The present invention provides systems for isolating toxins and collecting an eluate from a sampling column for subsequent testing and to methods of extracting and collecting an eluate using the same systems. Preferably, the systems comprise a sample holder such as an immuno-affinity column for holding the sample and a self-contained fluid delivery system that can deliver liquid, e.g., reagents, and gaseous fluids, e.g., compressed air. More preferably, the fluid control system of the fluid delivery system provides some amount of pressurized gas continuously to the headspace of the column even when a fluid is not being forced through the resin gel in the column.