表面解吸常压化学电离质谱法直接分析牙齿微区表面

摘要

A novel analytical platform based on a nanoliter needle for sampling and surface desorption atmos-pheric pressure chemistry ionization mass spectrometry ( SDAPCI-MS ) for analysis was developed for the di-rect, fast and micro-area analysis of different parts of a human tooth, including cavity, cavity edge, tooth cusp and tooth sulcus. The results showed that the mass spectra from the four sampling spots on the same tooth were different, and that SDAPCI-MS detected lactic acid, pyruvic acid, phenylacetic acid and propanoic acid were confirmed using tandem mass spectrometry( MS/MS) . Principal component analysis( PCA) of the mass spec-tral data successfully differentiated the different sampling spots, levels of tooth decay and levels of gum disease. Therefore, our nano-SDAPCI-MS approach provides a promising way for micro-area analysis with fast, minimal pretreatment sampling, enabling rapid, simple and reliable surface MS investigation.%采用纳升取样表面解吸常压化学电离质谱法( nano-SDAPCI-MS)结合主成分分析( PCA)，建立了一种采用具有微米级针尖的金属取样针直接对龋齿不同部位取样并进行快速质谱分析的方法。数据分析结果表明，同一颗龋齿不同部位的质谱指纹谱图之间存在差异；在不需要样品预处理的前提下通过串联质谱快速测定了龋齿中的乳酸、丙酮酸、苯乙酸和丙酸等成分。采用PCA方法可较好地将龋齿病灶位置与邻近正常组织进行区分，也可对不同牙病及健康牙齿进行区分。本方法可方便地对牙齿进行直接微区分析，为鉴别牙齿疾病及观测治疗效果提供了一种快速、简单的方法，为生物体中微细部位的快速取样及直接质谱分析提供了一种可能的解决方案。