The separation of suspended particulate material into organic, mineral and organo-mineral fractions

A method for the separation of particulates in river waters into three chemically distinct fractions has been optimised and evaluated. The method involves centrifugation using heavy liquid density gradients with exclusion densities of 1.61 and 1.80 g/cm3. An artificial mixture of organic and mineral materials and a sample of river water particulates, have been fractionated using this technique. Compared to other fractionation techniques, the method involves little sample contamination, achieves separation of mineral free organic matter and is relatively cheap. Suggestions for improvements to the technique, further applications and possible uses are discussed.