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Peer Reviewed
See detailInnovative analytical strategy using ion-mobility for structural or functional selenium isomers identification by ion mobility spectrometry
Far, Johann ULiege; Kune, Christopher ULiege; Lobinski, Ryszard et al

Poster (2013, July)

Selenium (Se) is a trace element which is both essential and toxic depending on its concentration and its chemical form. Se-rich yeast is one of the most popular Se source for supplementation. The ... [more ▼]

Selenium (Se) is a trace element which is both essential and toxic depending on its concentration and its chemical form. Se-rich yeast is one of the most popular Se source for supplementation. The classical method of speciation is related to multidimensional liquid chromatography (LC) hyphenated to mass spectrometry (MS) Recent advances in Se speciation led to greatly improve the Se speciation in these samples but isomers identification and quantification remain challenging. This work focuses on the elaboration of an innovative analytical strategy for the detection and the structural elucidation of isobaric selenium compounds present in Se-rich yeast. A specific complex formation agent acts as a chemical probe for the detection of chemical function. The addition of a complexing agent can improve the discrimination between structural or functional Se isomers using ion mobility techniques as Ion Mobility Spectrometry (IMS) by increasing the molecular weight (i.e. the m/z ratio in MS) and the collision cross section of a target ion after selective complexation. This Ion Mobility orthogonal separation improves the structural elucidation. Crown ethers used as shifting agents can specifically form complexes with primary amines. The addition of crown ether to different low molecular weight fractions obtained by multidimensional LC of a water extract from Se-rich yeast permitted to detect Se isomers and confirmed their structure using IMS. [less ▲]

Detailed reference viewed: 53 (10 ULiège)
Peer Reviewed
See detailInnovative analytical strategy using ion-mobility shifting additive for isobaric selenium compound identification in selenomethionine standards by IMS
Kune, Christopher ULiege; Far, Johann ULiege; Eppe, Gauthier ULiege et al

Conference (2013, July 09)

Selenium (Se) is a trace element which is both essential and toxic depending on its concentration and its chemical form. Selenomethionine (SeMet) is one of the widely used selenium standard during ... [more ▼]

Selenium (Se) is a trace element which is both essential and toxic depending on its concentration and its chemical form. Selenomethionine (SeMet) is one of the widely used selenium standard during Selenium speciation studies. This work was focused on the elaboration of an analytical strategy for the detection and the structural elucidation of an isobaric Se interference, which is found in standard solutions of SeMet by high resolution mass spectrometry (Rm/Δm > 20.000). The structural elucidation of these compounds requires the isolation of the respective parent ion. Nevertheless, the mass difference between SeMet and its interference is less than 0.02Da which is well below the window selection of conventional techniques in mass spectrometry (Quadripole, ion trap). The empirical formula and double bound equivalent (DBE) of these ions suggest different tridimensional structures which lead to a discrimination depending on the ion mobility. This separation is observed, both in gaseous and liquid phase, by Ion Mobility Spectrometry (IMS), Capillary Electrophoresis (CE) and Liquid Chromatography (LC) which are hyphenated to mass spectrometry as detector. The separation efficiency of these ions by IMS and CE is improved by using specific shifting agents (18-Crown-6 Ether) selective to only one of these ions. This strategy has successfully separated the two isobaric ions present and leads to the structural elucidation of the isobar contaminant of SeMet. [less ▲]

Detailed reference viewed: 61 (29 ULiège)
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See detailAN INNOVATIVE APPROACH TO SELECT THE PREDICTION MODEL IN THE DEVELOPMENT OF NIR SPECTROSCOPIC METHODS
Ziemons, Eric ULiege; Mantanus, Jérôme ULiege; Rozet, Eric ULiege et al

Poster (2012, March)

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results ... [more ▼]

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results. Implementation of a NIR quantitative method is performed using an iterative heuristic approach that will ultimately build a model allowing the prediction of the concentration of the analyte of interest. In this context, the aim of the present study was to develop an innovative approach based on statistical tolerance intervals and the desirability index FMI (Fitting Model Index) to select the most appropriate prediction model from a list of candidate models instead of using conventional criteria such as R², RMSEC, RMSECV and RMSEP [1-2] without objective decision rules. This new approach is illustrated on different steps of a real pharmaceutical manufacturing process: water and Active Pharmaceutical Ingredient (API) determinations in pharmaceutical pellets. Variability sources such as production campaigns, batches, days and operators were introduced in the calibration and validation sets. Partial Least Square (PLS) regression on the calibration sets was performed to build prediction models of which the ability to quantify accurately was tested with the validation sets. Regarding the product specifications, the acceptance limits were set at 20% and 5%, for the moisture and API determination, respectively.As can be seen from Figure 1 and 2, this innovative approach based on the desirability index FMI of the accuracy profile enabled to build and select the most appropriate prediction model in full accordance with its very final goal, to quantify as accurately as possible the analytes of interest. [1] Hubert Ph. et al., J. Pharm. Biomed. Anal., 36, 2007, 579-586. [2] Rozet E. et al., Ana. Chim. Acta, 591, 2007, 239-247. [less ▲]

