Determination of depleted uranium in human hair by quadrupole inductively coupled plasma mass spectrometry: method development and validation

Abstract

The presence of depleted uranium (DU) in the environment and its possible transfer to humans has been a matter of concern for the potential risks to human health. Depleted uranium has been used for military purposes in the last few years of conflict due to its great availability and low cost. Uranium content has been mainly determined in biological fluids, such as urine and blood. Human hair can be considered as a good alternative indicator of exposure to DU thanks to its ability of accumulating chemical elements over a long period of time. Determining the isotopic composition of elements always requires using a sensitive and precise analytical technique. In this regard, isotope ratio quadrupole inductively coupled plasma mass spectrometry was considered as a qualified analytical technique and consequently employed in the present study in combination with a desolvating sample introduction system. The method was in-house validated at three different levels of concentration of depleted uranium (50, 500 and 1000 ng/l) according to common standards and guidelines. The limit of quantification of the method in hair was 7.21 μg/kg with a within-laboratory reproducibility, in terms of variation coefficient, of 16.8, 6.1 and 5.5% for the three levels, respectively. A novel analytical approach was applied to the specificity studies for hair contaminated by DU with different background levels of NU.