Ultrasound Assisted Extraction

In liquid-solid extraction (LSE) the analyte is extracted from the solid by a liquid, which is separated by filtration. Numerous extraction processes, representing various types and levels of energy, have been described steam distillation, simultaneous steam distillation-solvent extraction (SDE), passive hot solvent extraction, forced-flow leaching, (automated) Soxh-let extraction, shake-flask method, mechanically agitated reflux extraction, ultrasound-assisted extraction, y -ray-assisted extraction, microwave-assisted extraction (MAE), microwave-enhanced extraction (Soxwave ), microwave-assisted process (MAP ), gas-phase MAE, enhanced fluidity extraction, hot (subcritical) water extraction, supercritical fluid extraction (SFE), supercritical assisted liquid extraction, pressurised hot water extraction, enhanced solvent extraction (ESE ), solu-tion/precipitation, etc. The most successful systems are described in Sections 3.3.3-3.4.6. Other, less frequently... 

Stage Fraction/exfractant Conventional extraction Ultrasound- assisted extraction Microwave- assisted extraction... 

Reversed-phase high-performance liquid chromatography Scoville heat unit Solid-phase micro extraction Ultrasound-assisted extraction Ultra-high-performance liquid chromatography Ultra-performance liquid chromatography combined with mass spectrometry Ultraviolet... 

Alcohol reflux extraction, ultrasound assisted extraction, Soxhlet extraction and supercritical fluid extraction (SPE) are the main teehniques used to isolate triterpenoids from Cornus spp. fimits [Zhao et al., 2005], Thin layer chromatography (TEC), HPLC and cyclodextrin-modified micellar eleetrokinetie ehromatography (CD-MEKC) have also been apphed for separation and determination of these three triterpenic acids in Iriiits [Zhang et al., 2005 Wang et al., 2008]. The isolated triterpenie compounds and their glycosides were identified by speetroscopie analysis NMR, IR and MS. 

Saponification—Liquid-hquid extraction Soxhlet extraction Ultrasound-assisted extraction Microwave-assisted extraction Pressurized liquid extraction Supercritical fluid extraction Matrix solid-phase dispersion... 

Hromadkova, Z., Kovacikova, J. Ebringerova, A. (1999). Study of the classical and ultrasound-assisted extraction of the corn cob xylan. Industrial Crops and Products, Vol. 9, 2, (Januar 1999), pp. (101-109), ISSN 0926-6690... 

General trends are focused on reduced-solvent extractions or adsorption-based methods — enviromnentaUy friendly solvents for both solid and liquid samples. In recent decades, advanced techniques like supercritical fluid extraction (SFE), ° pressurized liquid extraction (PLE)," microwave-assisted extraction (MAE), ultrasound-assisted extraction, countercurrent continued extraction (www.niroinc.com), solid... 

Peres, V.P. et al.. Comparison of soxhlet, ultrasound-assisted and pressurized liquid extraction of terpenes, fatty acids and vitamin E from Piper gaudichaudianum Kunth, J. Chromatogr. A, 1105, 115, 2006. 

Herrera MC and Luque de Castro MD. 2005. Ultrasound-assisted extraction of phenolic compounds from strawberries prior to liquid chromatographic separation and photodiode array ultraviolet detection. J Chromatogr A 1100(1) 1 —7. 

Previous investigations of heterogeneous sonochemistry have involved ultrasonic extraction of pollutants from sediments and ultrasound assisted reactions employing solid catalysts. However, more extensive quantitative results are needed concerning sonochemistry in environmentally relevant systems. We report results of a preliminary set of experiments, involving the ultrasonic irradiation of bromobenzene, trichloroacetonitrile, and chloropicrin in the presence of silica solids (15 im and 10 nm). 

Londono-Londono J, Rodrigues de Lima V, Lara O, Gil A, Pasa TBC, Arango GJ, Pineda JRR (2009) Clean recovery of antioxidant flavonoids from citrus peel optimizing an aqueous ultrasound-assisted extraction method. J Food Chem. doi 10.1016/j.foodchem.2009.05.075... 

