Siberian Federal University

A method for the quantitative determination of benzodiazepines (diazepam, alprazolam, clonazepam, midazolam, hydazepam, phenazepam) in human blood plasma using high- performance liquid chromatography with tandem mass spectrometry (HPLC/MS/MS) has been developed. Detection was performed using a triple quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode with electrospray ionization (ESI). The calibration curves are linear in the concentration range of 1–500 ng/ml, the retention times are between 5.3 and 6.2 minutes, and the total chromatographic analysis time does not exceed 9 minutes. The influence of matrix effects on the accuracy of determination has been shown, and the recovery rates range from 64 % to 86 %. This method allows for the reliable determination of studied benzodiazepines in human blood plasma within the studied analytical range and can be used for the detection and quantification of benzodiazepines in clinical, toxicological, and pharmacokinetic studies