โ Scribed by Walter A. Aue; Robert F. Moseman
No coin nor oath required. For personal study only.
A typical, pellet-type alkali flame detector was monitored photometrically. Its predominant (but not exclusive) mode of response is negative, i.e. alkali emission decreases when gas chromatographic effluents are burned in the flame. As a detector for organic halides, the optical emission of the alkali flame appears to simulate some characteristics of its more often used electrical conductivity response. For instance, it is possible to distinguish between chlorine, bromine and iodine, and the (negative) response for chlorides i.s proportional to the amount of chlorine entering the flame. Calibration curves for selected chlorinated hydrocarbons approach linearity on a logarithmic scale within two orders of magnitude, with minimum detectable amounts between 3-5 ng. Carbon compounds give signals approximately fifty times weaker than monochlorinated compounds. All characteristics considered, the pellet-type alkali source seems to differ considerably in its spectral behavior from other types of sources which have been described in the literature, especially those using a resistanceheated wire coated with sodium sulfate.
๐ SIMILAR VOLUMES
The coupling of an aerosol alkali flame ionization detector with high performance liquid chromatography is described. The design of a heated interface allows vaporization of the liquid mobile phase, which prevents extinguishment of a detector flame. Detection limits ranging from \(1.10 \mathrm{pg} \
## Abstract The effect of using ammonia as a carrier gas on the response of the flame ionization detector (FID) has been investigated. It was found that the FID response, calculated as the effective carbon number (__ECN__), increased for all the compounds studied when ammonia, rather than helium, w