Study of the electrothermal atomization of selenium (IV) in transversely-heated graphite atomizers in the presence of nickel compounds as chemical modifiers

The electrothermal atomization of selenium, in transversely-heated graphite atomizers, was studied with regard to the effect of the addition of nickel nitrate and nickel chloride as chemical modifiers. Particular importance w as given to the behavior of the analyte in aqueous standards and in sodium chloride containing solutions, after thermal reduction of the modifiers pri or to the injection of the analyte solution into the atomizer. Thermal redu ction of either nickel compound brings about an enhancement in the sensitiv ity of selenium measurements, as compared to those obtained by the injectio n of both the analyte and the modifier together into the atomizer. Addition ally, thermal reduction of the modifiers permits the presence of chloride, as sodium chloride, to be tolerated in amounts as high as 500 mu g Cl- with sensitivity losses lower than 10%. (C) 1999 Elsevier Science B.V. All righ ts reserved.