Fe₃O₄@chitosan‐bound boric acid composite as pH‐responsive reusable adsorbent for selective recognition and capture of cis‐diol‐containing shikimic acid

Abstract

Recently, shikimic acid (SA) has aroused great concern as the starting raw material for the synthesis of antiviral drug (Tamiflu) against the spread of influenza virus in the body. In this work, magnetic chitosan composite modified with boric acid and its application in SA recognition and separation was described. Chitosan (CT) with plenty of hydroxyl and amino groups was first coated on the surface of magnetic core Fe3O4, then carboxylic groups were grafted to the surface of Fe3O4@CT via anhydride modification, followed by the introduction of 3‐aminophenylboronic acid (APBA). The uniform morphology and composition analysis of the adsorbent (Fe3O4@CT‐COOH‐BA) were characterized by FT‐IR, XRD, XPS, SEM, TEM and UV–visible spectroscopy. The adsorption capacity of as‐prepared material was explored in detail by batch mode experiments. The adsorption kinetics fitted well with a pseudo‐second order model, and the adsorption isotherms was well described by the Langmuir model with a maximum adsorption capacity of 23.8 mg g−1 at 25 °C. Solution pH plays a crucial role in adsorption process and the optimized pH was 8.0. In addition, Fe3O4@CT‐COOH‐BA could be easily reused through an external magnet and the adsorption capacity reduced by only 4% after five adsorption–desorption cycles. These results prove that boric acid modified magnetic chitosan composite is an effective and practical adsorbent for specific recognition and selective adsorption of cis‐diol‐containing compounds.

Significant Improvement of Adsorption for Phosphate Removal by Lanthanum-Loaded Biochar

“…A UV–visible spectrophotometer operating at a wavelength of 700 nm was used to measure the equilibrium concentration of phosphorus ions in the solution. The phosphorus removal rate was calculated by eq : R = C 0 − C normale C 0 × 100 % where R (%) is the phosphorus removal rate, C 0 (mg/L) is the initial concentration of phosphorus ions before adsorption, and C e (mg/L) is the equilibrium concentration of phosphorus ions in the solution. , In addition, the adsorption capacity q e of phosphorus per material was calculated as: q normale = V × C normale − C 0 M where q e (mg/g) is the equilibrium adsorption capacity, V (L) is the volume of solution, and M (g) is the mass of adsorbent. − …”

High Selectivity and Reusability of Biomass-Based Adsorbent for Chloramphenicol Removal

“…The product (CCF) was dried at 60 • C overnight for use. The approach for synthesizing Fe 3 O 4 was reported by Zhu et al [19]. Briefly, 27.0 g of FeCl CCF and solid NaOH were placed in a flask with 300 mL deionized water and stirred at 55 • C for 6 h. The solution was cooled down to room temperature and washed three times with ethanol and three times with deionized water.…”

Recent trends in sorbents for bioaffinity chromatography

“…As another strategy commonly employed in the synthesis of boronate affinity sorbents, phenylboronate ligands are immobilized on functionalized support materials via organic linkers. Different supports like core-shell magnetic structures [111][112][113], alginate [114], silica [110,115], zirconia [116], graphene oxide [117], and methacrylate-based polymer [118] with different porous properties have been used in the preparation of boronate affinity sorbents with this strategy. The PBA ligands that have been widely used in post modifica-tion of support materials are APBA and VPBA.…”