波长色散X射线荧光光谱法快速测定内外墙涂料中的钛、钙、钡、锌、镁和硅

正内外墙涂料一般由成膜物、颜填料、溶剂和一些助剂组成,其中颜料起遮盖和赋色的作用,主要成分有二氧化钛、碳酸钙和硫酸钡等。内外墙涂料中颜填料的质量对于涂料产品的品质和物理性能有直接的关系,快速测定内外墙涂料中的无机成分,一方面可以间接地快速判定涂料产品的物理性能是否合格,另一方面可以分析由于颜填料掺假导致涂料存在的问题。通过分析发现内外墙涂料中的颜填料无机成分主要为钛、钙、钡、锌、镁和硅等元素的化合物。目前     

气相色谱法测定涂料中三种醇类抗冻剂含量

建立了内外墙涂料样品中三种抗冻剂醇类物质气相色谱测定方法。涂料样品经乙醇萃取、离心,上清液进气相色谱氢火焰检测器检测,外标法定量。结果表明,乙二醇、1,2-丙二醇和丙三醇在20~500 mg/L浓度范围内线性关系良好,相关系数均大于0.999,方法检出限在10~20 mg/kg之间,三个添加水平平均回收率(n=6)在87.3%~93.4%之间,相对标准偏差(RSD)为5.0%~6.7%。该方法简单快速、回收率和精密度良好,适用于内外墙涂料中乙二醇、1,2-丙二醇和丙三醇的同时测定。利用气相色谱测定涂料中醇类组分含量,从而可快速鉴定涂料低温稳定性能,达到快速检测筛选的目的。     

X射线荧光光谱法同时测定涂料中的铅、铬、硒和钴

提出了用X射线荧光光谱法同时测定涂料中有害重金属铅、铬、硒和钴的一种新的测试方法. 考察了样品量不同和样品粒度不同对待测元素测试结果的影响. 选用不含待测元素的新鲜涂料作为基体物质制备标准样品, 较好地消除了基体的影响. 各待测元素在50～1000 mg/kg的范围内, 均呈线性关系;Pb、 Cr、 Se、 Co的检出限分别为3.6、 1.2、 0.5及1.5 mg/kg;方法精密度和仪器精密度的相对标准偏差分别低于1.3%和0.50%;用于实际样品测得的结果与电感耦合等离子体原子发射光谱法法测得的结果基本一致.     

ICP-AES法同时测定玻璃组份中的Ca、Mg、Ti、Fe、Pb、Cd、Al、Si、B、Zn、Cu元素

建立了一种用电感耦合等离子发射光谱(ICP-AES)法测定玻璃成份的简便、快速、准确、精密度好的方法．研究了样品的处理、标准样品的配制、谱线干扰等问题,并采用和基体匹配的方法消除基体的影响,进行了标准样品的分析、对照、精密度等试验,均取得了满意的结果．     

塞曼火焰原子吸收法测定内墙涂料中铜锌镉

应用原子吸收法测定内墙涂料中的重金属含量的报道甚少.本文介绍用塞曼火焰原子吸收法测定内墙涂料中铜、锌、镉的方法.该法快速简便、无干扰.精密度与准确度均较好.     

X射线荧光光谱法快速测定内外墙涂料中二氧化钛

工业用二氧化钛主要有锐钛型和金红石型两种,由于其光学性能好、折射率高且稳定,因此作为颜料被广泛用于涂料、化纤、造纸、塑料等领域[1]。二氧化钛颜料在不同种类涂料中应用范围较广,约占涂料所用无机颜料的70%,它不仅具有装饰效果,还能改善涂料的耐候性和涂膜的机械强度等,因此研究测定涂料中二氧化钛的含量,可以间接快速分析内外墙涂料中掺杂、掺假、以假充真的现象,并能对内外墙涂料对比率性能进行分析。     

无机硅酸盐涂料的研制及应用

以硅酸盐溶液为主要原料,利用少量自制的含偶联功能基团的有机硅聚合物乳液与硅酸盐进行杂化反应,同时与填料等有效的结合制备了无机硅酸盐涂料,并对涂料的性能进行研究。结果表明：制备的无机硅酸盐涂层具有优异的贮存稳定性、柔韧性、防水性、耐污性、阻燃性以及耐霉菌性等,满足建筑内外墙涂料的相关标准要求。     

