Synonyms: Nickelate(1-), ((N,N'-1,2-ethanediylbis(N-((carboxy-kappaO)methyl)glycinato-kappaN,kappaO))(4-))-, potassium (1:1), (OC-6-21)-;Potassium nickel ethylenediaminetetraacetate;Nickelate(1-), ((N,N'-1,2-ethanediylbis(N-((carboxy-kappaO)methyl)glycinato-kappaN,kappaO))(4-))-, potassium, (OC-6-21)-;Potassium ((N,N'-ethylenebis(N-(carboxymethyl)glycinato))(4-)-N,N',O,O',ON,ON')nickelate(1-);dipotassium 2,2'-{ethane-1,2-diylbis[(methoxycarbonyl)imino]}diacetate