悬浮固化-分散液液微萃取-液相色谱-串联质谱测定纺织废水中磷系阻燃剂

建立了悬浮固化-分散液液微萃取结合液相色谱-串联质谱测定纺织废水中5种痕量磷系阻燃剂的方法。通过对萃取过程中萃取剂、分散剂的种类与体积、盐浓度、溶液pH值等对萃取效率的影响因素优化,确立了最佳萃取条件。采用了密度小于水的十一烷醇（400 μL）为萃取剂,甲醇（300 μL）为分散剂,控制溶液pH值在6~9之间,NaCl添加量为2 g,萃取时间为涡旋2 min。在优化的萃取条件下,该方法在2~100 μg/L均有良好的线性关系,相关系数大于0.995,除二（2,3-二溴丙基）磷酸酯（BIS）的检出限为5 μg/L外,三（2-氯乙基）磷酸酯（TCEP）、三（1,3-二氯-异丙基）磷酸酯（TDCP）、三（1-氮丙啶基）氧化膦（TEPA）和三（2,3-二溴丙基）磷酸酯（TRIS）的检出限均为2 μg/L。后整理、染色和印花等实际废水样品加标试验表明,方法的平均回收率为71.6%~114.5%,RSD为2.7%~11.2%（n=6）。对11个样品进行检测,其中3个废水样品检出TCEP与TDCP化合物,含量为2.6~3.4 μg/L。本方法简单,快速,灵敏度好且环保绿色,能够对纺织废水中的5种痕量磷系阻燃剂进行准确的定性与定量检测。     

基于金属有机骨架材料的磁固相萃取与高效液相色谱-紫外检测法分析饮料和方便面中4种防腐剂

通过简单的搅拌共混方式制备了磁性氨基功能化的金属有机骨架化合物（MOFs）材料,得到的复合材料磁性和热稳定性良好,比表面积大,被用于不同极性防腐剂（苯甲酸、山梨酸、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯）的萃取。优化磁固相萃取及解吸条件后,将解吸液引入高效液相色谱-紫外检测分析仪器,采用Purospher^® STAR LP C18色谱柱（250 mm×4.6 mm,5 μm）分离,以甲醇-10 mmol/L醋酸铵水溶液（50：50,v/v）为流动相进行梯度洗脱。结果表明,目标防腐剂的检出限为0.51~1.89 μg/L;苏打水、维生素饮料和方便面面饼中目标防腐剂的加标回收率为72.2%~109%。该方法简单快速,准确可靠,适用于饮料和食品中不同极性防腐剂的分析,为食品安全及质量监控提供了有效的技术有段。     

双金属氮化物Co3W3N/CNTs纳米复合材料的制备及其室温常压氮还原性能

采用水热法并经氨气保护热处理制备了双过渡金属氮化物Co3W3N/CNTs复合材料,得到了价格低廉且拥有良好氮电化学还原性能(NRR)的催化剂。通过调节已经预氧化的CNTs与过渡金属氮化物前驱体CoWO4的比例以及氨气热处理温度,实现了Co3W3N在CNTs表面的均匀负载。扫描电子显微镜(SEM)及透射电子显微镜(TEM)测试结果显示该电化学活性纳米微粒均匀地分散于CNTs表面,表明经预氧化的CNTs由于表面富集了较多的活性基团,有利于双过渡金属氮化物的分散生长。热处理后CNTs表面的Co3W3N微粒尺寸约为20 nm,相较于无载体的Co3W3N尺寸(100 nm)有明显减小。室温条件下,在N2饱和的0.01 mol·L^-1 H2SO4溶液中测试了该纳米复合材料在不同过电位下的NRR,该材料在-0.3 V(vs RHE)时的产氨率及法拉第效率分别可达12.73μg·h^-1·cm-2和13.59%,对比同样条件下,纯相Co3W3N的产氨率及法拉第效率仅为1.08μg·h^-1·cm^-2和1.76%。结果表明,通过水热反应和氨气保护热处理的Co3W3N/CNTs纳米复合材料具有良好的NRR性能。     

介孔SBA-15棒负载的Pd3Cl催化剂催化Sonogashira偶联反应（英文）

通过静电吸引策略将具有高度分散性的原子精确纳米团簇[Pd3Cl(PPh2)2(PPh3)3]+(Pd3Cl)负载在介孔SBA-15棒上。结构明确的Pd3Cl/SBA-15催化剂在以水作为溶剂以及温和的反应条件下对催化Sonogashira碳-碳偶联反应展现了较好的催化性能以及循环性。在此基础上,我们研究了Pd3Cl团簇结构与性能之间的关系,并证实内核的Pdδ+(0<δ<2)与配体之间的协同效应是催化反应的关键。     

