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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 10: Spectroscopy and Microscopy I with X-rays and Ions

KFM 10.9: Vortrag

Dienstag, 13. März 2018, 12:40–13:00, EMH 225

LABORATORY(CONFOCAL) MICRO-XRF ON CRYO-FIXATED BIOLOGICAL SPECIMEN — •Frank Förste, Tobias Drechsel, Ioanna Mantouvalou, and Birgit Kanngießer — IOAP TU Berlin, Hardenbergstraße 36, 10623 Berlin

The non-destructive imaging of elemental distributions in specimen is of high interest in many fields of research as for example in biology, geology or archaeometry, when sectioning or sampling is undesirable. In biology, specimen have a high content of water, which leads to the challenge, that specimen must be fixated to stop a change in elemental distributions due to drying or shrinking during measurements. Most commonly specimens are either freeze-dried or cryo-fixated, the latter being the method of choice regarding the maximal sample integrity. X-ray fluorescence (XRF) techniques like micro-XRF (up to 2D) or confocal micro-XRF (up to 3D) can easily be combined with a cryogenic sample environment, thus, fulfilling the above-mentioned requirements for elemental imaging of biological specimen. In this work, a modified commercial micro-XRF spectrometer (M4 Tornado, Bruker Nano GmbH) is used [1]. The instrument enables micro-XRF as well as confocal micro-XRF with high speed acquisition and lateral resolutions of 30 *m at Cu Kα. We present the addition of a liquid nitrogen Cryo-Jet (Oxford Instruments) which cools the specimen to 120 K rendering longtime measurements of biological specimen feasible. Characterization and stability measurements show the feasibility for cryomeasurements in the laboratory. As a first application, sunflower roots which show different uptake of heavy metals are investigated.