Polypyrrole-Modified Nylon 6 Nanofibers as Adsorbent for the Extraction of Two β-Lactam Antibiotics in Water Followed by Determination with Capillary Electrophoresis

Polypyrrole-functionalized magnetic Bi2MoO6 nanocomposites as a fast, efficient and reusable adsorbent for removal of ketoprofen and indomethacin from aqueous solution

Pharmaceutical and personal care products (PPCPs) as emerging organic pollutants have received widespread attention. A novel composite adsorbent was successfully prepared through the modification of polypyrrole (PPy) onto the surface of magnetic Bi₂MoO₆ (MnFe₂O₄/Bi₂MoO₆/PPy) and acted as excellent adsorbent to remove organic compounds from aqueous solution. The adsorbent was characterized by SEM, TEM, FT-IR, XRD, BET, VSM, XPS and PES. The resulting composites combined the advantages of all three parts and possessed porous structure and magnetic properties, which showed excellent adsorption performance for ketoprofen (KET) and indomethacin (IDM), as evidenced by 87.03% and 86.24% of removal in just 120 min at initial concentration of 10 mg/L, respectively. The adsorption processes of MnFe₂O₄/Bi₂MoO₆/PPy for PPCPs were well fitted with the pseudo-second order kinetic model and described better by Langmuir isotherm model. The possible adsorption mechanisms of KET and IDM by MnFe₂O₄/Bi₂MoO₆/PPy were provided. Additionally, the effect of other coexisting substances was also explored using Cu²⁺ as a model. Moreover, the adsorption performances were further studied to remove several dyes, in which showed superior affinity for anionic dyes. In practical application, it had almost equal removal capacity for KET both in the Yellow River water and sewage treatment plant inlet water.

Determination of sulfa antibiotic residues in river and particulate matter by field-amplified sample injection-capillary zone electrophoresis

In the present research, field-amplified sample injection-CZE (FASI-CZE) coupled with a diode array detector was established to determine trace level sulfa antibiotic. Sulfathiazole, sulfadiazine, sulfamethazine, sulfadimethoxine, sulfamethoxazole, and sulfisoxazole were selected as analytes for the experiments. The background electrolyte solution consisted of 70.0 mmol/L borax and 60.0 mmol/L boric acid (including 10% methanol, pH 9.1). The plug was 2.5 mmol/L borax, which was injected into the capillary at a pressure of 0.5 psi for 5 s. Then the sample was injected into the capillary at an injection voltage of -10 kV for 20 s. The electrophoretic separation was carried out under a voltage of +19 kV. The capillary temperature was maintained at 20˚C throughout the analysis, and six sulfonamides were completely separated within 35 min. Compared with pressure injection-CZE, the sensitivity of FASI-CZE was increased by 6.25-10.0 times, and the LODs were reduced from 0.2-0.5 to 0.02-0.05 μg/mL. The method was applied to the determination of sulfonamides in river water and particulate matter samples. The recoveries were 78.59-106.59%. The intraday and interday precisions were 2.89-7.35% and 2.77-7.09%, respectively. This provides a simpler and faster method for the analysis of sulfa antibiotic residues in environmental samples.