A novel non-aqueous capillary electrophoresis - tandem mass spectrometry method for the simultaneous separation, identification and quantification of nine designer benzodiazepines (bentazepam, etizolam, deschloroetizolam, diclazepam, flubromazepam, flubromazolam, nimetazepam, phenazepam, and pyrazolam) was developed. A non-aqueous running electrolyte consisting of 25mM ammonium acetate with 100mM trifluoroacetic acid in acetonitrile was used. The separation was carried out using a semipermanent coated capillary (successive multiple ionic-polymer coating) with a strong anodic electroosmotic flow at a negative separation voltage within twelve minutes. Electrospray ionization with a triple quadrupole mass spectrometry was utilized for the identification and quantification of selected designer benzodiazepines in a positive ionization mode. The developed method was validated and applied on the analysis of spiked serum sample following a simple liquid-liquid extraction. The LODs of the designer benzodiazepines were between 1.5 and 15.0ngmL-1.
Keywords: Benzodiazepine; Capillary electrophoresis; Designer drug; Mass spectrometry; Nonaqueous electrolyte; Toxicological analysis.
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