Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47907.
Anal Chem. 2013 Dec 17;85(24):11843-50. doi: 10.1021/ac4025279. Epub 2013 Nov 22.
A sampling probe based on ambient desorption ionization was designed for in vivo chemical analysis by mass spectrometry in surgical and endoscopic procedures. Sampling ionization of analytes directly from tissue was achieved by sealing the sampling tip against the tissue surface without allowing leakage of the auxiliary gas used for desorption ionization. The desorbed charged species were transferred over a long distance (up to 4 m) through a flexible tube of internal diameter as small as 1/16 in. to the inlet of the mass spectrometer used for analysis. The conditions used for desorption electrospray ionization (DESI) were optimized to achieve biocompatibility for clinical applications while obtaining adequate efficiency for the analysis. This optimization involved the removal of high voltage and use of pure water as a spray solvent instead of the organic solvents or aqueous mixtures normally used. Improved sensitivity was achieved under these conditions by increasing the gas flow rate in the transfer tube. The destructive effect on tissue surfaces associated with typical desorption ionization was avoided by altering the local gas dynamics in the sample area without compromising the overall analysis efficiency.
一种基于环境解吸电离的采样探针被设计用于通过质谱法在外科和内镜手术中进行体内化学分析。通过将采样尖端密封在组织表面上，同时防止用于解吸电离的辅助气体泄漏，实现了对组织中分析物的直接采样电离。解吸的带电物质通过柔性管（内径小至 1/16 英寸）长距离（长达 4 米）传输，传输到用于分析的质谱仪入口。优化了解吸电喷雾电离（DESI）的条件，以实现临床应用的生物相容性，同时获得足够的分析效率。这种优化包括去除高压，并使用纯水作为喷雾溶剂，而不是通常使用的有机溶剂或水混合物。通过增加传输管中的气体流量，在这些条件下实现了更高的灵敏度。通过改变样品区域中的局部气体动力学，避免了与典型解吸电离相关的对组织表面的破坏性影响，同时不影响整体分析效率。
