Enhancement of the Response of the Hydrogen Flame Ionization Detector to Compounds containing Halogens and Phosphorus

Abstract

A PROCEDURE has been developed for selectively increasing the responsiveness of a hydrogen flame ionization detector¹ to compounds which contain chlorine, bromine, iodine or phosphorus. The basis of operation of this detector is the increase in the electrical conductivity of a hydrogen flame which occurs when organic compounds are burned in the flame. It has been observed that if a wire, glass or ceramic probe which contains sodium is heated in the flame, the products of combustion of compounds which contain halogens or phosphorus increase the rate of release of sodium vapour from the heated probe. The sodium is then ionized by the flame. The relatively large increase in the electrical conductivity of the flame which results supplements the increase that is observed in the absence of the heated probe. Compounds containing these halogens or phosphorus may thus be distinguished from other compounds which may be present.