Determination of 5 Kinds of Residual Solvents in Mifepristone by Using Headspace Gas Chromatography

OBJECTIVE To establish a headspace gas chromatography method for determination of five residual solvents including ethanl, dichloromethane, ethyl acetate, tetrahydrofuran and pyridininm in mifepristone. METHODS The determination was performed on an Agilent DB-624 Capillary column(30 m×0.53 mm×3 μm) with nitrogen as carrier gas and FID as detector. Dimethyl sulfoxide was used as solvent, and the equilibrium temperature and time of headspace vial was 90 ℃ and 30 min, respectively. RESULTS Five residual solvents showed good linearity(r>0.999) in the concentration ranges, respectively. The average recovery were 98.7%, 96.9%, 95.7%, 95.1% and 95.2%, respectively, and the LOD were 0.000 578%, 0.000 258 8%, 0.000 745%, 0.000211%, 0.001 196 %, respectively. CONCLUSION The method is simple, accurate, repeatable and sensitive. It is suitable for the determination of residual solvents in mifepristone.