Some kinetically based approaches were then proposed. The kinetic
fractionation is an extractive approach using a first-order
two-reaction model dividing the extracted metal by a chemical
agent into ‘‘labile’’ and ‘‘slowly labile’’ pools (Bermond et al.,
1998). Labile pools of Cd, estimated by this approach in a soil/EDTA
system, predicted bioavailable fractions in 11 un-polluted soil
samples