A quality control method for a diisononyl phthalate includes a measuring step of irradiating the diisononyl phthalate with a laser to measure a Raman spectrum; and an acceptance or rejection decision step of determining an acceptance or a rejection of a quality of the diisononyl phthalate on the basis of a high and low intensity relationship between an intensity of a first spectral peak, which is ascribed to a vibration of molecular chains in a straight chain hydrocarbon, and an intensity of a second spectral peak, which is ascribed to a vibration of isopropyl groups, in the measured Raman spectrum.
QUALITY CONTROL METHOD FOR DIISONONYL PHTHALATE, PRODUCING METHOD FOR RESIN COMPOSITION, RESIN COMPOSITION, AND CABLE OR TUBE