Method for measuring freezing points of perfumes, essential oil and composite essential oil

The invention provides a method for measuring freezing points of perfumes, essential oil and composite essential oil. The method comprises the following steps: (1) putting a sample of to-be-measured liquid-state perfumes, essential oil or composite essential oil into a test tube which is cleaned and dried, putting a magnetic stirrer into the test tube, inserting a temperature probe into the to-be-measured sample, inserting a turbidity probe into the test tube, sealing the opening of the test tube and putting the test tube into a reaction tank of a multi-tube parallel reaction workstation; (2) starting magnetic stirring, and cooling the to-be-measured sample under continuous stirring until crystals are precipitated in the test tube and the liquid becomes turbid; and (3) slowly and continuously heating until the liquid in the test tube is completely clarified, thereby obtaining a freezing point detection value according to the temperature measured by the corresponding temperature probe when infrared transmittance which is measured by the turbidity probe turns. The method provided by the invention has the characteristics of convenience in operation, easiness in temperature control, accurate and reliable detection result and high sensitivity.