Determination of Cadmium at ultra-trace levels by CPE-molecular fluorescente combined methodology

MARÍA CAROLINA TALÍO; MARTA O. LUCONI; ADRIANA N. MASI; LILIANA P. FERNÁNDEZ

Mendoza

Congreso; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2008

Sociedad de Biología de Cuyo

Trace heavy metals are considered to be one of the main sourcesof pollution since they have significant effect on its ecologicalquality. Cadmium is very important in environmental and biologicalsciences; it is highly toxic even at low concentrations,causing damages to organs such as the kidneys, liver and lungs. Ahighly sensitive micelle-mediated extraction methodology for thepreconcentration of trace levels of cadmium as a prior step to itsdetermination by molecular fluorescence has been developed.Metal was complexed with o-phenanthroline (o-phen) and eosin(eo) in buffer Tris medium pH 7,6 and quantitatively extractedinto a small volume of the surfactant-rich phase of PONPE 7.5after centrifugation. The chemical variables affecting cloud pointextraction (CPE) were evaluated and optimized. The calibrationfor Cd(II)/o-phen/eosina was: y = 7 109 [Cd2+] + 4,635; R2 =0,9592; LOD: 3,90x10-3 mg L-1; LOQ: 0,013 mg.L-1 . The methodpresents good sensitivity and selectivity and was applied to thedetermination of trace amounts of cadmium in water samples withsatisfactory results. The proposed method is an uncommon applicationof CPE-luminescence to metal analyze, and comparable asfor sensitivity and accuracy to atomic spectroscopies.