Trimpin Sarah, Lu I-Chung, Rauschenbach Stephan, Hoang Khoa, Wang Beixi, Chubatyi Nicholas D, Zhang Wen-Jing, Inutan Ellen D, Pophristic Milan, Sidorenko Alexander, McEwen Charles N
Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA.
MSTM, LLC, Newark, DE, 19711, USA.
J Am Soc Mass Spectrom. 2018 Feb;29(2):304-315. doi: 10.1007/s13361-017-1788-7. Epub 2017 Oct 27.
Ionization processes have been discovered by which small and large as well as volatile and nonvolatile compounds are converted to gas-phase ions when associated with a matrix and exposed to sub-atmospheric pressure. Here, we discuss experiments further defining these simple and unexpected processes. Charge separation is found to be a common process for small molecule chemicals, solids and liquids, passed through an inlet tube from a higher to a lower pressure region, with and without heat applied. This charge separation process produces positively- and negatively-charged particles with widely different efficiencies depending on the compound and its physical state. Circumstantial evidence is presented suggesting that in the new ionization process, charged particles carry analyte into the gas phase, and desolvation of these particles produce the bare ions similar to electrospray ionization, except that solid particles appear likely to be involved. This mechanistic proposition is in agreement with previous theoretical work related to ion emission from ice. Graphical Abstract ᅟ.
已经发现了电离过程,通过该过程,无论大小以及挥发性和非挥发性的化合物在与基质结合并暴露于低于大气压的压力下时会转化为气相离子。在此,我们讨论进一步定义这些简单且意外过程的实验。发现电荷分离是小分子化学物质、固体和液体通过进样管从高压区域进入低压区域时的常见过程,无论是否加热。这种电荷分离过程根据化合物及其物理状态以截然不同的效率产生带正电和带负电的粒子。提出的间接证据表明,在新的电离过程中,带电粒子将分析物带入气相,并且这些粒子的去溶剂化产生与电喷雾电离类似的裸离子,只是似乎涉及固体颗粒。这一机理主张与先前关于冰中离子发射的理论工作一致。图形摘要ᅟ。