Me[14]-N4大环四烯镍(Ⅱ)催化、BrO3-氧化丙酮酸的振荡化学反

本文报道了一种以２，３，９，１０－四甲基－１，４，８，１１－四氮杂环十四－１，３，８，１０－四烯镍（Ⅱ）配合物［Ｎｉ（ㄔＩＭ）］＾２＋为催化剂、ＮａＢｒＯ３为氧化剂、丙酮酸为有机废物、稀硫酸为介质的振荡化学反应新体系。对该体系的振荡特性进行了描述。研究了Ａｇ＾＋、Ｈｇ＾２＋、还原性物质、自由基抑制剂、四氯化碳以及温度对振荡的影响。     

Quantitative Determination of Microcystins in Rat Plasma by LC–ESI Tandem MS

A rapid and sensitive method was developed and validated for the determination of MCYST (microcystin)-RR, -LR, and [Dha⁷] MCYST-LR in rat plasma by liquid chromatography-tandem mass spectrometry. The analytes were extracted from rat plasma by protein precipitation, followed by solid-phase extraction. Liquid chromatography with electrospray ionization mass spectrometry, operating in selected reaction monitoring (SRM) mode, was used to quantify MCYST-RR, -LR, and [Dha⁷] MCYST-LR in rat plasma. The recoveries for each analyte in rat plasma ranged from 70.8 to 88.7%. The calibration curve was linear within the range from 0.005 to 1.25 μg mL^?1. The limit of detection were 1.4, 1.0, 0.6 ng mL^?1 for MCYST-RR, -LR, and [Dha⁷] MCYST-LR. The overall precision was determined on three different days. The values for within- and between-day precision in rat plasma were within 15%. This method was applied to the identification and quantification of microcystins in rat plasma with acute exposure of microcystins via intravenous injection.     

Surfactant‐free synthesis of amphiphilic copolymer of poly(styrene‐co‐acrylamide) in aqueous emulsion with the assistance of ultrasound

The hydrophilic monomer acrylamide (AM) and hydrophobic monomer styrene (St) have been directly copolymerized in a surfactant‐free aqueous emulsion with the assistance of powerful ultrasound. Fourier Transform Infrared spectrocopy (FT‐IR), nuclear magnetic resonance (NMR), and differential scanning calorimetry (DSC) measurements revealed that copolymers of AM and St were obtained. Elemental analysis was used to calculate the composition of the copolymer. Size exclusion chromatography (SEC) measurement showed that the molecular weight (M_w) of the copolymer is 1.86 × 10⁵ g/mol and the polydispersity index (PDI( = 2.31. The self‐assembly behavior in different solvents was investigated utilizing laser light scattering (LLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM); the copolymer film showed amphiphilicity, as measured by contact angle goniometry. Copyright © 2008 John Wiley & Sons, Ltd.     

Sol–gel preparation and characterization of Bi4(Si1−xGex)3O12 solid solutions

Micro-crystals of Bi₄(Ge_xSi_1?x)₃O₁₂ (x = 0, 0.25, 0.5, 0.75, 1) solid solution series were synthesized by a sol–gel method, using stoichiometric Si(OC₂H₅)₄, GeO₂, Bi(NO₃)₃·5H₂O as the starting materials. The as-prepared series were studied by X-ray diffraction, Raman spectra, differential thermal analysis, and fluorescence spectra. Experiments showed that single phase of Bi₄(Si_1?xGe_x)₃O₁₂ was obtained by the sol–gel method. For all the composition, Bi₄Si₃O₁₂ and Bi₄Ge₃O₁₂ can completely dissolve into each other. The refined cell parameters were in proportion to the composition. Bi₄Ge₃O₁₂ showed the strongest fluorescence emission while Bi₄Si₃O₁₂ showed the weakest fluorescence emission.     

Synthesis of molecularly imprinted polymer nanoparticles for the fast and highly selective adsorption of sunset yellow

Novel molecularly imprinted polymer nanoparticles were synthesized by precipitation polymerization with sunset yellow as the template and [2‐(methacryloyloxy)ethyl] trimethylammonium chloride as the functional monomer. The molecularly imprinted polymer nanoparticles were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and their specific surface area and thermal stability were measured. The molecularly imprinted polymer nanoparticles had a high adsorption capacity in wide pH range (pH 1–8) for sunset yellow. The adsorption equilibrium only needed 5 min, and the quantitative desorption was very fast (1 min) by using 10.0 mol/L HCl as the eluant. The maximum adsorption capacity of the molecularly imprinted polymer nanoparticles for sunset yellow was 144.6 mg/g. The adsorption isotherm and kinetic were well consistent with Langmuir adsorption model and pseudo‐second‐order kinetic model, respectively. The relative selectivity coefficients of the molecularly imprinted polymer nanoparticles for tartrazine and carmine were 9.766 and 12.64, respectively. The prepared molecularly imprinted polymer nanoparticles were repeatedly used and regenerated ten times without significant absorption capacity decrease.     

