Determination of Residual Organic Solvents in Finasteride Raw Materials by Headspace Capillary Gas Chromatography

The study aimed to establish a method for determining residual organic solvents in finasteride raw materials, specifically methanol, acetone, chloroform, and methylbenzene, using headspace gas chromatography. The method involved separation on a Phenomenex ZB-624 capillary column with dimethyl sulfoxide as the solvent and utilized a flame ionization detector. The results showed linear ranges for the solvents with high correlation coefficients (r=0.9996 to 0.9998) and recovery rates between 94.7% and 97.5%. The detection limits ranged from 0.0216 to 10.93 μg/ml. The residual amounts in 5 batches of samples met the Chinese Pharmacopeia (2010 edition) requirements, indicating that the method was sensitive, reproducible, and suitable for its intended purpose.