High-performance liquid chromatography on glass chips using precisely defined porous polymer monoliths as particle...

Area of Science:

• Analytical Chemistry
• Microfluidics
• Separation Science

Background:

• Integrating miniature packed bed separation columns into microfluidic systems for nano liquid chromatography presents significant challenges.
• Existing methods often involve complex retaining elements or the key stone effect, limiting flexibility and stability.

Purpose of the Study:

• To demonstrate a flexible and stable method for integrating miniature packed bed separation columns into microfluidic chips.
• To utilize laser-assisted fabrication of photopolymerized frits for column retention and integration.

Main Methods:

• Laser-assisted generation of narrow, photopolymerized frits using an optimized pre-polymeric solution of butyl acrylates and a porogen.
• Fabrication of frit-type structures with lengths < 100 µm capable of withstanding > 250 bar packing pressures.
• Integration of these frits as in- and outlet retainers for columns within microfluidic glass chips.

Main Results:

• Successful integration of miniature packed bed columns into microfluidic chips using the novel frit fabrication method.
• Achieved high-quality chromatographic separations of seven polycyclic aromatic hydrocarbons via reversed-phase chromatography.
• Demonstrated excellent performance with plate heights as low as 2.9 and extremely fast separations with sub-second peak widths on short columns (≤ 25 mm).

Conclusions:

• Laser-assisted frit generation provides a flexible and robust solution for integrating packed bed columns in microfluidic systems.
• The developed method enables high-performance nano liquid chromatography with rapid analysis times, suitable for various applications.
• This approach overcomes major integration issues, paving the way for advanced microfluidic separation devices.