Abstrato

Preconcentration by a N,N‘-bis 2-hydroxy-5-bromo-benzyl 1,2 diaminopropane adsorbed on surfactant coated alumina before simultaneous determination of Pb and Cd by ETAAS

Ali Moghimi, Mohammad Amiri

A simple, highly sensitive, accurate and selective method for simultaneous determination of trace amounts of Pb(II) and Cd(II) inwater samples is presented. The method is based on selective chelation of Pb(II) and Cd(II) on surfactant coated alumina, modified with a SchiffÂ’s base N,NÂ’- bis 2-hydroxy-5-bromo-benzyl 1,2 diaminopropane (H2 L). The retained ionswere then elutedwith 4ml of 4Mnitric acid and determined by electro thermal atomic absorption spectrometry(ETAAS) at 283.3 and 228.8 nm for Pb and Cd respectively. The influence of flow rates of sample and eluent solutions, pH, breakthrough volume, effect of foreign ions on chelation and recovery were investigated. 1.5g of surfactant coated alumina adsorbs 40mg of the SchiffÂ’s base which in turn can retain 16.0±1.0mg of each of the two ions. The limit of detection(3) for Pb(II) and Cd(II) were found to be 5.89 and 1.78ng l-1respectively. The enrichment factor for both ions are 100. The mentioned method was successfully applied on determination of lead and Cd(II) in different water samples. The ions were also speciated by means of three columns system.