| 摘要 |
PURPOSE: To produce a high purity hydrogen peroxide water in which metal based impurities, especially Al, Fe and Cr, are removed to <=2ppb, moreover to <=1ppb. CONSTITUTION: In the purification of the hydrogen peroxide water, an acid whose acidic dissociation index pKa at 25 deg.C in water is <=5 is added to the water in a ratio of 0.005-5meq. per 1L hydrogen peroxide water, then the hydrogen peroxide water is brought into contact with a H type highly acidic cation exchange resin having sulfo groups or a mixed bed of the H type highly acidic cation exchange resin having sulfo groups and a highly basic anion exchange resin. |
