Inelastic collisional deactivation of the analyte excited state is demonstr
ated as a dominant cause for non-spectroscopic matrix interference in induc
tively coupled plasma atomic emission spectrometry (ICP-AES) for commonly u
sed plasma operating conditions in routine analysis. A mathematical simulat
ion of the inelastic collisional model was examined. Comparison between the
theoretical model and experimental results using atomic and ionic lines of
the analytes Zn, Ba, Mg, Mn and Sr validates the inelastic collisional dea
ctivation model as a dominant cause for non-spectroscopic matrix effect. Ma
trices evaluated were NH4Cl, NH4SCN, (NH4)(2)SO4, and H2SO4 to represent di
fficult-to-ionize matrices (DIE) and NaCl and CaCl2 to represent easy-to-io
nize element matrices (EIE). (C) 1999 Elsevier Science B.V. All rights rese
rved.