The Photo-Conductivity Detector--A New Selective Detector for HPLC

Abstract

A new, sensitive, and selective detector for HPLC has been developed. By utilizing a postcolumn UV reactor coil to initiate photochemical reactions of the solute molecules and a differential conductivity cell to detect any ionic products formed, a sensitive response for halogenated compounds and many nitrogen- and sulphur-containing compounds has been achieved. Sensitivities for several compounds are in the low picogram range. The design of the detector and the theory of the photo-conductivity response are discussed. Examples of separations of halogenated benzenes, nitrosamines, and sulfonamides are shown, and the theory of operation and methods of system optimization are discussed.