Method for the determination of the priority pollutant metals by HPLC

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• The United States Environmental Protection Agency (EPA) relies on atomic absorption spectrophotometry for priority pollutant metals analysis.
• Atomic absorption spectrophotometry, while sensitive, has limitations for comprehensive metal analysis.

Purpose of the Study:

• To introduce and validate a novel analytical method for priority pollutant metals.
• To assess the efficacy of dibenzyldithiocarbamate (DBDC) complexation for metal separation and quantification.

Main Methods:

• Complexation of priority pollutant metals using dibenzyldithiocarbamate (DBDC).
• Separation of metal-DBDC complexes via liquid chromatography on a C18 column.
• Quantification using ultraviolet-visible spectrophotometry.
• A quaternary solvent system (methanol, acetonitrile, tetrahydrofuran, acetate buffer) was employed for separation.

Main Results:

• The method successfully determined ten priority pollutant metals: Cd, Cu, Cr, Hg, Ni, Pb, Sb, Se, Tl, and Zn.
• Beryllium was not assessed; silver and arsenic did not form DBDC complexes.
• Manganese was identified as a determinable interference, and cobalt was used as an internal standard.
• Detection limits ranged from 0.1 ppb for selenium to 1.8 ppb for thallium.

Conclusions:

• The DBDC complexation method provides a viable alternative for the analysis of several priority pollutant metals.
• This approach enhances the analytical capabilities for environmental monitoring of toxic metals.