Magnetic Nanocomposite (CDs@Fe3O4) for Preconcentration and Ultra-Sensitive Determination of Sulfathiazole in Wastewater Spectrophotometrically

There has been serious environmental and health damage caused by the excessive discharge of organic wastewater. In this article, a magnetic nanocomposite adsorbent, cyclodextrin@Ferrous-ferric oxide (CDs@Fe3O4), was used for the efficient adsorption of sulfathiazole (STZ) from wastewater due to its special amphiphilicity. The amount of separated STZ was determined using a diazotization-coupling reaction with 1,5-dihydro naphthalene. It was determined whether initial drug concentration, pH, dosage of adsorbent, contacting time, and temperature influenced the adsorption process. The proposed method showed a linear range from 0.5 to 4.0 μg/mL STZ. With an STZ concentration of 20 μg/mL and 80 mg of adsorbent, CDs@Fe3O4 has the best adsorption and removal effect on STZ at a pH of 7.0 and room temperature that reaches 99.1%. An external magnetic field can quickly separate CDs@Fe3O4 adsorbed with STZ drug, and then HCl treatment can easily regenerate the composite. Despite recycling five times, the magnetic composite is able to remove more than 99% of STZ. The proposed method was applied successfully using synthetic water samples. The obtained results showed recovery values from 96.27 to 100.02% with RSDs ranging from 0.32 to 2.48%. Thus, an environmentally friendly and economical method will be developed to treat drug wastewater.