Formation of calcium monofluoride in graphite furnace molecular absorption spectrometry, part 2: interference mechanisms of chloride, bromide and sulfate salts

Abstract

In this study, the interference mechanisms of chloride, bromide and sulfate together with sodium in the determination of CaF by high resolution continuum source molecular absorption spectrometry were investigated. In order to differentiate gas phase and condensed phase interactions, Ca, F and the interferent were either mixed or separately pipetted on opposite locations of a solid sampling platform. It was assumed that when the Ca + F + interferent were mixed on the platform, both condensed phase and gas phase interactions occurred, whereas when the interferent was separated from Ca + F, they made contact only upon vaporization, and any interference was attributed to gas phase interactions. The results revealed that gas phase reactions were responsible for suppressing interferences in the CaF absorbance.