离子色谱柱后衍生法测定汞,锰,镉,钴,锌,镍和铜

提出了用离子色谱柱后衍生法同时测定汞和其它金属离子的新方法。本方法中样品离子以阴离子交换分离，用２－（５－溴－２－吡啶偶氮）－５－二乙氨基酚和非离子表面活性剂ＴｒｉｔｏｎＸ－１００显色体系作柱后衍生，分光光度法测定。     

Studies on Mesoporous Self-Organizing Aluminosilica

A detailed study on the preparation of highly ordered MCM-41 molecular sieves based on our new delayed neutralization process is presented. The rate of acidification does not have an apparent effect on the XRD patterns of MCM-41 but affects the morphology. The synthesized products give a thicker constant wall thickness (about 1.70 nm) of mesopore and a sharp pore size distribution. However, the structural order depends on the carbon chain length, the amount of alcohols as cosurfactants, and the synthetic temperature. A tubular morphology of the MCM-41 material, with hollow tubules 0.3 to 3 m in diameter, can be obtained by careful control of the surfactant–water content and the rate of condensation of silica under high-alkalinity conditions. In tubules-within-a-tubule, the wall of the tubule consists of coaxial cylindrical pores of nanometers characteristic of MCM-41. The hierarchical order structure takes place through a liquid crystal phase transformation mechanism in which an anisotropic membrane-to-tubule phase change is involved.     

Syntheses of 5‐(3‐Arylsydnon‐4‐yl)Tetrazole Derivatives

3‐Arylsydnone‐4‐carbohydroximic acid chlorides ( 1 ) could react with sodium azide to produce the corresponding 3‐arylsydnone‐4‐carbazidoximes ( 2 ), but not 1‐hydroxytetrazoles 3 . Treatment of 3‐arylsydnone‐4‐carbazidoximes ( 2 ) with acid chlorides such as acetyl chloride ( 4a ), propionyl chloride ( 4b ) and benzoyl chloride ( 4c ) in the presence of excess triethylamine generated the derivatives of the azidoximes 5 . To obtain the desired tetrazoles, the azidoximes 2 should first cyclize directly with acetyl chloride ( 4a ) or propionyl chloride ( 4b ) to afford the acetyl or propionyl derivatives 6 . The cyclized tetrazole derivatives 6 underwent deacylation upon heating in ethanol to give 1‐hydroxy‐5‐(3‐arylsydnon‐4‐yl)tetrazoles ( 3 ).     

Pyrene-assisted synthesis of size-controlled gold nanoparticles in sodium dodecyl sulfate micelles

Gold nanoparticles prepared by chemical reduction in sodium dodecyl sulfate (SDS) solution are size-controlled with the addition of pyrene. Micellar electrokinetic capillary chromatography (MEKC) is applied to the system to examine the size and polydispersity of gold nanoparticles and to show that pyrene has the extraordinary effect in decreasing the size and narrowing the dispersity of gold nanoparticles. The MEKC electropherograms further suggest that pyrene could be oxidized by the aqueous Au(III) complexes first. All the reduced Au complexes were then solubilized in the pyrene-SDS micelles. The growth of gold nanoparticles beyond the embryonic stage was subsequently inhibited by the encapsulating SDS and electrophilic pyrene.     

离子型表面活性剂自组装体系在化学中的应用

本文介绍了离子型表面活性剂在氧化物表面自组装体系的原理及特点，离子型表面活性剂分子从溶液中自发地吸附到氧化物表面形成单分子胶束、双分子胶束和混合胶束，该体系对许多疏水性有机化合物以及经螯合有机基团的金属离子具有很强的吸附富集作用，本文根据不同自组装体系的结构分类详述了它们在分析化学和环境化学中应用研究，并且展望了该技术的应用前景。     

Comparisons of disposable and conventional silver working electrode for the determination of iodide using high-performance anion-exchange chromatography with pulsed amperometric detection

