you posted a too vague question. At first:

- what a kind of molecule(s) ( bio-molecules , proteins…)is or are labeled or will be labeled

? Please define the conditions of the exchange. According to the structure, there are p.e. (grossly) 3 types of hydrogens:

-non exchanging

-fast exchanging

-slow exchanging

In what a solvent are you working ?

H+ and OH- can affect the exchange. the rate in this case is the slowest at pH 2.5 and increases as the pH becomes basic.

The temperature affects the exchange too.

I synthesized for the first time the following nitrone :

Phenyl-tert-Butyl-d9- nitrone (see Thesis K. Sommermeyer /1975/ for details)

After the synthesis the small tert-butyl peak ( ca. 1,5 ppm/ Varian 60 MHz NMR spectrometer)in the NMR spectrum belongs to the partial and undeuterated methyl groups.

NMR is a possibility for the monitoring of the exchange during the synthesis.

You can earn Infos about the exchange e.g. quenching with NMR and tandem mass spectrometry.

JRG

I agree with JRG that the Q is too vague