用IR和负离子FAB—MS测定EDTA,DTPA及其碱金属盐类结构

用ＩＲ和负离子ＦＡＢ－ＭＳ测定不同ｐＨ值下ＥＤＴＡ，ＤＴＰＡ，及其碱金属盐类，能直接给出它们的结构及其分子量，对于其碱金属盐类的混合物，不经分离，可以直接测定，能同时得到混合物中各组分的相对分子质量。     

Evidence for the overestimation of molecular masses of proteins after chemical modification and chemical crosslinks on sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE)

Human trypsin inhibitor (home prepared), lactalbumin, trypsinogen, carbonic anhydrase, and bovine serum albumin were submitted to succinylation and their molecular masses were determined by SDS-PAGE according to the method of Weber and Osborn (1969 J. Biol. Chem. 244, 4406) before and after chemical modification. High estimates of their molecular masses were obtained. The monomer and dimer of arrowhead inhibitor proteinase-B (Chinese vegetable legume) obtained after chemical crosslink(s) were also submitted to SDS-PAGE and their apparent molecular masses were also determined and compared to the native arrowhead inhibitor proteinase-B. Abnormally high estimates of their molecular masses were obtained. Our results agree with those in the literature.     

Chemistry of ethyleneimine

Products of addition to both primary and secondary amino groups were obtained by reaction of 2-aminomethylethyleneimine with some acrylic acid derivatives. The structures of the compounds obtained were proved by means of their IR and PMR spectra and also by their subsequent chemical transformations.See [1] for communication X.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1212–1216, September, 1975.     

Preparation of complex carbon-silica adsorbents with different properties

Summary The surface properties of complex adsorbents prepared through the pyrolysis of benzyl and n-heptyl alcohols and their mixtures on the surface of silica gel were investigated. The reactions were carried out in an autoclave at 500°C. A series of adsorbents having different porous structure, chemical nature of the adsorption centers and their topography were obtained. The best resolution of different mixtures was obtained by the carbon-silica adsorbent prepared through the pyrolysis of n-heptanol.     

Living Radical Polymerization in Homogeneous System by Using Iniferter: Design of Block Copolymers

Benzyl N-ethyldithiocarbamate(BEDC) and xylylene bis(N-ethyl-dithiocarbamate)(XEDC) were prepared, and used as mono- and bi-functional photoiniferters, respectively, of the polymerization of styrene and methyl methacrylate. These photopolymerizations were performed via a living radical polymerization mechanism in homogeneous system. The polymers obtained by BEDC and XEDC still contained one and two reactive N-ethyldithiocarbamate end groups, respectively, bonded at their chain ends. When these polymers were reacted with nucleophiles and copper(n) ion, the chain extension reactions were observed to occur depending on their functionality. By using the polymers obtained by BEDC and XEDC as mono- and bi-functional polymeric photoiniferters, the AB and ABA block copolymers were also obtained, respectively. Similar results were obtained by using benzyl N,N-diethyldithiocarbamate(BDC) and xylylene bis(N,N-diethyldithiocarbamate)(XEDC) as mono- and bifunctional photoiniferters, respectively. These results were also compared and discussed.     

Dichloranhydrides of pyrimidyl-4-amidophosphoric acids

4-Trichlorophosphazopyrimidines or their hydrochlorides were obtained by the reaction between 4-aminopyrimidines and phosphorus pentachloride. Without separation, these compounds were converted into dichloranhydrides of the corresponding pyrimidyl-4-amidophosphoric acids of their hydrochlorides by the action of anhydrous formic acid.     

Fluorimetric determinations of nucleic acids using iron, osmium and samarium complexes of 4,7-diphenyl-1,10-phenanthroline

New sensitive, reliable and reproducible fluorimetric methods for determining microgram amounts of nucleic acids based on their reactions with Fe(II), Os(III) or Sm(III) complexes of 4,7-diphenyl-1,10-phenanthroline are proposed. Two complementary single stranded synthetic DNA sequences based on calf thymus as well as their hybridized double stranded were used. Nucleic acids were found to react instantaneously at room temperature in Tris-Cl buffer pH 7, with the investigated complexes resulting in decreasing their fluorescence emission. Two fluorescence peaks around 388 and 567 nm were obtained for the three complexes using excitation lambda(max) of 280 nm and were used for this investigation. Linear calibration graphs in the range 1-6 microg/ml were obtained. Detection limits of 0.35-0.98 microg/ml were obtained. Using the calibration graphs for the synthetic dsDNA, relative standard deviations of 2.0-5.0% were obtained for analyzing DNA in the extraction products from calf thymus and human blood. Corresponding Recovery% of 80-114 were obtained. Student's t-values at 95% confidence level showed insignificant difference between the real and measured values. Results obtained by these methods were compared with the ethidium bromide method using the F-test and satisfactory results were obtained. The association constants and number of binding sites of synthetic ssDNA and dsDNA with the three complexes were estimated using Rosenthanl graphic method. The interaction mechanism was discussed and an intercalation mechanism was suggested for the binding reaction between nucleic acids and the three complexes.     

