凝胶净化-高效液相色谱法检测对位红在辣椒酱和辣酱油中的残留量

运用高效液相色谱(HPLC)法分析并采用凝胶净化系统(GPC)预处理,建立了测定辣椒酱、辣酱油等复杂样品中对位红残留量的检测方法。辣椒酱、辣酱油样品用乙腈提取,经过净化、浓缩,用乙腈定容进行检测。色谱柱为资生堂MG-ⅡC18柱,直接采用等度洗脱,流动相为乙腈-水;采用可变波长检测器(VWD),检测波长为485 nm。对位红标准溶液在0.02~1.0 mg/L浓度范围内,药物峰面积与浓度呈良好的线性关系,其相关系数的平方(R2)为0.9978。辣椒酱、辣酱油样品中添加药物回收率分别为:71.0%±2.5%~90.4%±4.0%和72.1%±3.1%~91.8%±2.0%;对位红在复杂样品中的残留量检测的定量限为0.05μg/g。     

Synthesis,crystal structure and photoluminescence of a three‐dimensional zinc coordination compound with NBO‐type topology

The assembly of metal–organic frameworks (MOFs) with metal ions and organic ligands is currently attracting considerable attention in crystal engineering and materials science due to their intriguing architectures and potential applications. A new three‐dimensional MOF, namely poly[[diaqua(μ₈‐para‐terphenyl‐3,3′,5,5′‐tetracarboxylato)dizinc(II)] dimethylformamide disolvate monohydrate], {[Zn₂(C₂₂H₁₀O₈)(H₂O)₂]·2C₃H₇NO·H₂O}_n, was synthesized by the self‐assembly of Zn(NO₃)₂·6H₂O and para‐terphenyl‐3,3′,5,5′‐tetracarboxylic acid (H₄TPTC) under solvothermal conditions. The compound was structurally characterized by FT–IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction analysis. Each Zn^II ion is located in a square‐pyramidal geometry and is coordinated by four carboxylate O atoms from four different TPTC^4? ligands. Pairs of adjacent equivalent Zn^II ions are bridged by four carboxylate groups, forming [Zn₂(O₂CR)₄] (R = terphenyl) paddle‐wheel units. One aqua ligand binds to each Zn^II centre along the paddle‐wheel axis. Each [Zn₂(O₂CR)₄] paddle wheel is further linked to four terphenyl connectors to give a three‐dimensional framework with NBO‐type topology. The thermal stability and solid‐state photoluminescence properties of the title compound have also been investigated.     

奇异半线性抛物方程初值问题解的存在性与不存在性,Blow-up问题及解的无限增长性

该文研究一类奇异半线性抛物方程初值问题的非负局部解存在与不存在的条件，解的BloW-Up问题及当t时解的无限增长性．     

Monomers that form conducting polymers as structure-directing agents: synthesis of microporous molecular sieves encapsulating poly-para-phenylenevinylene

We have developed a novel concept that uses monomers required for making conducting polymers as organic structure-directing agents, for the synthesis of microporous molecular sieves. We show that these monomers facilitate the formation of crystalline and amorphous molecular sieves depending on the synthesis procedure. The monomers filling the pores of the silicates can be polymerized under certain conditions, resulting in a polymer immobilized and protected inside the matrix. The concept was exemplified with para-phenylenemethylene-bis(1-tetrahydrothiophenium) and para-phenylenemethylene-bis(trimethylammonium) that were used to template microporous molecular sieves and subsequently to obtain poly-para-phenylenevinylene (PPV) inside the matrix. The organic self-assembled organic-inorganic material was extensively characterized and the implication on electrical conductivity is presented.     

Beta沸石上合成对叔丁基苯酚和2,4—二叔丁基苯酚

首次在三相条件下,在Ｂｅｔａ沸石催化剂上研究了苯酚与异丁烯烷基化合成对叔丁基苯酚和２,４－二叔丁基苯酚。通过对Ｈｂｅｔａ沸石高温焙烧和吡啶中毒试验研究了烷基化反应活性和选择性的变化规律;用ＮＨ３－ＴＰＤ和Ｐｙ－ＩＲ测定了试样的酸量和酸种类,结果表明Ｈｂｅｔａ沸石具有很好的烷基化活性,苯酚的转化率可达９２％,经１１２３Ｋ焙烧后苯酚转化率为８８％,对叔丁基苯酚和２,４－二叔丁基苯酚的选择性分别为７０～７５％和１４～２０％,中等强度的Ｂｒｎｓｔｅｄ酸是苯酚与异丁烯烷基化反应的活性中心。粘合剂含量低于３０％对烷基化活性基本无影响     

Friedel–crafts reactions of pendant vinyl groups in macroporous monosized poly(meta‐divinylbenzene) and poly(para‐divinylbenzene) particles

Residual vinyl groups in macroporous monosized polymer particles of poly(meta‐DVB) and poly(para‐DVB) prepared with toluene and 2‐EHA as porogens have been reacted with aluminum chloride as Friedel–Crafts catalyst with and without the presence of lauroyl chloride. In the reaction between aluminum chloride and pendant vinyl groups a post‐crosslinking by cationic polymerization takes place. A reaction occurring simultaneously is the addition of HCl to the double bonds. The progress of these reactions was studied by characterization of vinyl group conversion, pore size distribution, specific surface area, morphology, and swelling behavior. In the reaction with aluminum chloride the poly(para‐DVB) particles showed a substantially higher conversion of pendant vinyl groups than the particles made of poly(meta‐DVB) independent of porogen type. The reaction with aluminum chloride led to a reduced swelling in organic solvents and an increased rigidity of the particles prepared with toluene as porogen. This is confirmed by an increase in the total pore volume in the dry state and a change in the pore size distribution of these particles. Also in the reaction with lauroyl chloride poly(para‐DVB) particles have shown a higher conversion of pendant vinyl groups than poly(meta‐DVB) particles and the acylation was almost complete at the early stage of the reaction. The swelling in organic solvents is reduced as a result of the incorporation of acyl groups into the particles prepared with toluene as porogen. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1366–1378, 2000     

Assessment of errors in the determination of Mark–Houwink–Sakurada and Stockmayer–Fixman constants using size‐exclusion chromatography with on‐line viscometric detection: Analyses of poly(p‐substituted styrenes) in tetrahydrofuran

In this work, we present values for the Mark–Houwink–Sakurada (MHS) and Stockmayer–Fixman (SF) constants for a series of homopolymers of para‐substituted styrenes (4‐X‐styrene; X = OCH₃, OCH₂CH₃, CH₃, F, Cl, and Br) in THF at room temperature. The respective values of K (in 10⁻⁵ dL/g) and α were: 0.685 and 13.2; 0.662 and 14.1; 0.740 and 8.41; 0.781 and 5.24; 0.726 and 8.95; 0.700 and 7.79. The respective values for K_θ (in 10⁻⁴ dL/g) and K' (in 10⁻⁷ dL/g) were: 6.01 and 16.1; 6.22 and 9.07; 7.64 and 17.4; 5.59 and 23.7; 6.29 and 17.3; 4.44 and 10.3. These constants were measured using size‐exclusion chromatography with on‐line viscometry. As part of this work, we investigate the applicability of common model fitting procedures to this method of measuring MHS/SF constants and the effect of uncertainties in their estimated values on the accuracy of molecular weight analysis. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2557–2570, 1999