Determination of Manganese in Sea Water and Common Salt by Atomic Absorption Spectrophotometric Method with 2-Hydroxy-1-naphthaldoxime Extraction

Abstract

An atomic absorption spectrophotometric method combined with 2-hydroxy-1-naphthaldoxime (HNA) extraction technique was studied for the determination of manganese in sea water and common salt. Manganese formed a complex with HNA, and was extracted into chloroform. The optimum conditions on the extraction of manganese were examined. The effect of coexisting diverse substances in the aqueous phase were also examined. The extract was decomposed with nitric acid-perchloric acid mixture, and then dissolved with 0.1 N hydrochloric acid. The resulting solution was sprayed into an acetylene-air fiame. Less than 10μg of manganese was quantitatively extracted into 10ml of 0.02 _M-HNA chloroform solution from aqueous solution at pH 10, by shaking for 10 min. When a known amount of manganese was added to the sea water samples, the manganese was recovered satisfactorily. The coefficient of variation was 2.4% at 10μg of manganese (n=10). Some samples of sea water, common salt and imported salt were analized.