Indirect determination of inorganic chloride and of organic chlorine from chloroacetic acids, by flame atomic absorption spectrometry based on chromyl chloride formation

Abstract

An indirect method for the determination of inorganic chloride by measuring chromium at 357.9 nm by flame atomic absorption spectrometry (FAAS) through the production of chromyl chloride (CrO₂Cl₂) is proposed. The method has been extended to the determination of chlorinated acetic acids (CAA)[monochloro-(CAA), dichloro-(DCA) and trichloro-(TCA) acetic acid], by determining liberated chloride ion. Back-extraction at pH 12 allows the determination, under optimum conditions, of inorganic chloride and equivalent concentrations of CAA up to 30 µg ml^–1, with a detection limit of 0.12 µg ml^–1. The precision, accuracy, selectivity and reliability of the method are discussed.