Atomic Absorption Interferences Using a Tantalum Boat Atomizing System

Abstract

A tantalum boat was used to study interference effects for the elements zinc, copper, manganese, iron, and sodium. The maximum absorption signal depended on the temperature of the boat and on how long a particular temperature was applied. The parameters were different for each element. Calibration curves for zinc, copper, and manganese differed for the different anions with which they were associated. For anions studied (chloride, nitrate, and sulfate), chloride in each case produced the largest absorption signal for the metal atom. Absorption responses of zinc, copper, and manganese were studied in the presence of a series of added ions: Na⁺, Ca²⁺, Fe²⁺, Mg²⁺, Cu²⁺, SO₄²⁻, and PO₄³⁻. The effects of all except Ca²⁺ and PO₄³⁻ were negligible. Ca²⁺ and PO₄³⁻ caused the largest signal depression, although SO₄²⁻ also caused some. As the temperature of the tantalum boat was increased, the interference effect decreased but did not vanish. The absorption signal of Na⁺, studied in the presence of Li⁺, Rb⁺, and Cs⁺, was enhanced slightly in each case, but the effect was less than that observed for the same systems when aspirating a liquid sample into a flame cell.