Research Group Inorganic Trace Analysis
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Depending on the analytical question, the following methods can be applied:

  • ICP-MS (multi-element method, isotopic determination possible, sensitivity in the range of ng / l)

  • ICP-OES (multi-element method, sensitivity in range of µ g / l)

In some (rare) cases, liquid samples can be analyzed directly. However, appropriate sample pre-treatment is required in most cases to, e.g., dissolve particulates and to remove organic matrix. Additionally, Solid Phase Extraction techniques facilitate analysis: they offer analyte pre-concentration and matrix dilution.

Usually, solid samples have to be dissolved prior to analysis, either by boiling with concentrated acids on a heating block or by performing a microwave (MW) assisted closed-vessel treatment.

The direct analysis of solid samples can be done via "slurry analysis": samples are powdered and a solvent is added to obtain a stable particle suspension. A limiting factor with slurry analysis is the sample inlet system (nebulizer capillary!), hence this approach is usually combined with Graphite furnace AAS analysis or ETV sample introduction.

The ETV-system is also suitable for the analysis of solid samples of approx. 3mm diameter. The ETV-device can be connected to the ICP-OES or to the ICP-MS; this provides good flexibility regarding sensitivity and linear working range.

Spatially resolved elemental analysis of solid samples can be achieved via Laser Ablation which provides lateral resolution (x/y) in the µm range. Due to its low sample consumption, the Laser Ablation device is used in combination with ICP-MS. However, depending on the analytical question, LA-ICP-OES analysis is possible as well.

Possible combinations of the abovementioned techniques and instruments.