*2.4.3. Analysis of total bismuth in seawater*

The general procedure for the extraction and recovery of bismuth (III) ions from seawater samples onto PQ+.Cl impregnated PUFs was performed as follow: A 100 mL of water samples were filtered through 0.45 μm membrane filter, adjusted to pH zero with H2SO4 (0.5 mol L-1) in the presence of KI (0.1%w/v) and ascorbic acid. The sample solution was then passed through PQ+.Cl impregnated PUFs (1.0 ± 0.001 g) packed column (10 cm x 1.0 cm i.d.) at 5 mL min.-1 The retained bismuth(III) species were then recovered and analyzed as described above. The recovered bismuth (III) ions were then determined by ICP-OES.
