Temporally Resolved Boltzmann Plots and Excitation Temperatures of Iron Atoms in a Helium Radiofrequency Atomization/Excitation Source for Atomic Emission Spectrometry

Abstract

A polychromator that allows simultaneous measurements of the emission intensities of multiple lines with different excitation energies was constructed. Thus, temporally resolved Boltzmann plots of iron atomic levels became measurable. The polychromator was applied to a helium radiofrequency atomization/excitation source that was developed for direct determination of trace elements in liquid and solid samples of small size. To examine the excitation characteristics and the nonthermal equilibrium in the plasma, temporally resolved excitation temperatures on low and high energy levels of iron atoms and of iron ions were calculated. The observed results indicate that the excitation temperatures fluctuate depending on the change in plasma density and sample vaporization.