Helium direct current discharge ionization detector for gas chromatography

A novel helium direct current discharge ionization detector for gas chromatography (GC) has been developed. Two platinum electrodes are applied to sustain the discharge. Helium was used as both the GC carrier and the discharge support gas. The effects of configuration and operational conditions on the response characteristics of the detector were studied. The analytical performance of the detector for the determination of some permanent gases such as H-2, N-2, O-2, Ar, CO, CO2 and CH4 was proved to be ideal. The detector has the advantages of high sensitivity, good stability, little dependence on the purity of helium, and extremely simple configuration and structure. The analytical figures of merit were shown to be comparable with those of the conventional helium ionization detector and the discharge ionization detectors. Also, the ionization mechanism of the detector was investigated. Furthermore, some practical sample analyses were done and the results were satisfactory.