聚甲基丙烯酸甲酯接枝聚氧乙烯在甲苯中的聚集态结构

两亲接枝共聚物;胶束;聚甲基丙烯酸甲酯接枝聚氧乙烯在甲苯中的聚集态结构     

Preparation,characterization and application of a new 25,27‐bis‐[2‐(5‐methylthiadiazole)thioethoxyl]‐26,28‐dihydroxy‐para‐tert‐butyl calix[4]arene stationary phase for HPLC

A new para‐tert‐butylcalix[4]arene column containing thiadiazole functional groups was prepared and used for the separation of polycyclic aromatic hydrocarbons, phenolic compounds, aromatic amines, benzoic acid and its derivatives by high‐performance liquid chromatography (HPLC). The effect of organic modifier content in the mobile phase on retention and selectivity of these compounds were investigated. The results indicate that the stationary phase behaves like reversed‐phase packing. However, hydrogen bonding, π–π and inclusion interactions seem to be involved in the separation process. The column has been successfully employed for the analysis of clenbuterol in pork and pig casing; the limit of detection and the limit of quantitation for this method by HPLC‐UV detection was 0.03 and 0.097 μg/mL, respectively; the method is demonstrated to be suitable and a competitive alternative analytical method for the determination of clenbuterol.     

Effects of exchanged surfactant cations on the pore structure and adsorption characteristics of montmorillonite

Ca-montmorillonite (Ca-Mont) was exchanged with two quaternary amines, tetramethylammonium (TMA) chloride and hexadecyltrimethylammonium (HDTMA) bromide, to study the surfactant ion exchange effect on the pore structure, surface characteristics, and adsorption properties of montmorillonite. The revolution of both the surface area and pore structure of montmorillonite was characterized based on classical and fractal analyses of the nitrogen isotherms as well as the XRD patterns. The change of surface characteristics was identified from FTIR patterns and zeta-potential plots. The adsorption isotherms of acid dye, Amido Naphthol Red G (AR1), were then measured to identify the effects of the ion-exchange process on the adsorption properties of montmorillonite. It was found that the exchange processes might induce an increase or decrease in the surface area, pore size, pore volume, and surface fractal dimension D of montmorillonite, depending on the size, the molecular arrangement, and the degree of hydration of the exchanged ion in the clay. On the other hand, it was also found that the hydrophobic bonding by conglomeration of large C(16) alkyl groups associated with HDTMA could cause positive charge development on the surface of montmorillonite, which was not observed for TMA-modified montmorillonite (TMM). The effects of the alteration of the surface characteristics of montmorillonites on their adsorption selectivity for acid dye were discussed.     

以3-硝基邻苯二甲酸根构建的环状双核Zn（Ⅱ）, Cd（Ⅱ）配合物的合成及晶体结构

以3-硝基邻苯二甲酸和咪唑及2,2’-联吡啶为配体构筑了2种配合物[Zn₂（npa）₂（Im）₄]（1）和[Cd₂（npa）₂（2,2’-bipy）₂（H₂O）₂]·2H₂O（2）（npa^2-=3-硝基邻苯二甲酸根,Im=咪唑,2,2’-bipy=2,2’-联吡啶）。用元素分析、红外光谱对其进行了表征,并用单晶X-射线衍射测定了配合物的晶体结构;测定了配合物1和2的热稳定性。2个配合物均为双核分子,具有M₂C₈O₄十四元大环结构。配合物1的双核单元通过分子间氢键形成3D网络结构,配合物2的双核单元通过分子间氢键和π-π堆积形成2D层状结构。     

Three New Anthraquinones from Polygonum cillinerve

Three new anthraquinones, emodin-8-β-D-（2＂-O-coumarate）glucoside 1, emodin-8-β-D-（6＇-O-acetyl）glucoside 2 and physicon-8-β-D-（6＇-O-acetyl）glucoside 3, were isolated from the roots of Polygonum cillinerve and their structures were established by spectroscopic methods. The biological activity indicated that compound 1 had the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl （DPPH） radicals （the IC50 = 8.5 μmol/L）, and compound 1-3 showed no activities against HL-60 and BCJC-823 cells by MTT method in vitro.     

Preparation and Evaluation of Molecularly Imprinted Monolithic Column for Felodipine in Micro-liquid Chromatography

This study concentrated on the production of molecularly imprinted polymers (MIPs) as highly selective sorbents for felodipine (FLD), a representive dihydropyridine calcium antagonists. Demonstrated chromatographically through a selection factor, these MIPs showed high selectivity for the template molecule among a group of structurally similar compounds. The recognition was found to correlate with structural similarity to the template compound.     

Three-dimensional mesomeric networks assembled from helix-linked sheets: syntheses, structures, and magnetisms

Two new three-dimensional nickel coordination polymers, [Ni3(BTC)2(4,4'-bpy)2(H2O)5].1.5H2O (1) and [Ni(PDB)(4,4'-bpy)].0.5H2O (2)(4,4'-bpy = bipyridine, BTC = 1,2,4-benzenetricarboxylate, PDB = pyridine-3,4-dicarboxylate), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Both compounds contain 2D scaffolding motifs, and most interestingly adjacent scaffolds are connected by infinite helical chains into unique three-dimensional mesomeric networks. Moreover, temperature-dependent magnetic susceptibilities for the two compounds were studied, and ferromagnetic interactions through syn-anti carboxylate bridges between Ni sites have been observed.     

流动注射在线富集-FAAS测定合金钢中微量镍

提出了流动注射在线离子交换富集-火焰原子吸收光谱法测定合金钢中微量镍的分析方法.在线离子交换采用双柱正向富集和反向洗脱流路方式,使用80目732强酸型阳离子交换树脂在酸度为0.10mol/L HCl中富集样品中的Ni2+,并用2.0mol/L HCl洗脱.设计了流动注射在线离子交换富集双柱流路的操作程序,优化了各项仪器...