Determination of ultra-trace rare-earth elements in human plasma by inductively coupled plasma mass spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS),a highly sensitive inorgnic analytic technique,fits to determine ultra-nace rare-earth elements in human plasma. Under the optimized conditions detection limits for 15 rare-earth elements are in the range of 0.7 (for Eu)-5.4 (for Gd) ng.L-1. Indium as an internal standard element is used to compensate for matrix suppression effect and sensitivity drift. Three kinds of preparation methods, diluted with 1% HNO3, digested with HNO3-H2O2 and with HNO3-HClO4, are checked and compared,and the former is the simplest way to be measured. The samples diluted with 1% HNO3, stored in 4 degrees C, are very steady for 16 days. With the method, 11 healthy plasma samples in Changchun area of China are analysed.

Amperometric quantification of polar organic solvents based on a tyrosinase biosensor

A novel amperometric biosensor for quantification of the electrochemically inert polar organic solvents based on tyrosinase electrode was preliminarily reported. The biosensor was fabricated by simply syringing an aqueous solution of tyrosinase/PVAVP (PVAVP: copolymer of poly(vinyl alcohol) grafting with 4-vinylpyridine) onto glassy carbon electrode surface followed by drying the modified electrode at +4 degrees C in a refrigerator. The current generated from electrochemical reduction of quinone is a probe signal. The biosensor can be used for quantification of polar organic solvents, and its mechanism was characterized with in situ steady-state amperometry-quartz crystal microbalance experiments. The detection limit, sensitivity, and dynamic range for certain organic solvents are dependent on the kind and concentration of the substrate probe and the hydrophobicity of the immobilization matrix. The response time for all the tested organic solvents is less than 2 min.

Hydrothermal synthesis and structure of [{Mo8V4O36(VO4)(VO)(2)}(n)](7n-) bi-capped alpha-Keggin fragments linked to a chain

The title compound, (H(2)en)(3)H3O {MO8V4O36 (VO4) (VO)(2)} . 4H(2)O, was hydrothermally synthesized and structurally characterized by means of IR, ESR spectrum and single crystal X-ray diffraction. It crystallized in a monoclinic system with space group P2(1)/c, a=1. 980 4(4) nm, b=2. 063 4(4) nm, c=1. 192 0(2) nm, (beta =94. 76(3)degrees and deep black colour. The compound contains V-centered bi-capped alpha -Keggin fragments {Mo8V7O42} that are linked together by edge-shared units (VO5)-O-N via V-O-V bonds, forming a chain.

A novel method for preparing ordered SnO2/TiO2 alternate nanoparticulate films

A novel method using LB films as precursors to prepare pure inorganic ordered film with periodic structure was developed. Surfactant-stabilized SnO2 nanoparticulate organosols and TiO2 nanoparticulate organosols were prepared and used as spreading solutions. Using LB technique, the good film-forming ability of the surfactant-stabilized SnO2 nanoparticles and TiO2 nanoparticles was confirmed by the determination of the pi -A isotherms. The surfactant-stabilized SnO2 and TiO2 nanoparticulate monolayers were fabricated on the water surface and then were transferred to solid substrates (CaF2, quartz, silicon, and so on) alternately, layer-by-layer. Then the as-deposited alternate LB film was treated at different temperatures. The as-deposited alternate LB film and the treated film were characterized by Fourier transform infrared spectroscopy, UV visible spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results indicate that our method was successful. The as-deposited alternate LB film formed a periodic structure with a long spacing of 6.5 nm that was composed of SnO2 nanoparticles, TiO2 nanoparticles, and arachidic acid. The treated film composed of SnO2 nanoparticles and TiO2 nanoparticles formed a pure inorganic periodic structure with an ordered distance of 5.4 nm. (C) 2001 Academic Press.

Synthesis and characterization of a novel hybrid single crystal [Ga-3(PO4)(3)F-2]H3O center dot (H3NCH2CH2)(2)NH2

A novel three-dimensional fluorinated gallium phosphate has been hydrothermally,synthesized by using diethylenetriamine as an organic structure-directing agent. X-ray single crystal structure analysis indicates this compound crystallizes in the orthorhombic space group P-bca, a = 1. 605 6 (7) nm, b = 1.011 4 (4) nm, c=1. 854 6(5) nm, V=3. 011 6(19) nm(3), Z=4. The three-dimensional framework based on linkage of corner-sharing polyhedron PO4, GaO4F and GaO4F2 delimit ten-ring channels along b axis in which the triply protonated amines are located serving as charge compensating guests and supporters.

Study on the properties of poly(beta-hydroxybutyrate) grafted with maleic anhydride

The thermal stability, crystallization behavior and biodegradability of poly(beta -hydroxybutyrate) (PHB) grafted with maleic anhydride (MA) were studied by DSC,TGA, optical microscopy and WAXD. The results showed that thermal stability of maleated PHB was obviously improved, comparing with that of pure PHB. The temperature of decomposition was enhanced about 20 degreesC After grafting MA, the crystallization behavior of PHB changed evidently. The rate of spherulite growth decreased, the crystallization temperature from the melt state reduced, and the cold crystallization temperature from the glass state increased. With the increase in graft degree, the banding texture of spherulite became more distinct and orderly. Moreover, the introduction of MA groups promoted the biodegradation of PHB.

