I would like to remove free oxygen from mineral oil.  I use it for
vegetable matter preservation, and the presence of oxygen can allow
molding.

I have experimented using 'sacrificial' components to bind the
dissloved gas, and couled continue using that process with a better
sacrificial component.  Might also work to 'bubble wash' the liquid if
possible.  I just don't know what COMMON gas I could use.

Argon works better than nitrogen for the purpose, you can use CO2 also.

The proces will be faster if you put ultrasonic source into your oil
while passing the fine stream of gas though it. Alternatively you can
heat up the oil (it will reduce its viscosity and air solubility) but
it has to cool under inert gas afterwards.

Another simple procedure would be degassing using an efficient oil
vacuum pump - dual stage that produces 5 mTorr and good pumping rate
costs somewhere around $2000. So you would evacuate your oil, let it
bubble for a while under vacuum, let the inert gas (argon, nitrogen)
in and repeat the procedure 2 more times - this should be very
efficient.

For de-gassing solvents, the normal bubble-wash is Nitrogen, however
Argon works better.

For use with biodiesel (and analogues), which is susceptible to
oxidation by free, dissolved, atmospheric oxygen, the industry leading
edge is to add an anti-oxidant (seemingly obvious).  For your
application I would recommend trying Ascorbic Acid [Vitamin-C] (this
is the normal for Biodiesel) in catalytic amounts.

Hope this helps

Matt

Great ideas both, and thank you !

I don't have any Ascorbic Acid, but I DO have Citric Acid in my lab --
but I never thought citric acid (powder) would dissolve in the oil ...
  so I never tried it !

Does it for sure ?  

Or must it be mixed with... what ? 

Thanks tons for any help

Nicole

I already have a hydro-vaccum setup in the lab.... and for the life me
right now cannot remember its official name !!  Must be 'online
pressure' (grin).

Do you think that would suffice ?  I sure know it'll blister your finder !!!

N

I already have a hydro-vaccum setup in the lab.... and for the life me
right now cannot remember its official name !!  Must be 'online
pressure' (grin).

Do you think that would suffice ?  I sure know it'll blister your finger !!!

N

just remember if you add in a bubble wash, you'll still have gas
dissolved in the mineral oil.  it won't be oxygen though.