Ultrasound-enhanced supercritical CO2 was used to extract the essential oil of masson pine. The extraction technology was optimized through orthogonal experiments. The results showed that a good outcome can be achieved with an extraction pressure of 18 MPa, a temperature of 60 degrees C, a time of 90 min, a CO2 flow rate of 12 kg h(-1), an ultrasonic power of 250 W and an ultrasonic frequency of 22 KHz. Using these parameters, the average yield of essential oil was 88.12 %. GC-MS analysis showed that the ingredient with the highest content of 44.42% was longifolene in the essential oil of mass...
