Petrologie und Mineralische Rohstoffe

Analytical facilities

Electron microprobe

For access to the microprobe lab please contact PD Dr. Thomas Wenzel

Tabletop Scanning Electron Microscope

For access to the Tabletop Scanning Electron Microscope please contact PD Dr. Thomas Wenzel

Total Reflection X-Ray Fluorescence Analysis (TXRF)

TXRF is a special EDXRF method. The geometric setup allows for a very short distance between sample and detector, resulting in very high detection efficiency for the fluorescence radiation. This leads to an improvement of sensitivity by several orders of magnitude compared to conventional XRF techniques. Elements with atomic number of >13 (alumina) can be detected without the need for a vacuum. We use a S2 PICOFOX benchtop TXRF system from Bruker AS equipped with a Mo X-ray tube, operated at 50 kV and 600 µA. For analysis, a few mg of powdered sample material or a few µl of liquid sample are sufficient. Depending on the nature of the samples, detection limits (depending on the matrix) are in the low- to sub-µg/g range for solid samples and in the low- to sub-µg/l range for liquid samples.

For access to the TXRF lab please contact PD Dr. Michael Marks

Ion Chromatography

We work with the ion chromatographs Compact IC Flex and Compact IC Plus from Metrohm equiped with an automated filtration unit and an autosampler for analysing cations (Li, Na, K, Mg, Ca, Sr, Ba) and anions (fluoride, chloride, bromide, nitrate, sulfate, phosphate) in liquid samples (e.g., natural surface waters, mine waters, soil waters, and leaching solutions). Detection limits are in the low- to sub-mg/l range.

For access to the IC lab please contact PD Dr. Michael Marks

Combustion Ion Chromatography

CIC is a combined system of combustion digestion (pyrohydrolysis) and ion chromatography and is used for the simulataneous determination of halogens (F, Cl, Br, I) and sulfur in solid samples (e.g., whole-rock powders, soils, mineral separates). The analysis via combustion requires 5-10 mg powdered sample material, which is then heated to 1050°C in an Ar/H2O atmosphere. The halogen loaded vapor is then collected and condensed via a cooling system (absorption module) and subsequently analysed by ion chromatography. For analyses, we use a Metrohm Compact IC Flex chromatograph, combined with a Metrohm Absorber module, a combustion oven and an autosampler for solid samples (Analytik Jena).

For access to the Combustion IC lab please contact PD Dr. Michael Marks

Fluid inclusions

We investigate microvolumina of fluids entrapped in minerals during growth and alteration processes by microthermometry. Temperatures of phase transformations observed in fluid inclusions reflect the nature and characteristics of the fluid from which the host mineral precipitated or the conditions under which the host mineral underwent alteration. We use a heating-freezing stage coupled to a polarization microscope. For further investigation of fluid inclusions, we have full access to the in-house Raman spectroscopy, ion chromatography and TXRF laboratories.

Fluid inclusion heating/ freezing stage

LINKAM fluid inclusion lab:

heating/freezing stage, melt inclusion facility, modern image analysis and the possibility for inhouse micro-RAMAN investigations.

Crush-Leach lab

(coming soon - in construction)

Cathodoluminescence

Cathodoluminescence (CL) microscopy is used for the textural analysis of minerals and phases showing luminescence like carbonates, quartz, fluorite and others. The hot cathode method makes it possible to analyze minerals having low-medium amounts of iron, which is not possible with a normal cold cathode device. We use a HC6-LM CL microscope from LUMIC, which works under vacuum (5x10-4bar) with an acceleration voltage of around 14kV and a beam current between 0.15 and 0.3 mA. The device is attached to a OlympusU_P4RE microscope with an Olympus XC10 Camera

For access to the Cathodoluminescence lab please contact PD Dr. Thomas Wenzel.

Ultrafiltration and Rare Earth Element Analysis in Waters

Ultrafiltration is a method for separation of very small particles and large molecules from truely dissolved ions. It allows to analyze colloidal transport mechanisms in aqueous fluids, which is important for REE and HFSE. We use a Millipore Pellicon Ultrafiltration unit that can be equipped with filter cartridges of various cutoff sizes.
Rare earth elements are important geochemical tracers for a variety of processes. In our group we run a preconcentration routine that allows to analyze extremely low REE concentrations such as in low salinity ground and mining waters by ICP-MS. The REE patterns obtained from these waters provide information about fluid-rock interaction and fluid pathways


We have full access to the laboratories of the geochemistry section.