Ultrasound-assisted extraction is a rapid technique that can also be used with mixtures of immiscible solvents hexane with methanol-water (9 1), for example, is a system used for the Brazilian plant Lychnophora ericoides (Asteraceae). The hexane phase concentrated less polar sesquiterpene lactones and hydrocarbons, while the aqueous alcohol phase concentrated flavonoids and more polar sesquiterpene lactones. 

The experimental design was used to set the conditions to implement a dynamic continuous, ultrasound-assisted acid extraction... 

An ultrasound-assisted acid extraction was studied with the designs, after which the setup was established... 

D. Hristozov, C. E. Domini, V. Kmetov, V. Stefanova, D. Georgieva and A. Canals, Direct ultrasound-assisted extraction of heavy metals from sewage sludge samples for ICP-OES analysis. Anal. Chim. Acta, 516(1-2), 2004, 187-196. 

Yebra-Biurrun and S. Cancela-Perez, Continuous approach for ultrasound-assisted acid extraction-minicolumn preconcentration of... 

S. Cancela and M. C. Yebra, Flow-injection flame atomic absorption spectrometric determination of trace amounts of cadmium in solid and semisolid milk products coupling a continuous ultrasound-assisted extraction system with the online preconcentration on a chelating ami-nomethylphosphoric acid resin, J. AO AC Int., 89(1), 2006, 185-191. 

M. C. Yebra and S. Cancela, Continuous ultrasound-assisted extraction of cadmium from legumes and dried fruit samples coupled with on-line preconcentration-flame atomic absorption spectrometry, Anal. Bioanal. Chem., 382(4), 2005, 1093-1098. 

M. C. Yebra-Biurrun, A. Moreno-Cid and S. Cancela-Perez, Fast on-line ultrasound-assisted extraction coupled to a flow injection-atomic absorption spectrometric system for zinc determination in meat samples, Talanta, 66(3), 2005, 691-695. 

M. C. Yebra, A. Moreno-Cid and S. Cancela, Flow injection determination of copper and iron in seafoods by a continuous ultrasound-assisted extraction system coupled to FAAS, Int. J. Environ. Anal. Chem., 85(4-5), 2005, 315-323. 

M. C. Yebra and A. Moreno-Cid, Continuous ultrasound-assisted extraction of iron from mussel samples coupled to a flow injection-atomic spectrometric system, J. Anal. At. Spectrom., 17(10), 2002, 1425-1428. 

A continuous ultrasound-assisted extraction system connected to a flow injection manifold was implemented and relevant parameters were studied by the experimental design... 

The leaching conditions of a ultrasound-assisted device were studied to obtain the best experimental settings Microwave acid extraction was implemented to recover metals from solid materials. The operational conditions needed to form the hydrides were set after ana-... 

Extraction and Isolation of Polyphenolics Basic Protocol 1 Ultrasound-Assisted Aqueous Methanol Extraction of 11.2.1... 

ULTRASOUND-ASSISTED AQUEOUS METHANOL EXTRACTION OF POLYPHENOLICS... 

Ultrasound-assisted extraction provides efficient extraction in a shorter processing time than is needed for conventional extraction. The aid of ultrasound will result in a higher extraction yield and reduce solvent consumption. The extract may exhibit a wide range of colors (pale yellow, brown, red). For anthocyanin extraction in an acidic environment, the extract will be deep red, pink, or purple. The extract may contain considerable amounts of lipophilic compounds (e.g., chlorophyll, carotenoids, lipids). Prior to solid-phase extraction, those compounds can be eliminated from the extracts using liquid-liquid extraction. 

The ultrasound-assisted extraction of freeze-dried plant-based materials normally takes 2 hr. If the extract is evaporated to dryness, a total of 3 hr is necessary. As an additional sample preparation step, 2 to 4 days should be allotted for freeze-drying fresh plant materials, depending on the quantity of the material. Homogenizer-assisted extraction of fresh fruit takes <4 hr. 

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