Development of a plasma emission gas chromatographic detector for the simultaneous, selective detection of chlorine, bromine and carbon

Abstract

A helium microwave-induced plasma (He-MIP) was used in combination with oscillating interference filters as an element-selective detector for capillary gas chromatography. Spectral selection of the MIP radiation was achieved only by narrow band optical interference filters, without installation of a monochromator system. Oscillating optical filters were introduced into this system to register photoelectric signals with the aid of a lock-in amplifier and the modulation technique. A preliminary characterisation of this detector was carried out by investigating the selective and linear behaviour and determining the detection limits. Further, chromatograms of multi-component mixtures were recorded by multi-element detection using several filters and the introduction of a beam-splitting light-guide optic. In addition, tentative experiments, designed to examine the possibility of empirical formula measurements, have been demonstrated by two examples.