abstract |
A chelating agent of the embodiment is an amide compound in which a hydrogen atom of an —NH— site or an —NH 2 — site in an amine compound is substituted with a functional group derived from diglycolic acid. The amine compound is selected from the group consisting of a compound represented by a following general formula (1) and a polyethyleneimine having a molecular weight of 200 to 100,000. In the general formula (1), x, y and z respectively represent a number of repetitions for —CH 2 —CH 2 —NH—, x represents an integer of 1 to 10, y represents an integer of 0 to 5, and z represents an integer of 0 to 5. |