Some observations concerning preparation and storage of stream samples for dissolved inorganic phosphate analysis

The influence of storage conditions and duration of storage was studied by using about 100 stream samples from Fall Creek collected near Ithaca, New York. Freezing and refrigerated storage were found to be unsatisfactory, since changes in measured concentrations were usually observed after relatively short periods of time (24 hours). An isobutanol extraction procedure is described which minimizes storage problems and is useful for routine analysis of water samples for dissolved inorganic phosphate.