反相高效液相色谱法测定全血中马钱子碱和士的宁的含量

 建立了反相高效液相色谱法定量分析全血中马钱子碱和士的宁含量的方法。该方法应用Oasis  R ○ MCX固相萃取小柱进行提取、采用XTerra TM RP 18 色谱柱进行分离。在该条件下马钱子碱和士的宁的线性范围为0.05～10 mg/L ,最小检出限为0.15 ng。该方法测得马钱子碱和士的宁在低、中、高浓度下的回收率均在90%以上,日内、日间精密度均符合方法学要求。该方法灵敏、快速、准确,适用于临床血药浓度监测和法医毒化检验。     

初三学生化学三重表征转化的眼动实验研究

化学三重表征研究一直深受国内外学者的重视,目前,初级表征的研究已有一定的理论基础,但是,次级表征（即不同表征水平之间的转化）的研究仍是研究的弱点和难点。纸笔检测、口语报告研究方法都存在一定的局限。为了从信息加工过程研究三重表征间转化的基本特点,采用眼动分析法对12名初三学生进行3×3两因素混合实验。结果显示：（1）在初三上册期末,学优生基本可以进行三重表征之间的直接转化;（2）学中生符号表征较强且依赖于符号表征,表现出“双通道协同加工”现象,符号—宏观、微观转化水平较强,宏观—微观、符号和微观—符号、宏观转化水平较弱;（3）学困生普遍缺乏三重表征的思维和意识,三重表征间的转化水平较低,相比较而言,符号-宏观、微观表征转化稍强于宏观-微观、符号表征转化和微观-符号、宏观表征转化。     

Calculating the vertex unknowns of nine point scheme on quadrilateral meshes for diffusion equation

In the construction of nine point scheme,both vertex unknowns and cell-centered unknowns are introduced,and the vertex unknowns are usually eliminated by using the interpolation of neighboring cell-centered unknowns,which often leads to lose accuracy.Instead of using interpolation,here we propose a different method of calculating the vertex unknowns of nine point scheme,which are solved independently on a new generated mesh.This new mesh is a Vorono¨i mesh based on the vertexes of primary mesh and some additional points on the interface.The advantage of this method is that it is particularly suitable for solving diffusion problems with discontinuous coeffcients on highly distorted meshes,and it leads to a symmetric positive definite matrix.We prove that the method has first-order convergence on distorted meshes.Numerical experiments show that the method obtains nearly second-order accuracy on distorted meshes.     

Tris-(thiocyanato)-bis-(hexamethylenetetramine)-nona-(aquo) lanthanum(III): synthesis, crystal structure, IR and Raman characterization

The title compound (LaC₁₅H₄₂N₁₁O₉S₃) was prepared and characterized by means of X-ray, IR and Raman measurements. The crystals are orthorhombic: Pnma (No. 62), a = 21.117(2), b = 14.736(2), c = 10.082(1) Å, and Z = 4. The structure consists of polyhedra with a La(III) ion in the center of them and hexamethylene molecules, which link these polyhedra. Each La(III) ion coordinates seven molecules of water and two thiocyanate ions via nitrogen atoms. The IR and Raman spectra, which have been obtained and interpreted, are in good agreement with X-ray results.     

Four isostructural lanthanide(III) coordination compounds based on a new N‐oxydic pyridyl naphthalenediimide ligand: synthesis and characterization

Naphthalenediimides, an attractive class of electron‐deficient organic dyes with rich redox and photoredox properties, have been investigated extensively as building blocks for coordination networks or metal–organic frameworks in recent decades. However, most of the available work has focused on d‐block metal cations rather than f‐block lanthanide ions, whose complexes exhibit a large variability in coordination numbers. In this article, four coordination polymers composed of naphthalenediimides and lanthanide cations, namely catena‐poly[[[tris(nitrato‐κ²O,O′)lanthanide]‐bis{μ‐N,N′‐bis[(1‐oxidopyridin‐1‐ium‐3‐yl)methyl]‐1,8:4,5‐naphthalenetetracarboxdiimide‐κ²O:O′}‐[tris(nitrato‐κ²O,O′)lanthanide]‐μ‐N,N′‐bis[(1‐oxidopyridin‐1‐ium‐3‐yl)methyl]‐1,8:4,5‐naphthalenetetracarboxdiimide‐κ²O:O′] methanol disolvate], {[Ln(C₂₆H₁₆N₄O₄)_1.5(NO₃)₃]·CH₃OH}_n, with Ln = Eu, 1 , Gd, 2 , Dy, 3 , and Er, 4 , have been successfully synthesized under hydrothermal conditions. Single‐crystal X‐ray diffraction analyses revealed that the four compounds are isomorphic and that each asymmetric unit contains one nine‐coordinated Ln centre, one and a half diimide ligands, three nitrate anions and one uncoordinated methanol molecule. In addition, each metal centre is surrounded by nine O atoms in a distorted tricapped trigonal–prismatic geometry. Two centres are bridged by two cis ligands to form a ring, which is further bridged by trans ligands to generate one‐dimensional chains. Neighbouring chains are stacked via π–π interactions between pyridine rings to give a two‐dimensional structure, which is stabilized by π–π interactions between naphthalene rings, forming the final three‐dimensional supermolecular network. Solid‐state optical diffuse‐reflectance spectral studies indicate that compound 4 is a potential wide band gap semiconductor.     

