It is prepared by oxidation of ethylene sulfide with periodate. Iodate can be obtained by reducing a periodate with a sulfide. Cleavage reactions proceed via a cyclic intermediate called a periodate ester. The oxidants most used are ozone, sodium periodate, mCPBA, and peracetic acid. Sodium periodate is an inorganic salt, composed of a sodium cation and the periodate anion. Oxidation of thiirane with periodate gives ethylene episulfoxide. Oxidation of thioanisole can be effected with periodate. Sodium metaperiodate can be prepared by the dehydration of sodium hydrogen periodate with nitric acid. Potassium periodate is an inorganic salt with the molecular formula KIO. Laboratory settings often use potassium ferricyanide or potassium periodate for the catalyst. "Ortho"-periodic acid can lose all its protons, eventually forming the periodate ion [IO]. Periodate is an anion composed of iodine and oxygen.