A quantitative tunable element-selective detector for gas chromatography

Abstract

A detector based on the atomic-emission spectra that result when organic compounds are decomposed in a low-pressure, microwave-sustained helium plasma is described. All of the non-metallic elements normally found in organic compounds can be sensitively and selectively detected in a linearly proportional and quantitative manner by means of conventional diffraction grating spectrometer equipment. A controlled amount of a scavenger gas is used to prevent carbon deposition inside the plasma tube. The chromatographic column outflow is split between the element-selective detector and a non-selective flame-ionisation detector. The latter acts as a reference for interpreting element-selective detector results and assists with the determination of atomic ratios and the empirical formulae of organic compounds.