Synthesis of sulfonamide-functionalized magnetic microporous organic network for magnetic solid-phase extraction of polar aromatic amines from tea beverages

Abstract

Aromatic amines (AAs) are a typical class of carcinogenic contaminants frequently present in food packaging materials. Considering the huge consumption of tea beverages in our daily life and the frequently usage of packaging materials in tea beverages, establishment of sensitive and selective method to detect polar and trace AAs in tea beverages is urgently needed. Herein, a sulfonamide-functionalized magnetic microporous organic network (MMON-SO₂NH₂) was synthesized for the efficient magnetic solid-phase extraction (MSPE) of AAs from tea beverages through the pre-designed electrostatic attraction, π-π, hydrophobic, and hydrogen bonding interactions. MMON-SO₂NH₂ demonstrated large surface area (304.4 m² g^-1), rapid magnetic responsiveness (38.3 emu g^-1, < 15 s), and good stability and reusability (> 8 times), being an ideal magnetic adsorbent for AAs. The established MMON-SO₂NH₂−MSPE-HPLC-UV method gave wide linear ranges (1–1000 µg L^-1), low limits of detection (0.3–1.0 µg L^-1) and limits of quantitation (1.0–3.0 µg L^-1), large enrichment factors (80.3–85.6), and good anti-interference ability. Satisfactory recoveries were obtained, which demonstrated the potential of MMON-SO₂NH₂ for efficient enrichment of trace AAs in complex samples and uncovered the promising of sulfonamide-functionalized magnetic adsorbent in sample pretreatment.