Ultra dispersed particles of Fe(III) compounds in the strongly basic crosslinked ionic polymer-precursors for new sorbents and catalysts

The Mössbauer spectroscopy and SEM investigation shows that crosslinked ionic polymers containing strongly basic functional groups adsorb Fe(III)-containing cations from sulphate solution through the formation in the polymer phase of high dispersed particles of jarosite mineral type compounds. Using different procedures the particles sizes and morphology, their repartition on the surface and in the volume of the polymer granule, the composition of the “polymer-inorganic compound” structural units were modified that is important for sorbents and catalysts obtaining. On heating in water medium in a boiling water bath, a part of the jarosite type compounds in the polymer phase is converted into ultra fine β-FeOOH particles in superparamagnetic state and the rest, in relatively massive and magnetically ordered β-FeOOH particles. The higher is the content of the Fe(III) in the polymer phase, the shorter is the duration of heating in water for the appearance of relatively massive particles of β-FeOOH. The particles of the jarosite type compounds and of the β-FeOOH are formed both on the surface and in the volume of the polymer granule. Upon heating in water, a part of the Fe(III)-containing particles have migrated from the volume of the polymer granule to the surface. Thermogravimetric investigation (in an N₂ atmosphere) shows that on heating of the Fe(III)-containing polymer sample up to 900 °C, complicated processes take place.     

Scale up of 2,4-dichlorophenol removal from aqueous solutions using Brassica napus hairy roots

Chlorophenols are harmful pollutants, frequently found in the effluents of several industries. For this reason, many environmental friendly technologies are being explored for their removal from industrial wastewaters. The aim of the present work was to study the scale up of 2,4-dichlorophenol (2,4-DCP) removal from synthetic wastewater, using Brassica napus hairy roots and H₂O₂ in a discontinuous stirred tank reactor. We have analyzed some operational conditions, because the scale up of such process was poorly studied. High removal efficiencies were obtained (98%) in a short time (30 min). When roots were re-used for six consecutive cycles, 2,4-DCP removal efficiency decreased from 98 to 86%, in the last cycle. After the removal process, the solutions obtained from the reactor were assessed for their toxicity using an acute test with Lactuca sativa L. seeds. Results suggested that the treated solution was less toxic than the parent solution, because neither inhibition of lettuce germination nor effects in root and hypocotyl lengths were observed. Therefore, we provide evidence that Brassica napus hairy roots could be effectively used to detoxify solutions containing 2,4-DCP and they have considerable potential for a large scale removal of this pollutant. Thus, this study could help to design a method for continuous and safe treatment of effluents containing chlorophenols.     

Electrosynthesis and charge-transport properties of poly(3′,4′-ethylenedioxy-2,2′:5′,2′′-terthiophene)

Polythiophene containing 3,4-ethylenedioxythiophene (EDOT), poly(3′,4′-ethylenedioxy-2,2′:5′,2′′-terthiophene), was synthesized by electrochemical oxidation of the corresponding monomer, 3′,4′-ethylenedioxy-2,2′:5′,2′′-terthiophene, in acetonitrile. The resulting polymer was soluble in DMSO and THF, and was characterized by ¹H NMR and mass spectroscopies, and GPC. The electrical conductivity of the oxidized polymer film was found to be comparable to those for polythiophene and poly(methylthiophene) despite of its short π-conjugation length.     

Preparation of DNA–cyclodextrin–silica composite by sol–gel method and its utilization as an environmental material

A DNA–cyclodextrin–silica composite was prepared by the sol–gel method. This composite possessed the bi-functions of double-stranded DNA, such as intercalation into DNA, and cyclodextrin, such as inclusion into its intramolecular cavity. Therefore, we demonstrated the accumulation of harmful compounds from an aqueous multi-component solution using a DNA–cyclodextrin–silica composite column. As a result, the DNA–cyclodextrin–silica composite column can effectively accumulate not only planar structure-containing harmful compounds, such as dioxin and polychlorobiphenyl (PCB) derivatives, but also non-planar structure containing compounds, such as bisphenol A and diethylstilbestrol, from an aqueous multi-component solution. The accumulated amount of these harmful compounds was more than 90%. Additionally, the DNA–cyclodextrin–silica composite column was recycled by the application of methanol. Therefore, the DNA–cyclodextrin–silica composite may have the potential to be used as an environmental material for the accumulation of harmful compounds from industrial or experimental waste.     

Estimation of the mass of powder trapped at collision during ball milling from the kinetics of the mechanically activated decomposition of Ag oxalate

The present work aims at providing a direct experimental estimate of the amount of powder trapped at each collision during the mechanical processing by ball milling. Attention has been focused on the mechanochemical reactivity of anhydrous Ag oxalate powders, prepared by mixing Ag nitrate and Na oxalate aqueous solutions, and then filtering and drying the white precipitate formed. Suitable amounts of such powders were mechanically processed with a single milling ball. The mechanical processing induced the gradual decomposition of Ag oxalate into Ag and carbon dioxide. The process was followed by gravimetric analyses, and its kinetics related to individual collisions. It is shown that the decomposition process follows a simple exponential kinetics, which allows the identification and evaluation of an apparent rate constant. This can be regarded as a measure of the amount of powder trapped at each collision, which is roughly equal to 0.41 mg.     

