Are there TLC stains for organo fluor compounds or anorg. fluoride that are useful for selecting the product containing fractions post purification

Are there TLC stains that work with fluoride or with organofluor compounds? I have a fluorinated phosphonic acid that does not stain with conventional means. I did research in many of the known and available staining resources, but I did not find something reliable yet. KMnO4, Phosphomolybdic Acid (PMA) Stain and Cerium Molybdate Stain, p-anisaldehyde as well as Vanilla stain did appear not to work. Do you have experiences here? For me I was not able to see an unambiguously contrast to the background. Maybe there is also a protocol that decomposes an organofluor compound beforehand and makes fluoride visible on TLC? I performed many tests but nothing was really convincing until now. I know that a protocol for qualitative prove of F- uses chromic acid and the discoloration of alizarin dye - but this system is probably not applicable for TLCs.


