The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry     

Zhanfei Liu  Rachel L. Sleighter  Junyan Zhong  Patrick G. Hatcher 《Estuarine, Coastal and Shelf Science》2011

How dissolved organic matter (DOM) undergoes chemical changes during its transit from river to ocean remains a challenge due to its complex structure. In this study, DOM along a river transect from black waters to marine waters is characterized using an offline combination of reversed-phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS), as well as tandem ESI-FTICR-MS. In addition, a water extract from degraded wood that mainly consists of lignins is used for comparison to the DOM from this transect. The HPLC chromatograms of all DOM samples and the wood extract show two major well-separated components; one is hydrophilic and the other is hydrophobic, based on their elution order from the C₁₈ column. From the FTICR-MS analysis of the HPLC fractions, the hydrophilic components mainly contain low molecular weight compounds (less than 400 Da), while the hydrophobic fractions contain the vast majority of compounds of the bulk C₁₈ extracted DOM. The wood extract and the DOM samples from the transect of black waters to coastal marine waters show strikingly similar HPLC chromatograms, and the FTICR-MS analysis further indicates that a large fraction of molecular formulas from these samples are the same, existing as lignin-like compounds. Tandem mass spectrometry experiments show that several representative molecules from the lignin-like compounds have similar functional group losses and fragmentation patterns, consistent with modified lignin structural entities in the wood extract and these DOM samples. Taken together, these data suggest that lignin-derived compounds may survive the transit from the river to the coastal ocean and can accumulate there because of their refractory nature.  相似文献   

南极普里兹湾溶解态镉的分布     

孙维萍  扈传昱  韩正兵  薛斌  潘建明 《海洋通报(英文版)》2011,13(1):50-59

利用25次南极科考获得的海水样,采用原子分光光度法(AAS)测定了海水中溶解态镉的含量,研究了东南极普里兹湾不同空间与时间尺度下海水中溶解态镉的分布特征.并利用同航次相关的营养盐、叶绿素a等数据,分析了影响海水中溶解态镉分布的主要因素.研究结果显示,普里兹湾表层海水中溶解态镉的分布与叶绿素a具有良好的相关性,生物过程是...  相似文献   

南海溶解氧垂直结构的季节变化分析   总被引：2，自引：0，他引：2  

刘洋  鲍献文  吴德星 《中国海洋大学学报(自然科学版)》2011,(Z1):25-32

溶解氧在生物活动较小的情况下,与温盐相似,同样具有保守性。本文基于WOD05数据集中实际观测的溶解氧标准层资料,对南海溶解氧的垂直结构及其季节变化进行阐述,指出在浅水陆架区、中央海盆和吕宋岛以东深水区,溶解氧具有不同的垂向分布特点。重点分析了深水区的溶解氧垂向结构,发现其极大值存在季节性变化,量值在冬、春较大,夏、秋较小,出现的深度夏季最深,超过50 m,秋、冬较浅且现象不够明显;极小值基本不存在季节变化,出现的深度约860 m;对比温盐关系曲线,发现溶解氧极大值对应着南海次表层水团上界、衰减缓慢的稳定阶段对应次表层水团高盐核心水层、而极小值则对应中、深层水团的交界。  相似文献   

长江口邻近海域溶解态铝的分布及季节变化   总被引：2，自引：0，他引：2  

闫丽  任景玲  罗建  吴莹  周锋  郝锵  刘素美 《中国海洋大学学报(自然科学版)》2011,(Z1):259-266

基于2006年6、8、10月对长江口邻近海域的大面调查资料,分析了溶解态Al的分布及季节变化,讨论了水团混合、悬浮颗粒物及浮游植物水华对溶解态铝分布的影响。结果表明,3个航次溶解态铝的水平分布规律相似,都是近岸浓度最高,随着离岸距离的增加浓度降低,6、8、10月溶解态Al的平均浓度分别为(119±77)、(109±80)和(138±73)nmol/L,统计结果表明该海域的溶解态铝具有明显的季节变化。影响溶解态铝分布的主要因素有水团混合、底沉积物的再悬浮以及浮游植物的调节作用。  相似文献   

Dissolved organic matter and its role in red tide succession in the East China Sea in spring     

������  ����� 《中国海洋湖沼学报》2011,29(4):795-799

Dissolved fluorescent organic matter was measured using fluorescence excitation-emission matrix spectroscopy at three temporal points during a Synechococcus bloom after diatom bloom dispersion in spring, 2007. Carbohydrate and dissolved organic carbon were also analyzed. The relationship between organic matter and red tide succession was examined. The results show that after the diatom bloom, tyrosine-like fluorescence B intensity was very high within the water column and exhibited a negative correlation wi...  相似文献   

