An evaluation of a gas chromatographic electrolytic conductivity detector system (Hall detector) was conducted for the determination and confirmation of selected organochlorine pesticides at sub-ppm concentration levels in human biological extracts. The sample extracts were also analyzed with electron capture gas chromatography for comparison purposes. The linear regression lines for both sets of data were calculated by the least squares method. A high degree of correlation between the data sets was found. Also evaluated as part of the electrolytic conductivity detector system was a column with Carbowax 20M bonded to the surface of the support. The effect of repeated injections of extracts with a high content of lipids on the performance of the Hall detector and column was investigated. Gel-permeation chromatography was found to be valuable as a technique for additional clean-up of certain extracts having an adverse effect on the performance of the Hall detector due to excessive lipid material.