Quantification of zolpidem in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry.

Abstract

A simple and robust method for quantification of zolpidem in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS). Es-citalopram was used as an internal standard. Zolpidem and internal standard in plasma sample were extracted using solid-phase extraction cartridges (Oasis HLB, 1 cm3/30 mg). The samples were injected into a C8 reversed-phase column and the mobile phase used was acetonitrile-ammonium acetate (pH 4.6; 10 mm) (80:20, v/v) at a flow rate of 0.7 mL/min. Using MS/MS in the selected reaction-monitoring (SRM) mode, zolpidem and Es-citalopram were detected without any interference from human plasma matrix. Zolpidem produced a protonated precursor ion ([M+H]+) at m/z 308.1 and a corresponding product ion at m/z 235.1. The internal standard produced a protonated precursor ion ([M+H]+) at m/z 325.1 and a corresponding product ion at m/z 262.1. Detection of zolpidem in human plasma by the LC-ESI MS/MS method was accurate and precise with a quantification limit of 2.5 ng/mL. The proposed method was validated in the linear range 2.5-300 ng/mL. Reproducibility, recovery and stability of the method were evaluated. The method has been successfully applied to bioequivalence studies of zolpidem.

Cite this paper

@article{Bhatt2006QuantificationOZ, title={Quantification of zolpidem in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry.}, author={Jignesh S. Bhatt and Arvind G. Jangid and Raghavendra Shetty and Bhavin I. Shah and Sandeep Kambli and Gunta Subbaiah and Sadhana Singh}, journal={Biomedical chromatography : BMC}, year={2006}, volume={20 8}, pages={736-42} }