The Sensitive Spectrophotometric Method for the Determination of Cobalt with 2-(2-Quinolinylazo)-5-Diethylaminobenzoic Acid

摘要

A sensitive, selective and fast method for the determination of cobalt using 2-(2-quinolinylazo)-5-diethylaminobenzoic acid (QADEAB) as chromogenic reagent has been described. QADEAB reacts with Co(II) in acetate buffer (pH 4.0) and cetyl trimethylammonium bromide (CTMAB) media to form a violet complex of a molar ratio of cobalt to QADEAB equal 1:2. Its molar absorptivity at 630 nm is 1.4X10~5 L mol~(-1) cm~(-1). Beer's law is obeyed for cobalt concentration ranging from 0.01 to about 0.32 mug mL~(-1).