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

Autor: David M. G. Anderson, Malcolm R. Clench, Keith Oakes, Philippa J. Hart, Paul J. Trim, Sally Atkinson, Simona Francese, Marie-Claude Djidja, Laura M. Cole
Rok vydání: 2010
Předmět:
Zdroj: Analytical and bioanalytical chemistry. 397(8)
ISSN: 1618-2650
Popis: 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:YVO(4) laser. The laser operating in frequency-tripled mode (lambda = 355 nm) is capable of delivering 1.5-ns pulses of energy at up to 8 microJ at 5-10 kHz and 3 microJ 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.
Databáze: OpenAIRE