An Amino-functionalized Covalent Organic Framework Coating for Highly Efficient Solid Phase Microextraction of Trace Phenols in Water

Phenolic compounds, as ubiquitous pollutants, should be effectively separated by sample pretreatment technology prior to analysis because of the low concentration, strong polarity and complex sample matrix. Solid phase microextraction (SPME) is a solvent-free pretreatment technology integrating sampling, enrichment and injection. Combined with gas chromatography-mass spectrometry (GC-MS), it can achieve the rapid enrichment and detection of trace organic compounds in a complex matrix.

To develop a sensitive, simple, and environmentally friendly method for the determination of trace phenols.

An amino functionalized covalent organic framework (TpPa-NH₂) was synthesized by a solvent-free method in one step. SPME was used as the coating, four kinds of phenolic compounds were used as target analytes, and a new method for the detection of phenolic compounds was established by headspace extraction mode combined with GC-MS.

The extraction performance of TpPa-NH₂ was 3-5 times that of TpPa-1. Under the optimum conditions, the established analysis method for four phenols had wide linear ranges (10-5.0×10⁴ng/L), high linear correlation coefficients (0.996-0.999), and low detection limits (1.30-5.35ng/L). Both the intra-fiber repeatability (RSD from 2.2%-9.2%) and inter-fiber reproducibility (RSD from 4.2%-8.9%) were satisfactory, and the coating can be reused more than 90 times.

The introduction of an amino group can effectively improve the extraction performance of TpPa for phenolic compounds. The established method establishes the sensitive, convenient and green detection of phenolic compounds in actual samples, demonstrating a good application prospect.