冷原子—无色散原子荧光光谱法测定奶粉中汞的有关问题的探讨

本文第一次提出汞样品经硝酸消化后，汞（Ｈｇ）与氮氧化物（ＮｘＯｒ）形成络合物，在经典的加氯化亚锡（ＳｎＣｌ２）还原时，生成Ｈｇ与ＮＯ并能同时逸出，确定了Ｈｇ与ＮｘＯｒ存在配位关系，对汞的测定在数学计量上增加到１．５倍，结果表明，应用五氧化二矾消化奶样品能如实反映这一关系，并精确地得出其汞含量，在联合国环境规划署和粮食农业及世界卫生组织食品污染联合监测计划的第八届铅，镉，汞的分析质量保证中，应用本法     

Correlation Analysis of the Fluorescence Data of Some Benzaldehyde Derivatives by the Dual-Parameter Equation

Ithasbeenrecentlyestablishedthattherearefourcategoriesofpossiblecircumstancesforcorrelati0nanalyses0fradicalreactivitiesandspectralpropertiesbyEq.(l),Eq.(2)andEq.(3)."(I)Bothp0larandspin-del0calisationeffectsaretwortant,O.2l.O.(III)Thespin-delocalizationeffectspredominate,lpmdpJJ'I<0.2.(IV)Nocorrelationcanbeachieved.Wehavef0undthatthebehavi0roffluorescencespectraldataofsomestyrenes,'bycorrelati0nanalysiswiththedual-parameterEq.(…     

共价氢化物与汞离子反应的研究：Ⅱ.痕量硒的高灵敏分析新方法

本文详细研究了硒化氢与汞离子反应条件并建立了氢化物发生－冷原子荧光法间接测定痕量硒的新方法。考察了各种实验条件，并将此方法用于合成水样分析，得到一些有意义的结果。     

Optimization of Gold Nanoparticle-Based DNA Detection for Microarrays

DNA microarrays are promising tools for fast and highly parallel DNA detection by means of fluorescence or gold nanoparticle labeling. However, substrate modification with silanes (as a prerequisite for capture DNA binding) often leads to inhomogeneous surfaces and/or nonspecific binding of the labeled DNA. We examined both different substrate cleaning and activating protocols and also different blocking strategies for optimizing the procedures, especially those for nanoparticle labeling. Contact angle measurements as well as fluorescence microscopy, atomic force microscopy (AFM), and a flatbed scanner were used to analyze the multiple-step process. Although the examined different cleaning and activating protocols resulted in considerably different contact angles, meaning different substrate wettability, silanization led to similar hydrophobic surfaces which could be revealed as smooth surfaces of about 2–4 nm roughness. The two examined silanes (3-glycidoxypropyltrimethoxysilane (GOPS) and 3-aminopropyltriethoxysilane (APTES)) differed in their DNA binding homogeneity, maximum signal intensities, and sensitivity. Nonspecific gold binding on APTES/PDC surfaces could be blocked by treatment in 3% bovine serum albumin (BSA).     

Unfolding Features of Bovine Testicular Hyaluronidase Studied by Fluorescence Spectroscopy and Fourier Transformed Infrared Spectroscopy

Chemical unfolding of bovine testicular hyaluronidase (HAase) has been studied by fluorescence spectroscopy and Fourier transformed infrared spectroscopy (FTIR). Thermodynamic parameters were determined for unfolding HAase from changes in the intrinsic fluorescence emission intensity and the formations of several possible unfolding intermediates have been identified. This was further confirmed by representation of fluorescence data in terms of ‘phase diagram’. The secondary structures of HAase have been assigned and semiquantitatively estimated from the FTIR. The occurrence of conformational change during chemical unfolding as judged by fluorescence and FTIR spectroscopy indicated that the unfolding of HAase may not follow the typical two-state model.     

Fluorimetric Determination of Histamine in Fish Using Micellar Media and Fluorescamine as Labelling Reagent

An analytical method based on the use of fluorescamine to produce a fluorescent derivative with histamine and combined with micellar-enhanced fluorescence detection of the formed complex is developed for the sensitive and rapid determination of histamine in fishes. The fluorescence properties of the obtained complex in water and micellar solutions of sodium dodecyl sulfate (SDS), cetyltrimethylammonium chloride (CTAC) and brij-700 are reported. Physicochemical variables influencing the sensitivity of the method (pH, micellar, fluorescamine and NaCl relative concentrations) have been optimized. The stability of the formed complex, as shown by kinetic study, depends on the pH of the solution. Linear calibration curves allowing an effective histamine determination were established with large linear dynamic range (LDR), and low limits of detection (LOD) between 0.5 and 33 ng mL⁻¹, according to the solvent. Application to the analysis of fish samples (sardines) yielded satisfactory results. The method seems to be suitable for environmental fish quality control. Presented in part, at the 39th IUPAC Congress and the 86th Conference of the Canadian Society for Chemistry, August, 10–15, 2003, Ottawa (Canada).     

Analysis of the Effects of Protic,Aprotic, and Multi-Component Solvents on the Fluorescence Emission of Naphthalene and its Exciplex with Triethylamine

The emission spectra of naphthalene (NP)–triethylamine (TEA) systems were measured under steady-state illumination conditions in some protic and aprotic solvent-tetrahydrofuran (THF) mixtures. The fluorescence spectrum of the NP–TEA system in THF could be separated into two component bands (band A at 329 nm (fluorescence of NP) and band B at 468 nm (emission from an intermolecular exciplex)). The intensities of bands A and B decreased with increasing solvent polarity. The intensity of band B also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. The decrease in the intensity of band A with increasing solvent polarity is considered to be caused by the enhanced formation of an ion-pair parallel to the formation of an exciplex with increasing solvent polarity. The decrease in the intensity of band B is considered to be caused by the enhanced formation of ion-pair both parallel to and through the formation of the exciplex. The increase in the intensity of band A and the decrease in that of band B upon the addition of protic solvents is caused by the decrease in the concentration of free TEA. Acetonitrile only has a polar effect and trichloroacetic acid only has a hydrogen-bonding (protonation) effect, while alcohols have both the effects.