A method has been developed for rapid untargeted screening and determination of unknown contaminants in aquatic products by high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry. The samples were extracted by acetonitrile, dried under nitrogen, dissolved in methanol-water (3:7, v/v), and analyzed via the full MS scan/data dependent MS2 mode during the screening process. The Trace Finder software was used to match the precise mass, the isotope abundance ratio, the fragment ion to search for unknown contaminants in aquatic samples. The optimized QuEChERS method is used to purify the samples when quantifying. The quantitative analyses of triazole, caffeine, and ethoxyquinoline were performed via the target-MS2 mode. The correlation coefficients of the three compounds in fish and shrimp samples were higher than 0.99 in the linear range of 5-1000 μg/L. The limit of detection was 1 μg/kg, and the limit of quantitation was 5 μg/kg. The average recoveries were between 70.5% and 90.9% with the relative standard deviations ranging from 5.4% to 12.8%. The screening method has the advantages of fast, accurate, and high throughput; when combined with the quantitative method, it can be used to screen and determine unknown contaminants in the actual aquatic products.
Keywords: aquatic products; contaminants; high performance liquid chromatography (HPLC); high resolution mass spectrometry (HRMS); untargeted screening.