hi everyone,

so i got some reagent liquids that are quite old.
what is the proper way of disposing them?

I guess you mean reagent liquids, rather than aqua regia.

Their disposal depends entirely on what they contain.

Acids and bases should be neutralised.

Hydrocarbons can be burnt or purified, likewise aliphatic alcohols.

Heavy metals, other toxic compounds or elements, and halogenated organics need to be dealt with by a proper waste disposal facility, although Fenton's reagent will get rid of chloroform or DCM well enough.

This is the briefest outline, I guess (hope) your implied lack of knowledge means you're not talking about anything really dangerous here.

http://www.cwu.edu/chemi...%20Safety%20Handbook.pdf

thank you,
i am pretty sure nothing really dangerous in these test kits.
they are just old Mecke, Ehrlich and Marquis

also i corrected the spelling error

Ah, I see. Test kit reagents. I should have inferred more from the layman speak - of course that's where you would see the word

To me, a reagent is pretty much anything that's used to take part in a chemical reaction besides the solvent.

So, those test kit reagents are strongly acidic.

Marquis contains formaldehyde which is toxic and nasty. Formaldehyde is quite easily oxidised to formic acid.

Mecke contains selenious acid which is also toxic and nasty. Selenium is a toxic element so it should really be disposed of properly. That said, it's only present at 1%, so 10mg/mL.

Ehrlich contains p-dimethylaminobenzaldehyde which is 'only' mildly toxic. Probably the least nasty of the three, it also contains ethanol which is, of course, flammable.

I would advise taking them to your local dump, which should collect hazardous waste chemicals without question. (Assuming you live in a country where this infrastructure exists.)