Microfluidic Flow-through SPME Chip for Online Separation and MS Detection of Multiple Analyses in Complex Matrix

Area of Science:

• Analytical Chemistry
• Microfluidics
• Separation Science

Background:

• Sample preparation is a bottleneck in analytical chemistry, hindering analysis efficiency.
• Solid phase microextraction (SPME) offers a flexible approach to sample pretreatment, particularly in environmental and life sciences.
• Integrating SPME with microfluidic systems and mass spectrometry (MS) presents opportunities for enhanced analytical workflows.

Purpose of the Study:

• To address the lack of automation and calibration methods in on-chip SPME.
• To design and optimize a microfluidic chip integrating SPME, a micromixer, and electrospray ionization (ESI) for improved sample preparation.
• To develop a quantitation calibration method for on-chip SPME to enable accurate analyte quantification.

Main Methods:

• Geometric design of an SPME module on a microfluidic chip.
• Integration of a micromixer for varied elution conditions.
• Calculation of channel resistances to optimize the integrated chip design, proposing an annular channel for resistance balance.
• Development of a quantitation calibration method for on-chip SPME.

Main Results:

• A microfluidic chip design incorporating SPME, a micromixer, and ESI emitters was optimized.
• An annular channel design was proposed to balance channel resistances within the microfluidic chip.
• A novel quantitation calibration method was established for on-chip SPME, describing analyte distribution before adsorption equilibrium.

Conclusions:

• The developed on-chip SPME system with a micromixer and optimized geometry enhances analytical efficiency.
• The proposed calibration method facilitates accurate quantification in on-chip SPME applications.
• This work advances automated sample preparation for microfluidic-based analytical systems.