The zinc ion is chelated by one histidine and three cysteines. IMAC enrichment is based on phosphate affinity for immobilized metal chelated to the resin. Chelated zinc is used in toothpastes and mouthwashes to prevent bad breath. Chelated minerals were developed in the 1980s and 1990s. For this purpose, samarium-153 is chelated with ethylene diamine tetramethylene phosphonate (EDTMP) and injected intravenously. Multiple second generation photosensitisers contain a chelated central metal ion. In the closed state, the metal center is fully chelated to both ligands. Organotitanate catalysts such as tetraalkoxy titanates or chelated titanates are used in alkoxy-cured systems. If the substrate Mn(II) is chelated with lactate, MnP instead catalyzes the evolution of O. Unlike photolysis, the chelated species is not exclusive to iron(III) in order to be degraded.