Temperature Gradient Elution and Superheated Eluents in Chip-HPLC

Area of Science:

• Analytical Chemistry
• Separation Science
• Microfluidics

Background:

• Temperature control is crucial for optimizing liquid chromatography (LC) separations.
• High-speed and high-efficiency separations are desired in microscale LC.
• Existing methods for temperature control in microchip LC can be slow.

Purpose of the Study:

• To design and evaluate a device for rapid temperature programming in microchip liquid chromatography.
• To achieve maximal heating performance for enhanced separation efficiency.
• To demonstrate the utility of temperature gradient mode with various eluents.

Main Methods:

• Development of a device incorporating a low thermal mass microthermostat and a microfluidic glass chip.
• Evaluation of the device's heating performance, measuring heating rates and maximum temperatures.
• Application of the device for high-speed separations in temperature gradient mode using different mobile phases.

Main Results:

• The developed device achieved maximal heating performance of up to 4.7 °C s^-1 at temperatures up to 200 °C.
• High-speed separations were successfully performed in temperature gradient mode.
• The technology demonstrated effectiveness with both common reversed-phase eluents and environmentally friendly ethanol-based alternatives.

Conclusions:

• The novel microthermostat and microfluidic chip enable rapid temperature programming for microchip LC.
• This technology facilitates high-speed and high-efficiency separations.
• The approach is compatible with a range of eluents, including greener solvent options.