In the case of inductively coupled plasma atomic emission determination of gallium in metallurgical materials, matrix components can have a significant influence on the determination results. In addition to matrix spectral interference, there may also be non-spectral interference from macrocomponents. The element present in the discharge plasma at high concentrations can lead to a change in the conditions for excitation of the emission spectra, which will lead to a distortion of the intensity of the spectral lines of gallium. It has been established that the spectral lines of gallium are not free from spectral overlap from macrocomponents (iron, chromium, molybdenum, tungsten, nickel and cobalt). As a result, experimental study of non-spectral interference using gallium spectral lines is impossible. Using thermodynamic modeling, a quasi-analyte element was selected, which was proposed to be used to study the non-spectral matrix effect on the analytical signal of gallium during its atomic emission determination with inductively coupled plasma. Indium was proposed as a quasi-analyte. Based on the results of thermodynamic modeling, it was established that when varying the operating parameters of the atomic emission spectrometer (plasma temperature, argon and aerosol flow rate), the spectral behavior of gallium and the proposed indium quasi-analyte in argon plasma is similar. In this case, there is no spectral interference from the quasi-analyte on the spectral lines of gallium, and the increase in the value of the matrix interference estimate observed in some cases is random, which may be due to the time drift of the operating parameters of the atomic emission spectrometer. Thus, it is proposed to use indium as a quasi-analyte for the experimental study of non-spectral interference from matrix components (iron, chromium, molybdenum, tungsten, nickel and cobalt) instead of detectable gallium in metallurgical materials.