Comparison of different methods for uranium determination in water.

Photometry, laser photometry, liquid scintillation (LSC), gamma spectrometry and alpha spectrometry were used for estimating waterborne uranium concentration. The chemical procedures applied were pre-concentration, liquid extraction, chromatographic resin extraction and precipitation. Our results show that laser photometry is an easy and accurate method capable of estimating low uranium concentrations, parts of micrograms per litre. It is not applicable for higher concentrations, difficult water matrixes and isotope determination. The classical photometry is complementary, resolving the problem related to high concentrations, practically up to 10 mg/l. Alpha and gamma spectrometry resolve the problem of precise isotope determination, but with the disadvantage of hard chemical preparation and long measurement times. An intermediate method is LSC, with the problem of isotope estimation, due to poor energy resolution.