.

Juan Cacho - One of the best experts on this subject based on the ideXlab platform.

  • quantitative gas Chromatography olfactometry analytical characteristics of a panel of judges using a simple quantitative scale as gas Chromatography Detector
    Journal of Chromatography A, 2003
    Co-Authors: Vicente Ferreira, Jan Petka, Margarita Aznar, Juan Cacho
    Abstract:

    Some questions related to the ability of gas Chromatography-olfactometry (GC-O) to provide quantitative measurements of the concentration of a given odorant in an extract are explored and discussed. A panel of eight individuals has been used to evaluate the intensity of 15 odorants present at different concentrations. The use of very simple scales, such as a 0-3 scale, makes it possible to build calibration graphs based on the different stimulus-response models (Fechner, Stevens, Hill) and, with a proper calibration, up to nine different concentration levels can be discriminated by an eight-judge panel. The signal shows a good long-term stability, and its precision varies between 3.7 and 8% of the whole scale, with 5.7% as average. Sensitivity is extremely dependent on the compound: in the best case a concentration change of 20% can be detected, while in the worst, concentrations must differ more than one order of magnitude. In average, concentrations must differ between 2 and 4.7 times (including calibration error) or between 1.2 and 2.3 (excluding calibration error). The performance of the different judges, the effect of the close elution of two odors and the benefits derived from the use of more complex scales (7-points) are briefly discussed from the perspective of the analytical performance of GC-O methods.