Abstract:

An analytical method for the determination of urotropine residue in processed soybean products was developed
using ion exchange solid-phase extraction coupled with ultra performance liquid chromatography-electrospray ionization
tandem mass spectrometry (UPLC-MS-MS). Samples were extracted with 0.4% perchloric acid followed by clean-up using
solid-phase extraction. The analysis was carried out under negative electrospray ionization mode using multiple reaction
monitoring. Cleanert PCX cartridge showed better clean-up and enrichment than Strata-SCX and SepPak C18 cartridges for
urotropine residue. The average recoveries of urotropine in three kinds of processed soybean products at spiked levels of 5.0
and 50.0 μg/kg ranged from 76.0% to 83.6% with relative standard deviations (RSDs) smaller than 6%. This method is rapid,
sensitive, accurate, repeatable and suitable for routine analysis of large-scale samples.

Key words: urotropine, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS), processed soybean products