顶空液相微萃取测定溶剂型涂料中挥发性有机物

应用顶空液相微萃取法对溶剂型涂料中的挥发性有机物(VOC)进行分离富集,直接进样气相色谱法分析。对萃取溶剂进行了筛选,并研究了平衡温度、溶剂体积、萃取时间等影响因素对萃取效率的影响。在优化的条件下,苯、甲苯、二甲苯、三氯乙烯和四氯乙烯的检出限分别为0.25、0.25、0.75、1.25和1.75μg/L。进行了方法的准确度和精密度试验,平均回收率为94.14%~119.33%,相对标准偏差为2.9%~18.9%。     

电感耦合等离子体原子发射光谱法(ICP-AES)测定铜磁铁矿中铜、锰、铝、钙、镁、钛和磷的含量

通过样品处理、干扰实验、方法检出限、准确度和精密度实验,确定了最佳实验条件,建立了电感耦合等离子体-原子发射光谱法(ICP-AES)测定铜磁铁矿中铜、锰、铝、钙、镁、钛和磷含量的方法。试料经盐酸、硝酸、氢氟酸、高氯酸分解,用盐酸溶解盐类,过滤,采用电感耦合等离子体原子发射光谱法同时测定滤液中铜、锰、铝、钙、镁、钛和磷的含量。方法检出限为锰、钛和磷小于0.00085%,其它元素小于0.0054%,分析结果与分光光度法、X射线荧光光谱法(XRF)和原子吸收光谱法(AAS)分析结果一致,8个实验室对5个水平样品进行协同实验给出了方法的精密度。     

非完全汽化气相色谱法测定溶剂型涂料中的微量苯、甲苯、二甲苯

用乙酸乙酯稀释溶剂型涂料样品，在较低的汽化温度下直接进样，溶剂型涂料中未汽化的组分留在汽化室里，而苯、甲苯和二甲苯汽化后进入毛细管，用气相色谱法氢火焰离子化检测器进行检测，与国家标准分析方法进行比较，该法具有操作简单、精密度高等优点。     

HF and MP2 calculations on CN−, N2, AlF,SiO, PN,SC, ClB,and P2 using correlated molecular wave functions

Contracted basis sets of double zeta valence quality plus polarization functions (DZP) and augmented DZP basis sets, which were recently constructed for the first‐ and second‐row atoms, are applied to study the electronic ground states of the diatomic molecules CN^?, N₂, AlF, SiO, PN, SC, ClB, and P₂. At the Hartree–Fock (HF) and/or Møller–Plesset second‐order (MP2) levels, total and molecular orbital energies, dissociation energies, bond lengths, harmonic vibrational frequencies, and dipole moments are calculated and compared with available experimental data and with the results obtained from correlation consistent polarized valence basis sets of Dunning's group. For N₂, calculations of polarizabilities at the HF and MP2 levels with the sets presented above are also done and compared with results reported in the literature. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006     

Determination of vitamins A, D, E, and K in human and bovine serum, and β-carotene and vitamin A palmitate in cosmetic and pharmaceutical products, by isocratic HPLC

Summary An HPLC method has been developed for the determination of fat-soluble vitamins. Ten fat-soluble vitamins were separated simultaneously on a 25 cm×4.6 mm i.d. Hypersil C₁₈ column with acetonitrile-dichloromethane-methanol, 60:20:20 (v/v) as mobile phase at 1.0 mL min⁻¹ with wavelength-programmed ultraviolet-visible-absorbance detection. Total analysis time was 12 min. The limits of detection were 0.03, 0.01, 0.55, 1.84, 0.02, 0.02, 0.01, 0.16, 0.33, 0.01, and 0.01 ng mL⁻¹ for retinol, retinyl acetate, retinyl palmitate, β-carotene, ergocalciferol, cholecalciferol, tocopherol, tocopherol acetate, phylloquinone, menatetrenone, and menadione, respectively. Analysis of human serum 2–7 days after ingestion of oral vitamins and Chinese herbs led to the conclusion that the concentration of vitamins was higher than for control serum.     

