,is work presents the development of a flow injection system for differential pulse amperometry (DPA) for diazepam determination in the presence of oxygen. ,e thin flow cell consisted of the bare glassy carbon electrode, reference silver/silver
chloride, and stainless steel as the auxiliary electrode. Electrochemical reduction of diazepam (DZP) was characterised by cyclic
voltammetry. Azomethine reduction peak was used for DZP quantification. ,e detector response was linear in the range
20–250 µmol/dm3 of diazepam, with a calculated detection limit of 3.83 µg/cm3
. Intraday and interday precision were 1.53 and
10.8%, respectively. ,e method was applied on three beverage samples, energetic drink, and two different beer samples, and
obtained recoveries were from 93.65 up to 104.96%. ,e throughoutput of the method was up to 90 analyses per hour.