The paper compared the performance of two kinds of silver working electrode in electrochemical detector-the disposable and conventional electrode for the determination of iodide using high-performance anion-exchange chromatography (HPAEC) hyphenated with pulsed amperometric detection (PAD). The comparisons were carried out on the time of equilibration, long and short-term reproducibility, limits of detection and linearity of calibration. Results showed that disposable working electrode manifested equal or better results than conventional working electrode and could be used for iodide analysis. Besides, the disposable electrode could work for consecutive 2660 min (about 44 h, 10 min needed for each run) with no degradation. Due to its "disposable" property, disposable working electrode could be discarded if the detection sensitivity decreased to 80% so the time for polishing and reconditioning was spared and good reproducible results could be obtained. At last, the disposable electrode was applied for the determination of iodide in soil and sea water samples with the spiked recovery ranging from 96-104% and the detection limit of 0.5 microg/L (10 microL injection, three times of the baseline noise).     

Studies on the Reaction of α‐Chloroformylarylhydrazine Hydrochloride1 with N‐Heterocyclic Compounds

In addition to pyridines, α‐chloroformylarylhydrazine hydrochloride 1 can also react with some N‐heterocyclic compounds. The cycloaddition of 1 with isoquinoline was achieved to obtain 3 . The production of 4, 5, 6 given by cycloaddition of 1 with pyridazine was de pendent on the reaction condition. Some heterocyclic compounds bearing an X‐C=N (X:S, N) group on the ring can react with 1 to gain the derivatives of 2,4‐dihydro‐1,2,4‐triazol‐3‐one. 7, 8, 9 and 10 were given by reaction of 1 with 1,3,5‐triazine, 1,4,5,6‐tetrahydropyrimidine, 1,3‐thiazole and 2‐amino‐1,3‐thiazole, respectively. The reactions for 2‐amino‐1,3,4‐thiadiazole and 3‐amino‐1,2,4‐triazole had the same product 11 .     

Dual-targeted photothermal agents for enhanced cancer therapy

Photothermal therapy, in which light is converted into heat and triggers local hyperthermia to ablate tumors, presents an inherently specific and noninvasive treatment for tumor tissues. In this area, the development of efficient photothermal agents (PTAs) has always been a central topic. Although many efforts have been made on the investigation of novel molecular architectures and photothermal materials over the past decades, PTAs can cause severe damage to normal tissues because of the poor tumor aggregate ability and high irradiation density. Recently, dual-targeted photothermal agents (DTPTAs) provide an attractive strategy to overcome these problems and enhance cancer therapy. DTPTAs are functionalized with two classes of targeting units, including tumor environment targeting sites, tumor targeting sites and organelle targeting sites. In this perspective, typical targeted ligands and representative examples of photothermal therapeutic agents with dual-targeted properties are systematically summarized and recent advances using DTPTAs in tumor therapy are highlighted.

In this perspective, the design, applications and potential directions of photothermal therapeutic agents with dual-targeted properties are systematically described.     

Direct determination of free amino acids and sugars in green tea by anion-exchange chromatography with integrated pulsed amperometric detection

Solutes analysed with LC-MS are characterised by their retention times and mass spectra, and quantified by the intensities measured. This highly selective information can be extracted by multiway modelling. However, for full use and interpretability it is necessary that the assumptions made for the model are valid. For PARAFAC modelling, the assumption is a trilinear data structure. With LC-MS, several factors, e.g. non-linear detector response and ionisation suppression may introduce deviations from trilinearity. The single largest problem, however, is the retention time shifts not related to the true sample variations. In this paper, a time warping algorithm for alignment of LC-MS data in the chromatographic direction has been examined. Several refinements have been implemented and the features are demonstrated for both simulated and real data. With moderate time shifts present in the data, pre-processing with this algorithm yields approximately trilinear data for which reasonable models can be made.     

Interfacing the Biomation 6500 Transient Digitizer to an Apple II Microcomputer

An interface is described which permits high-speed data transfer between the Biomation 6500 waveform digitizer and an Apple II microcomputer system. Through the interface, one can make any number of scans of repetitive data which, having been acquired by the Biomation 6500, may then be averaged, stored and analyzed in a microcomputer environment.