Activation analysis of mercury in urine samples of electrolysis cell workers

The activation method of determination of trace amounts of Hg in human urine has been studied by introducing a simple amalgam deposition method. Human urine samples were obtained from the alkali chloride, electrolysis plant equipped with Hg cells. The capacity of Cu powder for Hg quantity, the pH conditions, and the shaking time were described. The results showed that the Hg contents in workers' urine samples varied from 33 ppb to 60 ppb depending on working conditions.     

Hydrophilic Treatment of the Dyed Nylon-6 Fabric using High-density and Extensible Antenna-coupling Microwave Plasma System

High density and well surface-distributed oxygen microwave plasma with an extensible antenna-coupling design was utilized to modify a densely weaved and large-surface-area Nylon-6 fabric within a short treatment time. Plasma pretreatment and subsequent acrylic acid (AAc) or 2-hydroxyethyl methacrylate (HEMA) grafting process were studied and optimized at the stage after dyed and finished procedure. The monomer-grafted dyed Nylon-6 fabrics evolved lasting hydrophilic properties and thereafter created or improved surface properties such as water diffusion, drainage, moisture regain and water absorbency, in different degrees. The pHEMA-grafted sample exhibited minor effect in color perception, which was also much hydrophilic than the pAAc-grafted one. Based upon surface analyses and wetting assessment, the penetration of HEMA monomer into the plasma-treated fabric matrix contributed to the facilitation of wetting properties. This work accordingly ensures such plasma-induced system to incorporate with the pattern of hydrophilic properties on the analogous textiles without interrupting their finishing process.     

Reduced Overlap Population Analysis for Triosmium Clusters

The use of reduced overlap population (ROP) analysis from EHMO calculations as a means to gauge the presence of metal–metal bonds in triosmium clusters is examined. A number of triosmium clusters containing bridging ligands have been used as test cases, including the bis-ethoxy bridged cluster Os₃(μ-OEt)₂(CO)₁₀, 1b, and some of its group 15 derivatives Os₃(μ-OEt)₂(CO)₉(EPh₃), 2. These latter clusters are newly synthesized and have been characterized completely, including by single-crystal X-ray crystallographic studies. In honour of Professor Dieter Fenske on his 65th birthday.     

零电流示波电位滴定法测定3，5－二羟基苯甲酸

本文报道了利用溴酸盐法零电流示波电位滴定法直接和间接滴定３，５－二羟基苯甲酸的含量。操作简便，终点指示明显，测定结果良好。     

Tetra‐μ‐acetato‐κ2O:O′‐bis[(4‐phenylpyridine‐κN)copper(II)]

The title compound, [Cu₂(C₂H₃O₂)₄(C₁₁H₉N)₂] or [Cu₂(MeCO₂)₄(phpy)₂] (phpy is 4‐phenyl­pyridine), consists of centrosymmetric dimers in which the Cu^II atoms display a square‐pyramidal CuO₄N coordination, with four acetate O atoms in the basal plane [Cu—O 1.975 (3)–1.987 (3) Å] and the phpy N atom in the apical position [Cu—N 2.150 (3) Å]. The Cu atoms are 2.654 (1) Å apart and are bridged by four acetate groups. The discrete dimers are extended into a three‐dimensional supramolecular array through intermolecular π–π‐stacking interactions.     

[（n—C4H9）4N][EuxM1—x（TTA）4]（M=La、Sm、Gd、Tb）的光致发光

合成了一类组成为[(n-C4H9)4N][EuxM1-x(TTA)4](M=La、Sm、Gd、Tb）的固体配合物，通过测定其红外光谱，X射线粉末衍射谱和荧光光谱，研究了配合物结构和发光性质随Eu^3 浓度变化的规律。红外光谱和XRD谱的分析结果表明，在体系中没有新化合物生成，而荧光光谱分析结果表明发光强度与Eu^3 浓度不成线性关系，不发光的基质配合物组分对发光有不同大小和不同类型的影响，提出一种可能的发光机制解释这一共发光现象。     

Development and validation of a hydrophilic interaction liquid chromatography-tandem mass spectrometric method for the analysis of paroxetine in human plasma

