Sponge-nested polymer monolith sorptive extraction.

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Traditional particle-packed supports in solid-phase extraction (SPE) have limitations.
• Polymer monoliths offer advantages like high porosity and pH stability but often lack mechanical integrity.
• Free-standing polymer monoliths are rarely used due to poor mechanical stability.

Purpose of the Study:

• To develop mechanically robust and easily adaptable polymer monoliths for sample preparation.
• To investigate the use of a melamine-formaldehyde sponge as a template for creating stable polymer monoliths.
• To evaluate the performance of these novel sponge-nested polymer monoliths for extracting endocrine disruptors.

Main Methods:

• Divinylbenzene polymer monoliths were synthesized within a melamine-formaldehyde sponge matrix using varying polymerization times.
• The resulting sponge-nested polymer monoliths (NMSE supports) were characterized for surface area and mechanical properties.
• Miniaturized monoliths were prepared by cutting the larger templated structures.
• The NMSE supports were applied to the solid-phase extraction of bisphenol A, 4-tert-butylphenol, and 4-tert-octylphenol from aqueous samples.

Main Results:

• Sponge-nested polymer monoliths exhibited high robustness and tunable size/shape.
• Surface areas ranged from 237 m² g⁻¹ to 369 m² g⁻¹.
• The developed NMSE supports are low-cost ($40/40 monoliths).
• Optimal performance was achieved with 6-hour polymerization, yielding limits of detection of 5.6–6.5 µg L⁻¹ for endocrine disruptors using HPLC-UV.

Conclusions:

• Melamine-formaldehyde sponge templating provides a viable method for creating mechanically stable polymer monoliths.
• Sponge-nested polymer monoliths (NMSE) are effective, low-cost sorptive extraction supports for environmental analysis.
• The direct immersion method using NMSE requires minimal equipment and offers efficient extraction of target analytes.