Hello, A friend of mine has synthesized a compound with pentafluorophenyl groups, and is willing to characterize it via an additional 19F-NMR. However, the person responsible for recording NMR spectra is inexperienced in 19F-NMR, so we need help on recording the spectra. We have trifluoroacetic acid, hydrogen tetrafluoroborate, aqueous KF and aqueous HF in our laboratory. In my searches, I have found that trifluoroacetic acid is a good candidate as a reference material. How can we use the compound as a reference? Our NMR spectrometer does not require TMS for 1H and 13C NMR, for example. So the operator knows almost nothing about using a reference material and expects knowledge from us. In the past, we attempted to record the spectra without a reference material, and the spectra contained peaks in the positive region, but literature suggests those values in the negative region. So we could not rely on the spectrum. What do you suggest? Thank you.