Estimation du délai entre la consommation d'héroïne et le prélèvement chez des consommateurs chroniques

Scientific conference (2012, November 22)

Urinary Levels of Bisphenol A, Triclosan and 4-Nonylphenol in a General Belgian Population

Poster (2012, October)

Validation of the quantitative determination of tetrahydrocannabinol and its two major metabolites in plasma by UHPLC/MS-MS according to the total error approach

in Journal of Analytical Toxicology (2012), 36(1), 25-29

In Belgium, driving under the influence (DUI) of cannabis is prohibited and has severe legal consequences for the driver if the blood plasma concentration of Δ9-tetrahydrocannabinol (THC) exceeds 1 µg/L ... [more ▼]

In Belgium, driving under the influence (DUI) of cannabis is prohibited and has severe legal consequences for the driver if the blood plasma concentration of Δ9-tetrahydrocannabinol (THC) exceeds 1 µg/L. A method to quantify low concentrations of THC and its hydroxylated (THC-OH) and carboxylated (THC-COOH) metabolites in plasma was developed for DUI but also for other applications. Ultra-high-performance liquid chromatography coupled to mass spectrometry seems to be a very convenient method to combine fast chromatographic separation and good sensitivity. The method was validated according to total error approach. Chromatographic separation was achieved in a 3-min total run time. The limits of quantitation were lower or equal to 1 µg/L for all compounds. The linearity of the method was acceptable in the validated range of concentrations (from 0.5 to 50 µg/L for THC, from 0.9 to 50 µg/L for THC-OH and from 1.1 to 100 µg/L for THC-COOH). The biases were lower than 13%, and the relative standard deviations for repeatability and intermediate precision did not exceed 15%. Lower and upper β-expectation tolerance limits did not exceed the acceptance limits of 20% for concentrations higher than 2 µg/L for THC and THC-OH and higher than 4 µg/L for THC-COOH. The acceptance limits were 30% for THC and THC-OH concentrations lower than 2 µg/L and for THC-COOH concentrations lower than 4 µg/L. [less ▲]

Cocaïne dans les eaux de rivière (projet COWAT)

Poster (2011)

Dosage des pesticides organochlorés et des PCBs dans le sérum par GC/QQQ

Conference (2010, October)

Détermination de la composition de l'héroïne par UHPLC/MS-MS

Conference (2010, June)

Dosage par GC/QQQ de huit pesticides organochlorés dans le sérum

in Acta Clinica Belgica (2010), 65(1), 58-64

Quantitative Determination of eight organochlorine pesticides in serum by GC coupled to tandem mass spectrometry

in Acta Clinica Belgica (2010), 65(1), 58-64

Innovative development and validation of an HPLC/DAD method for the qualitative and quantitative determination of major cannabinoids in cannabis plant material

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 ▲]

Innovative development and validation of an HPLC/DAD method for the qualitative and quantitative determination of major cannabinoids in cannabis plant material

Poster (2009, October)