Validation of High-Resolution Continuum Source Flame Atomic Absorption Spectrometry for Determination of Selected Toxic Metals in the Decontamination Process of Wastewater Discharged in Natural Receivers

A new method based on high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was validated for the determination of selected toxic metals in wastewater resulting from mining activity, compared to inductively coupled plasma optical emission spectrometry (ICP-OES) and line-source flame atomic absorption spectrometry (LS FAAS). The HR-CS FAAS method was characterized by detection limits (LODs) in the range (μg L–1) 1(Mn)–30(Pb), better than ICP-OES for Cu, Fe, Ni, Co, Pb and Mn, and poorer for Cd, Zn and Cr. Dunnett’s test showed that both methods were not affected by significant bias against certified values. The recovery in the HR-CS FAAS method was in the range of 98–103% with relative extended uncertainty of 9–18% and precision of 2–11%. Compared to LS FAAS, the HR-CS FAAS presented better LODs for Pb and Cr. The HR-CS FAAS method is suitable for determining selected toxic elements in filtered water samples without any chemical treatment.