by adjusting the mobile phase so that volume ratios of phosphate buffer , methanol , and acetonitrile are 45:35:20 , and using nitrazepam as the internal standard , seven other benzodiazepines ( demoxepam , oxazepam , chlordiazepoxide , norchlordiazepoxide , temazepam , diazepam , and nordiazepam ) can be resolved at 254 nm .
C0005064
benzodiazepines
C0029997
oxazepam