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Volume 46, Number 1
(January - February 2001) |
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Volume 46, Number 1
(January - February 2001) |
On-line Preconcentration Using an Amberlite XAD-16 Resin and Determination of Cadmium by Flow-Injection Inductively Coupled Plasma Atomic Emission Spectrometry
by H.A. Acevedo1, F.A. Vazquez1, R.G. Wuilloud2, R.A. Olsina2,3 and L.D. Martinez2,3
1Universidad
Nacional del Nordeste, 3400 Corrientes, Argentina
2Area
de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Univesidad
Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis
Argentina
3Consejo
Nacional de Investigaciones Cientificas y Técnicas
Key words: flow-injection, ICP-AES, preconcentration and determination, cadmium in drinking water samples, 5-Br-PADAP
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-bromo-
-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 mg
l-1. The precision for 10 replicate determinations
at the 5 mg 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 coefficientof 0.9995 at levels near the detection limits
up to at least 100 mg l-1.
The method was successfully applied to the determination of cadmium in
drinking water samples.
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