Don't know anything about RTM but I might offer a few suggestions.

If your release agent is silicone based and in sufficient amounts, you may try and image its location using SEM-EDX looking for Silicon. You may also try and determine it quantitatively by XRF on Silicon. All of this can be non-destructive but strongly depends on the nature of the samples you'll be looking at, so they're only suggestions. Other destructive techniques will include FTIR-ATR, ICP, MS, depending on your sample and how it can be analyzed and/or prepared for analysis.

If your sample is fluorine based, again you may use SEM-EDX at low kV to try and detect a little bit less than 0.1. % atomic Fluorine (went down to 0.05% on greaseproof papers). Destructive methods include mineralization of your sample by Schöniger combustion and quantification by specific F- electrode or ion-chromatography.

Hope that helps

Thank you very much for your sugestions Pierre.

I think your ideas can help but they are only recommendet for smale samples. I need Ideas for bigger parts.

Only technique I can think of would be LIBS for Silicon. Don’t expect it would work on Fluorine though.

Dear colleagues,

how are you?

Indeed, I do completely agree that LIBS would be a promising technique!

Moreover, based on the fact that changes of the wetting behaviour might occur due to transfer of release agents, also the larger-area aerosol wetting test (AWT) might be an option for detecting the presence of release agents (and for smaller coverages AWT might even differntiate bewteen distinct layer thicknesses of release agent).

I might indicate a publication following the subsequent link Article Nondestructive testing of contaminated CFRP surfaces with th...

What type of resin system, temperature, and realease agent are you currently useing?