Advanced Materials Research Vols. 554-556

Abstract: A new sepctrofluorimetric method for the determination of doxycycline (DC) was developed based on its enhancement of the fluorescence intensity of europium ion in the presence of sodium dodecyl sulfonate(SDS). The mechanism of fluorescence enhancement was studied. Optimum conditions for the determination of DC were also investigated. The linear range was 0.10- 3.00μg/mL. The detection limit was 1.3ng/mL. There was no interference from the excipients normally used in tablet formulations and the serum compositions. The proposed method was successfully applied to the determination of DC in tablets.

Abstract: Abstract. A novel molecularly imprinted polymer (MIP) with high selectivity for sulfonamides was synthesized using reverisible addition fragmentation chain transfer (RAFT) polymerization technique with 2-cyanoprop-2-yl-dithionaphthalate as RAFT reagent, sulfadimethoxine as template, methacrylic acid (MAA) as functional monomer. The obtained MIP was characterized by static adsorption and the results indicated that the MIPs had high adsorption affinity to sulfonamides. The MIP was sucessfully empolyed as the adsorbtion sorbent of solid phase extraction for enrichment and clean-up four sulfonamides from food samples. Under the optimized conditions, good linearities were ranged from 0.010-10 µg/mL with r2≥0.9991.The recoveries at three spiked levels were ranged from 91.0-110.2% with RSD less than 5.8%.

Abstract: Assessment of the pollution for the selected six heavy metals (Pb, Cu, Zn, Fe, Mn and Ni) in ten surface sediments sampled from Aha Lake in a dry season was made in the present investigation. Principal component analysis (PCA) was used to assess the sources of the heavy metals contamination and two components were extracted. Analysis of the lake characteristics and point source pollution revealed that the discharge of industrial effluent and coal mining wastewater were the possible sources of these heavy metals contamination. Based on the speciation characteristics of heavy metals in sediments, the method ratio of secondary phase to primary phase (RSP) was applied to evaluate the loadings and the bioavailability of these heavy metals. The RSP evaluation exhibited that Pb, Zn, Fe, Mn and Ni were mainly associated with Fe-Mn oxides besides residual phase, while Cu mainly existed in organic phase and residual phase. In summary, the potential risk posed to the lake caused by the heavy metals was high and descended in the order of Mn > Ni > Zn > Pb > Cu > Fe.

Abstract: Three curcumin analogues were synthesized from 4-chlorobenzaldehyde and cyclohexanone，cyclopentane and aceton，and their spectroscopic properties were determined. The synthetics had the structural properties such as the target compounds，which showed their particular spectroscopic properties．

Abstract: The stain of Fusarium sp. HJ01 used in 4-chlorophenol (4-CP) degradation was isolated in our laboratory. The effects of pH, temperature, 4-CP concentration, carbon source on 4-CP degradation rate were studied. It was concluded that Fusarium sp. HJ01 could grow with 4-CP as the sole carbon and energy source. 4-CP concentration of 100mg/L in the pH range of 4~10 and temperature range of 25°C~35°C could be degraded completely. The capacity of 4-CP degradation was effectively enhanced by the addiction of sucrose. The kinetics of 4-CP degradation could well accord with the Haldane model for 4-CP as the sole carbon source and with first order equation for added other sucrose.

Abstract: Single crystal of 5-sulfosalicylato potassium was grown by the method of slow cooling in solution. The crystal shows a good cleavability along the b axis.

Abstract: A series of catalysis hydrolytic depolymerization of PET catalyzed by zinc acetate, zinc sulfate, stannous oxide respectively under microwave irradiation at different temperature with time was studied, in which the microwave power was 260W, the ratio of water to PET was 10:1 and the dosage of the catalysts was 0.5% of PET. The relative number average molecular weight of the undepolymerized PET was determined by end-group method. The results show that the molecular weight of the undepolymerized PET decreases with the reaction time increasing, and tends to be stable at the end of the depolymerization reaction. Under the same time, the temperature is higher, the molecular weight is smaller. The molecular weight of the undepolymerized PET reduces most quickly with stannous oxide among the three catalysts.

Abstract: Hypocrellin have been isolated from S. bambusaicola (which has been commonly used as medicinal fungi under the name of “Zhu Huang” in China for treatment of rheumatism and pneusomia in traditional Chinese medicine). as fungal metabolites which exert photodynamic activity towards bacteria and fungi.and show significant cytotoxicity in the A-549 and HCT-8 solid tumor cells. The number of scientific articles on hypocrellin clinical application as well as basic science, steadily increases in both English language and non-English language literatures. This review article will focus on chemical probe and proton transfer reactions of Hypocrollins published in English language journals.

Abstract: We developed a approach to determine residues of trichlorfon and dichlorvos in aquatic products by liquid chromatography-tandem mass spectrometry(LC-MS/MS).In our method,samples were extracted with dichloromethane.The extraction was dehydrated by anhydrous sulfate column and then concentrated.The concentrated liquid was dissolved by acetonitrile solution and defatted with n-hexane.The lower solution was determined by LC-MS/MS with ESI,using positive ion multiple reaction monitoring mode. With external standard method,the average recoveries of trichlorfon were 81.6%-90.4 %. The average recoreries of dichlorvos were 97.0%-102.6 % The relative standard of dichlorvos were all below 10.2 %. The limits of quantification were 2.5μg/kg.The method has great potential for routine analysis of monitoring trichlorfon and dichlorvos residues in aquatic products. It is to develop a simple, high-sensitivity detection method of trichlorfon and dichlorvos for food safety.

Abstract: Ultrasonic extraction and purification using solid-phase microextraction column for the determination of 7 types of organochlorine pesticides including α, β, γ, δ-BHC, 2,4 '-DDT, 4,4'-DDT and heptachlor from the Saussrrea cotus were investigated in this study. The pretreatment of Saussrrea cotus samples, the effect of different ultrasonic time on the extraction efficiency and the effect of different ratio of dichloromethane: petroleum ether on purification efficiency were studied. Results show that the satisfactory extraction conditions for pre-treatment process are: 30 minutes ultrasonic treatment; the volume ratio of dichloromethane and petroleum ether mixture is 3:7.