Magnetic solid-phase extraction based on carbon nanotubes for determination of sulfamethoxazole, acetyl sulfamethoxazole and aditoprim residues in edible swine tissues with liquid chromatography tandem mass spectrometry

Sulphonamides (SAs) are widely used in animal husbandry. In our work, based on multi-walled carbon nanotubes, a novel residue method was developed for highly sensitive and determination trace levels of sulfamethoxazole, acetyl sulfamethoxazole and aditoprim in edible swine tissues by LC-MS/MS with magnetic solid-phase extraction. The samples were extracted using 2% ammoniated acetonitrile and purified by magnetic solid phase extraction (MSPE). Under the optimal conditions, good linearity was obtained ranging from 5 to 160 mu g kg(-1). The limits of detection (LOD) and quantification (LOQ) were 2 mu g kg(-1) and 5 mu g kg(-1) respectively. The average recoveries were 73.9-94.8% at different spiking levels. The inter-day RSDs were 6.2-10.7% and the intra-day RSDs were 2.4-5.4%. MSPE based on multi-walled carbon nanotubes was a simple and efficient method to enrich and separate the analyses and could be successfully applied for extraction of sulfamethoxazole, acetyl sulfamethoxazole and aditoprim residues in swine tissues.