Theoretical concepts of on-line liquid chromatographic-biochemical detection systems. I. Detection systems based on labelled ligands.

A theoretical foundation for on-line coupling of liquid chromatography (LC) with fluororeceptor assays based on fluorescent ligands is presented. Using a recently developed LC-receptor affinity detection (RAD) system as a model, equations are derived which describe the detector response and the signal-to-noise ratio as a function of important biochemical and instrumental parameters. The effect of ligand and label affinity, and receptor concentrations on the detector performance were investigated. It was found that the response of the RAD system is correlated with the affinity of the injected compounds and that the relative affinity order of binding ligands is maintained in the RAD system.