Nanofiltration (NF) is a promising technique to achieve sustainable and efficient separation of antibiotics with high industrial value. In this work, carboxymethyl- β -cyclodextrin (CM- β -CD) modified nanofiltration membrane was fabricated through interfacial polymerization (IP) for high concentration cephalexin solution separation, which is a classic antibiotic pharmaceutical wastewater. In principle, CM- β -CD can slow down the diffusion of amine monomers via electrostatic attraction, steric effect, hydrogen bonding and adsorption of the piperazine (PIP) monomer onto the hydrophilic surface, which renders amine monomer the high local concentration. The fabricated NF membranes possessed a larger proportion of dense primary layer on the surface. In addition, the accumulation of CM- β -CD between the substrate membrane and polyamide (PA) layer played the role as a barrier with specific cavity structure and bulk carboxylate to enhance the rejection of cephalexin. The cavity structure and stacking gap of CM-β-CD simultaneously rendered the membrane interlayer highly permeable. The optimal CM- β -CD modified membrane exhibited high rejection of cephalexin (94.7%) and water permeability of 122.4 L m −2 h −1 MPa −1 when the concentration of cephalexin was 3473.9 ppm (10 mmol/L). This work furnished an available way to prepare a novel nanofiltration membrane with efficient separation performance for relevant pharmaceutical production wastewater.
A critical challenge in using deep eutectic solvents (DESs) in capillary electrophoresis (CE) is to develop separation systems in which a DES can really work as a single entity. To achieve this, the authors recently demonstrated a novel strategy that takes advantage of the aqueous dispersibility of hydrophobic DESs (or more accurately hydrophobic eutectic solvents (HESs)). However, the previous work was limited only to the separation of achiral analytes, e.g., analogues, homologues, and isomers. The present study was designed as a follow-up study in order to explore the feasibility of employing HES-type pseudo-stationary phases (PSPs) in CE for chiral separations . By using carboxymethyl-β-cyclodextrin (CM-β-CD) as a model chiral selector, we provide the first evidence that there is a potential synergistic effect between HESs and traditional chiral selectors. Specifically, the combined use of HES (−)-menthol:octanoic acid and CM-β-CD allowed excellent enantioseparations of several basic drugs which were not able to be resolved in the single CM-β-CD system. The enantioresolutions were significantly improved while the migration times of the enantiomers were also shortened due to the hydrophobic mechanism of the HES-type PSP. Critical factors influencing the novel chiral CE system were systematically investigated. Since HESs are considered as “designer” solvents with highly tunable properties, this study demonstrates the potential of employing HESs (or HDES)-type PSPs in CE for chiral separations .
This work presents a synergistic system for enantioseparation in capillary electrophoresis (CE) with a chiral ionic liquid (CIL) based on D-10-camphorsulfonic acid as additive and carboxymethyl-β-cyclodextrin (CM-β-CD) as the chiral selector. The proposed method showed excellent enantioseparation performance towards sixteen chiral drugs. In contrast to the single CM-β-CD system, the notably improved resolution (Rs) and selectivity factor (α) of model drugs were observed in synergistic system. Several key parameters such as CIL concentration, CM-β-CD concentration, buffer pH and separation voltage were investigated, after which Statistical Product and Service Solutions (SPSS) was used to prove the potential synergistic effect. The nuclear magnetic resonance (NMR) results further demonstrated the function of the CIL and the superiority of synergistic system. Finally, chiral impurity determination of chlorpheniramine maleate sample was successfully carried out using the established method.
危险品化学品经营许可证（带存储）