Re: Positive Test for Platinotype
Beakman (beakman@netcom.com)
Sun, 28 Apr 1996 18:17:35 -0700 (PDT)
> Place a tiny drop of hydrogen peroxide solution on a dark region of the print.
> (The hydrogen peroxide should be the ordinary domestic variety, so-called
> '10-' or '20-volume', i.e. 3% to 6%.)
> If the print contains a significant amount of platinum, the clear drop will
> turn white within a few seconds with minute bubbles of gas (oxygen) and may
> even effervesce ('fizz'). The platinum is unaffected, because this is a
> catalytic decomposition of hydrogen peroxide:
>
> 2H2O2 -> O2 + 2H2O
Ahhhh! I always wondered why my sensitizer fizzed when I added
the platinum solution, but not when I added the palladium. I put the
H2O2 in the shot glass first, then the palladium solution and then the
platinum solution. Thanks Mike!
David