The electrolytic efficiency of amperometric detection in normal-phase high-performance liquid chromatography

The electrolytic efficiency of the wall-jet detector in normal-phase high-performance liquid chromatography (between 0.1 and 5%) is significantly less than its efficiency in reversed-phase separations. A large-volume wall-jet cel with a Ag/Ag⁺ reference serves as the detector system in evaluating the effects of various chromatographic conditions on efficiency. Anthraquinone, phenanthrenaquinone (both at 10^-3–10^-4 M) and three estrogen gen steroids (at 10^-2–10^-3 M) are used as samples with ethanol/ hexane eluents. The effect of pH depends on the sample; increased ethanol concentrations and lower flow rates improve the efficiency.