References of "Debrus, Benjamin"
     in
Bookmark and Share    
Full Text
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 ULg; Debrus, Benjamin ULg; Lebrun, Pierre ULg 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: 299 (84 ULg)
Full Text
Peer Reviewed
See detailImplementation of new Fast-GC-MS and UHPLC-MS/MS data in a conventional GC-MS database for heroin profiling
Debrus, Benjamin ULg; Broséus, Julian; Guillarme, Davy et al

Conference (2009, October)

Detailed reference viewed: 54 (11 ULg)
Full Text
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 ULg; Debrus, Benjamin ULg; Lebrun, Pierre ULg 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: 159 (64 ULg)
Full Text
Peer Reviewed
See detailTransfer of heroin profiling method from conventional GC-MS to Fast-GC-MS and UHPLC-MS/MS
Debrus, Benjamin ULg; Broséus, Julian; Guillarme, Davy et al

Conference (2009, August)

Detailed reference viewed: 32 (5 ULg)
Full Text
Peer Reviewed
See detailA new statistical method for the automated detection of peaks in UV-DAD chromatograms of a sample mixture
Debrus, Benjamin ULg; Lebrun, Pierre ULg; Ceccato, Attilio ULg et al

in Talanta (2009), 79

One of the major issues within the context of the fully automated development of chromatographic methods consists of the automated detection and identification of peaks coming from complex samples such as ... [more ▼]

One of the major issues within the context of the fully automated development of chromatographic methods consists of the automated detection and identification of peaks coming from complex samples such as multi-component pharmaceutical formulations or stability studies of these formulations. The same problem can also occur with plant materials or biological matrices. This step is thus critical and time-consuming, especially when a Design of Experiments (DOE) approach is used to generate chromatograms. The use of DOE will often maximize the changes of the analytical conditions in order to explore an experimental domain. Unfortunately, this generally provides very different and “unpredictable” chromatograms which can be difficult to interpret, thus complicating peak detection and peak tracking (i.e. matching peaks among all the chromatograms). In this context, Independent Components Analysis (ICA), a new statistically based signal processing methods was investigated to solve this problem. The ICA principle assumes that the observed signal is the resultant of several phenomena (known as sources) and that all these sources are statistically independent. Under those assumptions, ICA is able to recover the sources which will have a high probability of representing the constitutive components of a chromatogram. In the present study, ICA was successfully applied for the first time to HPLC–UVDAD chromatograms and it was shown that ICA allows differentiation of noise and artifact components from those of interest by applying clustering methods based on high-order statistics computed on these components. Furthermore, on the basis of the described numerical strategy, itwas also possible to reconstruct a cleaned chromatogram with minimum influence of noise and baseline artifacts. This can present a significant advance towards the objective of providing helpful tools for the automated development of liquid chromatography (LC) methods. It seems that analytical investigations could be shortened when using this type of methodologies. [less ▲]

Detailed reference viewed: 175 (47 ULg)
Full Text
Peer Reviewed
See detailNouvelle méthodologie pour le développement automatisé de méthodes analytiques en chromatographie liquide pour l’analyse de mélanges de composés inconnus
Debrus, Benjamin ULg; Lebrun, Pierre ULg; Rozet, Eric ULg et al

in Spectra Analyse (2009), 268

Nowadays, many strategies to optimize chromatographic methods are available. However, the development of chromatographic methods remains the most limiting step in the process of synthesis or ... [more ▼]

Nowadays, many strategies to optimize chromatographic methods are available. However, the development of chromatographic methods remains the most limiting step in the process of synthesis or identification of new molecules that could lead to therapeutic agents or new biomarkers despite the availability of new technologies both in chemistry (chemical combinatorial, high throughput screening...) and in analytical biochemistr y (proteomics, metabolomics, herbal ... fingerprinting). Therefore, the aim of this study is to test a new methodology for developing automated chromatographic methods combining experimental planning, independent component analysis, analysis of predictive error propagation and multiple linear regression modeling. Finally, this automated methodology has enabled us to successfully separate the components of an unknown mixture. [less ▲]

Detailed reference viewed: 192 (31 ULg)
Full Text
Peer Reviewed
See detailCE-MS method development for peptides analysis, especially hepcidin, an iron metabolism marker.
Martin, Gaëlle ULg; Mansion, François ULg; Servais, Anne-Catherine ULg et al

in Electrophoresis (2009), 30(15), 2624-31

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the ... [more ▼]

