ON THE INFLUENCE OF NITROGEN AND OXYGEN ON THE GD-OES ANALYSIS RESULTS

The effect of nitrogen and oxygen impurities in argon on the analytical line intensity of various elements and other discharge parameters of a dc glow discharge has been studied. The two gaseous impurities were introduced into the discharge gas argon as molecular gaseous additions as well as sputtering products from the samples. Both elements may initiate chemical reactions in the plasma leading to a reduction of the number of free atoms of the determined elements available for excitation in the discharge plasma. Considering the main components of the investigated sample, nitrogen or oxygen contents exceeding the critical threshold of about 0.1 mass-% may alter the analytical line intensities of the elements of interest significantly. The effect of smaller gaseous impurity contents could be detected only by the determination of the emission yield. The line intensity may increase or decrease depending on the elements present in the discharge plasma.