FLOW-INJECTION METHOD FOR DETERMINATION OF URANIUM IN URINE AND SERUMBY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

The uranium concentration in urine of a population that is not occupat ionally exposed to uranium compounds is in the range 1-40 ng l(-1) wit h a median around 10 ng l(-1). This is analytically challenging for ro utine analysis because at such low levels it is difficult to prevent c ontamination during sample preparation. The method presented here is b ased on sample introduction via a flow injection analysis system and i nductively coupled plasma mass spectrometric detection, and requires v irtually no sample preparation, except for acidification of the urine sample with a few drops of HNO3. The analysis is fully automated and f ast with an analysis time of 60 a per sample. The lower limit of detec tion is 1.5 ng l(-1). Memory and matrix effects may be decreased by ad ding 1 g l(-1) of a surfactant (Triton-X 100) to the carrier stream. T he validity of the results is demonstrated through measurement of stan dard reference materials, standard dilution experiments and, at higher concentrations, by comparison with results obtained by an independent method based on laser induced fluorescence.