University of California Water Resources Center

Development of a simple and inexpensive density gradient centrifugation method, utilizing silica so's, for separating and isolating various fractions of suspended matter and bottom sediments was begun. There is presently no effective means for fractioning suspended material in natural waters into its natural components. The technique will be especially useful and researchers in estuarine productivity and toxicology. The influence of preservatives and density shift reagents on the separating and resolving powers of the centrifugation method and the density shift reagents and preservatives on analysis of chlorophyll a, proteins, and carbohydrates was examined. Preliminary results indicate that the development of suitable methodology will require considerable additional effort. The technique has demonstrated that it is an important means of separating certain algal associations.