The thermal decomposition of methylphenidate in the gas chromatograph mass spectrometer

Abstract

Methylphenidate undergoes partial thermal decomposition in the injection port of a gas chromatograph. This decomposition explains inconsistencies in some of the previously published mass spectra of the drug. The decomposition products were identified by gas chromatography mass spectrometry as methyl phenylacetate and a tetrahydropyridine. The extent of decomposition was found to be a function of the injector temperature and was also influenced by other factors, resulting in considerable variability. The ethyl ester analog behaved similarly. Derivatization with trifluoroacetic anhydride eliminates the thermal decomposition.