Method for the determination of the priority pollutant metals by HPLC.

The United States Environmental Protection Agency (EPA) currently specifies atomic absorption spectrophotometry as the method of analysis for the priority pollutant metals. While the method is very sensitive, it does suffer from limitations. As an alternative, the use of dibenzyldithiocarbamate (DBDC) to complex the priority pollutant metals from the sample, with subsequent separation of the complexes by liquid chromatography and quantification by ultraviolet-visible spectrophotometry, is reported. Of the thirteen priority pollutant metals, ten can be determined with the method (Cd, Cu, Cr, Hg, Ni, Pb, Sb, Se, Tl, and Zn). Of the remaining priority pollutant metals, beryllium was not investigated, while silver and arsenic did not form complexes with DBDC. In addition, one potential interference, manganese, can be determined. Cobalt is added as an internal standard. Separation of the complexes on a C18 column is achieved with a quaternary solvent system consisting of 64% methanol, 12% acetonitrile, 5% tetrahydrofuran, and 19% pH 5 acetate buffer. Detection limits range from a low of 0.1 ppb (ng/mL) for selenium to a high of 1.8 ppb for thallium.