Sulfur Detection in Hydrocarbon Matrices. A Comparison of the Flame Photometric Detector and the 700A Hall Electrolytic Conductivity Detector

Abstract

The performance of the new Hall electrolytic conductivity detector (HECD), operated in the sulfur mode, as sulfur-specific gas chromatographic detector is compared to that of a flame photometric detector (FPD), with emphasis on organic hydrocarbon effects and interference. Specifically, linearity, limit of detection, hydrocarbon selectivity, hydrocarbon response quenching, and peak tailing are investigated and compared to each other and to various reference sources. The means of comparison is the use of two matched gas chromatograph, one with each detector, that sample a common gas stream. The limit of detection for each detector falls in the range of 1 to 6 × 10^-12 g sulfur/sec, with the HECD slightly more sensitive at 1 × 10^-12. Linearity of the HECD la at best 10⁴ compared to 5 × 10² for the linearized FPD. Selectivity of sulfur/hydrocarbon is greater than 10⁵ for both detector. The response quenching (due to hydrocarbons) of the FPD is considerably less noticeable in the HECD. Further, the naturally linear response of the HECD causes it to hold an advantage on detector peak tailing as compared to the FPD. In summation the Hall 700A electrolytic conductivity detector shows some performance advantages over the traditional flame photometric detector as a sulfur-specific detector for gas chromatography.