PURPOSE: To prevent the loss of periodate and to obtain a high purity product in a high yield by treating sodium p-periodate with an acid in an aq. soln., separating formed sodium m-periodate crystals and adding alkali to the mother liquor.
CONSTITUTION: For example, 271.9g sodium p-periodate is suspended in 160.1g water and 102.9g aq. sulfuric acid soln. having 50wt.% concn. is added. The resulting suspension is heated to 100°C, allowed to stand for 30min and cooled to 20°C. Deposited crystals are separated by filtration and dried to obtain 195.1g sodium m--periodate. At this time, 329.9g filtrate contg. sodium m-periodate remains. This filtrate is mixed with 9.1g aq. sodium hydroxide soln. having 40wt.% concn., heated to 80°C, allowed to stand for 30min and cooled to 30°C. Deposited crystals are separated by filtration, washed and dried to obtain 23.7g sodium p-periodate crystals.
NAKAMURA MITSUO
KUWAZUKA TOSHIAKI
TANAKA YOSHINORI
