Disposable ionic liquid coating for headspace solid-phase microextraction of benzene, toluene, ethylbenzene, and xylenes in paints followed by gas chromatography-flame ionization detection

Solid-phase microextraction (SPME) with a disposable ionic liquid (IL) coating was developed for headspace extraction of benzene, toluene, ethylbenzene, and xylenes (BTEX) in paints. The SPME fiber was coated with IL prior to every extraction, then the analytes were extracted and desorbed on the injection port of gas chromatography, and finally the IL coating on the fiber was washed out with solvents. The coating and washing out of IL from the fiber can be finished in a few minutes. This disposable IL-coated fiber was applied to determine BTEX in water-soluble paints with results in good agreement with that obtained by using commercially available SPME fibers. For all the four studied paints samples, the benzene contents were under the detection limits, but relatively high contents of toluene, ethylbenzene and xylenes (56-271 microg g(-1)) were detected with spiked recoveries in the range of 70-114%. Compared to the widely used commercially available SPME fibers, this proposed disposable IL-coated fiber has much lower cost per determination, comparable reproducibility (RSD < 11%), and no carryover between each determination. Considering that IL possess good extractability for various organic compounds and metals ions, and that task-specific IL can be designed and synthesized for selective extraction of target analytes, this disposable IL coating SPME might has great potential in sample preparation.     

杯芳烃的分子设计(Ⅵ)--一种新的杯[4]磺胺衍生物的合成及晶体结构

杯芳烃是由酚单体通过亚甲基在羟基邻位桥连而成的环状低聚物, 它具有可调的杯状疏水空腔, 结构柔性较大, 构象可变, 并对中性分子和有机、无机离子具有选择性配位能力. 因此, 在其上下缘进行化学修饰所得到的杯芳烃衍生物可广泛应用于萃取分离、离子选择性电极、色谱分析、功能材料、催化及模拟酶等研究领域[1～4].     

Synthesis and Crystal Structure of a Novel Three-dimensional Cu(II) Compound {[Cu(2,2''-bipy)(C7H4O5S)(H2O)2]·(H2O}n

The title compound, {[Cu(2,2'-bipy)(C7H4O5S)(H2O)2](H2O}n (2,2'-bipy = 2,2'- bipyridine), was synthesized by the hydrothermal reaction of Cu(NO3)2(3H2O, 2,2'-bipyridine and 2-sulphobenzoic acid, and structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P with a = 9.21(3), b = 10.17(3), c = 10.77(3) (A), α = 77.017(16), β = 89.80(8), γ = 68.46(7)°, V = 911(5) (A)3, Z = 2, (D/s)max = 0.001, Mr = 473.94, Dc = 1.728 g/cm3, μ(MoKα) = 1.365 mm-1, F(000) = 486, the final R = 0.0246 and wR = 0.0628 for 3809 observed reflections with I > 2σ(I). The mononuclear crystal structure extends into a two-dimensional net- work via hydrogen-bonding interactions and a three-dimensional framework is further formed by means of π-π stacking interactions.     

冠醚共缩聚物的合成与性能（Ⅱ）

采用２，６－二羟甲基苯酚类化合物分别与单苯并冠醚（Ｂ１５ＣＳ、Ｂ１８Ｃ６）和Ｍ苯并冠醚（２Ｂ１８Ｃ６、２Ｂ２４Ｃ８、２Ｂ３０Ｃ１０）在酸催化下缩聚，合成了两个系列冠醚共缩聚物．这些聚合物Ｍ＝１２００—４５００，可溶于氯仿等溶剂，萃取性能和络合选择性均有所提高．作为树脂使用，动态吸附容量为０．０５—０．１５ｍｍｏｌ／ｇ，并有较好的色谱特性．     

