Ultraviolet determination of cobalt (III) with EDDHA (Ethylenediam-ine N N' bis o-Hydroxyphenilacetic acid)

A method for the u.v. determination of cobalt with EDDHA is proposed. Between pH 4-7 the spectrum show and absorption maximum at 255 nm. The effect of amount of reagent, anount of oxidant, acidity, time and temperature have also been studied. Beer's Law is obeyed over the range 0.1 to 2,34 μg Co(III) mL-1 with a minimum photometric error of 3.0%. The molar absortivity was (2.71 ± 0.02) 104 L mol-1 cm-1. The reproducibility, precision, stoichiometry of the complex and interferences have been investigated. (Author)