Determination of residual solvents in bulk pharmaceuticals by thermal desorption/gas chromatography/mass spectrometry

Thermal desorption (TD) techniques followed by capillary GC/MS were applied for the analysis of residual solvents in bulk pharmaceuticals, Solvents de sorbed from samples by heating were cryofocused at the head of a capillary column prior to GC/MS analysis. This method requires a very small amount of sample and no sample pretreatment, Desorption temperature was set at the p oint about 20 degreesC higher than the melting point of each sample individ ually. The relative standard deviations of this method tested by performing six consecutive analyses of 8 different samples were 1.1 to 3.1%, and anal ytical results of residual solvents were in agreement with those obtained b y direct injection of N,N-dimethylformamide solution of the samples into th e GC, This novel TD/GC/MS method was demonstrated to be very useful for the identification and quantification of residual solvents in bulk pharmaceuti cals.