表面解吸常压化学电离质谱原位检测萝卜中芥子碱及其含量衰减

采用表面解吸常压化学电离串联质谱（SDAPCI-MSn）技术，直接检测了白萝卜中的芥子碱，并考察了不同环境下芥子碱的衰减规律。 结果表明，常温下（25 ℃）白萝卜中的芥子碱浓度随时间迅速下降，在短时间衰减到一定程度后趋于平稳。 在低温下（≤4 ℃），白萝卜中的芥子碱衰减速度则非常缓慢，有利于保持白萝卜中芥子碱水平。 萝卜鲜汁中的芥子碱在接触空气后的衰减速度是日常存储条件下的300多倍。 虽然在不同的条件下，芥子碱衰减的速度不同，但均符合一级反应的衰减规律。

In situ Detection of Sinapine and Its Decline Studied in Radish Taproot by Surface Desorption Atmospheric Pressure Chemical Ionization Mass Spectrometry

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.