Chemical Facilities

Depending on the aim of research, different extraction and isolation methods can be used. An important extraction method in odour analysis is distillation in a high vacuum, also known as SAFE (solvent-assisted flavour evaporation). SAFE is particularly well known for the gentle isolation of thermally fragile flavour compounds from complex matrices. In addition to classic liquid extraction, we also use various headspace extraction methods. These methods are especially suitable for the extraction of highly volatile substances.

We synthesize odor-active compounds, for instance to elucidate structure-odor or structure-bioactivity-relationships, or to use them as internal standards in quantitative analysis. Purification is achieved by application of column chromatography, amongst others. The synthesized target components are characterized by analytical parameters such as mass spectra, NMR spectra or retention indices.

In chemical analyses, we mainly focus on gas chromatography, but liquid chromatography is also important for certain applications. Our equipment includes:

    • One- and two-dimensional (heart-cut) gas chromatographs with olfactory detection ports and mass spectrometers for the detection of odour-active compounds (GC-O/MS)
    • Comprehensive two-dimensional gas chromatography coupled to time-of-flight-mass spectrometry (GCxGC-TOFMS)
    • High-performance liquid chromatography coupled with mass spectrometry (LC-MS)

All instruments can be used with diverse application modes (e.g., liquid injection, thermodesorption, etc.).

Schlenk Method

The Synthesis Laboratory is equipped with a Schlenk line for synthesis of nanomaterials under inert atmospheres. The Schlenk line consists of a dual manifold of several ports. Our setup allows the removal (by vacuum) of the existing atmosphere and the direct incorporation of the inert phase (N2) into the reaction flask. A liquid nitrogen trap and oil bubbler are installed to maintain the pressure and contamination of the system at optimal conditions. High-temperature reactions are also possible by adapting reflux systems and heating mantles to sustain constant reaction volume and temperatures up to 450 °C.

Schlenk Line @biointerfaces lab

Autoclave reactor method

Steel autoclave reactor (Huanyu 100 mL) with a chemically inert PTFE inner line, allows synthesis at high pressure (up to 30 bar). Together with the natural convection oven (Memmert UM-600), reactions can be performed up to 200 °C. Control of temperature and solution vapor pressure within the reactor enables fine-tuning of the crystal phase and geometries of the desired materials.

 Autoclave reactor and convection oven @biointerfaces lab

Particle separation

Separation of synthesized nanoparticles can be achieved based on their sedimentation coefficient during centrifugation steps. We have two centrifuges to separate larger colloidal particles (ThermoScientific Megafuge, up to 5000 RCF) and for smaller particle sizes (IKA G-L S000, up to 12000 RCF).

 Centrifuges @biointerfaces lab

Particle dispersion

Preparation of nanoparticle suspensions requires proper dispersion of the samples in specific solvents. The Synthesis Laboratory uses a temperature-controlled sonication bath to induce the dispersion of nanomaterials by thermal and/or sonic control of surface interaction between nanoparticles, avoiding the agglomeration of the material due to e.g., van der Waals interactions.

 Sonication bath @biointerfaces lab

Water purification system

Reaction synthesis of nanomaterials demand high purity level of solvents and reagents; therefore, the Synthesis Laboratory counts with a Milli-Q Direct 5Q UV water purification unit to assure the use of water type I (18MΩ·cm) by reverse osmosis purification.

 Water purification unit @biointerfaces lab

Chemical reagent preparation

For preparation of chemical reagents the laboratory is equipped with an analytical scale (VWR LAG254i-M precision up to 0.003g) a shaking unit (IKA Rotator) and a pH-Meter (Fisher-Scientific accumet AE150 pH 0 – 14 / T° 0-90).

 Small lab equipment @biointerfaces lab