Characteristics of ultrasonic extraction
Ultrasonic action on liquid-liquid, liquid-solid two-phase, multi-phase system, surface system and membrane interface system will produce a series of physical and chemical effects, and generate various additional effects such as turbulence effect and perturbation in the micro-environment. Effects, interfacial effects, and energy-concentration effects are not easily obtained by some conventional means.
Ultrasonic extraction technology is fast, inexpensive, and efficient compared to conventional extraction techniques.
Compared with Soxhlet extraction, its main advantages are: 1 hole formation, enhance the polarity of the system, improve the extraction efficiency, and make it meet or exceed the efficiency of Soxhlet extraction; 2 ultrasonic extraction allows the addition of co-extractant to further Increase the polarity of the solvent; 3 is suitable for the extraction of the test component which is not heat resistant; 4 operation time is shorter than Soxhlet extraction, usually only 24 to 40 minutes.
Ultrasonic extraction and supercritical fluid extraction (SFE) comparison: 1 instrument is simple, the extraction cost is much lower; 2 can extract a variety of compounds, regardless of their polarity, because ultrasonic extraction can use a lot of solvents. SFE is mainly extracted with CO2 The agent is basically only suitable for the extraction of non-polar substances.
Ultrasonic extraction and microwave-assisted extraction comparison: 1 In some cases, faster than microwave-assisted extraction; 2 acid digestion, ultrasonic extraction is safer than conventional microwave-assisted extraction.
Ultrasonic extraction has wide adaptability and is not limited by the polarity of the target component and the molecular weight. In addition, the extract has less impurities, and the components to be tested are easily separated and purified. Ultrasonic extraction can eliminate or reduce the use of extractants to reduce the environmental pollution of solvents.