Sample preparation
Grinding and size classification, near-infrared detector sorting system
Comminution and sorting processes are often required in order to obtain homogeneous samples of a suitable size from solid materials. In environmental analysis, such solid materials may range from soil, sediment or rock samples to complex residual and recyclable materials. For sample volumes on a laboratory scale, the CFEA has various planetary and ball mills as well as ultrasonic probes for comminution and various sieve systems for preparative size classification. For large sample volumes as well as residual and recyclable materials, a 2-shaft shredding unit and a drum sieve system as well as a near-infrared detector sorting system including a conveyor belt are available, which can selectively sort out individual polymers from complex mixtures of recyclable materials.
Available analytical procedures include:
- planetary and ball mills
- ultrasonic probes
- sieving machines and towers
- drum sieve system
- near-infrared (NIR) detector sorting system
Thermal sample preparation
Samples may need to be thermally pretreated in order to break down components for analysis, to enrich them or to make them storable. Laboratory microwaves, muffle furnaces, drying ovens, calorimeters or thermoblocks for cuvette tests are available for high-temperature digestion. Various rotary evaporation systems can be used to condense liquid samples, including a multiple rotary evaporator with up to 12 places of max. 60 mL each. Freeze dryers and cryodistillation systems enable temperature-sensitive samples to be concentrated and, if necessary, stored for longer periods.
Available analytical procedures include:
- Microwave-assissted digestion
- Thermobloc for cuvettes
- Muffle furnace and drying ovens
- Calorimeter
- Rotary evaporator
- Cryodistillation
- Freeze dryers
Filtration, Centrifugation and sample preconcentration
A prerequisite for many analytical procedures in aqueous solution is the prior removal of undissolved components on the one hand and the enrichment of the target analyte to an analyzable concentration level on the other. Various filtration and centrifugation variants are available at the CFEA for particle removal, while for enrichment, different levels of automated equipment can be used for solid phase extraction (SPE/SPME) or liquid-liquid extraction (LLE). The choice of the appropriate method depends on both the sample to be analyzed and the downstream analysis. We will be glad to advise you.
Available analytical procedures include:
- Pressure filtration
- Vacuum filtration
- Syringe filtration
- (cooled) centrifuges
- SPE/SPME (Solid phase extraction)
- LLE (Liquid-liquid-Extraction)
- Soxhlet
Available instruments are summarized in the List of Equipment.
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Core Facility Environmental Analytics
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