IR Spectroscopy Using Disposable Polyethylene Cards: A Replacement for KBr Pellets and Mulls

Disposable IR cards are a simple alternative to KBr pellets and mineral oil mulls for the analysis of soluble compounds. These cards are commercially available from 3M. The film thickness is reproducible enough to allow for compensation in dual beam instruments or spectral subtraction in single beam instruments. Thus, making the whole spectral range useful. The cards are availabale in polyethylene and polytetrafluoroethylene. The polytetrafluoroethylene cards are useful for evaluation of the 3000-2800 cm^-1 region without compensation. Sample preparation involves dissolving the sample in a suitable solvent and adding a drop of the solution to the card. After the solvent has evaporated the card can be scanned.