A sensitive, simple, fast and rugged hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the determination of paroxetine was developed and validated over curve range 0.050-50 ng/mL using only 0.4 mL plasma. This is the first published LC-MS/MS method and the low limit of quantitation of this method is 10-fold lower than previously published methods. A simple liquid-liquid extraction method using methyl-tert butyl ether (MTBE) as the extraction solvent was used to extract paroxetine and the internal standard (IS) fentanyl-d(5) from plasma. The extract was evaporated to dryness, reconstituted and injected onto a silica column using a low aqueous-high organic mobile phase. The chromatographic run time was 2.0 min per injection, with retention times of 1.1 and 1.2 min for paroxetine and IS, respectively. The detection was by monitoring paroxetine at m/z 330 --> 192 and IS at m/z 342 --> 188, respectively. The inter-day precision and accuracy of the quality control (QC) samples were <5.0% relative standard deviation (RSD) and <2.9% relative error (RE). This method can be used for supporting therapeutical drug monitoring and pharmacokinetic or drug-drug interaction studies.     

In vivo activation analysis of organ cadmium using the Tsing Hua Mobile Educational Reactor

This work describes a nuclear facility forin vivo prompt gamma activation analysis (IVPGAA) using a moderated neutron beam from a 0.1 W Tsing-Hua Mobile Educational Reactor (THMER). The IVPGAA measurement is a new technique for toxic cadmium determination in organs, which can efficiently be used in clinical diagnosis. The low-power nuclear reactor provides a total neutron flux of 3.3·10⁴ n·cm^–2·s^–1 on the surface of the central vertical neutron beam tube to which a liquid phantom is positioned. The capability of such partial-body irradiation facility is demonstrated. The detection limit of cadmium in the left kidney for a skin dose equivalent of 1.66 mSv (166 mrem) was 1.34 mg in a 500-s irradiation/counting period, and the sensitivity in the left kidney was 103 counts mg^–1·mSv^–1. The performance of IVPGAA system using the THMER nuclear facility therefore has the advantages of mobility and feasibility with high sensitivity under low neutron and gamma doses.     

Coupling properties of imidazole dimer radical cation assisted by embedded water molecule: toward understanding of interaction character of hydrogen-bonded histidine residue side-chains

Geometry optimizations are performed at the DFTB3LYP6-311+G* level. Four intriguing coupling modes, totally eight stable structures are found in the potential energy surfaces of the water-assisted coupling of imidazole dimer radical cation. In these isomers, the water molecules are embedded between two imidazole moieties, and the oxygen atom is tridentate or quadridentate, respectively. The distinct redshifts of the vibrational frequencies of the O-H...N and N-H...O type H bonds indicate the strong interaction of two imidazole rings of respective isomer. Inspection of the highest occupied molecular orbital predicts the alterations of the geometry structures on oxidation and reduction. The low barrier of the fragment rotation demonstrates that the isomerization processes by experiencing the distinct transition states are easy to fulfill, especially for those with O-H...N and C-H...O H bonds. Both the energy difference of the 0 degrees-cis and 180 degrees-trans orientation and the barriers of the fragment rotation are lowered by the water assisting. The range of the zero point vibrational energy correction indicates that the influence on the complexes with N-H...O and O-H...N H bonds (0.13-0.17 kcal/mol) is more significant than those with O-H...N and C-H...O H bonds (+/-0.03 kcal/mol). The dissociation energies of these isomers indicate that the charges transfer easily through water in the dissociation process and then are distributed mainly over the imidazole ring connecting with water molecule. The isomer with proton transfer between imidazole fragments is the most stable one.     

SYNTHESIS OF A NOVEL "MESOGEN-JACKETED LIQUID CRYSTAL POLYMER" BASED ON VINYLTEREPHTHALIC ACID

Poly{2, 5- bis [ (p- methoxyphenyl ) oxycarbonyl] styrene } was successfully syn-thesized. This new polymer has a structure characteristic of mesogen-jacketed liquidcyrstalline polymers (MJLCPs) and does form a liquid crystal phase above its glass tran-sition. It thus became the starting member of a new series of MJLCPs. The synthesis ofthe polymer as well as the liquid crystalline properties of the polymer and its monomerwas discussed. A brief comparison of the new monomer and polymer with some previouslyreported counterparts was also included.