Separation of ionic liquid cations and related imidazole derivatives by alpha-cyclodextrin modified capillary zone electrophoresis

The separation and detection of 1-alkyl-3-methylimidazolium, including isomers, and related imidazole derivatives was performed by alpha-cyclodextrin (alpha-CD) modified capillary zone electrophoresis. The separations were carried out in a running buffer comprising 5.0 mM triethylamine and 2.0 mM alpha-CD adjusted to pH 4.5 by acetic acid. All the analytes were baseline separated within 8 min and the detection limits (signal-to-noise ratio = 3) ranged between 0.42 and 1.36 ppm. The method showed good linearity (within 3-50 times the detection limits, r > 0.99) and reproducibility (relative standard deviation < 0.8% for migration times and < 3% for peak areas), which should make it suitable for routine analysis. It was employed in detecting impurities in commercial chemicals, and 0.27% 1-methylimidazole in 1-ethyl-3-methylimidazolium chloride and 0.55% imidazole in 2-ethylimidazole were found. In addition, it was employed in process analysis during synthesis of ionic liquids and demonstrated a potential to provide information on the reaction mechanism.     

重楼皂甙提取工艺优化与近红外光谱在线质量控制

以滇重楼的根茎为实验材料,重楼甾体总皂甙的提取率为评价指标,运用L16(45)正交试验,考察了皂甙浸出过程中的浸泡时间、乙醇浓度、超声剂量、粗粉质量与浸泡用乙醇体积之比4个因素在4个水平下的工艺过程,筛选出了最佳提取工艺.实验结果表明粗粉(0.45 mm粒径)用30%的乙醇溶液浸泡36 h后,超声30 min,粗粉质量与(浸泡)乙醇的体积比115为最佳提取条件,重楼甾体总皂甙的提取率为9.50%.以近红外漫反射光谱技术为在线监控手段,利用模式识别方法对AB-8树脂分离精制过程中的吸附、杂质洗脱和甾体总皂甙解吸洗脱等工艺过程进行了在线质量监控方法研究,建立了优化的质量可控的分离纯化方法.     

29Si and 27Al MAS NMR spectra of mullites from different kaolinites

Mullites synthesized from four kaolinites with different random defect densities have been studied by 27Al and 29Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) and X-ray diffraction (XRD). All these mullites show the same XRD pattern. However, 29Si and 27Al MAS NMR spectra reveal that the mullites derived from kaolinites with high defect densities, have a sillimanite-type Al/Si ordering scheme and are low in silica, whereas those mullites derived from kaolinites with low defect densities, consist of both sillimanite- and mullite-type Al/Si ordering schemes and are rich in silica.     

Tracing drug release process with dual-modal hyperbranched polymer-gold nanoparticle complexes

Dual-modal surface enhanced Raman spectrum(SERS)-fluorescence polymer/metal hybrid complexes have been prepared for tracing drug release process in tumor cells. Firstly, the hyperbranched poly((S-(4-vinyl) benzyl S′-propyltrithiocarbonate)-co-(poly(ethylene glycol) methacrylate))(HPVBEG) was synthesized via the combination of reversible addition-fragmentation chain-transfer(RAFT) polymerization and self-condensing vinyl polymerization(SCVP). Subsequently, the anticancer drug doxorubicin(DOX) was linked to HPVBEG via pH sensitive Schiff base bonds to form HPVBEG-g-DOX conjugates.Through aminolysis reaction, HPVBEG-g-DOX was coordinated with gold nanoparticles(GNP), resulting in the formation of HPVBEG-g-DOX/GNP complexes. In neutral condition, the HPVBEG-g-DOX/GNP complexes were stable, and DOX was bound to the surface of GNPs. Therefore, the SERS of DOX could be observed, while the fluorescence of DOX was quenched by GNPs. Under an acidic environment, DOX was released from the surface of GNPs with breakage of Schiff base bonds.Thus, the SERS signal of DOX was gradually reduced. Correspondingly, the fluorescence signal of DOX was enhanced.Through dual-modal SERS-fluorescence technique, the DOX delivery and release process was traced in tumor cells. Moreover,the viability of MCF-7 cells incubated with HPVBEG-g-DOX/GNP complexes was investigated by Cell Counting Kit-8(CCK-8) assay. The experimental results showed that HPVBEG-g-DOX/GNP complexes had similar proliferation inhibition effect compared with free DOX. Definitely, the dual-modal SERS-fluorescence complexes for tracing drug delivery and release will have promising prospects on tumor diagnosis and therapy.     

