Rapid LC-MS/MS quantification of the major benzodiazepines and their metabolites on dried blood spots using a simple and cost-effective sample pretreatment.
BACKGROUND
Dried blood spots (DBS) sampling has gained popularity in the bioanalytical community as an alternative to conventional plasma sampling, as it provides numerous benefits in terms of sample collection and logistics. The aim of this work was to show that these advantages can be coupled with a simple and cost-effective sample pretreatment, with subsequent rapid LC-MS/MS analysis for quantitation of 15 benzodiazepines, six metabolites and three Z-drugs. For this purpose, a simplified offline procedure was developed that consisted of letting a 5-µl DBS infuse directly into 100 µl of MeOH, in a conventional LC vial.


RESULTS
The parameters related to the DBS pretreatment, such as extraction time or internal standard addition, were investigated and optimized, demonstrating that passive infusion in a regular LC vial was sufficient to quantitatively extract the analytes of interest. The method was validated according to international criteria in the therapeutic concentration ranges of the selected compounds.


CONCLUSIONS
The presented strategy proved to be efficient for the rapid analysis of the selected drugs. Indeed, the offline sample preparation was reduced to a minimum, using a small amount of organic solvent and consumables, without affecting the accuracy of the method. Thus, this approach enables simple and rapid DBS analysis, even when using a non-DBS-dedicated autosampler, while lowering the costs and environmental impact.
Unit of Toxicology, University Center of Legal Medicine, Rue Michel-Servet 1, CH-1211 Geneva 4, Switzerland.
Julien
J
Déglon
François
F
Versace
Estelle
E
Lauer
Christèle
C
Widmer
Patrice
P
Mangin
Aurélien
A
Thomas
Christian
C
Staub
D001569:Benzodiazepines / Q000032:analysis* / Q000378:metabolism / Q000592:standards; D001800:Blood Specimen Collection / Q000191:economics; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D059788:Dried Blood Spot Testing; D006801:Humans; D000432:Methanol / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000592:standards; D013997:Time Factors
D001569:Benzodiazepines; D000432:Methanol