Calculation of chemical bond parameters in La1-xCaxCrO3 (0.0 <= x <= 0.3)

The chemical bond parameters, that is, bond covalency, bond susceptibility, and macroscopic linear susceptibility of La1-xCaxCrO3 (x = 0.0, 0.1, 0.2, 0.3) has been calculated using a semiempirical method. This method is the generalization of the dielectric description theory proposed by Phillips, Van Vechten, Levine, and Tanaka (PVLT). In the calculation of bond valence, two schemes were adopted. One is the bond valence sums (BVS) scheme, and the other is the equal-valence scheme. Both schemes suggest that for the title compounds bond covalency and bond susceptibility are mainly influenced by bond valence and are insensitive to the Ca doping level or structural change. Larger bond valences usually result in higher bond covalency and bond susceptibility. The macroscopic linear susceptibility increases (only slightly for BVS scheme) with the increasing Ca doping level. (C) 1999 John Wiley & Sons, Inc.

β-烷氧羰乙基三氯化锡与Schiff碱配合物的合成、表征与结构

合成表征了32个标题化合物ROCOCHR~1CH_2SnCl_3·(2-HOC_6H_4CH=NC_6H_4-X)(R=Me,Et,n-Bu;R~1=H,Me;X=H,4’-Cl,3’-Br,3’-OH,3’,4’-Cl_2,4’-OMe),通过元素分析,UV-vis,IR和~1H NMR进行了表征n-BuOCOCH_2CH_2SnCl_3·(2-HOC_6H_4CH=NC_6H_4OMe-4’)的晶体结构分析表明,该晶体属单斜晶系,a=1.4661(3)nm,b=0.9307(2)nm,c=1.7888(4)nm,β=94.04(3)°;v=2.4348nm~3,Z=4;空间群P2_1/c.该化合物为含有分子内碳基氧配位,Schiff碱以酚羟基上的氧原子配位,中心锡原子为六配位,空间构型为畸变八面体构型的单分子有机锡化合物.

Eu(Ⅲ)、Tb(Ⅲ)双酞菁配合物的合成及其LB膜的荧光性

合成了八-4-（正壬氧基）酞菁铽（Ⅲ）（A）、八-4-（四氢糠氧基）酞菁（Ⅲ）（B）、双酞菁铽（Ⅲ）（C）、八-4-硝基酞菁铽（Ⅲ）（D）,并通过元素分析、红外光谱、质谱和紫外.可见光谱加以确认。配合物B的π-A曲线表明它有很好的成膜性,Y型沉积形成的LB膜材料有很强的荧光响应,随着LB膜厚度的增加,荧光性增强掺杂邻菲咯啉形成的混合LB膜,其荧光性比纯膜强。n（配合物B）：n（邻菲咯啉）＝1：10时有最好的荧光行为.

电感耦合等离子体光谱和质谱法分析贻贝标准物质

采用电感耦合等离子体光谱和质谱法分析了贻贝标准物质,光谱法测定K、Na、ca���Mg、P、Al、Fe、Zn、Nn和Sr,质谱法测定As、B、Cd、Co、Cr、Cu、Ca���Ce、Mn、Mo、Ni、Pb、Se、Sr、U和V。在优化的工作条件下,测定了来自基体元素K、Na、Ca���P、Cl和C的多原子离子~(39)K~(16)O、~(39)K_2、~(40)Ar~(23)Na、~(43)Ca~(16)O、~(42)Ca~(16)O、~(44)Ca~(16)O、~(31)P~(16)O_2、~(40)Ar~(37)Cl、~(35)Cl~(16)O、~(37)Cl~(16)O和~(40)Ar~(12)C对~(55)Mn、~(78)Se、~(63)Cu、~(59)Co、~(58)Ni、~(60)Ni、~(75)As、~(77)Se、~(51)V、~(53)Cr和~(52)Cr的干扰系数以及HNO_3+H_2O_2(3+2)、HNO_3+HClO_4(3+0.5)和HNO_3+H_2SO_4(3+0.5)等3种样品消解方法在一些生物重要元素的同位素处产生的表观浓度。光谱法的检出限0.001～0.75mg/L;质谱法的检出限0....

Synthesis, properties and crystal structure of organic-inorganic radical salt (DBTTF)(6)HPMo12O40 center dot 2H(2)O

Organic-inorganic radical salt (DBTTF)(6)PMo12O40 . 2H(2)O was synthesized by electrocrystallization and characterized by IR spectrum, electronic spectrum and ESR technology, Its magnetic property, conductivity and crystal structure were determined. The title compound crystallized in a triclinic system with P1 space group, a = 1.378 7(7), b = 1.420 4 (2), c = 1.570 2(2) nm, alpha = 104.57(1)degrees, beta = 103.41(2)degrees, gamma = 95.80(2)degrees, V = 2.853(2) nm(3) Z = 1 and a final R = 0.072 7.

