Maurer H, Pfleger K
J Chromatogr. 1981 Mar 13;222(3):409-19. doi: 10.1016/s0378-4347(00)84141-9.
A method for the determination of benzodiazepines and their main metabolites in urine after acid hydrolysis is described. The extract is analyzed by computerized gas chromatography-mass spectrometry. An on-line computer allows rapid detection using mass fragmentography with the masses m/e 211, 230, 241, 244, 249, 262, 276, and 285. The mass fragmentogram and the underlying mass spectra of the hydrolysis products (benzophenones and analogues) are documented.