苯二甲酰基桥联铁硫配合物［（μ－RS）Fe_2（CO）_6］_2（μ－OCC_6

通过由Ｆｅ３（ＣＯ）１２、ＲＳＨ和Ｅｔ３Ｎ所形成的［（μ－ＣＯ）（μ－ＲＳ）Ｆｅ２（ＣＯ）６］Ｅｔ３ＮＨ于室温下分别与对或间苯二甲酰氯的原位反应，首次合成６个结构新颖的苯二甲酰基桥联铁硫配合物［（μ－ＲＳ）·Ｆｅ２（ＣＯ）６］２（μ－ｐ－ＯＣＣ６Ｈ４ＣＯ－ｐ－μ）（Ｒ＝Ｅｔ，ｎ－Ｂｕ，ｔ－Ｂｕ）以及［（μ－ＲＳ）Ｆｅ２（ＣＯ）６］２（μ－ｍ－ＯＣＣ６Ｈ４ＣＯ－ｍ－μ）（Ｒ＝ｎ－Ｐｒ，ｎ－Ｂｕ，ｔ－Ｂｕ）。经元素分析、ＩＲ光谱及１ＨＮＭＲ表征了它们的结构，并讨论了产物的生成过程。此外，还提出了合成对苯二甲酰氯的一种新方法。     

Ligand Exchange Between Penta-Coordinated Phosphoryl Serine and Histidine Compounds

With the assistance of HPLC-ESI-MS/MS, the self-assembly products of serine and histidine penta-coordinated phosphorus compound were separated and identified. The expectative product was seryl-histidine dipeptide, but it was found that there was almost equimolar amount of histidyl-histidine dipeptide as well as seryl-histidine dipeptide. The mechanism was speculated that there was iigand exchange between penta-coordinated phosphoryl serine and histidine in the reaction process. As a result,two types of dipeptide were produced.     

Shortening of travelling-wave-amplified spontaneous emission by a transversal pumping scheme

An experimental investigation on shortening of travelling-wave ASE employing a transversal pumping is presented. A N₂ laser with =337.1 nm, pulsewidth: 700 ps is used as a pump source. An ASE pulse with duration of 45, 55 and 45 ps from dye solution of Rh 6G, Rh B and C311, respectively, is obtained. Pulse shapes of output signals generated from these solutions in three different pumping schemes are compared.     

Crystallization of binary carboxylic acids characterized with streaming potential measurement

The streaming potential of supersaturated solution of binary carboxylic acids, which have even carbon atoms, was determined to characterize crystallization under different temperatures. The value of the streaming potential was related to the type and solubility of the acids and the starting temperature of crystallization, and was easily influenced by the pressure difference of the liquid or the rate of temperature decline. When the temperature was declined to the point where a crystal nucleus appeared, the streaming potential reached the minimum. Thereafter, as the temperature was sequentially lowered, some minicrystals grew, and the streaming potential presented an ascendant tendency. The higher the starting temperature of the acids saturated solution, the higher is the temperature corresponding to the streaming potential minimum. The less the carbon atoms in the acids and the greater the solubility of the acids are, the higher is the temperature of the streaming potential minimum. Copyright © 2007 John Wiley & Sons, Ltd.     

鹿角短指软珊瑚Sinularia Cervicornis Tix-Dur 中的一个新糖甙-Cervicoside

珊瑚属腔肠动物门 ( Clelenterata) ,海鸡冠目 ( Alcyonacea) ,是一种热带与亚热带海洋中广泛分布Scheme 1　 Structure of cervicoside(1 )的低等海洋生物 .软珊瑚的次生代谢物中含有萜类和甾体类等各类生理活性物质[1～ 5] .我们在对鹿角短指软珊瑚的次生代谢产物研究中 ,分离到一个新三糖甙 ,命名为 Cervicoside( 1 ) ,结构见 Scheme 1 .该化合物具有较强的体外抗癌活性 .1　实验部分1 .1　样品　鹿角短指软珊瑚采自海南岛三亚海域 .样品储藏于中山大学化学与化学工程学院天然有机化学研究室 ,编号为 98- SY- 3.种属由中国科学院南海…     

硼掺杂还原态氧化石墨烯催化剂的制备及其蒽催化加氢性能的研究

制备了一系列硼掺杂的还原氧化态石墨烯催化剂并应用于蒽加氢反应。结果表明，随着催化剂处理温度的升高，催化剂中有序碳结构会发生变化，硼会取代材料骨架中的碳，进而影响蒽和氢气的吸附活化。经硼改性后，催化剂对蒽加氢反应表现出了很高的加氢活性，蒽的最高转化率可达97%，深度加氢产物八氢蒽的最高选择性可达19%。