A new solid-phase extraction disk based on a sheet of single-walled carbon nanotubes

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Conventional solid-phase extraction (SPE) methods face challenges with efficiency and eluent volumes.
• Developing novel sorbent materials is crucial for improving trace contaminant analysis in water.

Purpose of the Study:

• To develop and characterize a new SPE disk based on single-walled carbon nanotubes (SWCNTs).
• To evaluate the extraction performance of SWCNT disks for various organic pollutants in aqueous samples.
• To demonstrate the application of SWCNT disks for real-world water sample pretreatment.

Main Methods:

• Fabrication of SPE disks using single-walled carbon nanotubes (SWCNTs).
• Testing disk reproducibility and flow rates with aqueous solutions.
• Enrichment of phthalate esters, bisphenol A (BPA), nonylphenols (4-NP, 4-OP), and chlorophenols using stacked DD-disks.
• Elution of adsorbed analytes using methanol or acetonitrile.
• Application of the DD-disk system for real-world water sample pretreatment and analysis.

Main Results:

• SWCNT disks exhibited satisfactory reproducibility and efficient flow rates (1 L in 10-100 min).
• High extraction abilities were observed for all target analytes, including polar chlorophenols, outperforming C18 disks.
• Complete elution of analytes was achieved with small solvent volumes (8-15 mL).
• Detection limits down to 7 ng L(-1) for BPA were achieved in spiked real-world water samples.

Conclusions:

• SWCNT-based SPE disks represent a promising tool for environmental analysis due to their strong adsorption, high flow rate, and ease of preparation.
• The DD-disk system offers an efficient and effective method for preconcentrating trace organic contaminants from large volumes of water.
• This technology provides a viable alternative to existing SPE materials for environmental monitoring applications.