Abstract A nanostructured star‐shaped polythiophene dendrimer was prepared and used as an extraction medium for microextraction in packed syringe for clofentezine pesticide in milk and juice samples in combination with high‐performance liquid chromatography. The thermal behaviors, optical properties, and morphologies of the synthesized samples were investigated by thermogravimetric analysis, ultraviolet–visible spectroscopy and field‐emission scanning electron microscopy, respectively. A one‐at‐a‐time strategy was applied for optimizing the important extraction parameters such as the nature of desorption solvent, elution volume, pH, number of extraction cycles and sample volume. Under the optimized conditions, a detection limit of 2 × 10−4 μg mL−1 and a linear calibration curve with an R2 of 0.9983 were obtained for clofentezine. The average recovery of the analyte for juice and milk samples were 97.6 and 93% with relative standard deviation of 3.92 and 2.76%, respectively, for five replicates. The method was successfully applied to the high‐performance liquid chromatography determination of clofentezine in milk and juice samples.
