The NOMiNiC project
This project consists of to parts:
- DOM intercalibration. 25 chemical laboratories in the Nordic countries determined the amount of organic and inorganic carbon in a set of 10 samples that included natural and synthetic fresh and isolated sample material. The results have been statistically interpreted by means of e.g. Youlden analysis. The intra laboratory precision (relative standard deviation) varied from 5 to 16%. Use of reverse osmosis isolates of DOM are recommended for use as a non-labile material the preparation of house standards and for determination of methods merits.
- Physico-chemical characterisation of Nordic DOM. DOM in spring and fall precipitation, throughfall, soil water and surface water from 5 Nordic sites has been determined for their main physical and chemical characteristics. DOM in surface waters have been reverse osmosis isolated and are being determined for numerous characteristics. The largest variation in the characteristics of DOM is between seasons and between the various water compartments in a site. Generally the hydrophobic acid fraction (HPO-A) was the main DOM fractions in all water compartments and sites. The DOM fractionation is therefore not a “fingerprint” of the site.