电感耦合等离子体发射光谱(ICP-OES)法测定铅精矿中9种元素

采用硝酸-盐酸-氢氟酸-高氯酸溶样,优化仪器测定条件及消除干扰元素的条件实验等,建立了电感耦合等离子体发射光谱(ICP-OES)法测定铅精矿中砷、锑、铋、铜、锌、镁、铝、铁、镉的方法。其测定范围ω(As):0.02%~1.50%;ω(Sb):0.01%~10.00%;ω(Bi):0.03%~5.00%;ω(Cu):0.50%~10.00%;ω(Zn):2.00%~10.00%;ω(Mg):0.30%~2.00%;ω(Al):0.50%~3.00%;ω(Fe):5.00%~12.00%;ω(Cd):0.030%~0.20%。经加标回收实验,各元素的加标回收率为90%~104%(n=3)。方法准确、快速、可靠,适用于铅精矿中砷、锑、铋、铜、锌、镁、铝、铁、镉量的同时测定。     

Homo-atomic Nine-vertex Polyhedra of Group XIV Elements. Crystal structures and paramagnetic properties of [K-(2,2,2-crypt)]6E9E9 · 1.5 ethylenediamine · 0.5 toluene,E = Sn and Pb

The extractions of alloys of the nominal composition “KE_2.25” with ethylenediamine (en), (2,2,2)crypt, and toluene (tol) lead in good yields to paramagnetic compounds of the composition [K-(2,2,2-crypt)]₆E₉E₉ · 1.5 en · 0.5 tol (E = Sn ( 2 b ), Pb ( 2 c )). X-ray single crystal structure analyses show that two different E₉ clusters per asymmetric unit are present with configurations of distorted tricapped trigonal prismatic polyhedra. 2 b : space group P2₁/c (No. 14), Z = 4, a = 28.042(8), b = 23.527(5), c = 27.703(8) Å, β = 93.46(2)°; 2 c : space group P2₁/c (No. 14), Z = 4, a = 28.356(8), b = 23.757(5), c = 27.885(8) Å, β = 94.01(2)°.     

Design and synthesis of ansamycin antibiotics

Ansamycin antibiotics are a class of microbial metabolites that exhibit an array of biological activities. This review covers the synthetic chemistry and biological activity of benzenic ansamycins from 1989 to 2007. In the first section, synthetic approaches to the C15-benzene ansamycins (geldanamycin and related) are discussed. Access to the C17-benzene ansamycins (or ansatrienins) is disclosed in the second half of this article.     

Simultaneous Determination 9 Anabolic Steroids Residues in Animal Muscle Tissues by Gas Chromatography‐Mass Spectrometry

Abstract

A method was developed for determining 9 anabolic steroids (ASs) residues in animal muscle tissues by gas chromatography‐mass spectrometry (GC/MS). After undergoing enzymolysis, being homogenized, and then being picked‐up by ultrasound the sample was extracted with tert‐Butyl methyl ether, cleaned up through solid‐phase extraction (SPE) based on the reverse phase (RP) principle, and after derivatization of the analyst of interest, analyzed by GC/MS under selective ion monitoring (SIM). The limits of the detection (LOD) of the GC/MS method used for testing epitestosterone (ETS), nandrolon (17β‐NT), 17α‐methyl‐testosterone (MTS), testosterone 17‐propionate (PTS), 17β‐estradiol 3‐benzoate (BES), estrone (ESN), 17β‐estradiol (17β‐ES), 17α‐ethynylestradiol (EES), and estriol (EST) in animal muscle ranged from 0.10 to 0.33 µg/kg and the limits of quantification (LOQ) were from 0.24 to 0.82 µg/kg. The experiments using spiked samples, such as pork, beef, chicken, and fish, made it clear that at addition level of 2.0 µg/kg, the average recovery of the ASs ranged from 62.5% to 80.5%, and the coefficient of variation ranged from 12.5% to 26.8%, while at an addition level of 5.0 µg/kg, the average recovery was from 70.8% to 86.4%, and the coefficient of variation was from 8.8% to 18.4%.