Stereospecific derivatization of amphetamines, phenol alkylamines, and hydroxyamines and quantification of the enantiomers by capillary GLC/MS

The enantiomers of amphetamines, phenol alkylamines, and hydroxyamines are separated by using alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride as the chiral derivatizing agent for amino groups, Prior to N-acylation, amine salts are converted into the free bases and hydroxyl groups into O-silyl ethers by reaction with N-methyl-N-silylamides, N-Methyl-N-(trimethylsilyl)trifluoroacetamide, N-methyl-N-(triethylsilyl)trifluoroacetamide, or N-methyl-N-(tert-butyldimethylsilyl)trifluoracetamide was used to protect the hydroxyl groups by TIMS, TES, or the tBDMS groups. All these N-methyl-N-silylamides were able to convert amino salts to the free bases. The reaction is selective and rapid, and the diastereomeric derivatives are well separated by capillary gas-liquid chromatography, This procedure is suitable for simultaneous determination by gas chromatography/mass spectrometry with selected-ion monitoring and is also applicable to quantification of the compounds in a biological matrix.