Porous covalent organonitridic frameworks for solid-phase extraction of sulfonamide antibiotics

Porous covalent organonitridic frameworks (PCONFs) were applied as a packing in a solid-phase extraction cartridge for rapid extraction of eight sulfonamide antibiotics from complex samples. The detection was performed by liquid chromatography–tandem mass spectrometry under the multiple reaction monitoring mode. This enabled ultrasensitive, dependable and cost-effective simultaneous analysis of sulfacetamide, sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamethoxazole and sulfisoxazole. Main parameters affecting the performance of the PCONF-packed cartridge were investigated. Under optimized conditions, this method has attractive features such as wide linear ranges (2.5–1000 ng·L−1), low limits of detection (0.14–2.0 ng·L−1), and good repeatability (intra-day assay: 2.1%–5.6%; inter-day assay: 2.3%–12.9%). It was successfully applied in the analysis of sulfonamide residues in water, milk and chicken meat samples.