A previously published gas chromatography-mass spectrometry method (3, 4) was used to verify the absence of the following amphetamine-related compounds: amfepramone, amphetamine, benzodioxazoylbutanamine, benzphetamine, clobenzorex, dexfenfluramine, dimethoxybromoamphetamine, dimethoxymethylamphetamine, fencamfamin, fenproporex, mefenorex, methamphetamine, methoxyphenamine
, methylbenzodioxazolylbutanamine, methylenedioxyamphetamine, methylenedioxyethamphetamine, methylenedioxymethamphetamine, methylphenidate, 4methylthioamphetamine, norephedrine, norfenfluramine, phentermine, and pseudoephedrine.
An internal standard solution (50 [micro]L), comprising racemic methoxyphenamine (400 mg/L) and amphetamine (200 mg/L) in methanol, was added to each 5 mL of the calibrator, volunteer, and quality-control [prepared in batches by adding aqueous (R,S)-MDMA and (R,S)MDA to urine] samples.
Internal standard solution (50 [micro]L) containing racemic methoxyphenamine (4 mg/L) and amphetamine (1 mg/L) in water was added to 2 mL of each calibrator, volunteer, and quality-control sample [prepared in batches by the addition of aqueous (R,S)-MDMA and (R,S)-MDA stock solutions to plasma].
The diagnostic ions chosen for quantitative purposes were m/z 162 for MDMA, MDA, and amphetamine and m/z 148 for methoxyphenamine.