S oxhlet and Ultrasonic Extraction of Organics in Solids

Abstract

Soxhlet extraction is the removal and recovery of organic analytes from a permeable solid matrix by means of a solvent which is continually evaporated from a still‐pot and condensed in such a manner that it falls into and permeates through the matrix which itself is held in a permeable container in a siphonable chamber. Soxhlet extraction has been used for over 120 years (since 1879) and is commonly used as a benchmark for total extractable organic residues. Ultrasonic extraction is the removal and recovery of organic analytes from a permeable solid matrix by means of a solvent which is energized by sound energy at frequencies in excess of those audible to the human ear. Energy may be introduced into the sample by means of an ultrasonic probe which is inserted into the sample or an ultrasonic bath into which the sample plus solvent is immersed. The ultrasonic energy may be strong enough to disrupt and pulverize the matrix, thus increasing the extractability of the analyte. The operation of the Soxhlet extractor is intuitively easy to grasp. Extraction is viewed as being complete or close to complete. Ultrasonic extraction is convenient and straightforward. Ultrasonic baths provide relatively reliable sources of extraction energy. Soxhlet extraction is solvent intensive and requires laboratory facilities in which flammable and toxic solvents can be used safely. The glassware required is expensive and vulnerable to breakage. Cooling of the condenser of the Soxhlet apparatus requires a constant supply of cooling water. Residues are concentrated in the still‐pot and are thus vulnerable to thermal degradation. Only total residue can be extracted by Soxhlet extraction; little or no speciation is possible. Ultrasonic extraction must be performed under conditions which protect the hearing of laboratory personnel. The ultrasonic generator may generate heat which may affect the extraction process. Ultrasonic probes become pitted when used for the extraction of abrasive matrices such as soil, thus changing the energy generated and affecting the extraction efficiency of the procedure. Ultrasonic baths provide less intense extraction energy. Extraction of total residue is the aim of ultrasonic extraction; little or no speciation is possible.

Methods for Testing the Quality Attributes of Plant-Based Foods: Meat- and Processed-Meat Analogs

“…The extracted fat is subsequently determined gravimetrically. To decrease the extraction time, devices are available that utilize sonication to breakdown the structure, or apply high-pressure to achieve higher boiling points and consequently higher extraction temperatures [ 42 ].…”

The Effects of Soxhlet and Power Ultrasonic-Assisted Soxhlet Extraction on the Yield of Terpenoids Extract from Jasminum Sambac

“…Nasrul Fikry Che Pa, Teh Jian Hong, Syeed Saifulazry Osman Al Edrus and Siti Khatini Abd Talib technologies where one of the extraction methods is the power ultrasonic extraction. Power ultrasonic extraction is the removal and recovery of organic compounds from a permeable solid matrix using sound energy in high frequency [7]. The equipment which adopted the ultrasonication principle is the power ultrasonic probe sonicator system.…”

Comparison of three different protocols of alkaloid extraction from Glaucium corniculatum plant

“…This is mainly because it is very easy to carry out, and a formally recognized method used for the determination of a wide range of alkaloid content. In the Soxhlet extraction method, the solvent contacts the soluble sample directly, and the bioactive compounds in the sample are extracted directly into the solvent (Webster, 2006). Khamtache-Abderrahim et al (2016) recommended a Soxhlet protocol for the extraction of alkaloids from plants ( Khamtache-Abderrahim et al, 2016).…”

“…Ultrasonic extraction involves the transfer of bioactive components from a permeable solid matrix to the solvent through sound energy (Webster, 2006). Recently, innovative extractions, such as ultrasound extraction, have been shown to be an alternative to conventional procedures for the extraction of bioactive alkaloids from plants because they are more efficient and faster than conventional procedures.…”