Negative-ion mass spectrometry of amphetamine congeners.

Negative-ion chemical ionization mass spectrometry with a conventional combined gas chromatograph-mass spectrometer has been used for the analysis of amphetamine-like compounds. Ammonia was used as the reagent gas, which gives rise to few but specific sample-fragment ions, such as (M--1)- as the base peak, m/z 91, and a smaller peak corresponding to the end part of the side chain. Five reference compounds and a urine sample from an overdose case were analyzed. Comparative positive-ion chemical ionization reference spectra were also recorded.