α-B-Keggin型杂多化合物K_5H[Co_4(VW_9O_(33))_2]·5H_2O的合成和结构

合成了新化合物K_5H[Co_4(VW_9O_(33))·5H_2O,并运用IR,UV-ViS,DTA和单晶X射线衍射对其结构进行了表征.测定结果证实标题化合物具有α-B-Keggin型结构,两个(VW_9O_(33)~(7-)结构单元由四个Co(Ⅱ)O_6 八面体连接.杂多化合物属单斜晶系P2_(1/n),a=1.2307(3)nm,b=2.1250(4)nm,c=1.5817(3)nm,β=91.86(3)°,V=4.1343(14)nm~3,R=0.0895,R_w=0.2180.

The origin of nonlinearity in KTiOPO4

The origin of nonlinearity in KTiOPO4 was investigated quantitatively from the chemical bond viewpoint. All constituent chemical bonds in this crystal were considered and their contributions to the total linearity and nonlinearity were quantitatively determined. Calculated results agree satisfactorily with experimental data in both signs and numerical values. These results show us that TiO6 groups and P(1)O-4 groups have relatively larger linear contributions and the nonlinearity derives from KOx (x=8,9) groups and P(2)O-4 groups. (C) 1997 American Institute of Physics.

Synthesis of lanthanide-alkylaluminium bimetallic complexes and studies on their catalytic activities for polymerization of some polar monomers

Three new lanthanide (Ln)-alkylaluminium (Al) bimetallic complexes with the formula [(mu-CF3CO2)(2)Ln(mu-CF3CHO2)AIR(2) . 2THF](2) (Ln = Nd, Y, R=i-C4H9 (i-Bu); Ln=Eu, R=C2H5(Et); THF=tetrahydrofuran) were synthesized by the reaction of Ln(CF,CO,), (Ln=Nd, Y) with HAI (i-Bu)(2) and of Eu(CF3CO2)(3) with AlEt(3), respectively. Their crystal structures were determined by X-ray diffraction at 233 K. [(mu-CF3CO2)(2)Nd (mu-CF3CHO2)Al(i-Bu)(2) . 2THF](2) (Nd-Al) and [(mu-CF3CO2)(2)Y(mu-CF3CHO2)Al(i-Bu)(2) . 2THF](2) (Y-Al) are isomorphous and crystallize in space group with a=12.441(3) Angstrom [12.347(5) Angstrom for Y-Al], b=12.832(3) Angstrom [12.832(4) Angstrom], c=11.334(3) Angstrom [11.292(8) Angstrom], alpha=104.93 (2)degrees [104.45(4)degrees], beta=98.47(2)degrees [98.81(4)degrees], gamma=64.60(2)degrees [64.30(3)degrees], R=0.519 [0.113], R(w)=0.0532 [0.110], Z=1 and [(mu-CF3CO2)(2)Eu(CF3CHO2)AlEt(2) . 2THF](2)(Eu-Al) in space group P2(1)/n with a=11.913(6) Angstrom, b=14.051(9) Angstrom, c=17.920(9) Angstrom, alpha=101.88(11)degrees, beta=gamma=90 degrees, R=0.0509, R(w)=0.0471 and Z=2. The six CF3CO2- (including CF3CHO2-) of each complex, among which pairs are equivalent, coordinated to Ln and Al in three patterns: (A) the two oxygen atoms in one of the three CF3CO2- type coordinated to two different Ln; (B) the two oxygen atoms in the second of CF3CO2- type coordinated to Ln and Al, respectively; (C) one of the two oxygen atoms in the third CF3CO2- type bidentately coordinated to two Ln and another oxygen coordinated to Al and one of the two Ln, respectively. Unlike types A and B, in type C the carboxyl carbon with a hydrogen atom bonded to it was found to appear as an sp(3)-hybridized configuration rather than an sp(2)-one. 1D and 2D NMR results further confirmed the existence of such a disproportionated CF3CHO2- ligand. Methyl methacrylate (MMA) and epichlorohydrin (ECH) could be polymerized by Y-Al or Eu-Al as a single-component catalyst and highly syndiotactic poly(MMA) was obtained. THF could also be polymerized by Y-Al in the presence of a small amount of ECH.

Synthesis and structures of the complexes of beta-alkoxycarbonylethyltin trichlorides with N-aryl-2-hydroxyacetophenylideneimines

Sixteen novel beta-alkoxycarbonylethyltin trichlorides and the corresponding N-aryl-2-hydroxyacetophenylideneimines complexes have been synthesized and characterized. An X-ray crystal structure analysis of the complex of beta-methyloxycarbonylethyltin trichloride and N-4-methylphenyl-2-hydroxyacetophenylideneimine has been performed, The crystal belongs to space group , The cell parameters are: a = 1.0201(6) nm, b = 1.082 2(4) nm, c = 1.394 9(6) nm, alpha = 99.88(3)degrees, beta = 98.63(4)degrees, gamma = 97.86(4)degrees, Z = 2, The ligands coordinate to tin atom via phenolic oxygen atom. Coordination of carbonyl oxygen atom to tin atom still exists in the complexes, The coordination number of tin atom is 6.