Advanced Materials Research Vols. 1004-1005

Abstract: The PIL which were prepared from imidazole and epichlorohydrin were used as catalysts for the conversion of cellobiose to 5-HMF. Effects of the catalyst anion, solvents, reaction temperature, and recycling time were investigated in detail. The optimum reaction conditions for conversion of cellobiose into 5-HMFcatalysed by [IMEP]BF4 were temperature 180 oC, cellobiose 0.5 g, and [IMEP]BF4 0.25 g in DMSO(30 mL). In this condition the yield of 5-HMF can reach 39.2% for 420min. The good positive correlation between the concentration of glucose and the formation rate of 5-HMF was given, and the conversion of glucose into 5-HMF is the key step of formation of 5-HMF from cellobiose. Moreover, [IMEP]BF4 has well cycle performance in the optimum reaction condition.

Abstract: Humic acid acetamide compounds with lipophilic property could dissolve or disperse in oil phase, so they were an important fluid loss additive for oil-based drilling fluids. Compared with water-soluble humic acid derivatives, the fluid loss-reducing mechanism of them was different. With analyzing the mechanism of increasing the flow resistance of liquid phase, bridging plugging, plugging pore and improving the quality of mudcake, the fluid loss-reducing mechanism of lipophilic humic acid acetamide compounds is investigated.

Abstract: An activated carbon (AC) was prepared from keratin wastes by potassium hydroxide chemical activation. A number of analytical techniques, including Fourier transform infrared spectroscopy, N₂ adsorption-desorption and zeta potential, were used to characterize it. The surface area of AC is 750.6 m²/g and its structure was found to be a well-developed micropore. The pH effect of various experimental parameters on its use to adsorb the antibiotic nalidixic acid (NA) from aqueous solutions has been investigated. If pH was below its pK_a, anionic NA and negative surface charges on AC were neutralized by H⁺. Thereby NA was less water soluble and increased the opportunities for hydrophobic interaction with the surface of AC. The major mechanisms were identified as ion exchange, and hydrophobic and electrostatic interactions.

Abstract: Changes of microstructure and viscosity of two kind of enzymatic-deamidated rice protein samples (RA and RB) were analyzed. Scanning electron microscope (SEM) results revealed that network structure of native rice protein was filled with carbohydrate. While the skeleton structure of deamidated protein samples was exposed, and the network structure of RA was combined closely. The viscosity of rice protein was significantly decreased after deamidation, and the viscosity of RA and RB were 10.5 and 8.0, respectively.

Abstract: The influence of storage conditions on apparent viscosity of mixtures of β-sitosterol and lecithin in sunflower oil was studied using rheology. The results showed the apparent viscosity of oleogel decreased with the increase of the speed of shear and storage temperature, while incresed with prolong of time in experiment conditions. The β-sitosterol and lecithin ratio also affected the apparent viscosity; solutions with ratio (70 β-sitosterol-30 lecithin) performed the highest apparent viscosity. What’s more, all the samples were pseudoplastic fluid. The apparent viscosity of the oleogel depends on storage temperature, storage time and organogelator ratios.

Abstract: Inoculated with aerobic sludge from the UASB reactor of a pharmaceutical plant and excess sludge of a municipal sewage treatment plant, granulation of aerobic sludge was realized in a sequencing batch reactor fed with glucose as carbon substrate. Selective pressure created by means of increasing organic loading and decreasing sedimentation time enhances the formation of aerobic granular sludge. Granules started to appear after 35 days operation. The granules were composed of filamentous species with varying degrees of rod-and coccal-type bacteria. While COD and NH4+-N of influent retaining 1600mg/l and 160mg/l, COD and NH₄⁺-N of effluent respectively were 40mg/l and 1mg/l. The removal rates were higher than 95% and 99%.

Abstract: A sensitive method for simultaneously determining residues of oxytetracycline, tetracycline ,chlortetracycline and doxycycline in aquatic product was established by HPLC. Samples were extracted with Na₂EDTA-Mcllvaine buffer solutions and centrifuged.The sample extracts were cleaned up by C₁₈ solid-phase extraction cartridge and then were determined by UV detection at 355 nm.At fortification levels of 0.005~0.1 mg/kg, the average recoveries were of 75%~96% , The RSDs were of 1.02%~6.56%,Limit of detection was 0.002 mg /kg for oxytetracycline,tetracycline and doxycycline and 0.005 mg /kg for chlortetracycline.The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.

Abstract: The present work reports on complexation of hydroxypropyl-β-cyclodextrin (HP-β-CD) with salicylic acid (SA) by vacuum evaporation and inclusion behavior confirmed by FT-IR, OM and SEM. Complex stoichiometry, release mechanism and skin sensitivity were evaluated. The results showed that SA could be encapsulated into cyclodextrin at the ratio of 1:1. Negative values of Gibbs free energy, enthalpy and entropy changes indicated a feasible, spontaneous and exothermic process. Release studies evidenced a burst release in first 2 h, followed by a sustained release and the release rate was temperature-dependent. Furthermore, an improved water solubility and significant reduced irritation effect of SA could be obtained by HP-β-CD.

Abstract: Hydroxy derivatives of aromatic hydrocarbons, have hydroxyl getup directly attached to the ring, which is called phenols. This paper study the bioactivities and safety issues of Terpene Phenolic and its functions, characteristics and clearing strategies of terpene phenolic compounds, so as its biosynthetic mechanisms. The results show that the small amounts of water dissolved in phenol lower the melting point to below the room temperature.

Abstract: A method was developed for the simultaneous determination of Afiatoxin ( AFB₁、AFB₂、AFG₁、AFG₂) in four south medicines is developed by Liquid chromatograPhy with fluoreseence detection after immunoaffinity column clean一up and Pre一cloumn derivatization.four south medicine samples were extraeted with methanol一water (70:30,v/v),The extraets were Purified by imunoaffinity columns and the toxins were separated by reversed phase HPLC, and quantified with fluorescenee detection after photoehemieal derivatization. The separation was perfored on a C₁₈ column.Recoveries of the different medicines spiked with Aflatoxin, The average recoveries ranged from 94.0 %~92.3 % by addition of avermectin standards at three different concentration levels of 10 μg/kg) to four south medicines as matrixes. The sensitivity, accuracy and precisiothod were able to meet the requirements for pesticide residue analysis.