Facultade de Fisioterapia

Ultrasensitive determination of mercury in waters via photochemical vapor deposition onto quartz substrates coated with palladium nanoparticles followed by total reflection X-ray fluorescence analysis

Authors: Vanesa Romero, M. Gryglicka, Inmaculada de la Calle, Isela Lavilla, Carlos Bendicho

Journal: Microchimica Acta, 183 (1): 141-148, 01/2016

DOI: http://dx.doi.org/10.1007/s00604-015-1612-7

 

Abstract

We describe a method for ultrasensitive detection of mercury (Hg) by total reflection X-ray fluorescence following photogeneration of Hg vapor and trapping onto quartz substrates coated with nanostructured palladium. The nanostructured coating was characterized by transmission electron microscopy. Hg vapor was generated by online photo-UV reduction in the presence of acetic acid, which acts as a precursor for reducing species. Trapping of Hg occurred as a result of amalgamation. A trapping time of 30 min and an acetic acid concentration of 2 mol L−1 provided the best results. An enrichment factor of 127 and a limit of detection as low as 54 ng L−1 of Hg were achieved. The repeatability of the method (expressed as the relative standard deviation at a level of 1 μg L−1) was 3 %. The method was successfully applied to the determination of Hg in water samples spiked with 10 μg L−1 of Hg. Recoveries ranged from 96 to 101 %.