Molecularly imprinted solid-phase extraction of cephalexin from water-based matrices.

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biomedical Science

Background:

• Beta-lactam antibiotics, such as cephalexin (CFX), are widely used and their presence in the environment and biological fluids requires monitoring.
• Existing methods for antibiotic determination can be complex and time-consuming.

Purpose of the Study:

• To synthesize a molecularly imprinted polymer (MIP) for selective cephalexin (CFX) detection.
• To apply the MIP in solid-phase extraction (SPE) for quantifying CFX in human urine and river water.
• To evaluate the MIP's performance in a tandem SPE system for increased sample volume analysis.

Main Methods:

• Synthesis of a cephalexin (CFX) molecularly imprinted polymer (MIP).
• Application of MIP in molecularly imprinted solid-phase extraction (MISPE) for human urine analysis.
• Implementation of a tandem SPE system with MIP for river water analysis.

Main Results:

• The MIP demonstrated cross-selectivity for amoxicillin (AMX), enabling simultaneous quantification of CFX and AMX in human urine with high recoveries (78% for CFX, 60% for AMX).
• MISPE provided clear extracts, simplifying analysis compared to nonpurified samples.
• The tandem SPE system allowed for the determination of CFX in river water with recoveries exceeding 50% from large sample volumes (200 mL).

Conclusions:

• The developed MIP is effective for the selective determination of cephalexin (CFX) in complex matrices like human urine and river water.
• The MIP-based MISPE method offers a facile and efficient approach for antibiotic monitoring.
• The tandem SPE system enhances the applicability of MIPs for analyzing trace levels of antibiotics in environmental samples.