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the addition of cyclodextrins or organic solvents in the BGE or the use of coated capillaries. Best results in terms of resolution, symmetry and efficiency were obtained with a BGE made of 500 mM ammonium acetate pH 4.5/ACN 70:30 v/v. Using the methodology of experimental design, BGE concentration, sheath liquid composition and MS-coupling parameters were then optimized in order to obtain the best signal intensity for hepcidin. Finally, a 225 mM BGE and a sheath liquid composed of isopropanol/water 80:20 v/v containing 0.5% v/v formic acid were selected as it constitutes the best compromise for selectivity, peak shape and sensitivity. [less ▲]

Detailed reference viewed: 104 (23 ULg)
Peer Reviewed
See detailDesign Space for analytical methods. A Bayesian perspective based on multivariate models and prediction
Lebrun, Pierre ULg; Boulanger, Bruno ULg; Jullion, Astrid et al

Conference (2008, September)

Detailed reference viewed: 34 (13 ULg)
Peer Reviewed
See detailThe Expected Design Space for analytical methods: a new perspective based on modeling and prediction
Lebrun, Pierre ULg; Boulanger, Bruno ULg; Debrus, Benjamin ULg et al

Conference (2008, June)

The Design Space (DS) of an analytical method is defined as the set of factor settings that provides satisfactory results, with respect to pre-defined constraints. The proposed methodology aims at ... [more ▼]

The Design Space (DS) of an analytical method is defined as the set of factor settings that provides satisfactory results, with respect to pre-defined constraints. The proposed methodology aims at identifying a region in the space of factors that will likely provide satisfactory results during the future use of the analytical method in routine, through an optimization process of this method. First, the DS is statistically defined as derived from the β-Expectation prediction interval. Second, multi-criteria perspective is added in this definition as it is often required for optimizing analytical method. Finally, a Monte-Carlo simulation is envisaged to numerically predict and identify the DS under uncertainty. Examples based on high-performance liquid chromatography (HPLC) methods will be given, illustrating the applicability of the methodology. [less ▲]

Detailed reference viewed: 66 (8 ULg)
See detailUse of Independent Component Analysis and clustering methods to find and identify relevant components in a matrix of UV-spectral data
Lebrun, Pierre ULg; Debrus, Benjamin ULg; Boulanger, Bruno ULg et al

Scientific conference (2008, May)

In the framework of the elaboration of new pharmaceutical formulations, statistical methodologies can accelerate and automate the development and optimization of quantitative methods. To fulfil this ... [more ▼]

In the framework of the elaboration of new pharmaceutical formulations, statistical methodologies can accelerate and automate the development and optimization of quantitative methods. To fulfil this objective, design of experiment (DOE) are widely used. In this context, the same mixture of analytes is injected while LC operating conditions are assessed. This gives plenty of very different chromatograms that can be tedious and time-consuming to interpret. Recently, the independent component analysis (ICA) has shown its usefulness to interpret chromatogram, i.e. to separate numerical signals from a matrix containing data provided by liquid chromatography system equipped with ultra violet diode array detector (LC-UV DAD). A matrix containing peaks corresponding to different analytes is then obtained. A brief summary of the ICA algorithm, applied to this problem, will be first given. The aim of the current work is to show that an automated methodology can be used to match together ICA-identified peaks that correspond to the same analytes in different chromatograms. In this way, this task, attributed to analytical experts, can be quickened and easier. This methodology uses classical hierarchical agglomerative clustering with special dissimilarity measures between spectra. [less ▲]

Detailed reference viewed: 33 (16 ULg)
Full Text
Peer Reviewed
See detailDevelopment of a new predictive modelling technique to find with confidence equivalence zone and design space of chromatographic analytical methods
Lebrun, Pierre ULg; Govaerts, Bernadette; Debrus, Benjamin ULg et al

in Chemometrics and Intelligent Laboratory Systems (2008), 91

A new method for modelling chromatographic responses is presented as a critical piece for the achievement of automated development of analytical methods. This methodology is based on four parts. First, we ... [more ▼]

A new method for modelling chromatographic responses is presented as a critical piece for the achievement of automated development of analytical methods. This methodology is based on four parts. First, we propose to use a very little set of statistical equations to create predictive models for retention time based responses as the apex, the width and the asymmetry of peaks. Second, an experimental design is set up to realize experiments. Third, using grid search over the domain, multi criteria decision is taken with respect to different local or global optimization criteria, used as desirability functions. This allows finding an optimal chromatogram. Fourth, we advice to investigate how the predictive error of the models propagates around optimal solution. This allows to give confidence in the optimal solution, in finding a set of zones that presumably will give an acceptable solution. Design spaces can be derived with a similar technique. The approach is exemplified with a real case and predictions of models at optimal analytical conditions are validated through new experiments. Flexibility is left over all the presented methodology. [less ▲]

Detailed reference viewed: 157 (35 ULg)