It is shown that the common practice of imaging the plasma directly onto the spectrometer entrance slit in analytical glow discharge optical emission spectrometry (GDOES) may induce analytical error when used with samples which are chemically heterogeneous. An alternative method for transferring the source emission to the entrance slit is demonstrated to eliminate the potential error, suggesting its routine use in analytical GDOES.
Michael R. Winchester, "Optically Induced Analytical Error in Glow Discharge Optical Emission Spectrometry," Appl. Spectrosc. 50, 245-251 (1996)