THERMOSPRAY AND ATOMOSPHERIC PRESSURE CHE MICAL-IONIZATION LIQUID-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSIS OF BENZODIAZEPINES AND THEIR METABOLITES

To assess the LC/MS methods for the determination of these compounds i n biological materials positive ion mass spectra were measured for ben zodiazepines and their metabolites by thermospray-liquid chromatograph y/mass spectrometry (TSP-LC/MS) and atomospheric pressure chemical ion ization-liquid chromatography/mass spectrometry (APCI-LC/IWS). In both TSP-LC/MS and APCI-LC/MS, LC analyses were performed on a TSKgel octy l-80Ts in the solvent system of methanol-ammonium acetate at a flow ra te of 1.0 ml/min. TSP mass spectra showed only a [M + H](+) ion for mo st of compounds, while APCI mass spectra showed [M + H](+) and some fr agment ions. The analysis of these compounds with TSP gave better dete ction limits than with APCI by scan mode, and gave the same results fo r detection limits as with APCI by selected ion monitoring (SIM). The data, described in this paper, should serve as a basis for the qualita tive and quantitative analyses of benzodiazepines and their metabolite s in biological samples.