Ji Wenhua,Zhang Mingming,Gao Qianshan,Cui Li,Chen Lizong,Wang Xiao
Hydrophilic molecularly imprinted polymers (H-MIP) with molecular recognition ability for iridoid glycosides (IGs) have been obtained via bulk polymerization combined with hydrolysis of ester groups. H-MIP were characterized by Fourier transform infrared spectroscopy (FT-IR). The hydrophilcity was measured by the contact angle measurement and the water dispersion stability. The obtained H-MIP demonstrated high selectivity and specific binding ability to five IGs in aqueous media. The group extraction efficiency of molecular imprinted solid-phase extraction (MISPE) for five IGs was investigated, including loading sample, breakthrough volume, washing solvent, and elution solvent. Compared with non-imprinted solid-phase extraction (NISPE), the higher average recovery (95.5 %) of five IGs with lower relative standard deviations values (below 6.1 %) using MISPE combined with high-performance liquid chromatography (HPLC) were achieved at three spiked levels in three blank samples. Under the optimum MISPE conditions, the wide linear range with the correlation coefficient of R
2 ≥ 0.9950 for five IGs with low limits of detection (LOD) and quantification (LOQ) (0.01–0.08 and 0.03–0.27 μg mL −1 , respectively) were obtained. Chromatograms obtained using MISPE columns demonstrated that the matrix interference has been minimized and great interferences around IGs were also eliminated efficiently. These results indicated that the developed MISPE-HPLC method was selective, accurate, and applicable for the determination of IGs in water media.
Preparation of hydrophilic molecularly imprinted polymers via bulk polymerization combined with hydrolysis of ester groups
A new thermoset PLA resin was synthesized. The structure and performance of the thermoset PLA resin were characterized by Fourier transform infrared spectroscopy (FTIR), 1 H Nuclear Magnetic Resonance ( 1 H-NMR), 13 C Nuclear Magnetic Resonance ( 13 C-NMR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) testing methods. The results indicate that thermoset PLA resin has been synthesized successfully, and the thermal stability of thermoset PLA is better than that of linear PLA. Thermoset PLA resin and ramie/thermoset poly(lactic acid) (PLA) composites were prepared by casting and hot-pressing, respectively. The degradation behavior was evaluated by surface morphology observation, scanning electron microscope (SEM), pH detection and FTIR analysis. The results show that the thermoset PLA resin fully degrades after 20 days, and the degradation rate of ramie/thermoset PLA composites is only 45.27% after 30 days, which is lower than that of thermoset PLA. The reason is due to that ramie fabric as the barrier hinders the moisture and microorganisms enter the interior of the composites. Moreover, according to the FTIR analysis, the ester groups of thermoset PLA are firstly hydrolyzed, and thermoset PLA is decomposed into low molecular weight oligomers. Then thermoset PLA and oligomers are continuously hydrolyzed by moisture and microorganisms until mineralized into H 2 O and CO 2 . Besides, the soil pH value detection proves that no acidic or alkaline harmful degradation products are produced during the soil degradation process.
危险品化学品经营许可证（带存储）