Do the VOCs that evaporate from a heavily polluted river threaten the health of riparian residents?

To understand the potential threat of volatile organic compounds (VOCs) to the health of residents living close to a heavily polluted river, this study investigated the species and the concentration of VOCs evaporating from a river and surveyed the health condition of the nearby residents. Air samples were taken seasonally at the upstream, midstream, and downstream water surfaces of the river, and at different locations at certain distances from the river. These samples were analyzed qualitatively and quantitatively through gas chromatography and electron capture detector (GC/ECD) for chlorinated organic compounds, and through gas chromatography and flame ionization detector (GC/FID) for ordinary hydrocarbons. The health data obtained from valid health questionnaires of 908 residents were analyzed through Statistical Package for Social Science (SPSS) software. Twenty-six species of VOCs were identified in the environment adjacent the river, many of which are carcinogenic or believed to be carcinogenic to humans. However, results of this study shows that the VOCs evaporating from the polluted river have not been definitively identified as a major factor of cancer in the residents. However, the risk of suffering from certain chronic diseases may increase in residents living less than 225 m away from the river due to the high levels of evaporated VOCs. Residents living less than 225 m away from the river and with nearby specific industries are 3.130 times more at risk of suffering from chronic diseases than those with no nearby specific industries.     

Real-time quality authentication of honey using atmospheric pressure chemical ionisation mass spectrometry (APCI-MS)

The aim of this study was to use gas chromatography-mass spectrometry (GC-MS) and APCI-MS techniques to detect adulteration in honey. The key volatile compounds in the headspace of the adulterated honey were marked by GC-MS and their representative fragment ions were utilised in scanning honey samples using the real-time APCI-MS system. The PLS models validated using independent data sets resulted in coefficient of the determination () of 0.97 and 0.96 and root mean square error in prediction (RMSEP) of 2.62 and 2.45 for the GC-MS and APCI-MS data sets respectively. The most efficient volatiles from GC-MS analysis and their corresponding fragment ions m/z from APCI-MS data analysis were then identified and used to develop new PLS models to predict the level of adulteration. The best PLS model gave of 0.95 and RMEP of 2.60% in the independent validation set indicating that the model was very accurate in predicting the level of adulteration.     

Synthesis of Heterocycle‐fused Pyridine N‐Oxides from Oximes and Diazo Compounds via RhIII‐Catalyzed C?H Activation and Annulation

A Rh^III‐catalyzed tandem C H activation and C N bond formation reaction between oximes and diazo compounds for the synthesis of heterocycle‐fused pyridine N‐oxides has been developed. The reaction exhibits good functional group tolerance and regioselectivity. After simple transformation, the 1‐substituted, 1,3‐disubstituted, 1,4‐disubstituted and 1,3,4‐trisubstituted heterocycle‐fused pyridines were all obtained in high efficiency. Moreover, this strategy has also been expanded to the synthesis of a key intermediate for the construction of one potential anti‐HIV agent.

     

不同预处理和干燥方式下养心菜粉色泽、功能成分和抗氧化性水平 的比较

为了研究养心菜的加工适用性,拓展其利用途径,采用未预处理（Untreated,UT）、沸水漂烫（Boiling Water Blanching,BWB）、沸水+护色漂烫（COLOR Protection+Water Blanching,CPB）、蒸汽漂烫（Steam Blanching,SB）与冻融（Freeze-Thawing,FT）五种预处理方式处理后,分别进行热风干燥（Hot Air Drying,HA）、热泵干燥（Heat Pump Drying,HP）,得到UT HP、UT HA、BWB HP、BWB HA、CPB HP、CPB HA、SB HP、SB HA、FT HP及FT HA 10种养心菜粉,比较不同预处理方式和干燥方式下养心菜色泽、功能成分及抗氧化能力水平的变化。结果表明：UT HP没食子酸和山萘酚含量最高,但色泽差、叶绿素含量较低,干燥时间长;CPB HP的干燥时间短,Vc含量最高,具有较高的抗氧化水平,但没食子酸含量较低;SB HP总酚、总黄酮、槲皮素含量最高,其他品质指标介于中间;FT HP养心菜具有最好的色泽、最高的叶绿素、游离氨基酸含量,但总酚、总黄酮、槲皮素、山萘酚以及抗氧化水平低。从主成分分析来看,BWB HP、CPB HP、SB HP 和BWB HA、CPB HA、SB HA的养心菜品质分别具有一定的相似性,UT HP、FT HP、UT HA、UT HA和其有明显差异。该文综合比较了养心菜不同预处理及干燥方法的优劣,在养心菜下游的功能性食品的开发过程中,可以根据需求选择合适的干燥方法。     

Antiwear properties of complex compounds of Sn(II) and Sn(IV) in lubrication of a bronze-steel contact

The wear characteristics of metal-organic chelate additives containing tin bonded to aliphatic dicarboxylic acids were investigated on a reciprocating motion test machine in lubrication of a steel-bronze contact. It was found that both the valence state of the tin and the chain lengths of the dicarboxylic acids affected the wear results. All the compounds reduce wear effectively and, at pressures below 1.76 MPa, they assure zero ZDTP and SnDTP additives in the steel-steel concentrated contact using the standard four-ball machine.