The Bruker TIMS TOF Flex - MALDI-2 is the first commercially available instrument to combine MALDI with a post-ionisation laser, referred to as MALDI-2. The TIMS TOF Flex with MALDI -2 combines all the abilities of the TIMS TOF Pro 2 with MALDI capability. Essentially the TIMS TOF Flex MALDI-2 can be a total solution for experiments requiring Mass Spectrometry Imaging and LC-MS approaches.

The instrument builds upon the QqTOF technology adding trapped ion mobility (TIMS), allowing for collisional cross section (CCS) measurements. This can be used in a number of ways, including separation of isomers prior to QqTOF measurement – allowing for the observation of isomeric or isobaric species that were otherwise inseparable. The other feature is the parallel accumulation serial fragmentation (PASEF) mode, where by TIMS tunnel 1 accumulates ions, and TIMS tunnel 2 releases them sequentially – allowing for separate MSMS spectra to be collected as the ions are released from TIMS tunnel 2. Combined with the high speed QqTOF (100 Hz), the instrument is able to acquire many more MSMS spectra, with greater sensitivity due to the accumulation in TIMS tunnel 1 and with higher quality due to the sequential release of precursor from TIMS tunnel 2. This PASEF feature can be used as a data dependant acquisition (ddaPASEF) or data independent acquisition (diaPASEF). The instrument can also be used in TIMS off mode – as a regular QqTOF. These works flow can be applied to bottom up proteomics, lipidomics and metabolomics. The instrument can be coupled to either a Thermo Vanquish Flex UHPLC for lipids and Metabolites, or a Thermo RSLC nano for nanoLC based proteomic analyses. Data is searched using PEAKS Studio X, or Metaboscape. Mascot and MaxQuant can also be used.

The MALDI aspect of the instrument involves a primary laser operable up to 10000 Hz at 355nm, and a post-ionisation laser operable up to 1000 Hz at 266 nm. The post ionisation to-date has been found to be very useful for lipids and metabolites. For Mass Spectrometry Imaging experiments, the TIMS TOF Flex –MALDI-2 can be operated with or without post ionisation laser, and also as TIMS on or TIMS off. The other important aspect of the TIMS TOF Flex – MALDI -2 is the decoupling of the sample topography from the resulting mass resolution and mass accuracy, by virtue of the orthogonal acceleration of ions into the TOF analyser. This has the net result of radically improving the mass accuracy and mass resolution achievable during MSI experiments. Typically, the measurement is very close, if not exact, at the 2nd decimal place, and additionally the water cooled TOF analyser maintains a very stable mass accuracy measurement. The acquired data is visualised using SCILS LAB software, and in the case of lipids and metabolities, analyte annotation can be made using Metaboscape. Utilising Metaboscape for both LC-MS and MSI work flows allows for much improved combination of the complimentary LC-MS and MSI datasets – combining the quantitative aspects of LC-MS with the spatial distributions aspects of MSI.

MSI for lipids, metabolites, peptides, and small proteins, all at high mass accuracy, will be possible with this instrument.

Overall, the TIMS TOF Flex – MALDI-2 has caused a positive disruptive influence in the MSI community and UQ-CMM are fortunate to be able to provide access to this innovative technology.

Location: Hawken Building #50 (Room L106)

Contact: Brett Hamilton: b.hamilton@uq.edu.au