Utilizing temperature as an active parameter for optimization in chip-based liquid chromatography is an important step toward high-speed and high-efficiency separations on the microscale. A device including a low thermal mass micro thermostat and a microfluidic glass chip as central elements were designed and evaluated for maximal heating performance of up to 4.7 °C s-1 at up to 200 °C. With this enabling technology, high-speed separations in temperature gradient mode were performed both in common reversed-phase eluents and environmental friendly ethanol-based alternatives.