Imidocarb dipropionate (IMD) is an antimicrobial agent that is widely used in veterinary medicine for treatment of many diseases especially anaplasma marginale in cattle. This may lead to the retention of its residues in edible bovine tissues, milk and urine samples. Thus the quick determination of minor concentrations of IMD is of great interest to ensure food safety. A novel electrochemical sensor was introduced for the sensitive, fast and selective determination of IMD in drug substance and commercial product, furthermore its application to determine IMD residues in bovine meat, milk and urine samples. The prepared nanoparticles sensor was based on a multiwalled carbon nanotube composite modified with gold nanoparticles GNPs/MWCNT. The linear response obtained for IMD using the GNP/MWCNT was found to be over the range of 0.20–3.6 n mol l−1 with a good linearity and high correlation (0.9999). The limits of detection and quantification were found to be 36 p mol l−1 and 109 p mol l−1 respectively. The developed method was simple, rapid, economic, and challenging to green chemistry. The high sensitivity, good reproducibility, and wide linear range mark the modified electrode suitable for determination of the residues in bovine meat and milk as real samples with excellent recoveries.

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Aqueous alkaline degradation was performed for oseltamivir phosphate (OP) and valacyclovir hydrochloride (VA). Isocratic stability indicating the use of high-performance liquid chromatography (HPLC) was presented for each drug in the presence of its degradation product. The separations were performed using the Nucleosil ODS column and a mobile phase consisting of phosphate buffer (pH = 7), acetonitrile, and methanol 50:25:25 (v/v/v) for OP. For VA separation, a Nucleosil CN column using phosphate buffer (pH = 7) and methanol 85:15 (v/v) was used as a mobile phase. Ultraviolet detection at 210 nm and 254 nm was used for OP and VA, respectively. The method showed high sensitivity concerning linearity, accuracy, and precision over the range 1–250 μg mL−1 for both drugs. The proposed method was used to determine the drug in its pharmaceutical formulation and to investigate the degradation kinetics of each drug’s alkaline-stressed samples. The reactions were found to follow a first-order reaction. The activation energy could also be estimated. International Conference on Harmonisation guidelines were adopted for method validation.

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