Mise en place d’une méthode semi-quantitative en toxicologie clinique par UHPLC-PDA en utilisant une extraction SPE en micro-élution

Abstract

(190-400 nm). Résultats : Les rendements d'extraction étaient satisfaisants de même que la précision (CV% répétabilité < 6,54 %). Les CV inter-essais étaient élevés (CV > 15 % pour certaines molécules) mais diminuaient lorsqu'ils étaient rapportés aux 2 étalons internes (flurazépam et prazépam). La semi-quantification s'est faite à l'aide de 2 facteurs de réponses et les LOD et LOQ ont été comparées aux valeurs thé-rapeutiques ou toxiques. Conclusion : La méthode décrite est simple et rapide. Les résultats ont montré la capacité de la cartouche Strata r -X à extraire des molécules appartenant à plusieurs classes pharmacologiques avec des propriétés physico-chimiques différentes.Mots clés : Screening, SPE, UHPLC-PDA, toxicologie clinique, micro-élution Abstract -Objectives: A semi-quantitative method in clinical toxicology was developed using an extraction with a micro-elution solid phase (SPE) followed by an analysis with an Ultra-High-Performance Liquid ChromatographyPhotodiode Array system (UHPLC-PDA). The study was performed on 122 medicinal compounds according to the recommendations of the NF EN ISO 15189. Methods: After testing different SPE cartridges, the Strata r -X cartridge was selected based on its better extraction yields. A manual extraction protocol from plasma was set up for 3 concentrations (0.1 mg/L, 1 mg/L and 10 mg/L) with methanol as the eluting solvent. UHPLC analysis was performed with a mobile phase gradient of ammonium acetate 5 mM/Acetonitrile (ACN) (85/15, v/v) at pH 3.8 ± 0.05 and ACN on a BEH column C18 1.7 μm, 2.1 mm × 150 mm. The flow rate was 0.45 mL/min and the analytes were detected by PDA (190−400 nm). Results: Extraction yields were satisfactory, as well as the precision (repeatability CV% < 6.54%).Inter-assay CVs were high (CV > 15% for a few molecules) but were less significant when relativized by the two internal standards (flurazepam and prazepam). The semi-quantification was achieved with the support of two endpoints, and LOD and LOQ values were compared with therapeutic or toxic values. Conclusion: The method described is simple