In the practice of analytical Raman spectroscopy, it becomes increasingly important to employ a procedure for the correction of the relative intensity of Raman spectra. The determination of the intensity response function of a Raman instrument traditionally has been carried out through a white light source that has been calibrated for its relative spectral irradiance. While this method will furnish a correction curve to yield spectra corrected to relative Raman intensity, it is often cumbersome and fraught with experimental difficulties that can profoundly affect the reliability of the correction procedure. An alternate methodology that permits a simplified calibration of the Raman instrument response function is based on the use of luminescent glass standards that transfer a white light calibration onto the Raman measurement system. In this procedure, a measurement of the luminescence of an intensity standard, whose relative irradiance has been determined, provides a means to establish the instrument response function. This function then serves to correct the sample spectrum to the true relative Raman intensity. Based on this approach, NIST is developing a series of Standard Reference Materials (SRMs) for the calibration of Raman intensity. This process, and the results obtained therefrom, is described for Raman spectroscopy measurements employing 785 nm excitation. The procedure is valid for both macro-sampling and micro-sampling Raman work.
Citation: ACTA Microbiologica Polonica
Issue: No. 3-4
Pub Type: Journals
employing 785 nm excitation, intensity calibration, intensity standards, luminescent glasses, raman spectroscopy, Standard Reference Materials