القابلية على الربط العضوي المعدني/ القابلية على استخلاب المعادن
from http://en.wikipedia.org/wiki/Chelation
Chelation (from Greek χηλή, chelè, meaning claw; pronounced [ˌki:ˈleɪʃən]) is the binding or complexation of a bi- or multidentate ligand. These ligands, which are often organic compounds, are called chelants, chelators, chelating agents, or sequestering agent. The ligand forms a chelate complex with the substrate. The term is reserved for complexes in which the metal ion is bound to two or more atoms of the chelating agent, although the bonds may be any combination of coordination or ionic bonds.

see this search
http://www.google.com/search?num=100&hl=en&lr=&safe=off&as_q...