Simultaneous Determination of 22 Benzodiazepines in Chinese Patent Drugs and Health-Care Foods by Liquid Chromatography-Tandem Mass Spectrometry
A sensitive liquid chromatography-tandem mass spectrometric(LC-MS/MS) method has been developed for simultaneous determination of 22 benzodiazepines in Chinese patent drugs and health-care foods samples.Compounds were extracted with ether-dichloromethane(8 ∶ 2,V/V) in pH 11 borax buffer solution,the extract was concentrated to dry,dissolved in acetonitrile:water(2 ∶ 8,V/V),detected by positive electrospray ionization tandem mass spectrometry in the multiple reaction monitoring(MRM) mode,and quantified by isotope internal standard method.There were good linear correlations between the peak areas and concentration of the 22 benzodiazepines,the linear range was 0.5-50.0 L and correlation coefficients were above 0.9990.The limits of detection(LOD) of these 22 benzodiazepines were in the range of 0.0085-0.062 L,limits of quantification(LOQ) were in the range of 0.028-0.21 L.The average recoveries of benzodiazepines were 58.0%-116.5%,at spiked levels of 1.0,2.0 and 5.0 kg,the relative standard deviations(RSDs) of the method were between 2.4% and 12.2%.