Characterisation of selected hypnotic drugs and their metabolits using electrospray ionisaton with ion trap mass spectrometry and with quadrupole time-of-flight mass spectrometry and their determination by liquid chromatography-electrospray ionisatio

摘要

Th eelectrospray ionisation-ion trap mass spectrometry (ESI-MS~n) of selected hypnotic drugs,i.e.zopiclone,zolpidem,flunitrazepam and teirmetabolites havebeen investigated.Sequential product ion fragmentation experiments (MS~n) have been performed in orde rto elucidate the degradatonpathways for the [M + H]~+ ions and their predominant fragment ions.These MS~n experiments show certain characteristic fragmentations in that functional groups are generallycleavedform thering systems as neutrla molecues such as H_2O,CO,CO_2,NO_2,amines and HF.When an aromatic entity is present in a drug molecule togehter with a nitrogen-containign saturted ring structureas with zopiclone and its N-desmethyl metabolite rfragmentation initially occurs at the latter ring with the former being resistant to fragmentation.The zopicone and its N-desmethyl metabolite fragmentation initially occurs at the latter ring with the former being resistant to fragmentation.The structures of fragment ions proposed for ESI-MS~n can be supported by electrospary ionistion-quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS).These molecules cna be identified and deermined in mixtures atlow ng/ml concentratiosn by the application of liquid chromatography (LC)-ESI-MS)~n whihc cna be used for their analysis in saliva samples.This paper includes a tabulationof mass lowsses/signals at low m/z values for these hypnotic drugs and many others in recent publications which will be of value inthecharacterisation of drug metabolites of unknown structure and also natural product pharmaceuticals isolatedfrom plants,etc.