hydrogen/deuterium exchange

initialism: HDX
https://doi.org/10.1351/goldbook.12427
Exchange of hydrogen atoms with deuterium atoms in a chemical species in solution prior to introduction into a mass spectrometer, or by ion/molecule reaction with a neutral gas inside a mass spectrometer.
Source:
PAC, 2013, 85, 1515. (Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)) on page 1547 [Terms] [Paper]