RESUMO
Natural uranium exists in earth crust and seawater. The concentration of uranium might increase by human manipulation or geological changes. The aim of this study was to verify susceptibility of laser flourimetry method to determine the uranium concentration in Caspian Sea and Persian Gulf water. Laser flourimetric method was used to determine the uranium concentration in several samples prepared from Caspian Sea and Persian Gulf water. Biological and chemical substances were eliminated in samples for better evaluation of the method. As the concentration of natural uranium in samples increases, the response of instrument [uranium analyzer] increases accordingly. The standard deviation also increased slightly and gradually. Results indicate that the laser flourimetry method show a reliable and accurate response with uranium concentration up to 100 micro g/L in samples after removal of biological and organic substances