To increase the extraction efficiency of quercetin from Pinus koraiensis seed scales (PKSS), an innovative chitosan-Cu-Fe (CS-Cu-Fe) ionic liquid system for efficient ultrasonic-assisted extraction (UAE) of PKSS quercetin (PKSSQ) was designed. A first-order kinetic model was applied to analyse the extraction performance, and key factors influencing the process were systematically optimized. The optimal conditions were as follows: 2.00 g sample, 0.016 mol [BMIM]Br, 0.6 %, 100 W, 53°C, 12:1 mL/g, and 14 min. Under these conditions, the actual PKSSQ yield was 2.92 mg/g ± 0.02 mg/g, which closely aligned with the theoretical yield of 2.96 mg/g. The extraction kinetics were compared across different methods, and the stability of the CS-Cu-Fe system was evaluated through recovery experiments. The CS-Cu-Fe was characterized using Fourier transforms infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), hysteresis loop (HL) measurement, electrical conductance (EC) measurement and scanning electron microscopy (SEM) of the extracted residues. CS-Cu-Fe demonstrated exceptional thermal stability, magnetic properties, and catalytic activity, significantly enhancing the PKSSQ extraction efficiency. FT-IR analysis revealed minimal spectral changes in CS-Cu-Fe, with notable EC differences. Owing to its stable core functional groups, CS-Cu-Fe maintained excellent thermal stability, crystal structure, soft magnetism, and catalytic efficiency. This study highlights the efficiency of the CS-Cu-Fe ionic liquid system in UAE of PKSSQ and the role of its stable core functional groups in improving the extraction and catalytic performance. This innovative approach provides a robust theoretical foundation for extracting and developing natural products from PKSS, with promising future applications.
Yanyun Zou,Qingli Chai,Ting Zhu,Xiaoxiao Yu,Guobin Mao,Ningxing Li,Jinyang Chen,Guosong Lai
In this work, an environmentally-friendly and cost-effective enzyme mimic was obtained by facile one-pot preparation of chitosan/Cu/Fe (CS/Cu/Fe) composite. This composite exhibited significantly enhanced oxidase-mimicking activity during catalyzing the oxidation of 3, 3′, 5, 5′-tetramethylbenzidine (TMB). The CS/Cu/Fe composite was comprehensively characterized and the possible catalytic mechanism was reasonably explored and discussed. Benefiting from the thermal stability and the compatibility with carbohydrate, the CS/Cu/Fe composite was further integrated with agarose hydrogel to fabricate a portable analytical tube containing oxidase mimic. Based on the inhibition of the catalytic oxidation of TMB in the presence of cysteine, as well as the recovery of oxidase-like activity of CS/Cu/Fe due to the specific complexation of cysteine and mercury ion (Hg 2+ ), the rapid colorimetric detection of Hg 2+ was successfully carried out in the analytical tube. This colorimetric method showed good linear response to Hg 2+ over the range from 40 nM to 8.0 μM with a detection limit of 8.9 nM. The method also revealed high selectivity and satisfactory results in recovery experiments of Hg 2+ detection in tap water and lake water. Furthermore, it was found that the effective removal of Hg 2+ could be realized in the analytical tube based on efficient Hg 2+ adsorption by CS/Cu/Fe composite and agarose hydrogel. This study not only prepared a robust and low-cost enzyme mimic, but also proposed a smart strategy to simultaneously monitor and remove toxic Hg 2+ from contaminated water.
危险品化学品经营许可证（带存储）