Detailed reference viewed: 79 (15 ULiège)
Peer Reviewed
See detailAn innovative approach to understanding L. monocytogenes in farmhouse cheese
Schvartzman Echenique, Maria Sol ULiege

Conference (2009, September 21)

Detailed reference viewed: 7 (0 ULiège)
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Peer Reviewed
See detailInnovative artificial fog production device - A technical facility for research activities.
Colomb, M.; Dufour, J.; Hirech, M. et al

Conference (2004)

A new innovative fog production device has been developed in close cooperation with partners of a European project called “FOG” funded by the EU. It is set up in the fog chamber of the road and bridges ... [more ▼]

A new innovative fog production device has been developed in close cooperation with partners of a European project called “FOG” funded by the EU. It is set up in the fog chamber of the road and bridges laboratory at Clermont-Ferrand. Most of the activities of this laboratory are dedicated to road safety but the facility is open to any other activity, such as environmental research. The recent developments consist in setting up a controllable device able to produce stable visibility levels and homogeneous fog, representative of various types of natural water droplet distribution. The fog characteristics were determined and compared to natural fog. Results are presented for a selection of conditions including stabilized visibility levels for dense fog, less than 50 metres meteorological visibility and two kinds of droplet distribution. [less ▲]

Detailed reference viewed: 56 (3 ULiège)
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Peer Reviewed
See detailInnovative bolted beam-to-column joints for seismic resistant building frames
Coméliau, Ludivine ULiege; Demonceau, Jean-François ULiege; Jaspart, Jean-Pierre ULiege

in Dubina, Dan; Grecea, Daniel (Eds.) CONNECTIONS VII proceedings (2012)

In the present paper, innovative joint configurations leading to more economical solutions for full-strength beam-to-column joints for seismic building frames are detailed. The specificities of these ... [more ▼]

In the present paper, innovative joint configurations leading to more economical solutions for full-strength beam-to-column joints for seismic building frames are detailed. The specificities of these joints are due to the fact that (i) the column is made of high strength steel while the beam are made of mild carbon steel and (ii) the design of some components allows partially neglecting the overstrength factor. Also, methods for the characterisation of specific joint components not directly covered by the Eurocode recommendations are proposed. [less ▲]

Detailed reference viewed: 107 (20 ULiège)
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See detailINNOVATIVE BOLTED BEAM-TO-COLUMN JOINTS IN MOMENT RESISTANT BUILDING FRAME: FROM EXPERIMENTAL TESTS TO DESIGN GUIDELINES
Hoang, Van Long ULiege; Demonceau, Jean-François ULiege; Jaspart, Jean-Pierre ULiege

in Dubina, Dan; Landolfo, Raffaele; Stratan, Aurel (Eds.) et al Application of High Strength Steels in Seismic Resistant Structures (2013)

Detailed reference viewed: 93 (8 ULiège)
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Peer Reviewed
See detailInnovative Concepts in Navigation Lock Design
Rigo, Philippe ULiege; Daniel, Ryszard

in The Port Infrastructure Seminar , 2010, TUDelft, NL (2010, June)

This paper presents the new report n°106 of PIANC InCom WG29 on Innovations in Navigation Lock Design, published by PIANC in August 2009, as well as some additional contributions on lock gates (gate ... [more ▼]

