[mir]

I am looking for a reductant to "kill"/quench my hydrogen peroxide in ethyl acetate, without destroying a quinone in my sample.

Sodium Thiosulphate is to powerful, and reduces the quinone to hydroquinone very easily.
I have thought of Sodium Sulphite, but I need to order it, and there is no time.
Catalase is a protein that is produced commercially, very effective but only works in water solution.
I was thinking of Sodium Nitrite, would that work?
Or maybe a iron compound?

Have you any suggestions?

[Borek]

What about some catalytic decomposition, with - say - MnO₂?

[AWK]

Many enzymes (especially immobilized on polymers) also work in organic medium

[mdlhvn]

You want to get quinone? Why do you extract quinone using an appropriate solvent.

[Ψ×Ψ]

You want to get quinone? Why do you extract quinone using an appropriate solvent.

Quinones (at least the ones I work with) tend to be painfully insoluble.