Laser-induced acoustic desorption of natural and functionalized biochromophores

Anal Chem. 2015 Jun 2;87(11):5614-9. doi: 10.1021/acs.analchem.5b00601. Epub 2015 May 20.

Abstract

Laser-induced acoustic desorption (LIAD) has recently been established as a tool for analytical chemistry. It is capable of launching intact, neutral, or low charged molecules into a high vacuum environment. This makes it ideally suited to mass spectrometry. LIAD can be used with fragile biomolecules and very massive compounds alike. Here, we apply LIAD time-of-flight mass spectrometry (TOF-MS) to the natural biochromophores chlorophyll, hemin, bilirubin, and biliverdin and to high mass fluoroalkyl-functionalized porphyrins. We characterize the variation in the molecular fragmentation patterns as a function of the desorption and the VUV postionization laser intensity. We find that LIAD can produce molecular beams an order of magnitude slower than matrix-assisted laser desorption (MALD), although this depends on the substrate material. Using titanium foils we observe a most probable velocity of 20 m/s for functionalized molecules with a mass m = 10,000 Da.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustics
  • Bilirubin / chemistry
  • Chlorophyll / chemistry
  • Hemin / chemistry
  • Lasers*
  • Molecular Structure
  • Porphyrins / chemistry*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • Porphyrins
  • Chlorophyll
  • Hemin
  • Bilirubin