title: A sensitive, rapid and specific determination of midazolam in human plasma and saliva by liquid chromatography/electrospray mass spectrometry.
abstract: A rapid, sensitive and selective liquid chromatography/electrospray mass spectrometry (LC/ES-MS) method was developed for the quantitative determination of the anaesthetic benzodiazepine midazolam (MID) in human saliva and plasma from patients undergoing anesthesia procedures. Biological samples spiked with diazepam-d5, the internal standard, were extracted into diethyl ether. Compounds were separated on a Xterra RP18 column using a mobile phase of acetonitrile/formic acid 0.1% at a flow rate of 0.25 mL/min under a linear gradient. Column effluents were analyzed using MS with an ES source in the positive ionization mode. Calibration curves were linear in the concentration ranges of 1-250 and 0.2-25 ng/mL in plasma and saliva, respectively. The limits of detection were 0.5 ng/mL in plasma and 0.1 ng/mL in saliva, using a 0.5-mL sample volume. The recoveries of the spiked samples were above 65%. The method was applied to ten real samples from patients undergoing midazolam treatment.
authors.affiliation: Institute of Legal Medicine, Forensic Toxicology Service, Faculty of Medicine, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Quintela
authors.forename: Angelines
authors.initials: A
authors.lastname: Cruz
authors.forename: Marta
authors.initials: M
authors.lastname: Concheiro
authors.forename: Ana
authors.initials: A
authors.lastname: de Castro
authors.forename: Manuel
authors.initials: M
authors.lastname: López-Rivadulla
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D008874:Midazolam / Q000032:analysis* / Q000097:blood* / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors
chemical_list: D008874:Midazolam