In this paper, effervescence‐assisted dispersive liquid–liquid microextraction (EADLLME), based on hydrophobic deep eutectic solvent (HDES) was developed as a green, simple, fast, and sensitive method for the extraction and preconcentration of captopril (CAP) from tablet and urine samples, followed by UV–Vis spectrophotometry. Initially, acetic acid was added to the green extraction solvent (HDES) at μL‐level. This mixture was then transferred by a syringe into bicarbonate fortified sample (contains complex of Ni [II] with CAP); an effervescence reaction occurred immediately between the acetic acid (AA) and sodium bicarbonate. The produced CO2 bubbles led to the dispersion of HDES into the sample. The resulting fine droplets from extractant dispersion facilitated the phase separation. After that, the absorbance of upper phase (HDES rich phase) was measured at 340 nm. Under optimized conditions, we achieved a desirable linearity in the range of 0.07–30 μg/L and low limits of detection of 0.04 μg/L. This developed method was successfully applied for the analysis of tablet and urine samples.

In this research, a simple and sensitive electrochemical technique based on using nanocomposite of (AgNP/CuMOF/PPy-rGO) modified carbon paste electrode for determination of metronidazole (MTZ) is described. Polypyrrole (PPy) hemispherical molecules coated reduced graphene oxide (PPy-rGO) was combined with CuMOF, a typical metal-organic framework, by hydrothermal method. AgNP/CuMOF/PPy-rGO was simply fabricated by creating AgNP inside and on the surface of the nanocomposite. The composition and morphology of the synthesized nanocomposite were investigated by SEM, FT-IR, EDX, and XRD. Cyclic voltammetry and ASSWV were utilized to determine the electrocatalytic activity of the sensor regarding the reduction of MTZ.Interestingly, some outstanding properties of the nanocomposite including high surface area of CuMOF, good conductivity of PPy-rGO, and the catalytic activity of AgNPs could result in the enhancement of the electron transfer rate, electrochemical behavior, and the reduction of peak currents at the surface of the proposed sensor. Sensitive, promising, and stable electrochemical sensor exhibited linear detection range of 0.08-160 μM at pH 5.0 with detection and limit of 24 nM (S/N = 3). The system was validated for precision with standard deviation less than 2.0%. Moreover, its feasibility was successfully assessed through analysis of tablet and human urine.

No abstract