3,4-Dinitrobenzamide Functionalized CdTe/ZnTe Quantum Dots as a Nanoprobe for Imaging Glutathione S-Transferase in Living Cells

A novel fluorescent nanoprobe for glutathione S‐transferase (GST) has been developed by incorporating 3,4‐dinitrobenzamide (a specific substrate of GST) onto CdTe/ZnTe quantum dots. The probe itself displays a low background signal due to the strong quenching effect of the electron‐withdrawing unit of 3,4‐dinitrobenzamide on the quantum dots. However, GST can efficiently catalyze the nucleophilic substitution of reduced glutathione on the p‐nitro group of the nanoprobe, leading to a large fluorescence enhancement. Most notably, this enhancement shows high selectivity and sensitivity towards GST instead of the other biological substances. With this nanoprobe, a simple fluorescence imaging method for intracellular GST has been established, and its applicability has been successfully demonstrated for imaging GST in different living cells, which reveals that A549 cells express GST about 3 times higher than NIH‐3T3 and Hela cells.     

Deep extractive desulfurization of diesel fuels by FeCl3/ionic liquids

The extractive desulfurization of dibenzothiophene（DBT）,benzothiophene（BT）,and 4,6-dimethyldi-benzothiophene （4,6-DMDBT） in model oil was carried out using anhydrous FeCl₃ and 1-methyl-3-octylimidazolium chloride system（[Omim|Cl·2FeCl₃）.This new system exhibited high extractive efficiency and the sulfur removal of DBT in model oil(V_IL/V_oil=1/20) could reach 99.4%at room temperature for 30 min,which was obviously superior to single[Omim]Cl as extractant（22.9%）.When the[Omim|CI·2FeCl₃ was used,the S-removal of 4,6-DMDBT and BT could also be up to 99.3%and 96.2%, respectively.Moreover,the ionic liquid could be recycled five times without a significant decrease in extractive ability.     

Enantiomeric separations of four basic drugs containing N-alkyl groups by a RP-HPLC system using SBE-β-CD as chiral mobile phase additive

The chiral separations of four pharmaceutical racemates which contain N-alkyl groups were satisfactorily resolved using SBE-β-CD as a chiral mobile phase additive(CMPA)in a RP-HPLC system(the resolution is 2.701 for ondansetron hydrochloride,1.996 for sulpiride,1.293 for clenbuterol hydrochloride and 0.816 for omeprazole).In addition,the effects of different parameters such as CD type and CD concentration were investigated.The separation mechanism arises through the combination of several potential interactions,including electrostatic interactions as well as hydrogen bonding interactions and hydrophobic inclusion interactions,which allow for the SBE-β-CD–drug complexation with strong stereoselectivity and stability.The resolution also relates to the number and location of N atoms in the enantiomers.This method will be applicable to the isolation of various types of biologically important enantiomers containing N-alkyl groups.     

Theoretical Study on the Hydrogen Bonding Interactions in Complexes of 5‐Hydroxytryptamine with Water

The energies, geometries and harmonic vibrational frequencies of 1:1 5‐hydroxytryptamine‐water (5‐HT‐H₂O) complexes are studied at the MP2/6‐311++G(d,p) level. Natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM) analyses and the localized molecular orbital energy decomposition analysis (LMO‐EDA) were performed to explore the nature of the hydrogen‐bonding interactions in these complexes. Various types of hydrogen bonds (H‐bonds) are formed in these 5‐HT‐H₂O complexes. The intermolecular C4H5^5‐HT···O^w H‐bond in HTW3 is strengthened due to the cooperativity, whereas no such cooperativity is found in the other 5‐HT‐H₂O complexes. H‐bond in which nitrogen atom of amino in 5‐HT acted as proton donors was stronger than other H‐bonds. Our researches show that the hydrogen bonding interaction plays a vital role on the relative stabilities of 5‐HT‐H₂O complexes.     

