AN APPROXIMATE METHOD FOR THE CALCULATION OF THE INFRARED MOLAR ABSORPTION-COEFFICIENT AND ABSORPTION INDEX SPECTRA OF LIQUIDS FROM TRANSMISSION MEASUREMENTS

A simple and effective approximate method for the calculation of infra red molar absorption coefficient spectra, E-m(<(nu)over tilde>), and a bsorption index spectra; k(<(nu)over tilde>), of liquids from transmis sion measurements is presented. In the approximate method, the apparen t absorbance due to reflection losses is calculated by assuming the ce ll is a single window. This simplifies the correction of the experimen tal absorbance for the contribution of reflection and eliminates the n eed for an iterative calculation. Although simpler, the method gives k and E-m values accurate to 1% for all but the strongest infrared abso rptions. Areas under these spectra are accurate to 0.5%. The method is demonstrated on a mixture of 90 mole% toluene and 10 mole% chlorobenz ene.