Direct spectrophotometric determination of trace amounts of mercury(II) in aqueous media as its dithizonate complex in the presence of a neutral surfactant

Abstract

The spectrophotometric determination of mercury in aqueous solution as its dithizonate complex in the presence of Triton X-100, a neutral surfactant that renders both the ligand and the complex water soluble, is described. The molar absorptivity, specific absorptivity and Sandell sensitivity of the complex at the wavelength of maximum absorption (490 nm) were found to be 3.868 × 10⁴ l mol^–1 cm^–1, 192.8 l g^–1 and 5.2 ng cm^–2, respectively. Beer's law was obeyed between 1 × 10^–6 and 2 × 10^–5M Hg²⁺. The interference caused by the presence of a number of common cations and anions was studied and the method was applied successfully to the analysis of a mercury-based pesticide.