Chlorine-selective monitoring for high-performance liquid chromatography with a hall electrolytic conductivity detector

Abstract

Simple, inexpensive modifications have been made to a commercial Hall electrolytic conductivity gas chromatographic detector in order to utilize it for high-performance liquid chromatographic (HPLC) halogen (chlorine) selective monitoring. A portion (0.1–0.3 ml/min) of the column eluent was introduced directly together with hydrogen make-up gas into the heated quartz furnace of a Hall detector, the presence of chlorine-containing compounds in the solvent liberating hydrogen chloride, which was detected in the conventional manner by changes in electrolytic conductivity. Optimization of the detector parameters are described, important features being the length of the inlet tube protruding into the furnace, the furnace temperature and the electrolyte flow-rate. The detector was shown to be sensitive to 50 ng (1.4 ng/sec) of chlorine in chloroalkanes, eluted by reversed-phase HPLC with methanol-water solvent systems, giving a linear response over at least one order of magnitude (0.8–8.0 μ of chlorine). The choice of HPLC solvents was, however, limited to methanol and methanol-water mixtures, as with other organic solvents extensive carbon deposits accumulated in the detector furnace. Applications of the detector are illustrated by its use for monitoring the fractionation of vinyl chloride oligomers isolated from PVC resins.