Application of matrix-assisted laser desorption/ionization Fourier transform mass spectrometry to the analysis of planar porphyrins and highly substituted nonplanar porphyrins

M. Kirk Green, Craig J. Medforth, Cinzia M. Muzzi, Daniel J. Nurco, Kalyn M. Shea, Kevin M. Smith, Carlito B Lebrilla, John A. Shelnutt

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

The applicability of matrix-assisted laser desorption/ionization (MALDI) Fourier transform mass spectrometry to the analysis of porphyrins has been examined. High resolution spectra were readily obtained with good sensitivity and a detection limit as low as 2 fmol. A mixed solvent system of toluene and ethanol (1:1 by volume) proved to be compatible with the 2,5-dihydroxybenzoic acid (DHB) matrix and solubilized most of the porphyrins examined in this study. Porphyrins which were insoluble in this solvent mixture could be dissolved in an appropriate solvent and deposited on a layer of DHB (layered MALDI). The parent ion was generally the largest peak in the spectrum, although for some metalloporphyrins the peak corresponding to (M - metal + 3H)+ was dominant. The extent of demetallation was found to depend on factors such as sample preparation, the metal ion and the laser intensity. Addition of more than one hydrogen occurred in many cases but was a minor process. Spectra of compounds ionized by different methods showed increasing fragmentation in the order MALDI <layered MALDI < fast-atom bombardment <laser desorption.

Original languageEnglish (US)
Pages (from-to)439-451
Number of pages13
JournalEuropean Journal of Mass Spectrometry
Volume3
Issue number6
StatePublished - 1997

Keywords

  • Fast atom bombardment
  • Fourier transform mass spectrometry
  • Laser desorption
  • Matrix-assisted laser desorption/ionization
  • Porphyrins

ASJC Scopus subject areas

  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Application of matrix-assisted laser desorption/ionization Fourier transform mass spectrometry to the analysis of planar porphyrins and highly substituted nonplanar porphyrins'. Together they form a unique fingerprint.

  • Cite this