海水腐植质的基本化学组成研究

STUDIES ON THE FUNDAMENTAL CHEMICAL COMPOSITION OF HUMIC SUBSTANCES IN SEAWATER

于1992－1993年用1H－NMR，13C－NMR和IR等分析技术对甲基化前后的海水腐植质（1992年从青岛近岸海水中吸附提取）的基本化学组成和结构特征进行研究，并与风化煤和海洋沉积物中的腐植质作比较。结果表明，IR和1H－NMR谱图显示，海水腐植质主要由脂肪链化合物组成，含有一定量的肽类和多糖，芳香结构较少。采用NNE技术的13C－NMR谱图中各类碳的相对含量为：脂肪族碳，33．2％；脂肪族连氧、氮碳，16．3％；多羟基碳，33．7％；芳香碳和连氧芳香碳，7．5％；醌基和羰基碳，9．3％。

The fundamental chemical composition and structural features ofthe humic substances (HS) in seawater (collected from Qingdao coast) before andafter methylation were investigated by using 1H-NMR, 13C-NMR and IRspectroscopy in 1992 - 1993. Comparative studies on the HS from weathered coaland marine sediments were conducted. The IR spectra showed that the HS inseawater are mainly composed of aliphatic compounds, and also contain somepeptides, polysaccharides and less aromatic components. However, the HS fromweathered coal contain more aromatic components and the HS from marine sediments contain more peptides. According to the integral areas of absorption bandsin 1H-NMR spectra, the ratio of aromatic to aliphatic hydrogen atoms of theHS in seawater was calculated to be 0.19, which conformed with its highaliphatic and low aromatic feature shown in IR spectra. The 13C-NMR spectrawith the use of NNE technique indicated the relative contents of various carbon at -oms:aliphatic carbon (CH3, CH2, CH and C-)(6.0 - 47 ×10-6) 33. 2%,aliphatic carbon linking oxygen or nitrogen (47 - 66 ×10-6), 16. 3%, polyhydriccarbon (66 - 108×10-6), 33. 7%; aromatic carbon and ones linking oxygen(108-167×10-6), 7.5%, as well as quinone and carbonyl carbon (167-187×187×106),9. 3%. These results provide important scientific bases for the simulated synthesisof the HS in seawater and for research on their formation process.