This paper presents the new report n°106 of PIANC InCom WG29 on Innovations in Navigation Lock Design, published by PIANC in August 2009, as well as some additional contributions on lock gates (gate contact technology). The paper highlights the main objectives and issues of his PIANC report with a specific emphasis on gates and specifically on the contact aspects. Locks are key structures for the development of the navigation in canals and in natural rivers where weirs regulate water levels to enable navigation. They may also be strategic infrastructure for port development. The core of this report has three major parts. The first part presents an exhaustive list of design goals associated with locks. This section is particularly important for decision makers who have to launch a new project. The second part reviews the design principles that must be considered by designers. This section is methodologically oriented. The third part is technically oriented. All main technical aspects (hydraulics, structures, foundations, including computational aspects, etc.) are reviewed, focussing on changes and innovations occurring since 1986. Perspectives and trends for the future are also listed. When appropriate, recommendations are listed. It is impossible to give the details of all lock innovation areas in this paper. As an example, the lock gates and, in particular, the modern views on their contact issues have been chosen. These new solutions are welcome to limit the maintenance and to extend the service life of lock gates. [less ▲]

Detailed reference viewed: 160 (5 ULiège)
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See detailInnovative designs for the imaging suite on Solar Orbiter
Auchere, Frederic; Song, Xueyen; Rouesnel, Frederic et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2005, August 01)

Orbiting around the Sun on an inclined orbit with a 0.2 UA perihelion, the Solar Orbiter probe will provide high resolution views of the Sun from various angles unattainable from Earth. Together with a ... [more ▼]

Orbiting around the Sun on an inclined orbit with a 0.2 UA perihelion, the Solar Orbiter probe will provide high resolution views of the Sun from various angles unattainable from Earth. Together with a set of high resolution imagers, the Full Sun Imager is part of the EUV Imaging suite of the Solar Orbiter mission. The mission's ambitious characteristics draw severe constraints on the design of these instruments. We present a photometrically efficient, compact, and lightweight design for the Full Sun Imager. With a 5 degrees field of view, this telescope will be able to see the global solar coronal structure from high viewing angles. Thermal solutions reducing the maximum power trapped in the High Resolution Imagers are also proposed. [less ▲]

Detailed reference viewed: 54 (3 ULiège)
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Peer Reviewed
See detailInnovative development and validation of an HPLC/DAD method for the qualitative and quantitative determination of major cannabinoïds in cannabis plant material
De Backer, Benjamin ULiege; Debrus, Benjamin ULiege; Lebrun, Pierre ULiege et al

Poster (2009, August)

GC is commonly used for the analysis of cannabis samples, e.g. in forensic chemistry. However, as this method is based on heating of the sample, acidic forms of cannabinoids are decarboxylated into their ... [more ▼]

GC is commonly used for the analysis of cannabis samples, e.g. in forensic chemistry. However, as this method is based on heating of the sample, acidic forms of cannabinoids are decarboxylated into their neutral counterparts. Converely, HPLC permits the determination of the original composition of plant cannabinoids by direct analysis. Several HPLC methods have been described in the literature, but most of them failed to separate efficiently all the cannabinoids or were not validated according to general guidelines. By use of an innovative methodology for modelling chromatographic responses, a simple and accurate HPLC/DAD method was develop [less ▲]

Detailed reference viewed: 252 (66 ULiège)
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Peer Reviewed
See detailInnovative development and validation of an HPLC/DAD method for the qualitative and quantitative determination of major cannabinoids in cannabis plant material
De Backer, Benjamin ULiege; Debrus, Benjamin ULiege; Lebrun, Pierre ULiege et al

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2009), 877(32), 4115-4124

GC is commonly used for the analysis of cannabis samples, e.g. in forensic chemistry. However, as this method is based on heating of the sample, acidic forms of cannabinoids are decarboxylated into their ... [more ▼]

GC is commonly used for the analysis of cannabis samples, e.g. in forensic chemistry. However, as this method is based on heating of the sample, acidic forms of cannabinoids are decarboxylated into their neutral counterparts. Conversely, HPLC permits the determination of the original composition of plant cannabinoids by direct analysis. Several HPLC methods have been described in the literature, but most of them failed to separate efficiently all the cannabinoids or were not validated according to general guidelines. By use of an innovative methodology for modelling chromatographic responses, a simple and accurate HPLC/DAD method was developed for the quantification of major neutral and acidic cannabinoids present in cannabis plant material: Δ9-tetrahydrocannabinol (THC), THC-acid (THCA), cannabidiol (CBD), CBD-acid (CBDA), cannabigerol (CBG), CBG-acid (CBGA) and cannabinol (CBN). Δ8-tetrahydrocannabinol (∆8-THC) was determined qualitatively. Following the practice of design of experiments, predictive multilinear models were developed and used in order to find optimal chromatographic analytical conditions. The method was validated following an approach using accuracy profiles based on β-expectation tolerance intervals for the total error measurement, and assessing the measurements uncertainty. This analytical method can be used for diverse applications, e.g. plant phenotype determination, evaluation of psychoactive potency and control of material quality. [less ▲]

