FTIR accessories: liquid cells
Liquids are analysed in transmission cells as a thin film between two IR windows. The choice of IR window material and path length is determined by the sample type and application. The sample is analysed neat or dissolved in a suitable solvent. For quantitative analysis, sealed liquid cells with known path length are available.
When selecting IR cell windows, optical (transmission range), chemical and mechanical properties have to be taken into account. We provide both round and square IR windows in all common materials.
Due to the hygroscopic nature of the materials of many IR cell windows and other accessories, storage in a dry atmosphere, such as a drying cabinet, is re commended.
Transmission spectroscopy is one of the basic techniques for IR analysis. The sample and wavelength to be analysed determine the choice of window material, path length and window arrangement. The Omni cell is universally applicable for the analysis of liquids and mulls and can be transformed in just a few steps from a sealed cell to a demountable cell, or used as a Nujol cell.
Many IR windows become dull and their surface scratched after an extended period of use. This kit contains all of the essential materials required to clean and re-polish windows to within a flatness of a few fringes. Re-polishing can be achieved efficiently and economically . The kit is accommodated in a handy case.
The high-pressure high-temperature cell enables IR spectroscopic analysis at temperatures up to 800 °C. The cell can be used at pressures from vacuum up to 66 bar and is also suited to the analysis of flowing gases.
The electric heating jacket is designed for transmission measurements on liquids and solids from RT to 250 °C. The heating jacket accomodates a liquid cell (static or flow) or a solid sample holder. The structure of the water heating jacket is basically equivalent to the electrical jacket, except that heating of the flow takes place e.g. with the help of a heat recirculation thermostat.
The variable temperature cell enables solid and liquid samples to be analysed for transmission over a temperature range from -190 °C up to 250 °C. Cooling of the cell is achieved by means of a cooling dewar. The selection of coolant is determined by the desired temperature; for -190 °C, liquid nitrogen is required. The cell holder is mounted directly on the floor of the dewar, the holder accommodates one liquid cell or one solid sample holder. The cell can also be used for analysis in UN/VIS spectroscopy.
IR sample cards are low-cost one-way sample carriers for fast qualitative IR analysis. The cards measuring 2" x 4" fit the standard sample holder of any spectrometer. The polystyrene film serves to verify the correctness of IR spectrometer wavelengths.
The cell holder accommodates rectangular cells with path lengths up to 50 mm. The Nujol cell can be dismantled quickly into its constituents parts and reassembled. It is used for routine analysis of liquids, pastes and mulls.
These high-pressure liquid cells are suitable for analysis of liquids at high pressure (max. 136 bar or 340 bar, depending on window material). The cell body is made from stainless steel, window material options are sapphire, ZnSe and Spectrosil B. The cells are permanently sealed and cannot be disassembled.
The transmission cell with continuously variable path length from 0.04 mm to 6 mm is used for the analysis of liquids and determination of absorption coefficient. It enables the variation of path length in a filled and assembled cell.
Due to the hygroscopic nature of the materials of many IR cell windows and other accessories, storage in a dry atmosphere, such as a drying cabinet, is essential. The drying cabinet has a temperature control range of 30 °C to 80 °C. A desiccant with colour indication enables constant monitoring of humidity.