I'm wondering if anyone here has any experience trying this. Here is a link to the type of filters I'm talking about. They filter down to 2.2 um and according to this paper many of the aluminum lake colorants like yellow lake 5 for example, are 5-10 um in size. So, theoretically it seems like these filters would work for taking out all these artificial colors. The real question is whether or not it would also filter out anything we want to keep in the flavor concentrates. I will be trying this out soon, but if anyone else already has, please weigh in!
it may be possible to precipitate it out of the solution. alkaline,acids,solvent or distilation
I am not sure, but I think the article you linked says "particle size" meaning the size of a grain of the dye powder. Even 5 micrometers would be 5000nm or 50000Å, which is far larger than the largest molecules (source).
Problem being that I doubt an individual molecule of the stuff is anywhere near the 200nm that the filters you linked are specced at. Seems worth experimenting with if you already have flavors with colorants that you wouldn't otherwise use.
Just out of curiosity what colors are you trying to remove?
I would assume that any flavor that contains added artificial coloring can be purchased without (IE LorAnn offers all of their flavors without coloring for the right order size). Other colors where they may contain a hint of caramel color but aren't artificially colored (Think FA Custard) I would assume the color is present because it can not be easily removed without jeopardizing flavor particles.
The very first flavor I'm going to try this on is Loranns Banana Cream, and I know you can order them without the coloring, but I have a bunch laying around. Plus, I'm mostly just curious to see what will happen. If that works I'll move on to the other "naturally" darker flavors like chocolates and FA Custard like you said, just to see what happens. I agree that most of those will probably be harder to remove or they wouldn't be in there in the first place. The difference between the Aluminum Lake colorants and dyes are that the lakes color by dispersing in solution rather than bonding to other molecules like dyes, I imagine those naturally colored flavors have some bonding going on.
For making NET's this is what everyone does until they can afford a vacuum filter setup. Not for color though , molecules are nanometre size not micrometres, pretty huge difference. Your filtering out dust mites and chunks of dead skin cells not molecules of coloring agents.
You can also use bentonite , it's a powder clay used in brewing and wine making. Mix it with the juice and let it settle out then siphon off the top layer of remaining flavor concentrate , it pulls out lipids (waxes) amines (proteins) and for tobacco ejuice at least , it leaves flavor alone
That bentonite is interesting, I'll have to look into that. I think the filter thing is only going to work for flavors that are artificially colored with the aluminum lake colorants. Their particle size remain at 5-10 um because they're insoluble