Determination of barium in sea water by graphite furnace atomic absorption spectrometry after preconcentration and separation by solvent extraction.

The determination of barium at a trace level by graphite furnace atomic absorption spectrometry was described. The reproducibility was improved to 3.6 % by the use of pyrolytic graphite coated furnaces. Moreover, the preconcentration and separation of barium from sea water by solvent extraction were investigated and applied to the determination of barium in sea water by the graphite furnace atomic absorption spectrometry. Barium was quantitatively separated and concentrated from interfering elements in sea water by the use of a mixture of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one and tri-n-octylphosphine oxide as extractants, and the mean value of the recovery was 98.6 %. Barium in the Pacific Ocean surface water was determined and 5.6 μg dm -3 was found.