Circular dichroism (CD), defined as the difference in absorption between left and right circularly polarized light, is used to spectroscopically study the structures of chiral materials. In this article, various methodologies are presented for characterizing the performance of CD spectrometers to determine (1) experimental conditions for optimal data collection, (2) noise characteristics dependent on machine parameters, (3) the relative significance of spectral data as a function of detector gain, and (4) stray light and dark current as a function of wavelength. The results of case studies of two commercial CD spectrometers (specifically, Jasco J810 and J815) are described. The analyses show that the variation of CD signal is Poisson distributed and hence can be considered shot noise. Also, optimum scan parameters are established and a weighting function of CD data significance is produced so that wavelength-dependent gain (as determined by the high tension, HT, voltage applied to the photomultiplier tube, PMT, detector) can be accommodated. Lastly, the amount of stray light and dark current for the photomultiplier tube is determined. Though specific to the Jasco CD spectrometers characterized in this study, it is expected that all CD spectrometers exhibit similar behavior and the methodology described here can be usefully applied to characterize CD spectrometers independent of manufacturer.
JULIE M DiNITTO and JOHN M KENNEY, "Noise Characterization in Circular Dichroism Spectroscopy," Appl. Spectrosc. 66, 180-187 (2012)
References are not available for this paper.
OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.