INVESTIGATION FOR THE DETERMINATION OF ULTRA TRACE AMOUNTS OF CO2+ COMPLEXED WITH 1,10-PHENANTHROLINE BY ADSORPTIVE VOLTAMMETRY

The spontaneous adsorption of the Co2+ complex with 1,10-phenanthroline on HMDE was utilized for the development of a voltammetric analytical method employing phase selective alternating current, with first harmonic AC1 in phase, DELTA-phi = 0-degrees, voltammetry. The dependence of the analytical voltammetric response on physical and chemical parameters in various supporting electrolytes was investigated in detail. Optimum conditions for Co2+ determination were established. The method is very sensitive and selective. The determination limit is 205 ng/l Co2+ (adsorption time, t(ads) = 20 min). The precision and accuracy were evaluated: 1.84-mu-g/l Co2+, RSD = 3.24%, RE = -0.54%; for 205 ng/l Co2+, RSD = 4.85%, RE = -3.90%. The results showed good reproducibility and reliability. The method was applied to natural waters, wines, mussel tissue and aquatic algae certified reference material.