A library of known intrinsic spectra is provided to identify at least one known material in a sample of interest. The library includes individual intrinsic spectra channels defined by the assignment of intrinsic spectra of at least one known material, and combinations thereof, so that the assigned intrinsic spectra of each intrinsic spectra channel is correlated to at least one known material. The at least one known material is identified in the sample of interest when intrinsic spectra obtained from the sample of interest is matched to an assigned intrinsic spectra of an intrinsic spectra channel of the library of known intrinsic spectra.