Determination of Trace Phthalates in Foods by C18-SiO2@C-Tip Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry

• • The C18-SiO2@C adsorbent (10 mg) achieved high enrichment of five phthalates from water, milk, and cola, with recoveries of 80.2%–104.6% across real samples, demonstrating robust matrix tolerance for complex food matrices. • • The method achieved limits of detection (LOD) as low as 0.04–0.15 μg·L−1 (S/N ≥ 3), enabling trace-level quantification well below regulatory thresholds for phthalates in food. • • Linear calibration was established over 0.5–10 ng·mL−1 with R² > 0.99, and spiked recoveries ranged from 74% to 100% with relative standard deviations (RSD) of 1.32%–3.49%, indicating high precision and accuracy for routine analysis. • • The core-shell design, featuring a hydrophilic carbon shell and C18-functionalized SiO2 core, provides dual extraction mechanisms, enhancing selectivity and reducing matrix interference, which is critical for complex food samples.