Electrochromatography in microchips packed with conventional reversed-phase silica particles

Area of Science:

• Analytical Chemistry
• Separation Science
• Microfluidics

Background:

• Microfluidic devices offer advantages in miniaturization and efficiency for chemical analyses.
• Electrochromatography (EC) is a powerful separation technique combining electrophoretic and chromatographic principles.
• Development of cost-effective and disposable platforms is crucial for widespread adoption of microchip-based analytical methods.

Purpose of the Study:

• To evaluate the applicability of a novel, inexpensive, and disposable microfluidic chip for electrochromatographic (EC) separations.
• To demonstrate the performance of a chip-based chromatographic packing material for the analysis of pharmaceutical compounds.
• To assess the effectiveness of a hydrodynamic pressure-based sample injection method in microfluidic EC.

Main Methods:

• Fabrication of a polydimethylsiloxane (PDMS) microfluidic chip incorporating reversed-phase (RP) silica particles (C18) without frits.
• Development and implementation of a hydrodynamic pressure-driven sample injection technique.
• Electrochromatographic separation of three cephalosporin antibiotics using the fabricated microfluidic chip.

Main Results:

• The microfluidic chip demonstrated successful electrochromatographic separation of cephalosporin antibiotics.
• The fritless chip design and C18 particle incorporation provided effective chromatographic retention and separation.
• The hydrodynamic pressure injection method proved reliable, minimizing sample bias.

Conclusions:

• The developed disposable microfluidic chip is a viable and inexpensive platform for electrochromatographic separations.
• This technology shows promise for the rapid and efficient determination of antibiotics and potentially other analytes.
• The integration of chromatographic packing and hydrodynamic injection in a microfluidic format enhances analytical capabilities.