担载液相催化剂的研究Ⅶ．乙烯羰化制丙醛的宏观动力学

担载液相催化剂的研究Ⅶ．乙烯羰化制丙醛的宏观动力学①胡斌孙懿张红平刘省明殷元骐②（中国科学院兰州化学物理研究所，兰州７３００００）关键词羰基化乙烯丙醛固定化催化剂动力学丙醛的生产方法有多种，工业上主要应用羰基合成法．在５０年代以前，以羰基钴作催化剂，...     

Multiplex electrochemiluminescence DNA sensor for determination of hepatitis B virus and hepatitis C virus based on multicolor quantum dots and Au nanoparticles

In this work, a novel multiplex electrochemiluminescence (ECL) DNA sensor has been developed for determination of hepatitis B virus (HBV) and hepatitis C virus (HCV) based on multicolor CdTe quantum dots (CdTe QDs) and Au nanoparticles (Au NPs). The electrochemically synthesized graphene nanosheets (GNs) were selected as conducting bridge to anchor CdTe QDs₅₅₁-capture DNA_HBV and CdTe QDs₆₀₇-capture DNA_HCV on the glassy carbon electrode (GCE). Then, different concentrations of target DNA_HBV and target DNA_HCV were introduced to hybrid with complementary CdTe QDs-capture DNA. Au NPs-probe DNA_HBV and Au NPs-probe DNA_HCV were modified to the above composite film via hybrid with the unreacted complementary CdTe QDs-capture DNA. Au NPs could quench the electrochemiluminescence (ECL) intensity of CdTe QDs due to the inner filter effect. Therefore, the determination of target DNA_HBV and target DNA_HCV could be achieved by monitoring the ECL DNA sensor based on Au NPs-probe DNA/target DNA/CdTe QDs-capture DNA/GNs/GCE composite film. Under the optimum conditions, the ECL intensity of CdTe QDs₅₅₁ and CdTe QDs₆₀₇ and the concentration of target DNA_HBV and target DNA_HCV have good linear relationship in the range of 0.0005–0.5 nmol L⁻¹ and 0.001–1.0 nmol L⁻¹ respectively, and the limit of detection were 0.082 pmol L⁻¹ and 0.34 pmol L⁻¹ respectively (S/N = 3). The DNA sensor showed good sensitivity, selectivity, reproducibility and acceptable stability. The proposed DNA sensor has been employed for the determination of target DNA_HBV and target DNA_HCV in human serum samples with satisfactory results.     

基于案例教学法的物理化学课程教学改革探索与实践

Case teaching method is adopted to reform physical chemistry teaching to mobilize students' learning enthusiasm, activate classroom atmosphere and help students to understand nonfigurative and difficult basic concepts and principles. Theory is combined with practice, and a lot of cases from daily life, industrial and agricultural production together with scientific research are introduced into the whole teaching process of physical chemistry. Thus, the teaching effect is greatly improved.     

CO LMR spectrum of ~(14)N~(16)O and its analysis with spectra of ~(14)N~(17)O and ~(14)N~(18)O

LMR spectra for v=1←0 transitions of 14N16O in X2Π1/2,3/2 states were observed at 5.6 μm and 5.4 μm of CO laser. Introducing the advanced isotopic molecular constant scaling function to Hund's case (a) diatomic structure model, these spectra were analyzed and fitted together with all reliable previous spectral data of 14N16O as well as 14N17O and 14N18O. A full set of precise molecular parameters and their vibrational dependencies have been determined with much higher precision (1 -2 orders for most parameters). Many of them have been obtained for the first time. Using isotopic scaling function, the molecular constants of 14N17O and 14N18O were deduced.     

CF X2Π（υ＝1）远红外及NO X2Π（υ＝1←0）中红外激光磁共振光谱的标识

根据塞曼效应理论和激光磁共振 (LMR)光谱原理 ,本文建立了一套用于标识激光磁共振光谱的模型方法 ,并成功地对CFX2 Π(υ =1)远红外及NOX2 Π(υ =1← 0 )中红外激光磁共振光谱进行了标识。为新自由基分子的激光磁共振光谱提供了快速而准确的标识方法     

偶氮氯膦-mA-锇-高碘酸钾催化光度法测定微量锇

在碱性介质中,锇（Ⅳ）对KIO4氧化偶氮氯膦－mA的褪色反应有明显的催化作用,据此建立了催化光度法测定微量锇（Ⅳ）的新方法,并用正交实验设计对反应条件进行了优化。方法的检测限为2．0μg/L。锇（Ⅳ）含量在7．0－25．0μg/L范围内服从比尔定律。此方法已用于贵金属精矿和二次合金中微量锇的测定,相对误差均为0．9％,回收率在95．38％－106．0％之间。