A new variable temperature and pressure infrared cell to study liquid and liquid–gas systems

A new general purpose high pressure infrared cell has been built, which allows one to work up to 2000 bar pressure with gas, liquid or supercritical fluid samples, in the temperature range from −70°C to +150°C. The optical pathway can be varied from ca. 0.1 to 4 mm, the different windows (CaF2, sapphire, diamond) allow measurements in a very wide (NIR, IR and far IR) spectral region (both to be set before pressurisation). Sample holders are built from PTFE, PCTFE or Vespel to avoid any unwanted metal catalysis of the reactions studied at high pressures. Mixing facilities assure rapid solubility equilibrium in gas–liquid systems.