Electroosmosis- and pressure-driven chromatography in chips using continuous beds

Area of Science:

• Analytical Chemistry
• Separation Science
• Microfluidics

Background:

• Traditional chromatography often faces limitations due to "wall effects" and the need for supporting frits.
• Microchip-based separation techniques offer potential for miniaturization and automation.

Purpose of the Study:

• To demonstrate the extension of microchip capabilities to various chromatography modes using continuous polymer beds.
• To eliminate wall effects and the requirement for frits in microchip chromatography.
• To assess the performance of microchip chromatography for both low- and high-molecular-weight analytes.

Main Methods:

• Filling microchip channels with continuous polymer beds anchored to the channel walls.
• Utilizing a quartz chip with integrated auxiliary components for flexible automation.
• Performing chromatographic separations in both fused-silica capillaries and microchips.

Main Results:

• Elimination of "wall effects" by anchoring polymer beds to channel walls.
• Successful separation of low-molecular-weight (alkyl phenones, antidepressants) and high-molecular-weight substances (proteins) with comparable resolution to capillaries.
• Rapid electrochromatographic separation of uracil, phenol, and benzyl alcohol in under 20 seconds.

Conclusions:

• Continuous polymer beds in microchips provide an effective alternative to traditional chromatography, eliminating wall effects and frits.
• The flexible, automated design of the quartz chip system is suitable for diverse analytical applications.
• Microchip chromatography demonstrates high performance for a wide range of analytes, enabling rapid separations.