Synthesis of Tetra (4-aminophenyl) porphyrin covalent organic framework/ 2D graphitic carbon nitride (TAPP/ 2D g-C3N4) composite as a sorbent for stir bar sorptive extraction of selected pesticides followed by HPLC-UV quantification

A novel stir bar sorptive extraction (SBSE) coating based on a porphyrin-based covalent organic framework (Tetra(4-aminophenyl) porphyrin, TAPP) combined with two-dimensional graphitic C 3 N 4 (2D g-C 3 N 4 ) was developed. The TAPP/g-C 3 N 4 composite exhibits unique structural features and enhanced intermolecular π–π interactions, resulting in superior extraction efficiency for model pesticides (hexaflumuron and teflubenzuron) from complicated food matrices. The composite was coated on a cost-effective and readily available magnetic glass, facilitating practical application of the SBSE method. Key analytical figures of merit included linear dynamic ranges of 0.10–200.00 µg L⁻¹, detection limits of 0.03–0.04 µg L⁻¹, limits of quantification of 0.10–0.13 µg L⁻¹, enrichment factors of 31.30–34.80, absolute recoveries of 62.60–69.60%, and bar-to-bar reproducibility of 5.50–6.00%. The method was successfully applied to tomato, potato, pear, apple, and watermelon, achieving spiking recoveries of 90.00–110.00%. Compared to individual TAPP or g-C 3 N 4 materials, the composite showed markedly improved extraction performance. Sustainability assessment using the Blue Applicability Grade Index (BAGI = 72.50) and Analytical Greenness Metric for Sample Preparation (AGREEprep = 0.75) confirmed the method’s environmental friendliness. These results demonstrate the potential of TAPP/g-C 3 N 4 as an effective SBSE coating for efficient pesticide extraction and enrichment.