Inductively coupled plasma optical emission spectrometry (ICP-OES) operated in axial-view mode and cold plasma conditions was investigated as a strategy for the measurement of rubidium to suppress the spectral interferences from argon emission lines. Dependences of the rubidium signal and the argon interferences on the radio frequency power and the carrier gas flow rate were studied. At the non-robust condition, signal-to-background ratio was improved by around 20-fold in comparison to that obtained at conventional robust condition.