Determination of Ni,Co, and Cu in seawater by total external reflection X-ray fluorescence spectrometry

Total external reflection X-ray fluorescence spectrometry is a promising method for the highly sensitive determination of heavy metals in seawater, offering such advantages as the mobility of the used equipment and the low cost of analysis. Various methods of sample preparation to the analysis of seawater aimed at the elimination of interferences with the salt matrix were compared. It was shown that the method based on the preliminary extraction of metals as diehyldithiocarbamate complexes followed by back extraction is characterized by the highest efficiency. A procedure was developed for the determination of Ni, Cu, and Co in seawater with limits of detection at a level of 0.16–0.26 μg/L.