Dapson in Heterocyclic Chemistry,Part II: Antimicrobial and Antitumor Activities of Some Novel Sulfone Biscompounds Containing Biologically Active Thioureido,Carbamothioate, Quinazoline,Imidazolidine, and Thiazole Moieties

The reaction of 4,4′-diisothiocyanato-1,1-diphenylsulfone 2 with aromatic amines and phenol derivatives afforded the corresponding thioureio derivatives 3–9 , respectively. Also, the reaction of 2 with catechol gave the corresponding carbamothioate derivative 11. Quinazoline derivatives 14 and 15 were obtained in good yield via reaction of 2 with anthranlic acid derivatives. Imidazolidine biscompounds 16 and 17 were readily synthesized from the reaction of 2 with N-(4-substituted-phenyl)cyanothioformanilides. The structure of the products was confirmed from elemental analysis as well as spectral data. Most of the synthesized compounds showed remarkable antimicrobial activity compared with chloramphenicol and Grisofluvine as positive controls. Compound 6 was almost as active an antitumor agent as the reference drug Doxorubicin.     

Simultaneous Determination of Baicalin, Baicalein, Wogonin, Oxysophocarpine, Oxymatrine and Matrine in the Chinese Herbal Preparation of Sanwu-Huangqin-Tang by Ion-Paired HPLC

A sensitive and reliable ion-paired high-performance liquid chromatographic method has been established for the simultaneous quantification of six major active ingredients, namely baicalin, baicalein, wogonin, oxysophocarpine, oxymatrine and matrine in the Chinese herbal preparation, Sanwu-Huangqin-Tang. HPLC analyses were performed on a Phenomenex luna C₁₈ column with mobile phase of methanol–acetonitrile–aqueous phosphoric acid at a flow rate of 0.9 mL min⁻¹. The complete separation was achieved within 35 min for the six target constituents. A good linear regression relationship between peak-areas and concentrations was obtained over the range of 12.10–242.0 μg*mL⁻¹ for baicalin, 5.05–101.0 μg*mL⁻¹ for baicalein, 0.95–19.0 μg*mL⁻¹ for wogonin, 2.75–55.0 μg*mL⁻¹ for oxysophocarpin, 2.75–55.0 μg*mL⁻¹ for oxymatrine and 4.90–98.0 μg*mL⁻¹ for matrine, respectively. The repeatability was evaluated by intra- and inter-day assays with relative standard deviation (RSD) being less than 5.1%. The recoveries, measured at three concentration levels, varied from 93.8 to 102.1%. The assay was successfully applied for determination of six bioactive compounds in Sanwu-Huangqin-Tang. The interaction of chemical constituents was observed when the herbs were used in compatibility. The results indicated that the developed assay method was rapid, accurate and could be readily utilized as a quality control method for Sanwu-Huangqin-Tang.     

ICP-AES法测定化妆品中铅、镉、砷、汞、锑、铬、镍、钡、锶等禁限用元素含量

建立了化妆品中铅(Pb)、镉(Cd)、砷(As)、汞(Hg)、锑(Sb)、铬(Cr)、镍(Ni)、钡(Ba)、锶(Sr)含量的电感耦合等离子体原子发射光谱法(ICP-AES)同步检测技术。采用微波消解,在较难消化的化妆品中加HF进行消化,铑(Rh)为内标元素消除基体干扰,以配备耐HF进样系统的ICP-AES进行测定。在0～1.0 mg/L范围内呈现良好的线性关系(相关系数≥0.9999),Pb、Cd、As、Hg、Sb、Cr、Ni、Ba、Sr检出限分别为0.0016,0.0007,0.0021,0.0013,0.0003,0.0009,0.0008,0.0009,0.0021 mg/L,方法回收率80.2%～111%,精密度1.7%～8.2%。结果表明,该方法适用于检测基体复杂的化妆品中Pb、Cd、As、Hg、Sb、Cr、Ni、Ba、Sr。     

Synthesis,characterization, thermal stability,conductivity, and band gaps of substitute oligo/polyamines or polyphenol

