Neutron activation analysis of water samples

Analysis of trace element concentrations in natural waters is useful in geochemical and pollution studies. NAA is most preferred for this purpose because of its simultaneous determination of a great number of trace elements with high sensitivity and accuracy. Some of these trace elements, however, may occur at very low concentrations, and the high Na, Cl, Br contents produce an extremely high background, interfering with determination of short- and medium-lived radioisotopes. Hence, enrichment of trace elements of interest (evaporation, chemical separation) and removal of interfering elements are generally employed prior to neutron irradiation. Drawbacks of radiochemical separations after neutron irradiation are discussed. Nuclear properties of isotopes utilized for NAA and elemental concentrations in natural waters are tabulated. 125 refs, 8 tabs, 5 figs