Vandell V E, Limbach P A
Department of Chemistry, Louisiana State University, Baton Rouge 70803, USA.
J Mass Spectrom. 1998 Mar;33(3):212-20. doi: 10.1002/(SICI)1096-9888(199803)33:3<212::AID-JMS619>3.0.CO;2-E.
The magnesium, nickel, copper, zinc and vanadium metalloporphyrins from octaethylporphyrin, etioporphyrin I and tetraphenylporphyrin were characterized using electrospray ionization mass spectrometry (ESI-MS). The ion abundance of each of the porphyrins present in binary mixtures was monitored as a function of the porphyrin concentration and is dependent on the metalloporphyrin oxidation potential. It was found that, for binary mixtures of metalloporphyrins whose oxidation potentials differ by less than 0.1 V, the resulting ion abundance of each species is directly proportional to the concentration of each analyte in the mixture. For binary mixtures whose oxidation potentials differ by more than 0.1 V, relative abundances of the radical cations of each metalloporphyrin are determined by the oxidation potential and concentration of each metalloporphyrin with the analyte of lowest oxidation potential being ionized preferentially. The ability to ionize selectively one porphyrin over another in a binary mixture offers the potential to use ESI-MS for the qualitative analysis of porphyrins present in complex mixtures.
使用电喷雾电离质谱（ESI-MS）对由八乙基卟啉、初卟啉I和四苯基卟啉制得的镁、镍、铜、锌和钒金属卟啉进行了表征。监测二元混合物中每种卟啉的离子丰度随卟啉浓度的变化情况，且其取决于金属卟啉的氧化电位。结果发现，对于氧化电位相差小于0.1 V的金属卟啉二元混合物，每种物质产生的离子丰度与混合物中各分析物的浓度成正比。对于氧化电位相差大于0.1 V的二元混合物，每种金属卟啉自由基阳离子的相对丰度由每种金属卟啉的氧化电位和浓度决定，氧化电位最低的分析物优先被电离。在二元混合物中选择性地使一种卟啉比另一种卟啉电离的能力为使用ESI-MS对复杂混合物中存在的卟啉进行定性分析提供了潜力。
