Abstract
A comparative study of the sequential extractions procedures of Tessier and Meguellati has induced us to consider the readsorption problem on the sediment fractions always present during the actual extraction of a given phase. So, whatever the attack order may be, the readsorption leads us to minimize the first steps and to overestimate the last ones. Hence, it is not possible, (i) to compare fractionations sequences that are different, (ii) to use sequential extractions procedures, except for the first phase extracted in the presence of all the other ones, to estimate the sediment‐bound metals availability. The other applications of these schemes still remain valid.