In this study, the oxidative polycondensation reaction conditions of 3,5‐dichloroaniline (DCA), 3,4,5‐trimethoxyaniline (TMA), 3,5‐bis(trifluoromethyl)aniline (BTFMA), and 4‐{[(3,5‐dichlorophenyl)imino]methyl}phenol (DCPIMP) were studied by using NaOCl oxidant in an aqueous alkaline medium between 40 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FT‐IR, Ultraviolet–visible (UV–vis), ¹H‐NMR, and ¹³C‐NMR and elemental analysis. The characterization was made by TGA–DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yields of oligo‐3,5‐dichloroaniline (ODCA), poly‐3,4,5‐trimethoxy aniline (PTMA), oligo‐3,5‐bis(trifluoromethyl)aniline (OBTFMA), and poly‐4‐{[(3,5‐dichlorophenyl) imino]methyl} phenol (PDCPIMP) were found to be 98, 48, 80, and 83% in using NaOCl oxidant. According to the SEC analysis, the number‐average molecular weight (M_n), weight‐average molecular weight (M_w) and polydispersity index (PDI) values of ODCA, PTMA, and OBTFMA were found to be 2200, 3800 g mol^?1, and 1.727; 4700, 7500 g mol^?1, and 1.596; and 1690, 1950 g mol^?1, and 1.154, respectively. According to TG analysis, the weight losses of ODCA, PTMA, OBTFMA, and PDCPIMP were found to be 78.55, 54.18, 99.38, and 59.70% at 1000°C, respectively. PTMA showed higher stability against thermal decomposition. Electrical conductivity of the polymers was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical band gaps ( ) of ODCA, PTMA, OBTFMA, and PDCPIMP were calculated from their absorption edges of cyclic voltammograms. The optical band gaps (E_g) values of all compounds were calculated from UV–vis measurements. Copyright © 2009 John Wiley & Sons, Ltd.     

NMR,RP-HPLC-PDA-ESI-MSn,and RP-HPLC-FD Characterization of Green and Oolong Teas (Camellia sinensis L.)

Untargeted (NMR) and targeted (RP-HPLC-PDA-ESI-MSⁿ, RP-HPLC-FD) analytical methodologies were used to determine the bioactive components of 19 tea samples, characterized by different production processes (common tea and GABA tea), degrees of fermentation (green and oolong teas), and harvesting season (autumn and spring). The combination of NMR data and a multivariate statistical approach led to a statistical model able to discriminate between GABA and non-GABA teas and green and oolong teas. Targeted analyses showed that green and GABA green teas had similar polyphenol and caffeine contents, but the GABA level was higher in GABA green teas than in regular green tea samples. GABA oolong teas showed lower contents of polyphenols, caffeine, and amino acids, and a higher content of GABA, in comparison with non-GABA oolong teas. In conclusion, the results of this study suggest that the healthy properties of teas, especially GABA teas, have to be evaluated via comprehensive metabolic profiling rather than only the GABA content.     

Theoretical study of the geometric and electronic structure of neutral and anionic doped silver clusters, Ag5X with X = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni

Density functional theory (DFT) has been applied to investigate the low-lying electronic states of neutral and anionic transition metal doped silver clusters Ag₅X^0,− with X = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni using the B3LYP functional with the Stuttgart SDD basis sets. The structural features, frontier orbital energy gaps (HOMO and LUMO), vertical detachment energies, and vertical and adiabatic electronic affinities are evaluated. For all doped silver clusters, both in neutral and anionic states, two-dimensional and three-dimensional low-energy isomers are found to coexist. For neutral clusters, dopant Sc, Ti, V, and Mn atoms largely decrease the frontier orbital energy gaps, while they are markedly increased by Sc and Fe atoms in the anionic clusters. A completely quenched dopant magnetic moment is found in Ag₅Sc, while high spin magnetic moments are located on the other dopant atoms in Ag₅X^0,−.     

Dynamic stereochemistry of hypervalent silicon, germanium and tin compounds containing amidomethyl C, O-chelating ligands

The results of NMR-spectroscopy studies of the structure, dynamic stereochemistry, and intermolecular interactions in solutions of organic derivatives of penta-and hexacoordinated silicon, germanium, and tin containing amidomethyl, lactamomethyl, and related bidentate ligands are surveyed. For the series of works “Dynamic stereochemistry of hypervalent compounds of silicon, germanium, and tin,” the author was awarded the Academia Europea Prize for young scientists from CIS in 1996. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1912–1934. November, 1997.