Kertesz Vilmos, Van BerkelGaryJ
Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory, Tennessee 37831-6365, USA.
J Am Soc Mass Spectrom. 2002 Feb;13(2):109-17. doi: 10.1016/s1044-0305(01)00337-3.
Reduction of the oligomers formed from on-line electropolymerization of aniline, the compound N-phenyl-1,4-phenylenediimine, and the thiazine dye thionin was observed in both an atmospheric pressure chemical ionization and an atmospheric pressure photoionization source. The reduction, which alters the mass of these analytes by 2 Da, was shown to occur by means of a surface-assisted process which involves reactive species, possibly hydrogen radicals, generated from protic solvents in the ionization plasma. Reduction was minimized by limiting protic solvents, by using a high heated nebulizer temperature, and by using a clean, heated nebulizer probe liner. The expected generality of this reduction process, and the possibility of similar reduction processes in other plasma ionization sources are discussed in relation to the use of these ion sources for on-line electrochemistry/mass spectrometry experiments.
在大气压化学电离源和大气压光电离源中，均观察到由苯胺、化合物N-苯基-1,4-苯二亚胺和噻嗪染料硫堇在线电聚合形成的低聚物的还原现象。这种还原使这些分析物的质量改变2 Da，表明其通过表面辅助过程发生，该过程涉及电离等离子体中质子溶剂产生的活性物种，可能是氢自由基。通过限制质子溶剂、使用较高的雾化器加热温度以及使用干净的加热雾化器探针衬管，可将还原作用降至最低。结合这些离子源用于在线电化学/质谱实验的情况，讨论了这种还原过程的预期普遍性以及其他等离子体电离源中类似还原过程的可能性。
