<<Disclaimer: Verify this information before applying it to your situation.>>

It's difficult to be totally grain-free.  So I'm not.  Every four days I
eat foods with some grain protein in them.  Things sweetened with cane
juice,  maltodextrin from corn, molasses from sugar cane.  I figured that
if I have an intolerance to these, it would show up in time, eating
something only every four days should be seldom enough for the intolerance
to unmask itself.  I haven't noticed any reactions.  I do eat fructose
every day, though.  Fructose is made from corn in the USA.  Maltodextrin
or something from corn goes through a chemical reaction that results in
fructose, then the fructose is purified out chromatographically i think.
So crystalline fructose is highly purified.

I wonder if it's still possible though, that the trace amounts of corn
protein in the fructose might be keeping reactions to the cane juice etc.
masked.

I'm very sensitive to corn apparently.  A few months ago I bought some
chicken in sauce.  Then i saw there was corn protein in the sauce.  So i
washed it well, there were tiny amounts of sauce left in interstices of
the chicken.  And ate it.  And I was sick for days.  But i'm sure that
small as the amount of corn protein was that caused *that*, the amount of
corn protein in crystalline fructose is far less.

Is non-grain-source fructose available?  I read that it's available in the
UK.

*Please provide references to back up claims of a product being GF or not GF*