Monitoring myoglobin by capillary zone electrophoresis with end-column amperometric detection

Capillary zone electrophoresis was employed for the determination of myoglobin in human urine using end-column amperometric detection with a carbon fiber microelectrode at a constant potential of 1.80 V vs. saturated calomel electrode (SCF). The optimum conditions of separation and detection are: 3.73 x 10-4 mol/L sodium diethyl malonyl urea (barbitone sodium), 1.34 x 10-4 mol/L HCl for the buffer solution, 20 kV for separation voltage, 5 kV and 5 s for injection voltage and injection time, respectively. The limit of detection is 4.4 x 10-8 mol/L or 84 amole signal to noise (S/N = 2). The relative standard deviation is 2.9% for the migration time and 2.5% for the electrophoretic peak current. The method can be used for the determination of myoglobin in human urine. The samples can be directly injected and need no pretreatment. The method is also rapid, less than 2 min, and has a recovery rate of 94-106%.     

Theoretical investigation of the decarbonylation of acetaldehyde by Fe+ and Cr+.

We report a comprehensive theoretical study on the decarbonylation of acetaldehyde by Fe+ and Cr+. Various intermediates, transition states, and products involved in the decarbonylation reactions are fully optimized at the B3LYP/6-311+G(2df,2pd) level of theory. The potential energy surfaces (PESs) corresponding to [M,O,C2,H4]+(M=Cr and Fe) are examined in detail using B3LYP and CCSD(T) methods, respectively. The validity of these theoretical methods is calibrated with respect to the available thermochemical data. Calculations suggest that the Cr+ mediated decarbonylation of acetaldehyde takes place in four steps on the sextet surface: encounter complexation, C-C activation, aldehyde H-shift, and nonreactive dissociation, in good accordance with the Co+ mediated decarbonylation of acetaldehyde [Zhao, Zhang, Guo, Wu, Lu, Chem. Phys. Lett. 2005, 414, 28], while for the Fe+/acetaldehyde system decarbonylation can occur on both the quartet and the sextet PESs. The quartet pathway, which experiences spin-orbit coupling between the two surfaces, is energetically more favorable; whereas along the sextet decarbonylation coordinate several high-energy barriers are revealed. The theoretical results are compared with the experimental product kinetic energy and angular distributions of decarbonylation of acetaldehyde by Fe+ and Cr+ measured using a crossed-beam technique [Sonnenfroh, Farrar, J. Am. Chem. Soc. 1986, 108, 3521].     

联二炔囊泡的光致聚合、热致变色及应用

物理化学实验为各大高校本科化学教学的主干实验课程之一。虽然各高校的物理化学实验内容已十分丰富,但仍然缺乏将不同章节知识点融会贯通以及与学科前沿密切联系的综合型实验内容。我们根据南开大学郭东升教授课题组发表的一篇有关联二炔程序性响应检测胆碱酯酶的工作设计了“联二炔囊泡的光致聚合、热致变色及应用”的物理化学实验,涉及到联二炔缔合胶体的制备、联二炔的紫外光致聚合反应和聚联二炔的热致变色,进而显示其在防伪领域的潜在应用价值。希望通过此实验,使学生对物理化学中的缔合胶体、光化学、热力学、动力学等章节有更深一步的贯通性掌握,并了解自组装、光聚合、变色材料和防伪等相关研究领域的前沿动态。     

Mesoporous silica nanospheres with the ability of photo-driven releasing sandela 803 for the application to wallpaper

Mesoporous silica nanospheres loaded with sandela 803 (S803@MS-S) are prepared for application to wallpaper. The nano-fragrance has high encapsulation efficiency and property of photo-driven release.     

流动注射化学发光法测定甲氨蝶呤

研究了甲醛增强高锰酸钾与甲氨蝶呤的化学发光反应，由此建立了一种测定甲氨蝶呤的流动性注射化学发光分析法，方法的检出限为３．４×１０＾－９ｇ／ｍＬ，相对标准偏差为１．１％（２．０×１０＾－６ｇ／ｍＬ甲氨蝶呤，ｎ＝１１）线性范围为１．０×１０＾－８～１．０×１０＾－５ｇ／ｍＬ。该法已用于甲氨蝶呤针剂及片剂中甲氨蝶呤含量的测定。     

Silicalite-1膜反应器中的丙烷芳构化

在丙烷芳构化反应中，氢气起着相当重要的作用；根据理论分析，消除氢气将会有利于芳构化反应的进行。在Ｓｉｌｉｃａｌｉｔｅ－１沸石分子筛膜反应器，丙烷芳构化反应中的芳烃选择性提高了１０％－２０％。针Ｓｉｌｉｃａｌｉｔｅ－ｌ膜反应器与氧化铝膜反应器中的反应结果相比较，表明膜反应器效果不仅取决于膜的渗透选择性，而且还取决于膜的渗透率。     

Mo－Cu－S原子簇化合物［Mo_2Cu_6S_6（SCMe_3）_2（O）_

基于标题簇合物的快原子质谱研究，提出该二簇合物在质谱过程中的可能断裂途径及其簇骼转换的相关性。     

An integrated microfluidic device for influenza and other genetic analyses

An integrated microfluidic device capable of performing a variety of genetic assays has been developed as a step towards building systems for widespread dissemination. The device integrates fluidic and thermal components such as heaters, temperature sensors, and addressable valves to control two nanoliter reactors in series followed by an electrophoretic separation. This combination of components is suitable for a variety of genetic analyses. As an example, we have successfully identified sequence-specific hemagglutinin A subtype for the A/LA/1/87 strain of influenza virus. The device uses a compact design and mass production technologies, making it an attractive platform for a variety of widely disseminated applications.     

Spiro-configured bifluorenes: highly efficient emitter for UV organic light-emitting device and host material for red electrophosphorescence

[structure: see text] Remarkable UV OLED devices using novel spiro-configured bifluorenes as UV emitters have been successfully achieved with external quantum efficiencies up to 2.6-3.1% and emission wavelengths as short as 370 nm. In addition, these large-gap materials have been shown to be effective hosts for red phosphorescent emitters in phosphorescent OLEDs. This result represents the first example that pure hydrocarbon molecules can serve as an efficient host for red electrophosphorescence devices.     

Preparation and characterization of silver/TiO2 composite hollow spheres

Silver-coated poly(methyl acrylic acid) (PSA) core-shell colloid particles were prepared by an in situ chemical reduction method. Crystalline silver/titania composite hollow spheres were obtained by coating the as-prepared PSA/silver particles with an amorphous titania layer and subsequently calcining in Ar atmosphere. SEM and TEM investigation indicated that the size of the as-prepared PSA/silver and PSA/silver/TiO(2) core-shell particles and silver/titania composite hollow particles was fairly uniform and the wall thickness of the hollow spheres was in the range of 40-80 nm. UV-vis absorption spectra were recorded to investigate their optical properties.