“…It has been reported (1,2,5,6) that several metal ions, including nickel, have been successfully titrated with disodium dihydrogen (ethylenedinitrilo)tetraacetate (EDTA)-a stable solution. Furthermore, EDTA is reported (2) to . 'Nickel present after dissolution of nickel dimethylglyoximate obtained from 0.1gram sample of NBS 102.…”