vapour phase interference

in analysis
Interference caused by a change in the fraction of analyte dissociated, ionized or excited in the gaseous phase. (Note: here 'dissociation' means the formation of free neutral atoms from free molecules in the gaseous phase. The term atomization is here not appropriate because the latter also covers the formation of free atomic ions.) These interferences may be called dissociation, ionization and excitation interference, respectively.
Orange Book, p. 171