Simultaneous determination of phenothiazine drugs and their metabolites residues in animal derived foods by high performance liquid chromatography tandem mass spectrometry

Due to their potential entry into the human body via the food chain, phenothiazine drugs and their metabolites pose specific health hazards, making their detection in edible tissues of paramount importance. In this research endeavor, a highly sensitive multi-residue analytical method has been devised for the detection of phenothiazine drugs and their metabolites in animal-derived food products, utilizing high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The preparation of samples involved the use of 1% formic acid in acetonitrile as the extraction solvent following sample weighing, with multiple extraction steps diligently performed to ensure optimal outcomes. The sample, post-extraction, was directly introduced into the purification column, yielding significant time savings and rendering the process more environmentally sustainable. This procedural step effectively eliminated interfering substances from the sample matrix, including proteins, salts, and phospholipids. Analysis of the extracted samples was conducted through HPLC-MS/MS, employing an electrospray ionization (ESI) ion source. A comprehensive panel of 20 phenothiazine drugs and their metabolites was successfully resolved within a mere 10-min chromatographic run. A robust linear correlation (R2 2 >= 0.99) was attained within a judiciously chosen range of concentrations. Method validation was meticulously conducted across multiple animal species, including trout, white shrimp, pork, beef and chicken. The developed analytical method has been effectively deployed for the screening and quantification of phenothiazine drugs in real-world samples sourced from commercial livestock and aquatic products.