Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v. v. i., Flemingovo nám. 2, 16610 Prague 6, Czech Republic.
J Mass Spectrom. 2011 Mar;46(3):256-61. doi: 10.1002/jms.1888.
Scanning electron microscopy was used to investigate rivulets that are formed on the analyzed surface during desorption electrospray ionization (DESI) experiment. Ferromagnetic nanoparticles added to the spray solvent in a form of colloid solution functioned as an additional surface probe. The existence of the rivulets was confirmed on glass and newly demonstrated on two different types of porous polytetrafluoroethylene (PTFE). The results show that in standard DESI set-up the rivulets are arranged into very regular shapes. Same rivulets were obtained in DESI experiments without high voltage on the sprayer. However, no such rivulets or any other regular patterns were found on a surface in nano-DESI (nanospray DESI without the carrier nebulizing gas) experiments. This indicates that symmetrical rivulets are created by the hydrodynamical rather than electrostatic forces. It was also demonstrated that blocking the rivulets by a simple physical barrier did not influence known surface charging effects.
扫描电子显微镜用于研究解吸电喷雾电离（DESI）实验中在分析表面上形成的射流。以胶体溶液形式添加到喷雾溶剂中的铁磁纳米粒子充当了附加的表面探针。射流的存在在玻璃上得到了证实，并在两种不同类型的多孔聚四氟乙烯（PTFE）上首次得到了证明。结果表明，在标准 DESI 装置中，射流排列成非常规则的形状。在没有在喷雾器上施加高压的 DESI 实验中也获得了相同的射流。然而，在纳米 DESI（没有载气雾化的纳米喷雾 DESI）实验中，在表面上没有发现任何射流或任何其他规则图案。这表明对称射流是由流体动力而不是静电力产生的。还证明，通过简单的物理屏障阻止射流不会影响已知的表面充电效果。
