Determination of Residual Organic Solvents in Letrozole by Headspace Capillary Gas Chromatography / 中国药房

ABSTRACT

OBJECTIVE: To establish headspace capillary gas chromatography for the content determination of residual solvents in letrozole, such as chloroform, ethanol, acetone, ethyl acetate, DMF and isopropanol. METHODS: Dissolved in dimethyl sulfoxide, chloroform, ethanol, acetone, ethyl acetate, DMF and isopropanol in letrozole were determined by headspace gas chromatography with HP-5 capillary gas chromatography. ECD was applied for chloroform, while FID was applied for the other residual solvents. RESULTS: The liner ranges of chloroform, ethanol, acetone, ethyl acetate, DMF and isopropanol were 1.028～10.28 mg?L-1(r=0.999 9), 94.68～946.8 mg?L-1 (r=0.999 7), 94.64～946.4 mg?L-1(r=0.999 7), 110.64～1 106.4 mg?L-1(r=0.999 7), 15.12～151.2 mg?L-1(r=0.999 6), 116.48～1 164.8 mg?L-1(r=0.999 5), respectively. The average recoveries of the residual organic solvents ranged from 97% to 102%. The detection limits were 20～90 ?g?L-1. The residual levels of the six organic solvents in three batches of samples were all up to the standard stipulated in Chinese Pharmacopeia. CONCLUSIONS: The method is simple, sensitive, accurate and reliable for the content determination of residual organic solvents in letrozole.