Determination of Trace Metals in Seawater by Graphite Furnace Atomic Absorption Spectrometry after Preconcentration Using Synergistic Extraction

Trace Cd, Mn, Pb, Co, Ni, and Cu have been quantitatively separated and concentrated from seawater matrices with a low concentration (mmol dm−3 level) of 1,1,1-trifluoro-4-mercapto-4-(2-thienyl)-3-buten-2-one and trioctylphosphine oxide cyclohexane solution. The synergistic extract was directly injected into the furnace and a reproducible signal with little memory effect was obtained. The extracted adduct enhanced the AAS sensitivity during thermal decomposition processes, and simultaneously resulted in depression of the interferences. The detection limits of the analytes ranged from several ng dm−3 to 100 ng dm−3. The proposed technique provides both the preconcentration and determination for trace analysis by a single extraction using a small volume of sample. Coastal seawater samples were analyzed by the method