冀中坳陷潜山油气输导体系及与油气藏类型的匹配关系   总被引：4，自引：0，他引：4  

吴伟涛  高先志  卢学军  崔周旗  孔令武  贾连奇  王海潮 《地球科学与环境学报》2011,33(1):78-83,88

通过总结前人研究结果,利用测井、钻井地质和地化等资料,对冀中坳陷潜山油气藏类型和油气输导体系特征进行研究,并结合已发现的潜山油气藏,建立了不同油气输导体系与潜山油气藏类型的匹配关系。结果表明:根据不同的圈闭遮挡条件,可将冀中坳陷潜山油气藏分为潜山顶、潜山坡和潜山内幕油气藏等3种类型;潜山油气输导体系发育断裂、不整合、内幕溶蚀层和复合型输导体系等4种类型;受碳酸盐岩地层、断层活动性影响以及与油气生成时间的匹配,断裂型输导体系具有高效性和时效性的特征,有利于形成潜山顶和内幕油气藏;不整合型输导体系由不整合上部底砾岩和下部淋浴带组成,具有"双层"输导的特点,有利于形成潜山顶和潜山坡油气藏;内幕溶蚀层型输导体系由潜山内部的溶蚀孔-洞-缝系统组成,其发育程度受内部地层泥质含量控制,有利于形成潜山内幕油气藏;复合型输导体系由单一型输导体系复合形成,具有"多样式"的特点,可以形成潜山顶、潜山坡和潜山内幕油气藏。  相似文献   

Temporal and spatial variability of dissolved organic carbon concentration in the Xijiang River, South China     

Zhen Tao  Quanzhou Gao  Wenping Guo  Zhengang Wang  Yongling Zhang  Chenji Xie  Xiakun Huang  Hongwei Zhong 《山地科学学报》2011,8(5):694-703

A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological...  相似文献   

新04号泉溶解气CO2异常特征分析     

朱成英  高小其  李艳萍  李新勇 《地震地磁观测与研究》2011,32(3):95-99

运用Mapsis软件前兆异常分析中的差分和从属函数,对新04号泉溶解气CO2进行异常识别,结果认为:①差分和从属函数异常形态均为高值异常;②差分异常对近场中强震和远场强震的映震率均为71.4％(5/7);从属函数异常对近场中强震的映震率为66.7％,而对远场强震的映震率为83.3％(5/6);两者均出现异常时,对近场中...  相似文献   

Evolution of animal multicellularity stimulated by dissolved organic carbon in early Ediacaran ocean: DOXAM hypothesis     

AKIHIRO KANO  YOKO KUNIMITSU  TETSUHIRO TOGO  CHIDURU TAKASHIMA  FUMITO SHIRAISHI  WEI WANG 《Island Arc》2011,20(2):280-293

Oxygenation of the ocean is presumed to be an important factor stimulating the evolution of multicellular animals. The appearance of the Ediacaran‐type biota (ca 575 Ma) was assigned to the aftermath of the Gaskiers glaciation (ca 580 Ma), when substantial oceanic oxygenation is believed to have started. However, several lines of evidence reveal that at least sponges evolved before this oxygenation. For understanding the first stage of animal evolution, we propose the hypothesis that Dissolved Organic Carbon (DOC) Stimulated the evolution for Animal Multicellularity (DOXAM). Recent geochemical studies of the Ediacaran sedimentary sequences have indicated that a substantial DOC mass was developed in the stratified ocean after the Marinoan glaciation (655–635 Ma), and this was supported by the inorganic and organic carbon isotope profiles of the Doushantuo Formation in South China. The DOC mass was an oxygen consumer in the water column; however, it could have provided a food source for filter‐feeding animals such as sponges and cnidarians, and established a primitive food‐web. Such an ecological structure is recognized in modern deep‐sea coral mounds. Results from the integrated ocean drilling program (IODP) Expedition 307 for a mound in northeastern Atlantic suggested that organic carbon suspended around the density boundary in the water column is the key feature to feed the heterotrophic deep‐sea coral community. Our hypothesis is consistent with the fact that the two most primitive animal phyla (Porifera and Cnidaria) are filter feeders. The evolution of filter feeding ecosystems removed the DOC mass and may have contributed to ocean oxygenation in the terminal Neoproterozoic when animal evolution passed into the second stage, with the appearance of bilaterians.  相似文献   

A Methodology for Clustering Lakes in Alberta on the basis of Water Quality Parameters     

Tahir Ali Akbar  Quazi K. Hassan  Gopal Achari 《洁净——土壤、空气、水》2011,39(10):916-924

In this study, a methodology for clustering 18 lakes in Alberta, Canada using the data of 19 water quality parameters for a period of 11 years (1988–2002) is presented. The methods consist of (i) principal component analysis (PCA) to determine the dominant water quality parameters, (ii) cluster analysis techniques to develop the characteristics of the clusters, and (iii) pattern‐match lakes to determine the appropriate cluster for each of the lakes. The PCA revealed that three principal components (PCs) were able to explain ～88% of the variability and the dominant water quality parameters were total dissolved solids, total phosphorus, and chlorophyll‐a. We obtained five clusters for the period 1994–1997 by using the dominant parameters with water quality deteriorating as the cluster number increased from 1 to 5. Upon matching cluster patterns with the entire dataset, it was observed that some of the lakes belonged to the same cluster all the time (e.g., cluster 1 for lakes Elkwater, Gregg, and Jarvis; cluster 3 for Sturgeon; cluster 4 for Moonshine; and cluster 5 for Saskatoon), while others changed with time. This methodology could be applied in other regions of the world to identify the most suitable source waters and prioritize their management. It could be helpful to analyze the natural controlling processes, pollution types, impact of seasonal changes and overall quality of source waters. This methodology could be used for monitoring water bodies in a cost effective and efficient way by sampling only less number of dominant parameters instead of using a large set of parameters.  相似文献