Metodología para la determinación de Hg en sedimentos y aguas empleando EAA

Abstract

The use of Hg in gold mining processes generates waste with a high content of this heavy metal, which can reach different aqueous media due to its constant discharge. According to the above, an analytical methodology for the determination of mercury (Hg) by Cold Vapor-Atomic Absorption Spectroscopy (CV-AAS) was validated taking into account the levels allowed by the EPA SW-846 standard for water samples and sediments. This work began with the implementation of Hg calibration curves and digestion processes to determine linearity, repeatability, and working range. The known concentration standards and real samples were evaluated under the typical analytical characteristics in the validation such as linearity, detection limit, quantification limit, precision, accuracy, repeatability, reproducibility, recovery percentages and uncertainty. The validated methodology met the required statistical parameters such as linearity and instrumental precision, registering variation coefficients less than 3%, a quantification limit of 0,35 µg/L and recovery percentages between 97,26 and 101,62%. A performance test was performed with reference samples to ensure reliable analytical results. Values ​​of uncertainties of ± 0,064, ± 0,0440 and ± 0,0410 were determined for liquid, solid and leached solid samples respectively.