Polyethylene Absorption Cells for Infra-Red Spectrophotometry

Abstract

The infra-red spectroscopy of aqueous solutions has been hampered not only by the infra-red absorption of water itself, but also by the difficulty of finding material for absorption cell windows which would be insoluble in water and still sufficiently transparent in the desired region. This problem is particularly irksome to biochemists who are primarily interested in aqueous solutions. Several groups of workers^1–4 have been successful in observing infra-red spectra in water solution by using cells sufficiently thin for absorption by water not to be excessive and by choosing materials such as silver chloride, barium fluoride, thallium bromide, etc., for windows. The expense and inconvenience of these special windows has prevented many from benefiting by this powerful technique, so that we have been led to consider the possibility of using polyethylene as a window material for aqueous solutions.