OPTICAL DESIGN AND SAMPLING METHODS FOR THE MEASUREMENT OF VIBRATIONAL CIRCULAR-DICHROISM WITH A NICOLET MAGNA FT-IR SPECTROMETER

A modified design for a Fourier-transform vibrational circular dichroi sm (FT-VCD) spectrometer is presented. The FT-VCD instrument is based on a Nicolet Magna-IR 550 equipped with an external bench for the meas urement of VCD spectra. VCD spectra of high signal quality were obtain ed with 20 minutes of collection rime at 4 cm(-1) resolution in the mi d-infrared region by conventional sequential collection of rapid-scan VCD and transmission interferograms, the simultaneous collection of th ese rapid-scan interferograms and step-scan collection. OF these three methods the simultaneous rapid-scan exhibited the lowest levels of no ise.