Simple and rapid synthesis of magnetic kiwifruit for the removal of sitagliptin and fampridine residues from aqueous media using HPLC method: optimization via central composite experimental design

In this study, the magnetic biosorbent was synthesized from kiwi peel and applied to eliminate Sitagliptin (STG) and Fampridine (FMP) from aqueous media using high-performance liquid chromatography (HPLC). The maximum removal percentage was found to be 69.04% and 63.76% for STG and FMP, respectively. The characterization of adsorbent was evaluated using a scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and vibrating-sample magnetometer (VSM). The optimization of variables, including pH, adsorbent dosage, and contact time, influencing the peak area were investigated via the central composite design (CCD). The highest peak area of the STG (actual: 2170.1, predicted: 2170.21) was obtained at a pH of 7.8, an adsorbent dosage of 15.5 mg, and a contact time of 35.5 min. Also, the maximum peak area of FMP (actual: 1932.5, predicted: 1901.11) was related to the pH = 7.8, adsorbent dosage of 11.8 mg, and contact time of 33.5 min. The significance and adequacy of the model and experimental variables were assessed using analysis of variance (ANOVA). The results indicated that the quadratic model is acceptable for the prediction of peak areas of STG and FMP. The magnetic kiwi peel as a simple and low-cost adsorbent with easy fabrication was found to be efficient for STG and FMP removal from the aqueous environments.