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. Graphical abstract The use of a porous covalent organonitridic framework (PCONFs) as solid-phase extraction (SPE) material is described here for the first time. An ultrasensitive, dependable and cost-effective method was developed for simultaneous analysis of eight sulfonamide residues in water, milk and chicken meat samples by coupling PCONF-based SPE with liquid chromatography-tandem mass spectrometry.