2012 Volume 61 Issue 11 Pages 917-924
In recent years, some kind of air or pure-nitrogen atmospheric pressure thermal plasma, used as an ionization and excitation source for ultra trace elemental analysis, have been developed. The cost effectiveness will be dramatically improved if high-density and high-temperature air or nitrogen thermal plasma is realized. However, the temperature and analytical performances of air and nitrogen plasma are lower than conventional argon inductively coupled plasma (ICP). In order to improve the plasma properties, air-ICP with a nitrous monoxide gas additive was studied. The rotational temperature was mesured by using a spectroscopic method for nitrous oxide mixed air-IPC from 0 to 100 % of the nitrous oxide conditions; the rotational temperature was slightly decreased from 3200 K to 2700 K. Also, it was found that the plasma volume was enlarged by twice, and the atomic and ionic emission intensity values of the analyte were increased up to 1.5 times when 40 % of N2O gas was added compared to our usual air-ICP.
