The measuring cell TSC spectro enables the investigation of numerous substances solved in organic and inorganic media by combining electrochemical and spectroscopic (UV/Vis) methods. The cell's internal space can be hermetically sealed by a housing made of PEEK, allowing the study of air and/or moisture sensitive samples.
The bottom part of the measuring cell is a gold-plated copper block (thermo block) with integrated Pt100 temperature sensor. Measurements can be carried out at temperatures ranging from -20 °C to +80 °C whereby the temperature is rapidly and precisely adjusted. Perpendicular to the surface of the thermo block, a fine platinum gauze is placed which serves as working electrode. The gauze is aligned in the centre of the optical path.
The position of the optical windows inside the PEEK housing is flexible which enables the user to adapt the measuring cell's design optimally to the different requirements of various samples regarding their absorption strength and concentration. The path length can be adjusted to values ranging from 1.4 mm to the thickness of the gauze electrode by screwing the optical windows to different positions.
To measure the optical transmission of the sample in solution, the optical fibres of the spectrometer are directly fixed to the internal collimator lenses via SMA connectors.
The cell is closed with a screw cap made of PEEK with exchangeable electrode. By default, the TSC Spectro is provided with a mirror-like polished electrode made of glassy carbon press-fitted in PEEK (electrochemically active surface area: 6 mm). In principle, all materials which can be pressed into PEEK are available, like for instance stainless steel and platinum.
The housing serves as electrolyte reservoir requiring an electrolyte volume of 0.5 mL to 2.0 mL. The housing consists of two separate parts, allowing membranes to be placed between the working electrode in the lower cell compartment and the counter electrode in the cap. This avoids diffusion of reaction products between the cathode and anode compartments.
A lateral inlet in the lower part of the housing enables the positioning of metal pseudo reference electrodes or capillary based micro-reference electrodes close to the platinum gauze. Alternatively, the insertion of a reference electrode via one of the two inlets in the cap is also possible. In addition, these inlets also can be used for subsequent insertion of liquids or gas by means of the capillary based filling set.
- Sample substance dissolved in organic or inorganic solvents (e.g. acetonitrile, H2O) in a concentration depending on the absorption strength of the sample; typically 0.05 - 0.5 mmol/L
- Variable position of the optical windows in the optical path in the range from 1.4 mm to thickness of the gauze electrode
- Sample volume: min. 500 μL (samples with low volatility + cap with “long” counter electrode), max. 2 mL (standard)
- Employed standard materials: gold-plated surface (thermo block), PEEK (housing, cap, screw plug, screw fittings), glassy carbon (upper electrode), platinum (gauze electrode), quartz (optical windows and collimator lenses), FKM, EPDM or FFKM (o-rings)
- Integrated Pt100 temperature sensor (thermo block)
- Temperature range (operation): -20 °C to +80 °C depending on sample amount and dew point
- Temperature range (storage): +10 °C to +30 °C
Details of the gauze electrode
|nominal mesh opening||0.12 mm|
|wire diameter||0.04 mm|
|wires / inch||152x152|
|open area||56 %|
- Simultaneous spectroscopic and electrochemical investigation via cyclic voltammetry of various organic dyes like N,N,N’,N’-tetramethyl-1,4-phenylenediamine (Wusters Blue) and 5-methyl-3-phenyl-1-p-tolyl-4,5-dihydro-1H-pyrazole-5-carboxylic acid methyl ester in 3-electrode configuration under temperature control.