PULSED DISCHARGE HELIUM IONIZATION DETECTOR UNIVERSAL DETECTOR FOR INORGANIC AND ORGANIC-COMPOUNDS AT THE LOW PICOGRAM LEVEL

The pulsed discharge helium ionization detector is a universal ionizat ion detector with sensitivity in the low picogram range. The response is approximately constant for saturated hydrocarbons on a per gram bas is. Unsaturated and aromatic hydrocarbons have lower sensitivities, by about 10-20%. Heterocyclic substituents such as oxygen, chlorine and bromine tend to lower the response on a per gram basis. The dependence of the response on various parameters such as pulse interval and powe r, voltage, flow-rate and detector volume has been investigated. The r esponse is linearly related to concentration over five orders of magni tude. The detector volume can be made small enough for high-speed micr obore chromatography.