Abstract: A chromatographic system for rapid analysis of fluid components having a wide molecular range in a single sample is disclosed. A single isothermal oven having a switching valve controls the flow between a single column module and a dual column module. The single column module contains a shielded column with an input receiving components from a sample input and output to a detector via the valve. The dual column module contains two shielded columns wrapped adjacent one another on a single ring with separate inputs and outputs and in communication with one another and detectors through the switching valve. One or both columns in the dual column module can be heated and monitored with one or more sensor wires.