微量进样-火焰原子吸收光谱法测定豚鼠内耳外淋巴液中钙、镁、钾、钠等元素含量

采用直接定量取样稀释、微量进样-火焰原子吸收光谱法测定了豚鼠内耳外淋巴液中Ca、Mg、K、Na等元素含量。方法简便、可靠，满足了生物样品测定的要求。     

Synthesis and controlled hydrolysis of organolanthanide complexes with mono- and dianionic benzimidazole-2-thiolate ligands

Treatment of Cp(3)Er with one equivalent of benzimidazole-2-thiol (H(2)Bzimt) in THF affords the monoanionic HBzimt(-) complex Cp(2)Er(η(2)-HBzimt)(THF)(2) (1). Reaction of Cp(3)Yb with two equivalents of H(2)Bzimt gives complex CpYb(η(2)-HBzimt)(2)(THF) (2) at room temperature. Treatment of Cp(3)Ln with three equivalents of H(2)Bzimt in reflux THF affords the homoleptic Ln(η(2)-HBzimt)(3)(THF)(2) (Ln = Er (3), Y (4)). Cp(3)Ln reacts with 0.5 equivalents of H(2)Bzimt to afford the dianionic Bzimt(2-) complexes [(Cp(2)Ln)(THF)](2)(μ-Bzimt) (Ln = Yb (5), Er (6), Dy (7), Y (8)) in good yields, in which the Bzimt(2-) ligand bridges the two metals in an μ-η(2):η(2) coordination mode. Interestingly, controlled hydrolysis of complexes Cp(2)Ln(η(2)-HBzimt)(THF)(2), CpLn(η(2)-HBzimt)(2)(THF) and [(Cp(2)Ln)(THF)](2)(μ-Bzimt) produces the same tetranuclear complexes [CpLn(μ(3)-OH)(μ-η(1):η(2)-HBzimt)](4) (Ln = Yb (9), Er (10), Y (11)), indicating that the hydrolysis selectivity greatly depends on the number of coordinated cyclopentadienyl groups. All complexes were characterized by elemental analysis, spectroscopic properties and X-ray single crystal diffraction analysis.     

互穿网络聚合物的某些进展

综述近年来热塑性互穿网络聚合物及以蓖麻油为原料合成的互穿网络聚合物的进展。     

Crystal structure and the standard molar enthalpy of formation of a coordination polymer [Cu(nip)(phen)]n

A coordination polymer [Cu(nip)(phen)]_n was hydrothermally synthesized by the reaction of Cu(NO₃)₂ with 5-nitroisophthalic acid and phen. Single-crystal structure analysis showed that the complex crystallized in the monoclinic space group P2₁/c; a = 10.6566(13); b = 12.5931(15); c = 13.0514(16) Å; β = 95.474(2)°, V = 1743.5(4) Å³; Z = 4. The standard molar enthalpy of formation of the complex was determined to be −554 ± 11 kJ mol⁻¹.     

Effect of PLGA as a polymeric emulsifier on preparation of hydrophilic protein-loaded solid lipid nanoparticles

Most proteins are hydrophilic and poorly encapsulated into the hydrophobic matrix of solid lipid nanoparticles (SLN). To solve this problem, poly (lactic-co-glycolic acid) (PLGA) was utilized as a lipophilic polymeric emulsifier to prepare hydrophilic protein-loaded SLN by w/o/w double emulsion and solvent evaporation techniques. Hydrogenated castor oil (HCO) was used as a lipid matrix and bovine serum albumin (BSA), lysozyme and insulin were used as model proteins to investigate the effect of PLGA on the formulation of the SLN. The results showed that PLGA was essential for the primary w/o emulsification. In addition, the stability of the w/o emulsion, the encapsulation efficiency and loading capacity of the nanoparticles were enhanced with the increase of PLGA concentration. Furthermore, increasing PLGA concentration decreased zeta potential significantly but had no influence on particle size of the SLN. In vitro release study showed that PLGA significantly affected the initial burst release, i.e. the higher the content of PLGA, the lower the burst release. The released proteins maintained their integrity and bioactivity as confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and biological assay. These results demonstrated that PLGA was an effective emulsifier for the preparation of hydrophilic protein-loaded SLN.