中国近海海水紫外吸收及直接用于测定海水COD

为探讨海水水质监测的简便可行方法，对渤海、北黄海、胶州湾、东海、长江口、南海及珠江口几百个海水样品紫外扫描发现，不同海区海水紫外吸收约在200～220nm之间。其中渤海、北黄海与胶州湾海水样品在208～210nm之间，而东海、长江口、南海及珠江口水样在205nm附近。海水紫外吸收吸光度与高锰酸钾法测COD值之间具有良好的线性关系。所以提出了用紫外分光光度法测定海水COD值的方法，发现紫外分光光度法与碱性高锰酸钾法测定海水COD值无显著性差异，可以满足快速监测的需要。

The Ultraviolet Absorptions of Seawater from Chinese Coastal Waters and Direct Determination of the COD of Seawater by Ultraviolet Spectrophotometry

The ultraviolet absorption of thousands of seawater samples from the Bohai Sea, the Northern Yellow Sea, the Jiaozhou Bay, the East China Sea, the mouth of the Yangtse River,the South China Sea and the mouth of the Zhujiang River was determined by ultraviolet spectrophotometry. The results show that all the absorption peaks appear between 200 and 220 nm. Or, to be more exact appear between 208 and 220 nm for samples from the Bohai Sea, the Northern Yellow Sea and the Jiaozhou Bay, and at about 205 nm for samples from the other waters. It is found that the results obtained by ultraviolet spectrophotometry and alkalescent permanganate titration for determining COD have a good linear relation, which indicates that the two methods have little difference in this regard. The method for determining the COD of seawater by ultraviolet spectrophotometry is introduced in the paper, which can meet the demands for rapid COD determination in scientific researches.