ABSTRACT
OBJECTIVE:To establish a method for the determination of 4 kinds of residual solvents in racemic ketoisoleucine calcium. METHODS:Headspace gas chromatography was performed on the column of DB-624 capillary column by temperature programmed,detector was FID,inlet temperature was 200 ℃,detector temperature was 250 ℃,carrier gas was nitrogen,flow rate was 1.0 ml/min,injection volume was 1 ml by headspace sampling,equilibrium temperature was 70 ℃ and equilibrium time was 30 min. RESULTS:The linear range was 120.04-480.16 μg/ml for methanol (r=0.997 8),200.21-800.83 μg/ml for ethanol (r=0.998 5),204.05-816.19 μg/ml for ethyl acetate(r=0.999 2),28.35-113.39 μg/ml for tetrahydrofuran(r=0.998 9);detection limits were 6.002 μg/ml,50.05 μg/ml,51.01 μg/ml and 7.087 μg/ml;RSD of precision was lower than 3%;recoveries were 95.0%-105.6%(RSD=3.95%,n=9),97.5%-106.4%(RSD=3.67%,n=9),98.1%-105.9%(RSD=3.16%,n=9)and 88.8%-99.2%(RSD=3.79%,n=9),respectively;4 kinds of residual solvents were not detected. CONCLUSIONS:The method is simple,accu-rate and reliable,and can be used for the determination of residual solvents in racemic ketoisoleucine calcium.