Problems exist in marine analytic chemistry to determine dissolved organic nitrogen (DON) which is present in small quantities in sea water, in various molecular forms and for almost 90% is of unknown structure.
Present detection methods are not very precise. They involve mineralisation of the ionic organic constituents followed by electrochemical or by spectro-colorometric analysis. In this project a method will be used where the mineralisation in the sodium hydroxide phase in a hydrogen atmosphere does not reduce the nitrites and the nitrates so that a direct measurement of DON is possible, after subtraction of ammonia. A digestor, which allows for semi-continuous operations is connected to a rinsing extractor and a valve system, as well as a HPLC detector. In each of the three parts of the instrument, the solution will be chosen which will allow for the highest number of measurements, the smallest size, and the lowest weight, and which will lead to the smallest number of contaminated samples. This will allow the instrument to be used on board research vessels, thus allowing a large amount of measurements to be made at lower cost.
Funding SchemeCSC - Cost-sharing contracts
1790 AB Texel, Den Burg