Copper determination ETAAS

N. Campillo, P. Vinas, I. Lopez-Garcia, M. Hemandez-Cordoba, Direct determination of copper and zinc in cow milk, human milk and infant formula samples using ETAAS, Talanta, 46 (1998), 615-622. 

Copper. A high spread of results was observed in both steps 1 and 2 for copper, which was suspected to be due to the final determination rather than to the extraction procedure itself. Ca interferences were suspected to occur at the emission line used in ICP (324.8 nm) by one laboratory however, two other laboratories used the same emission line and did not observe such interferences. The University of Barcelona tested the likelihood for such interferences at the emission line of 324.754 nm and the presence of a high background signal was observed, which was confirmed by the addition of Ca to the calibrant solutions. The copper content was actually considered to be close to the determination limits for a number of laboratories, and the accepted sets of results (6 ETAAS, 1 ICP and 1 ICP-MS) were too low to draw any firm conclusions on the state of the art of steps 1 and 2 in this material. 

Lead. Ca interferences were again suspected to affect the signal when ICP-AES was used. This was verified by the addition of Ca to the calibrant solution, which yielded similar interferences. Here again the very low Pb content extracted in steps 1 and 2 in the second intercomparison hampered firm conclusions to be drawn. In the case of step 2, a very high discrepancy was noted between the ETAAS results and the FAAS results (one order of magnitude). However, all the FAAS results were actually recognized to be below the limits of determination and were consequently withdrawn. When ETAAS was used as the technique of final determination, the use of the matrix modifier was highly recommended. As for copper, the small number of accepted sets of data (5 laboratories of which 3 were ETAAS, 1 ICP and 1 ICP-MS) were found to be insufficient to draw any firm conclusions. 

The dual-column and single-column ion-exchange precoilcentration flame AAS systems as well as the DDC-Cis sorbent extraction flame AAS and ETAAS systems used for the determination of cadmium were also used for the determination of copper in water samples. The detection limit for the dual-column system was 0.07-0.09 /ig l at 60 samples h [7] for the sorbent extraction preconcentration flame AAS system, 0.2 /xg r at 120 samples h [9] for the sorbent extraction ETAAS system, 0.02 /xg 1 at approximately 20 samples h [10]. The sensitivity of sorption column preconcentration methods with flame AAS detection should be sufficient for the determination of copper in most natural water samples. 

O. Acar. Determination of cadmium, copper and lead in soils, sediments and sea water samples by ETAAS using a Sc + Pd + NH4NO3 chemical modifier. Talanta 65 672-677, 2005. 

N. Carrion, A.M. Itriago, M.A. Alvarez, and E. Eljuri. Simultaneous determination of lead, nickel, tin, and copper in aluminium-base alloys using slurry sampling by electrical discharge and multielement ETAAS. Talanta 61 621-632, 2003. 

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