类固醇激素的低温等离子体质谱研究

Analysis of Steroid Hormone by Low Temperature Plasma Mass Spectrometry

将自行设计和搭建的低温等离子体装置作为离子源,成功地与常压高分辨质谱结合,并将其用于类固醇样品的定性分析。与常规电喷雾质谱相比,用低温等离子体质谱检测类固醇样品具有样品前处理简单、谱图干扰少等优点。对类固醇样品进行了一级质谱以及串联质谱的表征,发现其一级谱图能够体现出类固醇化合物的结构稳定性,而在串联质谱图中则出现了较多的丢水碎片。本工作结合能量计算详细比较分析了典型类固醇样品在碰撞诱导解离(CID)碎裂过程中的丢水过程。另外,通过比较二级质谱的不同以及对其碎裂过程的分析推测,睾酮和去氢表雄酮这对同分异构体得以区分。

A device to produce low temperature plasma( LTP) was designed and constructed to serve as the ion source of a high resolution mass spectrometry,and was applied to qualitatively analyze the steroid samples.In comparison with conventional electrospray ionization mass spectrometry,low temperature plasma mass spectrometry( LTP-MS) had some advantages such as simple sample pretreatment and less interference. Mass spectrometry and tandem mass spectrometry were used to characterize the steroid samples in this research,and it was found that the structural stability of each steroid sample was presented in its mass spectrum,while in the tandem mass spectra there were more fragments of H_2O lost. And then the fragmentation process of typical steroid samples in collision induced dissociation( CID) was discussed based on theoretical calculation. In addition,by comparing tandem mass spectrometry and the fragmentation process, a pair of isomers of testosterone and dehydroepiandrosterone could be distinguished successfully.