Improved microfluidic chip-based sequential-injection trapped-droplet array liquid-liquid extraction system for...

Area of Science:

• Analytical Chemistry
• Microfluidics
• Chemical Sensing

Background:

• Microfluidic systems offer advantages in sample handling and analysis.
• Improving the stability and reliability of microfluidic devices is crucial for practical applications.
• Sequential-injection analysis combined with liquid-liquid extraction enhances analytical sensitivity.

Purpose of the Study:

• To develop an improved microfluidic chip-based sequential-injection system for liquid-liquid extraction.
• To integrate chemiluminescence detection for enhanced sensitivity.
• To demonstrate the system's performance for the determination of aluminum ions (Al(3+)).

Main Methods:

• Fabrication of a microfluidic chip with recess arrays for droplet generation.
• Integration of a monolithic probe for improved system stability and reliability.
• Utilizing a slotted-vial array system for sequential sample and reagent introduction.
• Optimization of operational conditions for extraction and chemiluminescence detection.

Main Results:

• Achieved an enrichment factor of 85 within a 12-minute analysis cycle.
• Demonstrated low sample consumption (1.8 microL) and reagent consumption (120 nL/cycle).
• Obtained a detection limit of 1.6x10(-6) mol/L for Al(3+) with 4.5% R.S.D.

Conclusions:

• The developed microfluidic system offers a stable, reliable, and efficient platform for trace metal analysis.
• The system enables rapid sequential-injection liquid-liquid extraction and chemiluminescence detection.
• This approach significantly reduces sample and reagent consumption while maintaining high sensitivity.