| The spatial and temporal variations of acrylic acid were studied in the East China Sea(ECS), the Yellow Sea(YS), Jiaozhou Bay and adjacent waters. In order to obtain a preliminary feature of acrylic acid biogeochemistry, the relationships between the concentrations of acrylic acid and the environmental factors, such as temperature,salinity, were also investigated. The main research results were summarized as follws:(1) A method followed by HPLC analysis for the determination of acrylic acid in seawater has been developed. The detection limit of method was4nmol/L (S/N=3). The peak area is linear with acrylic acid concentration in the range of0.01-10μmol/L, with a correlation coefficient of0.9996. The average recovery was92.7%～96.8%and RSD was1.3～1.6%, the sea water which were filtered by0.2μm filter membrane can be saved for long time.(2) The concentrations of acrylic acid and other parameters, and mutual relations between them were fully researched in the algae culture of Phaoecystis globosa. The concentrations of acrylic acid’ranged from0.339to2.219μmol/L, The concentrations of acrylic acid and DMSPd had significant correlation. The concentrations of acrylic acid and DMSPd and the maximum concentration of every cell released appeared in the early stabilizing period of exponential phase. The concentrations of acrylic acid and DMS, DMSP, DMSPp also had obvious correlation, but the association was not more significant than the former.(3) The distributions of acrylic acid were determined in the East China Sea(ECS)and the Yellow Sea(SYS) during March-April, July, October-November, and December,2010. The concentrations of acrylic acid in surface water were0.359(0～0.145)μmol/L、0.258(0～1.06)μmol/L、0.142(0～0.520)μmol/L0.121(0～0.720)μmol/L, respectively. The acrylic acid concentrations showed a notable seasonal variation with the highest values in spring and the lowest ones in winter. Besides the ocean phytoplankton growth of seasonal change, the human activity has great influence. When the distribution patterns are compared with each other in different seasons, they nearly presented a decreasing trend from inshore to offshore sites, without being strongly biased by temporal change. In addition, the concentrations of acrylic acid exhibited a consistent diurnal variation in different seasons, with higher levels in day and lower ones at night, indicating that the production processes of acrylic acid may be related to the photosynthesis.The vertical profiles of acrylic acid in the stations of Yangtze estuary in each season were observed. The maximum of acrylic acid concentration was present at the depth of2-30m. This might mainly be related with acrylic acid bio-production from ocean phytoplankton in the layer Below the middle layer, the concentrations of acrylic acid reduced with the increase of the depth.The contents of acrylic acid and Chl-a existed certain linear correlation in each season, but the association are not significant. On the one hand, this may be due to the complex caused by the composition of algae. In spring, the concentrations of acrylic acid and the nutrient SiO32-, NO3-has good correlation, this may be due to that they had larger stimulative effect on phytoplankton growth. In summer, the concentrations of acrylic acid and DIN had good correlation, and the rest nutrients also had positive correlation, but correlation is not great. In spring, summer and autumn, the concentrations of acrylic and DMS, DMSP correlation were not siginicant(4) For the Yellow Sea Cold Water Mass in August2011, the temporal and spatial distribution of acrylic acid, the relationships between acrylic acid concentration and environmental factors were also analyzed, the results showed that in the surface water of cold water mass, the acrylic acid concentration was0～0.208μmol/L, with the average of0.081±0.075μmol/L. The center of cold water mass performanced high concentration of acrylic acid.The vertical distribution of acrylic acid in the Yellow Sea Cold Water Mass followed as:middle> bottom> surface, which is mainly because, the production of acrylic acid was due to comprehensive effect of bacteria and phytoplankton in vertical orientation. The change of Chl-a in vertical direction was middle> bottom> surface, and the distribution of bacteria in vertical profile was surface> bottom> middle. In the middle waters, phytoplankton growth was strong, and bacteria in the middle waters less than that in surface. The maximum concentration of acrylic acid appeared in the layer, in which the temperature and salinity has great change.In summer, the concentrations of acrylic acid in the Yellow Sea Cold Water Mass, showed obvious negative correlation with temperature, and showed weak correlation with salinity, this explains to the salinity has less effect to distribution of acrylic acid; The content of acrylic acid and Chl-a showed some correlation, the biomass affected the production and distribution of acrylic acid to some extent.(5) Distributions of acrylic acid were investigated in the surface water of the Jiaozhou Bay from December,2010to November,2011. The acrylic acid content of the Jiaozhou Bay ranged from0.03μmol/L to0.472μmol/L, with the mean value of (0.093±0.105)μmol/L. The distribution of acrylic acid has obvious zoning phenomenon. There was a gradually increasing trend from the mouth of bay to the inside of bay, and the annual concentration of eastern is higher than that of the west. This may be due to the offshore by human activities and surface runoff.Seasonal distribution of acrylic acid exhibited such a sequence:Acrylic acid (winter)> Acrylic acid (spring)> Acrylic acid (autumn)> Acrylic acid (summer), with the highest value in winter and the minimum in summer. This seems basically related to water temperature, biological activity, terrestrial input and water mixture.The concentrations of acrylic acid and DMS, DMSP presented a certain correlation, and presented a weaker negative correlation with pH. The concentrations of acrylic acid and Chl-a were unrelated which largely because of human activities and land runoff to the Jiaozhou Bay.(6) In April (low-water period) and August (high-water period) of2011, the seven rivers around Jiaozhou Bay were surveied on the two different periods, and the distribution of acrylic acid was analyzed. In the low-water period, the concentration of acrylic acid was higher, the average concentration was0.507±0.225μmol/L. The concentration of acrylic acid in the Moshui river was the highest, the concentration of acrylic acid in the Caowen river was the lowest. In the high-water period, the concentration of acrylic acid in the water was lower, and the average of acrylic acid was0.252±0.292μmol/L. The concentration of acrylic acid sea in Haibo river was the highest, while in Yanghe river downstream, and Caowen river upstream and downstream, the concentrations of the acrylic acid were low, which were lower than the detection limit. |
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