The metal coil or packed trap is then rapidly heated and the collected contents pass into column 2 for separation and detection by detector 2. This type of system can be used with temperature programming if so desired and can handle very complex multi-component mixtures.

The flow through column 1 can be arrested after trapping the solutes of interest and, after the trapped sample is separated on column 2, the flow through column 1 can be started again and a second fraction collected if so required. In fact, this procedure can be repeated as many times as is appropriate.

Figure 25. Apparatus for Heart Cutting, Stage 2