Determination of Ethanol and Toluene Residual Solvent in Diphenhydramine Hydrochloride Raw Materia by Headspace Capillary Gas Chromatography / 中国药房

ABSTRACT

OBJECTIVE:To establish a method for the determination of residual solvent of ethanol and toluene in diphenhydr-amine hydrochloride raw material. METHODS:Headspace capillary gas charmatography and butanone as internal standard were used. The column was Agilent DB-624 capillary column,inlet temperature was 200 ℃,hydrogen flame ionization detector was 250 ℃,the carried gas was high purity nitrogen,flow rate was 3.0 ml/min with temperature programmed,the splitting-ratio was 20∶1,the containers of headspace injector were in equilibrium at 80 ℃ for 30 min,and the injection time was 1 min. RESULTS:With this chromatographic condition,ethanol,toluene and internal standard peak were well separated;there was a good linear rela-tionship of ethanol and toluene in the range of 0.02-0.8 mg/ml (r=0.999 8 and r=0.999 4);RSDs of precision and stability test were lower than 3%;recoveries were 95.50%-103.50%(RSD=2.6%,n=9) and 96.91%-103.74%(RSD=2.2%,n=9). CON-CLUSIONS:The method is simple,sensitive and accurate,and can be used for the determination of residual solvent of ethanol and toluene in diphenhydramine hydrochloride raw material.