Detailed reference viewed: 534 (93 ULiège)
Peer Reviewed
See detailInnovative Electrodes for Dye Sensitized Solar Cells
Langley, Daniel ULiege; Giusti, Gael; Zhang, Shanting et al

Conference (2014)

Detailed reference viewed: 29 (2 ULiège)
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Peer Reviewed
See detailInnovative green supercritical fluid chromatography development for the determination of polar compounds
Dispas, Amandine ULiege; Lebrun, Pierre ULiege; Sassiat, Patrick et al

in Journal of Chromatography. A (2012), 1256

In the context of green analytical chemistry, a supercritical fluid chromatography method was developed. In order to prove the potential of this technology, a worst case was selected, i.e. the separation ... [more ▼]

In the context of green analytical chemistry, a supercritical fluid chromatography method was developed. In order to prove the potential of this technology, a worst case was selected, i.e. the separation of very polar compounds. For that purpose, an innovative methodology based on design of experiments (DoE) and design space (DS) was previously developed and successfully tested on liquid chromatography. For the first time, this methodology was applied to a supercritical fluid chromatography (SFC) separation. First, a screening design was used to select the stationary phase and the nature of the mobile phase based on a maximization of the number of peaks eluted and a minimization of the number of co-eluted peaks. Then, a central composite design with orthogonal blocks defined a set of experiments used to model the retention times of each peak at the beginning, the apex, and the end. The gradient slope, the isocratic plateau before the gradient, the temperature, and the concentration of trifluoroacetic acid (TFA) in the mobile phase were the potentially influential factors. The critical quality attributes (CQAs), i.e. the separation (S) between peaks of the most critical pair, and the analysis time were the responses considered to assess the quality of the separation. The DS was computed as the multidimensional subspace where the probability for the separation and analysis time criteria to be within acceptance limits was higher than a defined quality level. The DS was computed propagating the prediction error from the modeled responses to the quality criterion using Monte Carlo simulations. The optimal condition was predicted at a gradient slope of 3.8% min−1 to linearly modify the modifier proportion between 5 and 40%, an isocratic time of 3 minutes, a concentration of TFA of 25 mM, and a temperature of 60.5 °C. This optimal condition was experimentally tested to confirm the prediction. Furthermore, chromatographic conditions included in the DS and on the limits of the DS were experimentally tested to assess the robustness of the developed SFC method. [less ▲]

Detailed reference viewed: 109 (23 ULiège)
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Peer Reviewed
See detailInnovative high-performance liquid chromatography method development for the screening of 19 antimalarial drugs based on a generic approach, using design of experiments, independent component analysis and design space
Debrus, Benjamin ULiege; Lebrun, Pierre ULiege; Mbinze Kindenge, Jérémie et al

in Journal of Chromatography. A (2011), 1218

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 ... [more ▼]

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 antimalarial drugs. This global LC method development methodology (i.e. DoE–ICA–DS) was used to optimize the separation of 19 antimalarial drugs to obtain a screening method. DoE–ICA–DS methodology is fully compliant with the current trend of quality by design. DoE was used to define the set of experiments to model the retention times at the beginning, the apex and the end of each peak. Furthermore, ICA was used to numerically separate coeluting peaks and estimate their unbiased retention times. Gradient time, temperature and pH were selected as the factors of a full factorial design. These retention times were modelled by stepwise multiple linear regressions. A recently introduced critical quality attribute, namely the separation criterion (S), was also used to assess the quality of separations rather than using the resolution. Furthermore, the resulting mathematical models were also studied from a chromatographic point of view to understand and investigate the chromatographic behaviour of each compound. Good adequacies were found between the mathematical models and the expected chromatographic behaviours predicted by chromatographic theory. Finally, focusing at quality risk management, the DS was computed as the multidimensional subspace where the probability for the separation criterion to lie in acceptance limits was higher than a defined quality level. The DS was computed propagating the prediction error from the modelled responses to the quality criterion using Monte Carlo simulations. DoE–ICA–DS allowed encountering optimal operating conditions to obtain a robust screening method for the 19 considered antimalarial drugs in the framework of the fight against counterfeit medicines. Moreover and only on the basis of the same data set, a dedicated method for the determination of three antimalarial compounds in a pharmaceutical formulation was optimized to demonstrate both the efficiency and flexibility of the methodology proposed in the present study. [less ▲]

Detailed reference viewed: 145 (40 ULiège)