Abstract:

Surface desorption atmospheric pressure chemical ionization tandem mass spectrometry(SDAPCI-MSn), a novel method, was developed for the direct detection of sinapine in radish taproot samples, which allowed quantitative in situ studies of the decline of sinapine in radish taproot samples under different circumstances. The data demonstrated that at room temperature(25 ℃), sinapine in radish taproot declined gradually over a short time to a certain level, then the decline speed became slow. It was also found that sinapine declined very slowly at low temperature conditions(≤4 ℃), suggesting that the fresh radish taproot should be stored at low temperature to maintain the maximal amount of sinapine. When the radish juice was exposed to the air, the sinapine decline rate was more than 300 times higher than that of daily stored radish. All the decline processes were fitted with a first order linear equation.

Key words: surface desorption atmospheric pressure chemical ionization mass spectrometry, sinapine, radish taproot, decline process, a first order linear equation