Method of Raman spectrospy

A non-transitory computer-readable medium storing instructions that, when executed by one or more programmable processors, cause the one or more programmable processors to perform operations for performing a method of Raman spectroscopy comprising determining and providing Raman difference spectra for performing Raman spectroscopic measurements of at least one measurand of a medium in at least one application, wherein measured spectra of the medium include contributions of interfering influences that at least partially obscure spectra features associated to the at least one measurand, based on at least one measured spectrum of the medium determined by a Raman spectrometer and a reference spectrum of the contributions of the interfering influences included in a respective measured spectrum, the operations comprising:

• determining a second derivative with respect to a spectral line of a difference spectrum function corresponding to a difference between the respective measured spectrum and the product of a scaling coefficient and the reference spectrum;
• determining a coefficient value of the scaling coefficient corresponding to a magnitude of the contributions of the interfering influences included in the respective measured spectrum such that the coefficient value minimizes an error function representing an error of the difference spectrum function as a function of the scaling coefficient, wherein the error function includes a first term corresponding to an error exhibited by the difference spectrum function due to peaks included in the reference spectrum, the first term including at least one of:
• a first sum of areas enclosed underneath the second derivative of the difference spectrum function in all spectral regions in which the second derivative of the difference spectrum function is positive;
• and
• a second sum of areas enclosed underneath the second derivative of the difference spectrum function in all spectral regions in which the second derivative of the difference spectrum function is negative;
• and
• for at least one measured spectrum determined by the Raman spectrometer, determining and providing a Raman difference spectrum corresponding to the difference between the respective measured spectrum and the product of the coefficient value and the reference spectrum.