Determination of total uranium content in surface seawater of the adjacent sea area of eastern Guangdong—using carbonate precipitation-laser-induced fluorescence method

This study presents a method for quantifying total uranium concentration in seawater utilizing a 50 g/L sodium carbonate (Na2CO3) solution as a precipitant, coupled with laser-induced fluorescence spectroscopy. The effects of sodium carbonate concentration and dilution factor on measurement accuracy were systematically evaluated. Application of this method to certified seawater reference materials yielded results within 5% deviation from certified values. High precision was confirmed by triplicate analyses of surface seawater sample. Employing this method for assessing total uranium in surface waters off the eastern Guangdong coast across four seasons revealed concentrations ranging from 1.83 μg/L to 2.25 μg/L. Spatial distribution analysis indicated humogeneity, with no significant seasonal variation observed.These findings suggest an absence of point-source uranium contamination and desmonstrate that anthropogenic activities exert no significant seasonal influence on total uranium levels in this marine environment.