Determination of chlorine by InCl absorption spectrum in carbon tube atomizer

Abstract

Absorption spectrum of InCl in carbon tube has been measured in the UV region with a Jarrell-Ash AA-1 MARK II atomic absorption spectrophotometer and SLA-100 carbon tube atomizer. D2-lamp was used as a continuous light source and argon gas was employed as an inert sheath gas. The aqueous solution (5μl) which contains 0.4 mM indium nitrate and 50 mM ammonium chroride was introduced into the carbon tube and absorbance at the atomizer step (ca. 2690°C) was measured by shifting the wavelength every 0.1 nm between 264 nm and 269 nm step by step. As shown in Fig.1, the spectrum consists of absorption peaks at 267.2, 266.1 and 268.4 nm. Among them, the absorption peak at 267.2 nm, the strongest one, was used for determination of chlorine. As shown in Fig.2, the working curve (028.4μg/ml chlorine) was proved to be linear in the region of 07.1μg/ml chlorine.