Advanced Materials Research Vols. 581-582

Abstract: Objective: To establish a determination method for gliotoxin. Methods: Reverse-phase high performance liquid chromatography (HPLC) method was used：the column was Inertsil ODS-SP; detection wavelength set at 254 nm; mixed solution of menthol and water（50:50）was used as the mobile phase with flow rate of 1.0 mL/min. Results: The regression equation of gliotoxin content was y = 9E–08x–0.003. The linear range was 0.5-2.5mg/mL and the average recovery was 99.22%. Conclusion: This method is simple, effective and suitable for analysis of the gliotoxin. A reliable basis was provided for the determination of gliotoxin.

Abstract: The rheology behavior of waxy crude emulsion is an important basic information on safeguard research of crude oil-water flow. The non-newtonian characteristics of apparent viscosity of three kinds of waxy crude emulsions were studied experimentally around condensation point; three apparent viscosity forecasting models were evaluated by least-square regressions based on experimental data of shear balance and the average absolute deviation was taken as the measurement of fitness of a model to experimental data. It is concluded that the Pal-Rhodes model, whose relative deviation can be as high as 80%, is the worst forecasting model, but it need the least experiment data to obtain model parameters, only water cut was needed. Elgibaly model has the best forecasting results, the average absolute deviation of forecasting results of three waxy crude emulsions under the condition of different temperature, water cut and shear rate were all less than 15%, but compared with the other two models, Elgibaly model needs the most parameters.

Abstract: A simple and inexpensive procedure involving ethanolysis and urea complexation was developed to concentrate docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from marine fish oil in the form of their ethyl esters. The urea complexation process parameters including urea-to-fish oil ratio, the amount of ethanol and reaction temperature were investigated in single factor experiments. The results showed that the optimal process parameters for urea complexation were as follows: the ratio of urea-to-fish oil of 0.75:1, the ratio of ethanol-to-urea of 2:1, reaction temperature of 65 °C for 30 min. Under these conditions, the total fraction of DHA and EPA in concentrates was increased to 60.6%, in which the content of DHA and EPA was 24.2% and 36.4%, respectively. Combination of ethanolysis and urea complexation is a promising method to obtain concentrated n-3 polyunsaturated fatty acids (PUFA) from marine fish oil.

Abstract: The present study applied Aluminum anode electrochemical method to decolorize direct yellow R wastewater. Experiments were conducted in electrochemical cell system with dimensions of 60 mm ´ 40 mm ´ 2 mm, a steel cathode and aluminum anode. Decolorization efficiency and electrical energy consumption were also calculated to compare optimal values. The effects of factors consist of current density, initial pH, initial dye concentration and electrolyte solution concentration on color removal efficiency have been also investigated. The results of study suggested that direct yellow R dye decolorization was very effective by using treatment technique applied in the study. The optimal values of impact factors were also indicated by. The initial dye concentration of 50 mg/l, initial pH value of 6.76, and current density of 2.5 mA/cm² and Na₂SO₄ electrolyte concentration of 0.1mol/L were optimal conditions for dye decolorization. Besides that, the dye decolorization might reached the highest efficiency of 96.1% once it was conducted at temperature of 20°C, electrode distance of 16 mm and electrolyte time of 60 minutes. Energy consumption for decolorization in conditions mentioned above was 2.399 kWh/kg-dye.

Abstract: Electrocatalytic oxidation of polyacrylamide (PAM) at Ti/PbO2 anode was studied in a three-electrode cell without any diaphragm but with a sandwich bath by galvanostatic electrolysis. Turbidimetry was used to determine the concentration of PAM. The change of degradation ratio with current density and reaction temperature was studied through single factor experiment in order to determine the optimal conditions. The optimal conditions of PAM degradation by electrocatalytic oxidation were: current density was 200 mA•cm-2, and reaction temperature was 60 °C. Under these conditions, the degradation ratio of PAM reached 88% after 3.0 h electrolysis. The total dissolved salts (TDS) and different ions affected on the degradation ratio of PAM by changing the size of PAM molecule and the viscosity of solution. The results of experiments showed that the degradation ratio increased firstly then decreased with the increasing of ion concentration. When TDS was 3000 mg•L-1, the degradation ratio reached the highest level. The high valence cation promoted the degradation of PAM. Cl- and HCO3- promoted the degradation of PAM because of the direct and indirect electrocatalytic oxidation and hydrolysis in alkaline solution respectively.

