Determination of midazolam in human plasma by solid‐phase microextraction and gas chromatography/mass spectrometry

Abstract

A new method is described for the qualitative and quantitative analysis of midazolam, a short‐acting 1,4‐imidazole benzodiazepine, in human plasma. It involves a plasma deproteinization step, solid‐phase microextraction (SPME) of midazolam using an 85‐µm polyacrylate fiber, and its detection by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode, using pinazepam as internal standard. The assay is linear over a midazolam plasma range of 1.5–300 ng/mL, relative intra‐ and inter‐assay standard deviations at 5 ng/mL are below 7%, and the limit of detection is 1 ng/mL. The method is simple, fast and sufficiently sensitive to be applied in clinical and forensic toxicology as well as for purposes of therapeutic drug monitoring. Copyright © 2001 John Wiley & Sons, Ltd.