Recording Infrared Spectra for Quantitative Analysis

Abstract

Potential speed in acquisition of data, intrinsic wavelength reproducibility, and permanence make recorded spectra desirable sources of quantitative data. To permit using the Perkin-Elmer Moodel 21 spectrophotometer for quantitative work, optimum operating conditions for recording infrared spectra have been determined in a statistical study. Slits should be set as wide as consistent with analytical requirements but short of causing pen oscillation. Zero transmittance should be set with the help of a transmission reference, such as a screen. Suppression value and mode of slit operation do not significantly affect error. With these procedures, spectra can be recorded with a precision of 0.25% transmittance.