Study of the factors influencing the detection of oxygen with gas chromatography-microwave-induced plasma atomic emission spectrometry

Abstract

A systematic study of the factors influencing the oxygen response of the microwave-induced plasma gas chromatographic detector is presented. Plasma gases studied included argon (with admixtures of helium and hydrogen) and helium (with admixtures of argon and hydrogen). The pure argon plasma is superior to any of the other plasmas. A comparison of analysis wavelengths indicated no difference between the signal at the O atomic line and the OH molecular band with regard to interferences. The response at the OH molecular band system was preferred because the signal was larger.

The results indicate that the sensitivity is limited by the presence of oxygen-containing species in the plasma gases. An optimised system can produce detection limits of 1 ng s^–1 with analytical-reagent grade gases.