Identification of amphetamine isomers by GC/IR/MS

The methods of gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and gas chromatography/infrared spectroscopy/mass spectrometry (GC/IR/MS) are evaluated for their ability to differentiate side chain isomers of amphetamine. It is found that absorption bands from 3000 to 2850 cm-1 and 900 to 650 cm-1 are most useful for differentiating the alkyl amines, while the bands from 1600 to 900 cm-1 are only useful for differentiating primary amines from the other substituted amines. The combination of GC/IR/MS is superior for differentiating these side chain isomers.