| 摘要 |
PROBLEM TO BE SOLVED: To keep quality of high purity hydrogen peroxide water by controlling elution of impurities from a vessel and generation of a particle by a method wherein the vessel is washed with hydrogen peroxide water of which each metal content is a specific wt.ppt. SOLUTION: A polyethylene vessel is filled with about 31 wt.% of hydrogen peroxide water having 10 wt.ppt or under of each metal content, i.e., about 8 wt.ppt of aluminum, about 8 wt.ppt of calcium, and about 5 wt.ppt or under of the other metals, and allowed to stand at about 20 deg.C or under for about 60 hs. Hydrogen peroxide water is extracted, and that is filled with high purity hydrogen peroxide water of about 5 wt.ppt of aluminum, about 5 wt. ppt of calcium, about 5 wt.ppt or under of the other metals, and about 31 wt.ppt of about 20 particles/ml in the number of particle of about 0.2μm or over, and allowed to stand for about one month. Thereafter, the high purity hydrogen peroxide water is extracted, and each metal content and the amount of particles are measured. The result becomes about 6 wt.ppt of aluminum, about 6 wt.ppt of calcium, under about 5 wt.ppt of the other metals, and about 25 particles/ml in the number of particles.
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