Use of large-volume sample stacking in on-line solid-phase extraction-capillary electrophoresis for improved...

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Cephalosporins are crucial antibiotics, but their sensitive analysis can be challenging.
• Existing methods for cephalosporin detection may lack sufficient sensitivity or efficiency.

Purpose of the Study:

• To develop a highly sensitive analytical system for cephalosporin determination.
• To integrate on-line solid-phase extraction (SPE) with large-volume sample stacking (LVSS) in capillary electrophoresis (CE).

Main Methods:

• A novel system combining on-line SPE and large-volume sample stacking (LVSS) was utilized.
• Large sample volumes (250 µL) were processed, followed by desorption and injection into the CE system.
• LVSS was achieved by applying -5 kV for analyte preconcentration and solvent removal.

Main Results:

• Achieved limit of detections (LODs) in the ng/L range for cefoperazone and ceftiofur.
• Demonstrated significant improvements in sensitivity (up to 11,450-fold) compared to direct CE injection.
• Obtained excellent linearity (R² > 0.995) for cephalosporin quantification between 0.5 and 10 µg/L.

Conclusions:

• The integrated SPE-LVSS-CE system offers superior sensitivity for cephalosporin analysis.
• This approach enhances analyte preconcentration without compromising CE separation efficiency.
• The developed method provides a robust and sensitive tool for cephalosporin determination.