基于锌(Ⅱ)Schiff碱构筑模块和6-羧基吡啶-2-甲醇的3d-4f异金属四核簇合物的荧光和磁弛豫性质

用溶剂热方法合成了2个新的3d-4f异金属四核簇合物：[Zn₂Ln₂（salen）₂（CO₂PyCH₂O）₂（MeOH）2]（ClO₄）₂·2MeOH（Ln=Dy（1）,Tb（2）;H₂salen=N,N'-双（3-甲氧基水杨基）-1,3-二氨基丙烷;HCO₂PyCH₂OH=6-羧基吡啶-2-甲醇）。它们是由锌（Ⅱ）Schiff碱构筑模块和6-羧基吡啶-2-甲醇辅助配体组装而成的Zn-Ln₂-Zn型簇合物。磁性测量表明稀土离子间存在铁磁性相互作用。Zn₂Dy₂配合物1在2 000 Oe直流磁场下显示出磁弛豫行为;而Zn₂Tb₂配合物2不但有磁场导致的磁弛豫行为,而且还具有荧光性质。     

氨基的脱保护——乙酰苯胺水解实验教学设计*

通过开放性设计实验完成氨基脱保护实验的教学。指导学生以回收的乙酰苯胺为原料,自主设计乙酰苯胺在酸、碱条件下水解正交实验方案并分组独立操作,制备并提纯苯胺,比较不同条件下的苯胺收率,筛选出乙酰苯胺最佳的水解条件。对所选实验班级近3年的实验结果进行统计和分析,并通过验证实验考察了结果的可重复性。     

基于液相色谱-质谱技术的肾脏代谢组学分析方法研究

建立了一种基于高效液相色谱-超高分辨质谱技术的肾脏代谢组学分析方法。肾脏组织于液氮中研磨成粉后,采用甲基叔丁基醚/甲醇/水溶剂体系进行提取,分别得到强极性部分(下层)和弱极性部分(上层)提取物,依次采用HILIC亲水色谱柱和反相C18色谱柱进行梯度洗脱分离后,进行高分辨质谱分析。采用电喷雾离子源(ESI),正、负离子模式检测,扫描方式为全扫描,扫描范围为100~1000 Da,质量分辨率为120000。结果表明,该方法灵敏度高,专属性强,稳定性良好,可同时获取肾脏组织中的强极性和弱极性代谢物信息,可为肾脏疾病和药物肾毒性生物标志物的发现提供一种新的方法。     

Evolution of Artificial Base Pairs with Hydrogen Bond Complementarity

Artificial base pairs,from the perspective of synthetic biology,are designed to contain the features of modularity,orthogonality,and manipulability.And the development of artificial base pairs has beat endowed with responsibility to understand the biological process,improve the recognition capacity and stability of aptamers,and develop the nucleoside drugs,diagnosis,and drag delivery.In this review,we first gave a concise introduction of artificial base pairs based on their interaction modes including alternative hydrogen bonding,hydrophobic interaction,and metal coordination.Then we displayed the detailed information of artificial base pairs with hydrogen bonding interaction,and analyzed how the changes of their structures affect their functions.Subsequently,we highlighted the applications of functional artificial base pairs in aptamer discovery,diagnosis,and drug delivery.Finally,an insight into the remaining challenges and future perspective of the artificial bases was provided.     

Preparation of MnO2 Loaded Hydrothermal Carbon-coated Electrospun PAN Fiber Membranes for Highly Efficient Adsorption and Separation of Cationic Dye

Hydrothermal carbonaceous materials and MnO₂ have been proved to be promising adsorbents to remove organic dyes from wastewater. In this study, flexible MnO₂ loaded hydrothermal carbon-coated electrospun poly-acrylonitrile(AC/MnO₂/PAN) fiber membranes were fabricated by a facile one-step hydrothermal method and activated by NaOH solution. The composite fibers exhibited large adsorption capacity toward cationic dyes and excellent mechanical properties. The adsorption performance can be fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption for methylene blue(MB), methyl violet(MV) and malachite green(MG) are 1173.27,1106.31 and 1129.89 mg/g, respectively, according to Langmuir fitting. The AC/MnO₂/PAN fiber membrane also showed satisfactory performances for selective adsorption and recyclability. In addition, based on selective adsorption, the AC/MnO₂/PAN fiber membranes that are repulsive to the anionic dye methyl orange(MO) can separate the MB/MO mixture solution by dynamic filtration. Thus, this work not only provides a facile strategy to fabricate large capacity adsorbents, but also demonstrates the potential applications in the dye wastewater treatment field.     

Multiple Stimuli-Responsive Conformational Exchanges of Biphen[3]arene Macrocycle

Conformational exchanges of synthetic macrocyclic acceptors are rather fast, which is rarely studied in the absence of guests. Here, we report multiple stimuli-responsive conformational exchanges between two preexisting conformations of 2,2′,4,4′-tetramethoxyl biphen[3]arene (MeBP3) macrocycle. Structures of these two conformations are both observed in solid state, and characterized by ¹H NMR, ¹³C NMR and 2D NMR in solution. In particular, conformational exchanges can respond to solvents, temperatures, guest binding and acid/base addition. The current system may have a role to play in the construction of molecular switches and other stimuli-responsive systems.