STUDIES ON A HELIUM IONIZATION DETECTOR FOR GAS-CHROMATOGRAPHY

A new type of helium direct current plasma ionization detector (HeDCPID) for gas chromatography has been developed. The detector is simple in construction and can function with helium as the carrier gas without the need to subject the helium to excessive purification procedures. The noise level of the HeDCPID was below 1.2 x 10(-13) A when a stable plasma was obtained at an applied potential of 1200 V. Preliminary experiments indicate that the HeDCPID can detect all compounds and it appears to be extremely inexpensive to fabricate. The performance of the HeDCPID was evaluated in terms of the sensitivity for hydrogen, oxygen, nitrogen, and other gaseous substances. The sensitivities to these gases were shown to be in the range of 10(-13)-10(-11) g/ml. (C) 1995 Academic Press, Inc.