Introduction of a 20 kHz Nd:YVO4 laser into a hybrid quadrupole time-of-flight mass spectrometer for MALDI-MS imaging

Paul J. Trim, Marie Claude Djidja, Sally J. Atkinson, Keith Oakes, Laura M. Cole, David M.G. Anderson, Philippa J. Hart, Simona Francese, Malcolm R. Clench

Research output: Contribution to journalArticlepeer-review

62 Citations (Scopus)

Abstract

A commercial hybrid quadrupole time-of-flight mass spectrometer has been modified for high-speed matrix-assisted laser desorption ionisation (MALDI) imaging using a short-pulse optical technology Nd:YVO4 laser. The laser operating in frequency-tripled mode (λ = 355 nm) is capable of delivering 1.5-ns pulses of energy at up to 8 μJ at 5-10 kHz and 3 μJ at 20 kHz. Experiments to improve beam homogeneity and reduce laser speckle by mechanical vibration of the fibre-optic laser delivery system are reported along with data from trial and tissue imaging experiments using the modified instrument. The laser appeared to yield best results for MALDI-MS imaging experiments when operating at repetition rates 5-10 kHz. Combining this with raster imaging allowed images of rat brain sections to be recorded in 37 min. Similarly, images of the distribution of peptides in "on-tissue" digest experiments from tumour tissues were recorded in 1 h and 30 min rather than the 8-h acquisition time previously used. A brief investigation of targeted protein analysis/imaging by multiple reaction monitoring experiments "on-tissue" is reported. A total of 26 transitions were recorded over a 3-s cycle time and images of abundant proteins were successfully recorded.

Original languageEnglish
Pages (from-to)3409-3419
Number of pages11
JournalAnalytical and Bioanalytical Chemistry
Volume397
Issue number8
DOIs
Publication statusPublished - 1 Aug 2010
Externally publishedYes

Keywords

  • Imaging
  • MALDI
  • MRM
  • Raster
  • Vanadate

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry

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