[Covek]

For years I have been using Home Depot denatured alcohol as a fuel reagent. I would mix Lanthanum nitrate, acetic acid and denatured alcohol to end up with a clear colorless solution. Last month when I mixed a colorless solution of La(NO3)3 + acetic acid with alcohol, the solution became pink. It wasn't an instantaneous reaction. It took 10-20 min for it to become pink. Any ideas?
If it is an organic contamination, I am fine. If it is a metal, I have an issue. I called the manufacturer, but they didn't want to admit any changes. 

[chenbeier]

Why not using absolute ethanol. Denatured alcohol can contain pyrimidin, methylethylketone, pentanole, and others.

[Covek]

Because of the fear. That is how we started the process and we are afraid to change it.
The only question for me is if the pink discoloration comes from a metal contamination or not. If it is some organic chelate with Lanthanum ions, that would be fine because it would burn in the flame spray and give La2O3.
Pink color appears after a few minutes upon mixing La nitrate and alcohol. Would that me an indication that a chelating reaction took place?