Embodiments of an apparatus including a front-end pre-concentrator module including an inlet, an outlet, and at least one valve to control flow through the inlet, the outlet, or both. The apparatus includes a back-end pre-concentrator module including an inlet, an outlet, and at least one valve to control flow through the inlet, the outlet, or both, and also includes a gas analysis module having an inlet and an outlet and including a gas chromatograph having an inlet and an outlet. The outlet of the front-end pre-concentrator and the outlet of the back-end pre-concentrator are coupled to the inlet of the gas analysis module. Other embodiments are also disclosed and claimed.