Determination of residual organic solvents in ampicillin sodium for injection by capillary gas chromatography with headspace sampling

OBJECTIVE To develope headspace gas chromatography method for the determination of residual organic solvents in ampicillin sodium for injection. METHODS The samples were injected into DM-624 capillary column by headspace sampler and analysed with FID detector using methanol as the internal standard. RESULTS The linear ranges of dichloromethane, acetone and iso-propanol were 2.633-1 316.8μg·mL-1(r=0.999 8), 1.569-784.4μg·mL-1 (r=0.999 9) and 1.562-781.2μg·mL-1 (r=0.999 9) respectively.The recoveries were 100.8%,98.3% and 99.3% with RSD 2.0%,2.3%and 1.6%(n=5) respectively. CONCLUSIONS The method is simple, accurate and sensitive with good reproducibility. It can be used for the determination of the residual organic solvents in ampicillin sodium for injection.