超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯

采用超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯的含量。以四氢呋喃为溶剂对样品进行超声波辅助提取后,加入甲醇对聚合物进行沉淀,取上清液,经冷冻离心后进行气相色谱一质谱分析,并采用氘代邻苯二甲酸酯为内标,单点校正法定量。该方法应用于中、日、韩计量比对的样品测定中,两天进行的6次测定结果相对标准偏差为0．7％～3．0％。最终比对结果显示3个国家的数据取得很好的一致性,除DEP相对标准偏差为2．4％以外,其它5种邻苯二甲酸酯相对标准偏差为0．7％～1．2％,测定结果的相对扩展不确定度为1．8％～4．9％,证明该方法准确、可靠。     

石墨炉原子吸收法测定PU材料中的铬

采用微波消解技术进行样品前处理,建立了石墨炉原子吸收法测定PU材料中铬含量的方法。在波长429.0 nm下,利用石墨炉程序升温测定,狭缝设为0.5 nm,塞曼效应作为背景校正。标准工作曲线线性良好,相关系数r=0.9986,方法检出限为0.051μg/L,测定结果的相对标准偏差为3.78%,加标回收率为92%～120%(n=6)。该方法简便、可行,适用于PU材料中铬的测定。     

二苯乙烯基蒽衍生物:聚集诱导发光性质、机理及应用

与传统的发光分子相比,具有聚集诱导发光(AIE)性质的分子,在聚集态或固态条件下,由于独特的分子结构和聚集态结构,表现出显著增强的荧光发射,因而在光电器件、生物化学检测等领域展现出广阔的应用前景。本文总结了二苯乙烯基蒽(DSA)及其衍生物的AIE性质,分析了DSA类分子AIE现象的机理,如分子内转动受限、扭曲的分子结构及分子间聚集结构等,同时介绍了此类分子在固态发光、刺激-响应材料,以及生物检测和生物成像等方面的应用。     

Crystal Structure and Magnetic Property of a 2-D Hexa-Circular Ring Cu(II)/Na(I)-Substituted Sandwich-Type Arsenotungstate

A new compound H₈[NaCu₅Cl(H₂O)₃(B-α-AsW₉O₃₃)₂] 24H₂O (1) is synthetized by the reaction of the CuCl₂ 2H₂O and Na₂₇[NaAs₄W₄₀O₁₄₀] 60H₂O in aqueous solution, which is constructed from a {Cu₅Na} hexagon moiety sandwiched by two trilacunary [B-α-AsW₉O₃₃]^9? units. The structure is determined by single-crystal X-ray diffraction technique and further characterized by IR spectroscopy. Single-crystal X-ray diffraction analysis reveals that 1 is built by two trilacunary [B-α-AsW₉O₃₃]^9? units incorporating a {Cu₅Na} hexagon moiety and further linked to each other to form an infinitely extended 2-D network via Cu–O–W bridges. Notably, magnetic measurement demonstrates that the occurrence of intramolecular ferromagnetic Cu–Cu interactions within {Cu₅Na} hexagon moiety.     

Determination of 48 fragrance allergens in toys using GC with ion trap MS/MS

This paper presents a method for the simultaneous determination of 48 fragrance allergens in four types of toys (plastic toys, play clays, plush toys, and paper toys) based on GC with ion trap MS/MS. Compared with single‐stage MS, MS/MS is superior in terms of the qualification and quantification of a large range of compounds in complicated matrices. Procedures for extraction and purification were optimized for each toy type. The method proved to be linear over a wide range of concentrations for all analytes with correlation coefficients between 0.9768 and 0.9999. Validation parameters, namely, LODs and LOQs, ranged from 0.005–5.0 and from 0.02–20 mg/kg, respectively. Average recoveries of target compounds (spiked at three concentration levels) were in the range of 79.5–109.1%. Intraday and interday repeatabilities of the proposed method varied from 0.7–10.5% and from 3.1–13.4%, respectively. The proposed method was used to monitor fragrance allergens in commercial toy products. Our findings indicate that this method is an accurate and effective technique for analyzing fragrance allergens in materials composed of complex components.