Effect of O2 in plasma gas on parameters of nitrogen MIP-OES

We studied the effect of O-2 content in the range of 0.1-1.2% in plasma gas on the plasma characteristics, the analytical signal and the intensity of the molecular species in nitrogen MIP. The plasma temperature decreases from 4.50 x 10(3) to 4.39 x 10(3) K with increasing O-2 content. The Mg(ii)/Mg(i) intensity ratio decreases from 1.14 to 0.90, and the electron density decreases from 1.16 x 10(14) to 0.85 x 10(14). The intensities of N-2, N-2(+) and NH decrease, and the NO and OH intensities increase when O-2 is added. The influence of O-2 content on the intensity of several atomic and ionic emission lines (covering E-sum values from 2.1 to 15.4 eV) of 12 elements has been studied. The intensity of atomic lines with E-sum values lower than 6 eV was enhanced in the presence of O-2 but it was suppressed for the ionic lines tested. It was shown that the O-2 addition leads to a decrease in the LOD calculated from atomic lines and to an increase in the LOD calculated from ionic lines.

Automated summary

The effect of O-2 content in plasma gas on plasma characteristics and molecular species intensity was studied. An increase in O-2 content led to a decrease in plasma temperature, Mg(ii)/Mg(i) intensity ratio, and electron density. The intensities of N-2, N-2(+) and NH decreased, while NO and OH intensities increased. The addition of O-2 enhanced atomic line intensities with lower E-sum values but suppressed ionic line intensities.