[relliK]

Basically, I need to know if propylene glycol (PG) is soluble in an oil (olive oil as an example).

For more context, I'm getting an fragrant extract with PG as the solvent, and I want to dilute it with an oil. So if the PG solution isn't soluble, what should I do if I still want it to be in an oil?

I can't find any information on this, so it'd be great if someone could help. Thanks for reading, and I'm sorry if this question is too simple compared to other posts by you scholars.

[Arkcon]

What can you tell us about what you know about the structure of proplene glycol, and can you check the Wikipedia article for propylene glycol and make some inferences?

[relliK]

What can you tell us about what you know about the structure of proplene glycol, and can you check the Wikipedia article for propylene glycol and make some inferences?

From what I'm reading, it is soluble in water, diethyl ether, chloroform, and ethanol. It's an organic compound I haven't been able to make inferences on the compound. Do the hydroxyl groups have anything to do with miscibility in oils?

Also I like your profile picture!

[Enthalpy]

One useful classification among solvents is whether they're polar or not (and hydroxyls are a hint, yes).

The solvents you cited belong to one group. In which group would you put vegetable oils: the same, or the other one? This would give a hint (not always perfect) about the solubility.

The other approach is just to try, because both vegetable oil (can be a cheaper oil for this trial, like rapeseed) and propylene glycol are common and affordable.

[Archer]

Basically, I need to know if propylene glycol (PG) is soluble in an oil (olive oil as an example).

For more context, I'm getting an fragrant extract with PG as the solvent, and I want to dilute it with an oil. So if the PG solution isn't soluble, what should I do if I still want it to be in an oil?

I can't find any information on this, so it'd be great if someone could help. Thanks for reading, and I'm sorry if this question is too simple compared to other posts by you scholars.

I have seen how fragrance companies get around this issue. I was given two samples of fragrance, both smelled like 'Davidoff, cool water'.

One sample was soluble in polar matrices, gels etc. the other was soluble in waxes.

Both had very different GC profiles but totally indistinguishable to my nose

Smell receptors are much like any other endogenous receptor, the difference being aroma chemists like to refer to 'aromaphores' .

Your best bet for the result that you want is to mix the PG and the oil (small scale first). Mix thoroughly, if two phases are observed then you may be able to add a volume of water 3 x that of your PG solution.

This should remove a lot of the PG and force the aroma into the oil. The success rate of this is entirely dependent on the odour threshold of your aroma chemical as you need increasing volumes of oil vs PG to achieve a partition which vapours the oil rather than the aqueous.