Vibrational bands of each quinadridone pigment have been attributed in two mixtures: PO48 and PR206. The amounts of the PV19 and quinacridone quinone components have been estimated by preresonance Raman microspectrometry.
C. Binant and A. Lautie, "Identification of Quinacridone Pigment Mixtures Using Resonance Raman Microspectrometry," Appl. Spectrosc. 43, 851-855 (1989)