Application of monolithic supports to online extraction and LC‐MS analysis of benzodiazepines in whole blood samples

Abstract

A column-switching (CS) LC-MS method allowing high-speed determination of benzodiazepines (BZDs) in whole blood is presented. After protein precipitation with ACN followed by evaporation and reconstitution with the loading mobile phase, the online sample clean-up was carried out using a CS device. Two extractive precolumns were evaluated: a conventional restricted access material (RAM) sorbent and a monolithic silica support. Separation was achieved using a Chromolith Performance RP-18e (100 mmx4.6 mm id) monolithic silica column, and detection was performed by atmospheric pressure chemical ionization (APCI) MS. The method with both supports has been fully validated according to an accuracy profile approach. Finally, the monolithic silica column, demonstrating better validation data and a higher robustness than the RAM sorbent, was used for the analysis of several real forensic cases.

Separation and HPLC analysis of 15 benzodiazepines in human plasma

“…The SPE procedure also contributes to method selectivity: in fact, even those CNS drugs, which are detected within a 30-min run, are not extracted with the analytes and thus do not interfere with the analysis. Furthermore, this kind of procedure is surely more feasible and less time consuming than the liquid -liquid extraction (LLE) procedures often adopted for the same purpose [12,14,23]. Precision and sensitivity are also better than those reported for other existing HPLC-UV methods which analyse a similar number of BZDs [22,23] for forensic purposes.…”

Désorption en ligne de spots de sang séché : une approche intéressante pour l’analyse par LC-MS/MS de microéchantillons de sang

“…La cellule de désorption est placée ensuite dans un système LC (Agilent series 1100 system, Waldbronn, Germany). Afin d'assurer l'automation de la procédure de désorption, un système de commutation de colonnes est employé [11]. À cet effet, une vanne 6-voies (valve 1) assure la connexion entre la cellule de désorption et le système chromatographique, comprenant une colonne extractive (Chromolith Flash RP-18e, 25 mm × 4,6 mm) et une colonne analytique (Chromolith Performance RP-18e, 100 mm × 4,6 mm), connectées entre elles par une seconde vanne 6-voies (valve 2).…”

Experimental design for optimization of microwave-assisted extraction of benzodiazepines in human plasma

“…Liquid chromatography has become an important tool for routine determination of BZD owing to its specificity, rapidity and sensitivity [4][5][6][7][8]. Although high-performance liquid chromatography (HPLC) with mass spectrometry detection [5][6][7] is highly selective, the cost of the instrumentation makes it less suitable for clinical or toxicology laboratories.…”

“…Although high-performance liquid chromatography (HPLC) with mass spectrometry detection [5][6][7] is highly selective, the cost of the instrumentation makes it less suitable for clinical or toxicology laboratories. In contrast, HPLC-UV detection or diode array detection (DAD) instrumentation is widely available in most analytical laboratories [8][9][10][11][12].…”