Simultaneous determination of mercury and selenium in fish by CVG AFS

In this work, an analytical method was proposed for the simultaneous determination of mercury and selenium in fish samples using Atomic Fluorescence Spectrometry (AFS). Multivariate designs were performed to evaluate the variables and optimize the best condition of chemical vapor generation (CVG) and simultaneous determination of mercury and selenium by AFS. Fish samples were prepared via acid digestion in digester block with cold finger reflux system, which ensured that the elements were not lost by volatility. The proposed analytical method was validated, and excellent figures of merit have been achieved, such as detection limits of 0.33 and 9.18 ng g−1 for mercury and selenium, respectively. The method was applied for simultaneous determination of mercury and selenium in canned sardines. Mercury concentrations ranged from 0.057 to 0.203 μg g−1 and selenium concentration from 1.76 to 2.21 μg g−1, providing a mean molar ratio (Se:Hg) equivalent to 36.