Determination of cadmium, copper and lead in soils, sediments and sea water samples by ETAAS using a Sc+Pd+NH4NO3 chemical modifier

Cadmium, copper and lead in soils, sediments and spiked sea water samples have been determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman effect background corrector using NH4NO3, Sc, Pd, Sc + NH4NO3, Pd + NH4NO3, Sc + Pd and Sc + Pd + NH4NO3 as chemical modifiers. A comprehensive comparison was made among the modifiers and without modifier in terms of pyrolysis and atomization temperatures, atomization and background absorption profiles, characteristic masses, detection limits and accuracy of the determinations. Sc + Pd + NH4NO3 modifier mixture was found to be preferable for the determination of analytes in soil and sediment certified and standard reference materials, and sea water samples because it increased the pyrolysis temperature up to 900 degreesC for Cd, 1350 degreesC for Cu and 1300 degreesC for Pb. Optimum masses of mixed modifier components found are 20 mug Sc + 4 mug Pd + 8 mug NH4NO3. Characteristic masses of Cd, Cu and Pb obtained are 0.6, 5.3 and 15.8 pg, respectively. The detection limits of Cd, Cu and Pb were found to be 0.08, 0.57 and 0.83 mug l(-1), respectively. Depending on the solid sample type, the percent recoveries were increased up to 103% for Cd, Cu and Ph by using the proposed modifier mixture. The accuracy of the determination of analytes in the sea water samples was also increased. (C) 2004 Elsevier B.V. All rights reserved.