Role of auxiliary gas flow in organic sample introduction with inductively coupled plasma atomic emission spectrometry

Abstract

Auxiliary gas flow exerts a much greater effect on plasma properties with organic sample introduction than with aqueous sample introduction. Changing the auxiliary gas flow rate causes a major shift in the distribution of solvent loading in the plasma sample injection channel, which in turn influences the plasma excitation conditions, causing changes in excitation temperatures and height-resolved emission profiles. Observations of plasmas run with xylenes, amyl alcohol and carbon tetrachloride show that C₂ emission signals are the clearest indicator of organic solvent–plasma interactions, changing significantly both with solvent type and with operating power. The CN band emission also varies as plasma conditions are changed, but C atomic emission is least sensitive to changes in plasma conditions.