Advanced Materials Research Vols. 554-556

Abstract: The quantitative distribution of volatile compounds in the different oriental melon varieties and in the different parts of oriental melon was investigated. Volatile compounds were extracted by solid-phase microextraction (SPME) and analysed by gas chromatography-mass spectrometry (GC-MS). Fifty-four compounds were identified including 33 esters, 3 thioesters, 7 aldehydes, 8 alcohols, 1 acid, 1 ketone and 1 phenol, among which esters were found to be the major constituents in ripe oriental melon. The results showed that ethyl acetate, sulfur-containing esters and compounds containing a straight nine-carbon chain were present at high concentrations in oriental melons, particularly acetic acid phenylmethyl ester. The majority of ester compounds of oriental melon decreased and the aldehyde compounds increased after storage at -20 °C and the distribution of volatiles was also found to be different in the umbilicus, middle and pedicel of an oriental melon Qitian 1 according to their carbon chain length and quantity.

Abstract: Ellagic acid is widely used as today’s functional food ingredients and health-care food supplements because of its biological activities. pH-gradient counter-current chromatography was applied to the successful separation of ellagic acid from a crude sample. The experiment was performed with a two-phase solvent system composed of methyl tert-butyl ether-butanol- acetonitrile-distilled water (4:2:3:8, v/v) where 10 mM trifluoroacetic acid (TFA) was added to the upper organic stationary phase as a retainer and 10 mM ammonia to the aqueous mobile phase as an eluter. The separation of 0.6 g crude sample yielded ellagic acid at a high purity of over 98% as determined by HPLC, MS and NMR. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Abstract: Amber and copal belong to the natural resin, which are similar and transitional in the physical and chemical properties. The artificial heat-pressurized treatment is contributed to the polymerization of the natural copal, and turns into green, yellow-green and deep orange-yellow copal. It is very difficult to identify amber from the heat- pressurized treatment copal only based on the gemological parameters.The thermal behavior of amber and the copal before and after heat-pressurized treatment were analyzed by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(NMR). The results show that amber exists an evident endothermic peak around 123~132°C, and copal reveals an obvious endothermic peak at about 174~178°C, and the heat pressurized treatment copal occurs a clear exothermic peak around 150~152°C. The differences between endothermic or exothermic transition and peak position reveal occurring thermal oxidation or the bond breaking or the melting, which are of great significance in the identification.

Abstract: The offshore region of Haizhou Bay is characterized by intense anthropogenic activities. And the study on water quality status analysis in this offshore region has attracted more and more attention of the researchers and decision-makers. In this paper, an improved method (the PPCM-PCAM) which combines projection pursuit cluster model (PPCM) with principal component analysis method (PCAM) was developed to analysis water quality status. By using this improved method, water quality analysis of Haizhou Bay water area from January 2007 to December 2007 was studied. The analysis results show that the samples in Haizhou Bay water area can be described into 4 "category 1”, 4 “category 2” and 2 “category 3” states in 2007.