On-line preconcentration using an amberlite XAD-16 resin and determination of cadmium by flow-injection-inductively coupled plasma atomic emission spectrometry

ACEVEDO, HUGO A.; VAZQUEZ, FRANCISCO A.; WUILLOUD, RODOLFO G.; OLSINA, ROBERTO A.; MARTINEZ, LUIS D.

Chemia Analityczna (Warsaw)

Chemia Analityczna (Warsaw)

Año: 2001 vol. 46 p. 59 - 67

An on-line cadmium preconcentration and determination system implemented with inductively coupled plasma atomic emission spectrometry (ICP-AES) associated to flow injection (FI) method was studied. For the retention of cadmium, 2-(5-broma-2- pyridylazo)-5-diethylaminophenol (5-Br-PADAP) and Amberlite XAD-16 were used, at pH 9.5. The cadmium was removed from the micro-column in countercurrent with nitric acid. An enrichment factor of 60 was obtained with respect to ICP-AES using pneumatic nebulization, for the preconcentration of 50 ml of sample solution. The detection limit value for the preconcentration of 50 ml of aqueous solution of Cd was 0.04 mug l(-1). The precision for 10 replicate determinations at the 5 mug l(-1) Cd levels was 2.0% relative standard deviation (RSD), calculated with the peak heights obtained. The calibration graph using the preconcentration system for cadmium was linear with a correlation coefficient of 0.9995 at levels near the detection limits up to at least 100 mug l(-1). The method was successfully applied to the determination of cadmium in drinking water samples.