how to make concentrated hydrogen peroxide?

[ajkoer]

Before one separates the H2O2 out of Na2CO3.H2O2, sometimes the Na2CO3 can act like a base catalyst (for example, in the oxidation of ammonia to nitrite), so don't bother to remove it, use as is and keep it in its more stable form.

 

Also, l suspect given the sizzle (when one adds water to commercial oxygen bleaches), one really cannot extract the conc H2O2, as I would guess it is preset to decompose, and release O2 on contact with water, per its bleaching role.