Abstract: In this study, our purpose was to establish a UPLC method for the simultaneous determination of Paeoniflorin and Paeonol in Houyinan Tablet. The separation was performed on Acquity BEH C18 column(2.1mm×100mm,1.7μm), the mobile phase was acetonitrile-water with gradient elution at a flow rate of 0.2 mL•min-1, the detection wavelength was 230nm, the column temperature was 30°Cand the injection volume was 2μL. Paeoniflorin and Paeonol reached effective separation with the other components in this chromatographic conditions. Paeoniflorin and Paeonol were linear within the range of 0.0406~0.4064μg(r=0.9999) and 0.0426~0.4256μg (r=0.9999), respectively. The average recovery was 99.82% and 100.6%. The results of method validation indicated that the method was simple,quick,accurate, specific and less solvent consumption. It can be used for the quality control of Houyinan Tablet.

Abstract: Cellulose swelling and dissolving, rheological properties, crystallinity, gel Abstract. Untreated cellulose was directly and quickly dissolved in NaOH/thiourea/urea aqueous solvent at a 9/3/5/83 composition and pre-cooled at (-10 to +2)°C, and at a high shear force with 3500rpm agitating speed. The dissolving process was investigated by polarization microscope, XRD and rheometer. The result revealed that cellulose crystal forms was changed from cellulose I to cellulose II after dissolving and the crystallinity decreased. Moreover, the gel forming of cellulose has an obvious relationship with cellulose concentration and it’s easy to form gel when the cellulose concentration was above 8wt%.

Abstract: For the generation of antibodies against small hapten molecules, the hapten is cross-linked with some carrier protein to make it immunogenic. However, it was rarely systematically studied about the effect of modified carrier protein on the obtained antibody nature. In this study, folic acid as the model hapten was coupled to natural and surface-modified bovine serum albumin (BSA) using modifying agent amidocaproic acid (ACA) and hexamethylene diamine (HDA). The three immunogens of FA-BSA, FA-ACA-BSA, FA-HDA-BSA were confirmed by SDS-PAGE and ultraviolet spectrum (UV). The Balb/C mice were immunized with the artificial antigen to obtain three specific antibody with indirect competitive enzyme-linked immunosorbent assay (icELISA) method to compare the performance of antibodies obtained based on different imunogen. The results indicate that the conjugates were successfully synthesized and the coupling ratio from the high to the low was HDA-BSA > ACA-BSA > BSA, while the titer of antibody was ACA-BSA > BSA >HDA-BSA and the IC₅₀ was HDA-BSA < ACA-BSA < BSA. This suggests that sensitivity of antibody was improved by cationizing the carrier protein.

Abstract: Bis (mercaptoethanol oleate) dimethyl tin was synthesized and added to polyvinyl chloride (PVC) with various ratios. Specimens were prepared by mixing and rolling through a double-roller mixer, and their static thermal stabilities were estimated by the oven static thermal aging experiments. The influence of the bis (mercaptoethanol oleate) dimethyl tin on the dynamic thermal stability of PVC was tested through a haack torque rheometer (HAAKE PolyLab QC). The tensile strength and rate of elongation at break of the PVC specimens were evaluated by a servo-controlled tensile testing machine. The results show that the bis (mercaptoethanol oleate) dimethyl tin has excellent static and dynamic thermal stabilization effect on PVC, and to some extent, can improve the breaking elongation rate the PVC sample.

Abstract: Thixotropy, which is an important rheological behavior of waxy crudes, is very important to the hydraulic characteristics and safety of the restart process of crude oil pipelines. Thixotropic behaviors of four waxy crudes were studied experimentally under three kinds of loading conditions, which were constant shear rate, stepwise increase of shear rate and cyclic change of shear rate, namely hysteresis loop. Eight thixotropic models were evaluated by least-square regressions based on experimental data. The average absolute deviation was taken as the measurement of fitness of a model. It is concluded that the model, which was established on the basis of Houska model and Cheng’s idea that wax crude oil contains both complete and partial reversibility structures, is the most suitable model to describe the thixotropy of wax crude oil