Fernández Orsi Ricardo, Wuilloud Rodolfo G, de Wuilloud Jorgelina C A, Olsina Roberto A, Martinez Luis D
National University of San Luis, Chacabuco and Pedernera, Department of Analytical Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy, San Luis, Argentina.
J AOAC Int. 2002 Nov-Dec;85(6):1410-4.
An on-line cadmium preconcentration and determination system implemented with flame atomic absorption spectrometry (FAAS) associated with flow injection was studied. Cadmium was retained as Cd-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol Cd-(5-Br-PADAP) complex, pH 9.3. The Cd complex was removed from the knotted reactor (KR) with ethanol. A total enhancement factor of 140 was obtained with respect to FAAS (40 for KR and 3.5 due to the use of ethanol) with preconcentration time of 120 s. The detection limit value for preconcentration of 1 g sample was 0.5 ng/g. The repeatability for 10 replicate determinations at 5.0 ng/g Cd level was 3.5% relative standard deviation, calculated from peak heights obtained. The calibration graph using the preconcentration system for Cd was linear with a correlation coefficient of 0.9990 at levels near the detection limits to at least 2000 ng/g. The method was successfully applied to determination of total Cd in honey samples.
