HELIUM DIRECT-CURRENT DISCHARGE IONIZATION DETECTOR FOR GAS-CHROMATOGRAPHY

A novel helium direct current discharge ionization detector for gas ch romatography (GC) has been developed. Two platinum electrodes are appl ied to sustain the discharge. Helium was used as both the GC carrier a nd the discharge support gas. The effects of configuration and operati onal conditions on the response characteristics of the detector were s tudied. The analytical performance of the detector for the determinati on 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 sensit ivity, good stability, little dependence on the purity of helium, and extremely simple configuration and structure. The analytical figures o f merit were shown to be comparable with those of the conventional hel ium 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 satisf actory.