(Table 1) Heavy metal speciation in bottom sediments of the Black Sea

1) The first form is leached by a mixed acid-reducing agent [1 M hydroxylamine-HCl and 25% (v/v) acetic acid] following the procedure of Chester and Hughes (1967, doi:10.1016/0009-2541(67)90025-3).2) The second form is leached by 30% H2O2 solution (pH 2) following the procedure of Kitano and Fujiyoshi (1980; http://www.terrapub.co.jp/journals/GJ/pdf/1403/14030113.PDF).3) The third form is lithogenic (residue after two treatments).