Total reflection X-Ray fluorescence spectroscopy to study Pb and Zn accumulation in zebrafish embryos

Biotoxicity tests are used to evaluate potential harmful effects of chemical substances. Among them, zebrafish embryo toxicity test is a well-established procedure to study the negative effects of heavy metals. In respect to this, the measurement of the metal content accumulated in embryos during the toxicity test may help to understand adverse effects and identify target organs. However, because of the small masses involved, an analytical technique with high sensitivity is required. In this work, elemental chemical analysis of individual embryos was performed by means of total reflection X-ray fluorescence to study Pb and Zn bioaccumulation. A suitable protocol for sample preparation and total reflection X-ray fluorescence analysis was developed. At the end of fish embryo toxicity tests, zebrafish embryos exposed to Pb and Zn reference solutions or to leaching solutions of toxic and inertized municipal solid waste incinerator fly ashes were analyzed. A significant trend of bioaccumulation was observed for Pb with values one order of magnitude higher than the expected. Copyright (c) 2015 John Wiley & Sons, Ltd.