Use of a Sonogel-Carbon electrode modified with bentonite for the determination of diazepam and chlordiazepoxide hydrochloride in tablets and their metabolite oxazepam in urine

► Diazepam and chlordiazepoxide hydrochloride are determined using Sonogel-Carbon electrode modified by 5% bentonite. ► We use a low cost, sensitive, selective and time saving method for the quantification. ► The electrode has been successfully used for the determination of diazepam and chlordiazepoxide hydrochloride in Valium® and Omnalio tablets, respectively. ► The developed electrode has been applied successfully to the determination of oxazepam (the major metabolite in human body both of diazepam and chlordiazepoxide hydrochloride) in human urine real samples.