Ultrasonic waves due to multiple reflections form transient "points" of high pressure/temperature together with cavitation points (almost vaccum). Their creation/destruction generate strong shear forces to the samples (including sctrutural destrution) assisting extraction by facilitating contact between solvent and analites.

Thanks

Dear Lwfhp

Ultrasound-assisted extraction is an inexpensive, simple and efficient alternative to conventional extraction techniques. The ultrasound-assisted extraction can be used with any solvent for extracting a wide variety of natural compounds.

When high frequency ultrasound is employed, the extraction yield do not increase significantly however the degradation of the herb constituents is diminished. I n case of the low frequency sonication degradation becomes more important, especially when alkaloids are being extracted. This effect could be employed as a tool to help in extraction of medicinal compounds by using lower frequencies to assist in degradation of toxic alkaloids during the process.

The main benefits of use of ultrasound in solid–liquid extraction include the increase of extraction yield and faster kinetics. Ultrasound can also reduce the operating temperature allowing the extraction of thermo labile compounds.

Best Regards

Dear Lwfhp,

Ultrasound extraction is simple, cost effective, time effective and efficient method of extraction of an analyte from a particular sample. it can also be done wih different solvents and at different temperatures which can be controlled using a waterbath. However at higher times the sample gets degraded, so one must be careful and create a balance where the extracted entity is removed without destroying the inherent structure of the sample, such as pores etc.

Thank you all

Using ultrasound extraction, you can achieve following:

1. Breaking plant protection layer and cell wall.

2. Breaking Protein-and-Target compound binding.

3. Increasing extraction recovery.

5. Good for stabilizing thermos-sensitive target compounds, without the need of heating the extraction.

Best Regards,

Ying Li