Spiral TOF
The JEOL Spiral TOF is a Matrix Assisted Laser Desorption ionisation Time-of-Flight/Time-of-Flight ( MALDI-TOF/TOF) mass spectrometer. The UV laser is at 349 nm and can be operated at up 1000Hz up to 5000 m/z in Spiral Mode, and up to 250 Hz in all other modes of operation. The laser diameter is specified to 20 μm. The instrument can be used to measure large molecules such as polymers, proteins and antibodies in Linear mode MALDI-TOF. If higher mass resolution and mass accuracy are required, the instrument can be operated in Spiral mode, where mass resolving power up to 75,000 is possible. MS/MS experiments are carried out after precursor isolation in Spiral mode, leading to a narrow isolation window of 1 m/z, which allows for much higher quality MSMS spectra than is possible on most other MALDI-TOF/TOF instruments. Additionally MSMS on the Spiral TOF is a high energy CID process, allowing fragmentation options not possible other instruments. Typical experiments that can be carried out include rapid MALDI spot analysis, LC-MALDI analyses, and Tissue Imaging. In addition to the hardware we have several software packages for data analyses including, msTornado analysis, JEOL Polymer Analysis software, and Tissue imaging data can be visualised using SCILS LAB MVS or JEOL Imaging visualisation software. Data can be exported in Mascot Generic Format (mgf) for various proteomic database searching.
Spiral mode allows regular measurement of compounds of at least 10,000 m/z, perhaps even larger, at high mass resolution and high mass accuracy. Preliminary experiments on the instrument in Spiral Mode looking for some synthesised molecules at 2900 m/z, at threshold operating conditions produced a spectrum with a resolving power of 132,000, far exceeding the JEOL specifications. While this will not be the case for every sample, indications are that the Spiral is exceeding expectation in terms of mass resolving power of the Spiral mass analyser. We have also demonstrated near baseline isotopic resolution of 10K PEG, and excellent resolution of venom peptides from the Funnel Web spider up to 5000 m/z directly off tissue during Mass Spectrometry Imaging experiments in Spiral mode.
Location: Hawken Building #50 (Room L104)
Contact: Brett Hamilton: b.hamilton@uq.edu.au