Measurement Methods Of Dissolved Organic Carbon In Seawater

At present, the domestic dissolved organic carbon (DOC) analyzers are dependent on the very expensive imported equipments,this affects the development of our marine survey to some extent.we focuse on the current field of marine science in China,the situation and needs of organic carbon analysis,have developed a UV/persulfate DOC analyzer, UV-persulfate principle, the oxidation of organic carbon into carbon dioxide, by non-dispersive infrared detector, According to the peak height or the peak area of the sample to calculate DOC concentration. It consists of six units: inorganic carbon removal unit, sampling unit, oxidation unit, cooling unit, liquid carbon dioxide separation unit and detection unit. The work includes equipment process design, software control, structure and layout, through a large number of repeated calibration experiments,we focuse on the discussion of the various optimized components.The instrument using different samples such as pure water, sea water, lake water, the Yangtze River water measured Its DOC, and In water samples with different concentrations of standard materials.The organic carbon analyzer detection limit 3.2μmolC/L,the relative standard deviation<10.0%,linear measurement range of 5.00-800μmolC/L, recovery:from 92.0% to 103%.The instrument and Shimadzu DOC (Theory of High Temperature Combustion Method) was compared with experiment, this UV-persulfate instrument measured value: high-temperature combustion measurement value=90%.The main features of apparatus:simple, be able to complete the on-line continuous testing of water DOC, stable performance, high degree of automation, human-computer interactive operation, low cost.