[Chemical characteristics of water-soluble components of aerosol particles at different altitudes of the Mount Huang in the summer]

Aerosol was collected with Anderson cascade sampler at three altitudes of the Mount Huang in the summer 2011. Samples were analyzed by the ion chromatography (IC, Metrohm). The results showed that the mean mass concentrations of all the ions were 13.21 microg x m(-1), 10.94 microg x m(-3), 9.97 microg x m(-3), at the foot, mid height and the summit of the mountain, respectively. The mass concentration of water-soluble components of aerosol decreased with altitude. The major anion and cation of aerosols were SO4(2-) and NH4+, respectively. The descending order of mass concentration of major ionic species was: SO4(2-) > NH4+ > Ca2+ > NO3- and NH4+ account for about 75% of total ionic concentrations of PM2.1 in three sampling sites. The concentration of SO4(2-) and NH4+ decreased conspicuously with altitude. The major cation and anion of coarse mode particles were Ca2+ and NO3-, respectively. The slope of the linear regression line between anion and cation of PM10 and PM2.1 approximates 1, indicating acid-base balance in aerosol particles. Aerosols over the region Mount Huang were influenced by anthropogenic source of surrounding areas to a certain extent. The result also suggested that the correlation between NH4+ and SO4(2-) was 0. 98 and these ions predominantly existed in the form of (NH4)2SO4 and NH4HSO4. Backward trajectory analysis revealed that the air mass was originated from southern coastal regions, the East China Sea, the Yellow Sea and the northern China. Due to the northern air masses go through heavily polluted areas, concentrations of water-soluble ions in these air masses were higher than that of other air masses. The concentration of K+ in northern air mass was several times higher than that in southwestern air mass.

[Distribution of dimethylsulfoxide (DMSO) in the surface water of the Yellow Sea and the Bohai Sea]

The horizontal distributions and diurnal variations of particulate and dissolved dimethylsulfoxide (DMSOp, DMSOd) were studied in the surface water of the Yellow Sea and the Bohai Sea in June, 2011. The determination of DMSO was based on the DMS produced by NaBH4 reduction, which was analyzed using the purge-and-trap technique coupled with gas chromatographic separation and flame photometric detection. The concentrations of DMSOp and DMSOd ranged from 5.43 to 18.35 nmol x L(-1) and from 4.75 to 43.80 nmol x L(-1), respectively, with average values of (11.47 +/- 0.25) nmol x L(-1) and (13.42 +/- 0.58) nmol x L(-1). The results showed that no relationship was found between DMSOp and environmental factors such as chlorophyll a (Chl-a), temperature and salinity, whereas a positive correlation was observed between DMSOp/Chl-a and salinity, indicating that intracellular DMSO could act as a cryo-osmoregulator. A significant relationship was also found between DMSOd and dimethylsulfide (DMS), whereas there was no relationship between DMSOd and DMSOp or DMSOd and bacteria, implying that DMSOd in the surface water was produced mainly through the photochemical oxidation of DMS. In addition, both the DMSOp and DMSOd concentrations exhibited obvious diurnal variations with the higher values in the day time.

[Effect of design and operation parameters on volatile alkylsulfides removal in subsurface constructed wetlands]

A pilot-scale subsurface constructed wetland wastewater treatment system was sampled for one year to study the effects of bed aspect ratio, substrate medium size, water depth, HLR (hydraulic loading rate) and temperature (season) on removal of volatile alkylsulfides such as DMS (dimethylsulfide) and DMDS (dimethyldisulfide). The yearly experimental results demonstrated that the system showed good performance for DMS and DMDS removal in wastewater under different HLR ranging from 12 cm x d(-1) to 86 cm x d(-1). The system could remove 86% of DMS, and 95% of DMDS, respectively. ANOVA statistical analysis shows that HLR and temperature (season) are major factors controlling the system performance for the target analytes. According to ANOVA test, the HLR caused significant differences (p < 0.01) on the average DMS effluent concentrations, and temperature (season) caused significant differences (p < 0.01) on the average DMS and DMDS effluent concentrations. However, bed aspect ratio, substrate medium size and water depth did not cause significant differences (p > 0.05) on the average DMS and DMDS effluent concentrations. A survey of dissolved oxygen and ORP indicates that the constructed wetlands system showed strong reduced condition. On the basis of investigations of electron acceptors (such as SO4(2-), NO3- and NO2-) and dissolved organic pollutants (such as TOC and acetic acid) concentrations along with the length of constructed wetlands, it can be concluded that sulfate reduction and methanogenisis were estimated to be significant for DMS and DMDS removal in constructed wetland beds.

[Observation and analysis on water-soluble inorganic chemical compositions of atmospheric aerosol in Gongga Mountain]

Samples of aerosol are sampled by high volume sampler from Dec. 2005 to Nov. 2006 at high altitude of 1640 m of Gongga Mountain. Water-soluble ions in PM2.5 and PM10 are analyzed by ion chromatogram(IC). The results shows that the annual concentrations of total water-soluble inorganic ions are respectively 6.46 and 8.86 microg/m3 in PM2.5 and PM10, three major ions of SO4(2-), NO3-; and NH4+, account for respectively 82% and 85% in PM2.5 and PM10, Na+, NH4+, K+, Cl- and SO4(2-) were mostly distributed in fine particles, NO3-, Mg2+ and Ca2+ occupied each one half in coast of crude and fine particles. The correlation of Na+ and Cl- is significantly enhanced in wet season in Gongga Mountain, the correlation coefficient R2 are respectively 0.87 and 0.84 in PM2.5 and PM10. The concentration ratio of SO4(2-) and NH4+ is approximate to 1:2 in PM10, main existence form of SO4(2-) and NH4+ (NH4)2SO4 at Gongga Mountain.

Study of parameters affecting poly(3-hydroxybutyrate) quantification by gas chromatography

Poly(3-hydroxybutyrate) (PHB) quantification has been developed mostly using acidic methanolysis followed by GC analysis of the 3-hydroxybutyrate methyl ester. However, under our experimental conditions, only 62% of the ester was detected by GC analysis. Following the study of the different steps involved in this method (i.e., hydrolysis, esterification, and recovery of the ester), the recovery was shown to be limiting. Addition of water to the organic phase, required for its purification before injection, led to the partition of the ester between the organic and the aqueous phase. The influence of the length of acidic methanolysis time on the amount of ester detected was also investigated. NMR analysis was used to show that secondary products were absent in both phases, regardless of heating time. Moreover, increasing acid concentration and the use of lyophilized cells were shown to lead to the decrease of the treatment time. Concerning internal standard choice, methyl benzoate was found to meet all the requirements to correct injection volume errors or to follow organic phase volume changes as a function of acid and water concentrations. The validity of the method was checked on Rhizobium meliloti M5N1 cells, which are shown to produce about 60% PHB (w/w) when cultivated with fructose as the carbon source.

Tandem mass spectrometry for characterization of unsaturated disaccharides from chondroitin sulfate, dermatan sulfate and hyaluronan

Fast atom bombardment tandem mass spectrometry has been used in the characterization of non-, mono-, di- and trisulfated disaccharides from chondroitin sulfate, dermatan sulfate and hyaluronan. The positional isomers of the sulfate group of mono- and disulfated disaccharides were distinguished from each other by both positive- and negative-ion fast atom bombardment tandem mass spectra, which gave sufficient information characteristic of the isomers. The anomeric isomers of nonsulfated disaccharides were characterized by the technique in the positive-ion mode. This fast atom bombardment collision induced dissociation mass spectrometry/mass spectrometry technique was also applied successfully to the characterization of trisulfated disaccharide.