分子三维投影法在苯酚类化合物构效关系研究中的应用

对苯酚类化合物进行三维投影得到了5个形状参数,将其与3个Am指数及8个量子化学参数相结合.由最佳变量子集回归法对变量进行了压缩与选择,运用多元回归分析和人工神经网络法分别构造了预测数学模型,得到了满意的结果.     

Asymmetric ring-opening reaction of azabenzonorbornadienes with phenols promoted by palladium/(R,R)-DIOP complex

An efficient asymmetric ring opening reaction of azabenzonorbornadienes with various phenols using Palladium/(R,R)-DIOP complex has been demonstrated, the reaction afforded the corresponding products in excellent yields (80–95%) with moderate enantioselectivities (50–64% ees). The syn-configuration of the product was confirmed by the single X-ray crystallography.     

NaIO4/KI/NaCl: a new reagent system for iodination of activated aromatics through in situ generation of iodine monochloride

A new reagent system consisting of NaIO₄/KI/NaCl in aq AcOH has been found to be effective in iodinating a variety of activated aromatic substrates via in situ-generated iodine monochloride, to furnish iodoaromatics in excellent yields. This iodination procedure has been applied successfully for a cost-effective synthesis of 3,3′-diaminobenzidine, a key intermediate for preparing proton conducting membranes for fuel cell applications, with high yield and a purity of 99.7%.     

Quantification of two chromatographic unresolved dichlorophenols using gas chromatography-direct deposition-fourier transform infrared spectrometry and multivariate calibration

A method for the quantification of two chromatographically unresolved dichlorophenol isomers in water is described. Acetylation and concentration on graphitized carbon cartridges are carried out as a preliminary step. Detection is made by gas chromatography (GC) coupled to Fourier transform infrared spectroscopy (FTIR), using a direct deposition interface (DD). Infrared spectra in the maximum of the unresolved peak of 2,5- and 2,4-dichlorophenol for a series of standards with different amounts of these two compounds are used, to elaborate a multivariate calibration model (PLS-1 algorithm). By the method described, concentrations of dichlorophenol isomers in water at ng/ml level can be determined.     

Optimisation and validation of an automated solid phase extraction technique coupled on-line to enzyme-based biosensor detection for the determination of phenolic compounds in surface water samples

Summary A fully integrated screening system for phenolic compounds was developed incorporating on-line solid phase extraction, fractionation and biosensor detection. Two different types of biosensors, solid graphite and carbon paste electrodes incorporating the enzyme tyrosinase, were compared and used in the screening system. Interfacing of the solid phase extraction and fractionation with the biosensor detection was given special attention since the biosensors were not compatible with the organic modifier used for desorption of phenols from the solid phase extraction step. The system was validated with conventional analytical techniques. Surface water samples from the Ebro river were spiked with 1,10, and 25 μg L⁻¹ of catechol, phenol,p-cresol, respectively. Three out of seven samples were spiked and the correct samples were identified, containing phenols equivalent to the spiked concentrations.     

三乙醇胺改性煤渣自水溶液中去除酚类化合物的特性研究

用三乙醇胺处理制得了改性煤渣，研究了酚类化合物在改性煤渣/水间的界面行为，并探讨了其吸附机理，结果表明：三乙醇胺处理后的改性煤渣对酚类化合物有较强的吸附能力，吸附速度快；常温下，受温度影响小，三乙醇胺处理后的改性煤渣对酚类化合物有较强的吸附能力，吸附速率快；常温下，受温度影响小；选择性不明显；呈现出以表面吸附及分配作用共存的吸附形式。     

酚类在聚醚醚酮上的分离行为研究

酚类在聚醚醚酮上的分离行为研究于剑锋，吴通好，孙家（吉林大学化学系，理论化学研究所，长春，１３００２３）关键词：气相色谱固定相，聚醚醚酮，分离，酚类化合物聚醚醚酮［Ｐｏｌｙ（ｅｔｈｅｒ－ｅｔｈｅｒ－ｋｅｔｏｎｅ），简称ＰＥＥＫ］是近年来推出的一种新型...     

Fast separation of (poly)phenolic compounds from apples and pears by high-performance liquid chromatography with diode-array detection

Polyphenolic compounds in apples and pears were analysed by HPLC on C₁₈-modified silica. Gradient elution with phosphoric acid–methanol mixtures and phosphoric acid–acetonitrile mixtures gave complete separation of all polyphenolics of interest. The use of methanol as modifier was preferred because it provides a more rapid separation (20 min). Diode-array detection was used for the provisional identification of polyphenolic compounds not available as standards.     

Optimization of preconcentration and isolation for the determination of 15 phenols by supercritical-fluid extraction and gas chromatography with metallomesogenic stationary phase

Based on the merits of well-established capillary gas chromatography (GC), metallomesogenic polymer was used as the stationary phase and flame ionization detector (FID) was used as the detector, the analysis of phenolic compounds explored the possibility of application in complex matrices. We proposed the method combined supercritical-fluid extraction (SFE) of phenolic compounds, which had been enriched on the solid supports of XAD-4 resins, and then with their determinations by capillary GC-FID. The SFE parameters suitable for 15 phenols simultaneously adsorbed onto XAD-4 resins in aqueous solution were assessed by a 4⁵ factorial design method. The best results were 5 min static time, 10 min dynamic time, 0.25 ml methanol spiked, 80 °C oven temperature and 410 atm CO₂ pressure. Also, other parametric conditions for specific phenols were revealed and analyzed. In the comparison with Soxhlet extraction with regard to the recoveries and reproducibility, the developed SFE was quite superior and helped to reduce the detection limit of aqueous samples to 10⁻²-fold. Eventually, the polluted soils near a pharmaceutical factory were primarily tested and given the probable distribution.     

Uptake monitoring of anilines and phenols using modified zeolites

Uptake monitoring of a group of environmentally important phenolic and aniline compounds including aniline, phenol, 4-methylaniline, 4-aminophenol, 2-aminophenol, 4-nitrophenol, 2-nitrophenol and 2-methyl-4-nitrophenol was carried out using micellar electrokinetic capillary chromatography. For the removal of tested pollutants, the natural zeolites natrolite and clinoptilolite were examined in which the latter showed better uptakes ranging from 45 to 64% of pollutants from aqueous solution in 4 h. Modification of zeolites with cyclodextrins (CDs), especially, α-CD, considerably improves the uptake efficiency to 65-74% for clinoptilolite. The effects of equilibrium time, type and concentration of CDs were also investigated. The versatility of micellar electrokinetic capillary chromatography was shown for this type of study owing to its speed, resolution ability, and simplicity.