Simultaneous spectrophotometric determination of carbamazepine and phenytoin in serum by PLS regression and comparison with HPLC

Carbamazepine (CBZ) and phenytoin (PHT) are two antiepileptic drugs which are used simultaneously. In this paper a partial least-squares (PLS) calibration method is described for the simultaneous spectrophotometric determination of CBZ and PHT in plasma. Standard binary mixtures of CBZ and PHT have been resolved by application of PLS-1 to their UV spectra. Then, the binary standard solutions, spiked to plasma, were prepared and after the extraction of the drugs, their corresponding UV spectrum were analyzed by PLS regression to calculate the concentration of drugs in unknown plasma. A leave one out cross-validation procedure was employed to find the optimum numbers of latent variables using PRESS. A HPLC method was also applied for simultaneous determination of two drugs in the plasma and in methanol. The mean recoveries obtained by PLS were 98.4 and 98.2 for CBZ and PHT and those obtained by HPLC were 100.1 and 101.7, respectively. Although, the HPLC method showed better performance than PLS, it was found that the results obtained by PLS were comparable with those obtained by HPLC method.     

Synthesis of imidazolino [1,2-f]xanthin-2-ones and their methylene-group-substituted derivatives

8-Amino-7-theophyllylacetic acids and their esters were obtained by reaction of 8-amino(alkylamino, arylamino)theophyllines with haloacetic acids and their esters. The structures of the products were established, and the conditions for cyclization to imidazolino[1,2-f]xanthin-2-one derivatives were studied. The corresponding methylene-group-substituted derivatives were synthesized by reaction of the imidazolino[1,2-f]xanthin-2-one derivatives with aldehydes, isatin, aromatic nitroso compounds, and arenediazonium salts. The ylidene derivatives of this threering system were also obtained by reaction of 8-amino-7-theophyllylacetic acids or their esters with carbonyl compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1132–1135, August, 1976.     

Effects of the Brookite Phase on the Properties of Different Nanostructured TiO2 Phases Photocatalytically Active Towards the Degradation of N-Phenylurea

Different sol-gel synthesis methods were used to obtain four nanostructured mesoporous TiO₂ samples for an efficient photocatalytic degradation of the emerging contaminant N-phenylurea under either simulated solar light (1 Sun) or UV light. Particularly, two TiO₂ samples were obtained by means of as many template-assisted syntheses, whereas other two TiO₂ samples were obtained by a greener template-free procedure, implying acidic conditions and, then, calcination at either 200 °C or 600 °C. In one case, anatase was obtained, whereas in the other three cases mixed crystalline phases were obtained. The four TiO₂ samples were characterized by X-ray powder diffraction (followed by Rietveld analysis); Transmission Electron Microscopy; N₂ adsorption/desorption at −196 °C; Diffuse Reflectance UV/Vis spectroscopy and ζ-potential measurements. A commercial TiO₂ powder (i. e., Degussa P25) was used for comparison. Differences among the synthesized samples were observed not only in their quantitative phase composition, but also in their nanoparticles morphology (shape and size), specific surface area, pore size distribution and pH_IEP (pH at isoelectric point), whereas the samples band-gap did not vary sizably. The samples showed different photocatalytic behavior in terms of N-phenylurea degradation, which are ascribed to their different physico-chemical properties and, especially, to their phase composition, stemming from the different synthesis conditions.     

Synthesis and copolymerization of new methacrylic monomers for the creation of nonlinear optical polymer materials

A new methacrylic monomer, 3,5-bis[2-(N-ethylanilino)ethoxy]benzyl methacrylate (MBA), has been synthesized. Methacrylic copolymers with different content of bi-chromophore fragments in the side chain were obtained by radical copolymerization of methyl methacrylate and MBA, followed by azo-functionalization reaction. The composition of the obtained copolymers was established, and their thermal properties were determined. Thin films of synthesized copolymers were prepared by spin-coating and the nonlinear optical characteristics of the obtained materials were investigated.

     

聚酰亚胺中溶剂成份的剖析

报道了用红外光谱法和GC/MS法对聚酰亚胺中所含溶剂成份的分析与鉴定。在红外光谱分析中，采用液膜法测定红外光谱图提供官能团的有关信息确定溶剂可能结构。由EI源质谱仪获得聚酰亚胺中所含溶剂成份的MS图和数据。并提出它的碎片裂解途径和特征离子，进行了辅助分析，确定了所含溶剂结构。     

Synthesis and study of the properties of tetrazoles,azides, triazenes,and azo compounds of the thiadiazole series

Azo compounds and bistriazenes were obtained by diazo coupling of diazotized 5-amino-2-R-1,3,4-thiadiazoles; tetrazolo[4,5-b]-1,3,4-thiadiazoles, to which azido-tetrazole tautomerism is peculiar, were obtained by replacement of the diazo group by an azido group. The structures of the products were confirmed by their IR and UV spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 933–936, July, 1980.     

