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Trapped ion mobility spectrometry (TIMS) adds an additional separation dimension to mass spectrometry (MS) imaging, however, the lack of fragmentation spectra (MS2) impedes confident compound annotation in spatial metabolomics. Here, we describe spatial ion mobility-scheduled exhaustive fragmentation (SIMSEF), a dataset-dependent acquisition strategy that augments TIMS-MS imaging datasets with MS2 spectra. The fragmentation experiments are systematically distributed across the sample and scheduled for multiple collision energies per precursor ion. Extendable data processing and evaluation workflows are implemented into the open source software MZmine. The workflow and annotation capabilities are demonstrated on rat brain tissue thin sections, measured by matrix-assisted laser desorption/ionisation (MALDI)-TIMS-MS, where SIMSEF enables on-tissue compound annotation through spectral library matching and rule-based lipid annotation within MZmine and maps the (un)known chemical space by molecular networking. The SIMSEF algorithm and data analysis pipelines are open source and modular to provide a community resource. There is a need for dataset-dependent MS2 acquisition in trapped ion mobility spectrometry imaging. Here the authors report spatial ion mobility-scheduled exhaustive fragmentation (SIMSEF) which enables on-tissue metabolite and lipid annotation in mass spectrometry bioimaging studies, and use this to visualise the chemical space in rat brains. [ABSTRACT FROM AUTHOR]

Subwavelength-structures with different fill factors in the lateral dimensions result in unique phase shifts for the different polarization states of transmitted light. By using this additional degree of freedom for diffractive optical elements, we yield additional functionalities for compact optical systems with DOEs. As a fully operable example we present a binary subwavelength-grating which acts as a polarizing beamsplitter for TE- and TM-polarization over a wide range of incidence angles. We show our design approach, the manufacturing process with Soft-UV-Nanoimprint-Technology, as well as experimental results. We will also lay out possibilities for the design and application of multilevel polarization-functionalized gratings.

We report the design and optimized fabrication of deformed whispering gallery mode resonators in silica with solely ICP-RIE. This allows us to control the morphology of the resonators more freely and results in low surface roughness. The light was coupled into the resonator using a state of the art tapered fiber approach and we determined the Q-factor in the range of 105

Detection of fluorine with commercial ICPMS is impossible due to the high ionisation potential (IP) of fluorine. A novel approach through the formation of fluorine-containing polyatomic ions [M–F]+ in the plasma allows the successful detection of F at sub ppm levels by ICPMS/MS. Two theories behind [M–F]+ formation have been proposed, yet there is no clear understanding about the mechanism. Here, different metal solutions were tested for the characterisation of plasma processes in the formation of [M–F]+. Three characteristics: high [M–F]+ bond dissociation energy (BDE), low [M–O]+ BDE and low IP were found to be essential to get the highest sensitivity for [M–F]+. It was found that for elements with a higher [M–F]+ BDE than [M–O]+ BDE, the sensitivity decreases linearly with the second IP of the element, meaning that the major process in the plasma is the harvesting of F− by M2+ to form [M–F]+. Barium exhibited the highest sensitivity for [M–F]+. However, the robustness of this approach was questioned due to matrix effects, hence an argument for re-developing negative ion ICPMS/MS was discussed in which detection limits in the sub-ppb range could be reached. [ABSTRACT FROM AUTHOR]