Solid-phase combinatorial syntheses of mesomorphic 4-alkoxyphenyl 4-alkoxybenzoylaminobenzoates

Eighteen two-ring and 100 three-ring benzenoid amides were synthesised using a solid-phase combinatorial method involving acylation or benzoylation and palladium(0)-catalysed carbonylation of a secondary amine, obtained by the reductive amination of 4-iodoaniline and a backbone amide linker. The purity of the products obtained was high enough for investigation of their thermal properties. All the three-ring derivatives were shown to be mesomorphic, but the two-ring derivatives were not. The mesomorphic behaviour and the transition temperatures of the three-ring derivatives were virtually identical to those of samples obtained by liquid-phase synthesis and purified by column chromatography and recrystallisation.     

Application of Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) to remote sensing hyperspectral imaging

The application of the MCR-ALS method is demonstrated on two simulated remote sensing spectroscopic images and on one experimental reference remote sensing spectroscopic image obtained by the Airborn Visible/Infrared Imaging Spectrometer (AVIRIS). By application of MCR-ALS, the spectra signatures of the pure constituents present in the image and their concentration distribution at a pixel level are estimated. Results obtained by MCR-ALS are compared to those obtained by other methods frequently used in the remote sensing spectroscopic imaging field like VCA and MVSA. In the case of the analysis of the experimental data set, the resolved pure spectra signatures were compared to reference spectra from USGS library for their identification. In all cases, results were also evaluated for the presence of rotational ambiguities using the MCR-BANDS method. The obtained results confirmed that the MCR-ALS method can be successfully used for remote sensing hyperspectral image resolution purposes. However, the amount of rotation ambiguity still present in the solutions obtained by this and other resolution methods (like VCA or MVSA) can still be large and it should be evaluated with care, trying to reduce its effects by selecting the more appropriate constraints. Only in this way it is possible to increase the reliability of the solutions provided by these methods and decrease the uncertainties associated to their use.     

Construction and evaluation of ion-selective electrodes for potassium and calcium with a summing operational amplifier. Application to wine analysis

Electrodes selective to potassium and calcium with improved senstivity were constructed like conventional electrode (ISEs), but used an operational amplifier to sum the potentials supplied by the four membranes (ESOAs). The results obtained during the evaluation of their working characteristics were compared to those obtained by conventional ISEs and were found to be similar, but with higher precision. The electrodes were used in the potentiometric determination of potassium, calcium and magnesium in wines. The results given by ESOAs were more precise than those from ISEs. The results obtained by potentiometry were in good agreement with those from AES for potassium and AAS for calcium and magnesium.     

Composition and thermal stability of SiO2-based hybrid materials TEOS-MTEOS system

Hybrid materials with different amounts of organics permanently bound on the inorganic network obtained in the TEOS-MTEOS (tetraethoxysilan-methyltriethoxysilan) system are used for obtaining coatings with different optical and mechanical properties. To study the thermal stability of the mentioned materials, compositions with different molar ratios of the precursors were prepared. The influence of the solvent and water amounts on the gelation process was also investigated. The gels obtained were characterised by IR spectrometry and their decomposition temperatures were determined by DTA/TG. Thermal stability of the gels is rather influenced by their composition than the conditions of the gelation process. This revised version was published online in July 2006 with corrections to the Cover Date.     

四溴邻苯二甲酸双酯的固－液相转移催化合成

使用固－液相转移催化法合成了１８种标题化合物，产率最高达９３．４％，部分化合物结构由ＩＲ，１ＨＮＭＲ及元素分析鉴定．使用氧指数，塑化效率、拉伸伸长率及差热分析研究其阻燃、增塑性能及热稳定性。     

Simultaneous determination of mebeverine hydrochloride and sulpiride using the first derivatives of ratio spectra and chemometric methods.

Two methods are described for the simultaneous determination of mebeverine hydrochloride (MB) and sulpiride (SU) in their combinations. The first method depends on the first derivative of the ratio spectra by measurement of the amplitudes at 263.7 and 234.9 nm for MB and SU, respectively. The linear ranges and detection limits are 4.0-40.0 and 0.72 microg/ml for MB and 1.0-10.0 and 0.34 microg/ml for SU. In the second case, a chemometric (classical least squares) method was developed. The concentration data matrices were obtained by using different concentrations of pure drugs in 0.1 M HCl. The absorbance data matrix corresponding to each concentration data matrix was obtained by the measurements of absorbances in the range 200-300 nm in their zero order spectra; then calibration was obtained by using the absorbance data matrix and the concentration data matrix for the prediction of the unknown concentrations of MB and SU in their mixture. The numerical values were calculated by using Matlab R12 version 6.0 and Origin 5.0 software. The procedures do not require any separation steps. These two methods were successfully applied for assaying the pharmaceutical formulation, of Colona tablets.     

Metal hydroxides as catalysts for the Baeyer-Villiger oxidation of cyclohexanone with hydrogen peroxide

This paper reports the results obtained in the Baeyer-Villiger oxidation of cyclohexanone with a hydrogen peroxide/benzonitrile mixture as oxidant in the presence of synthetic metal hydroxides or their calcined products as catalysts. The metal hydroxides were obtained by coprecipitation. The best ε-caprolactone conversion results were provided by magnesium hydroxide.