Ultrasonically-Assisted Cloud Point Extraction

Cloud point extraction (CPE) is an pre-analytical procedure to separate and pre-concetrate analytes. In combination with ultrasonication, cloud point extraction can be intensified making the process more efficient, faster, and environment-friendlier. Ultrasonically-assisted cloud point extraction reduces solvent consumption and extraction time and also provides high enrichment factors for analytes significantly.

How Does Cloud Point Extraction Work?

Cloud point extraction (CPE) is a separation technique used for the extraction and preconcentration of analytes from a sample matrix. This method involves the formation of a cloud of micelles or liquid crystal aggregates in the sample matrix at a specific temperature known as the cloud point. The analytes are solubilized in the micellar phase, which can be separated from the sample matrix by centrifugation or filtration.
The CPE technique can be applied to a variety of sample matrices, including water, biological fluids, and environmental samples. It is commonly used for the extraction of organic compounds, such as phenols, polycyclic aromatic hydrocarbons (PAHs), and pesticides, from complex matrices.
What Means Cloud Point Extraction?
Cloud point extraction uses the physical transformation of liquids at a certain temperature, where the liquid turns cloudy. The cloud point in liquids is the temperature below which a transparent solution undergoes either a liquid-liquid phase separation to form an emulsion or a liquid-solid phase transition to form either a stable sol or a suspension that settles a precipitate.
Working Principle of Cloud Point Extraction: Cloud point extraction (CPE) uses the specific phase behaviour of nonionic surfactants in aqueous solutions, which shows phase separation after attaining a particular temperaturethe so-called cloud pointand/or the addition of a chelating agent. The main driver of separation during cloud point extraction is caused by the hydrophobic interaction between the analyte and surfactant, which allows capturing the analytes in the form of various metal complexes in the non-ionic surfactant rich phase.
CPE has several advantages over traditional extraction methods, such as solid-phase extraction and liquid-liquid extraction. It is a simple and cost-effective technique that requires only a small amount of organic solvents. It can also be used for the selective extraction of specific analytes and can be easily combined with other analytical techniques, such as chromatography and spectroscopy, for the quantitative analysis of analytes.
However, CPE also has some limitations, such as the need for careful control of temperature and the possibility of interference from other matrix components. Despite these limitations, CPE is a promising technology, which can be even made more efficient when combines with sonication.

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Ultrasonic CupHorn for the simultaneous sample preparation of multiple samples under same conditions for cloud point extraction of analytes.

The Ultrasonic CupHorn facilitates cloud point extraction as it allows for simultaneous sample preparation of several vials under the same conditions

How Does Sonication Make Cloud Point Extraction More Efficient?

Ultrasonicator UP100H is a lab homogeniser often used for sample preparation of cell culture plates.Ultrasonication can be used to assist and improve cloud point extraction (CPE) in several ways. Ultrasonication involves the use of high-frequency sound waves to create cavitation bubbles in a liquid medium. When these bubbles collapse, they generate localized high temperatures and pressures that can disrupt the sample matrix and enhance the solubilization of analytes in the micellar phase during CPE.
Here are some ways in which ultrasonication can assist and improve CPE:

  1. Enhance Micelle Formation: Ultrasonication can enhance the formation of micelles by increasing the contact between the surfactant molecules and the sample matrix. This can lead to faster and more efficient solubilization of analytes in the micellar phase, resulting in higher extraction yields.
  2. Reduce Extraction Time: Ultrasonication can reduce the extraction time required for CPE by accelerating the mass transfer of analytes from the sample matrix to the micellar phase. This is due to the mechanical effects of ultrasonication on the sample matrix, which can disrupt the intermolecular forces that hold the analytes in the matrix.
  3. Improve Extraction Efficiency: Ultrasonication can improve the extraction efficiency of CPE by enhancing the contact between the surfactant molecules and the analytes. This can lead to a more complete solubilization of analytes in the micellar phase, resulting in higher extraction efficiencies.
  4. Increase Sensitivity: Ultrasonication can increase the sensitivity of CPE by improving the preconcentration of analytes in the micellar phase. This can allow for the detection of analytes at lower concentrations than would be possible without preconcentration.

Overall, ultrasonication can be a useful tool for improving the performance of CPE by enhancing micelle formation, reducing extraction time, improving extraction efficiency, and increasing sensitivity.

This video clip shows the Hielscher ultrasonic homogenizer UP100H, an ultrasonicator widely used for sample preparation in laboratories.

Ultrasonic Homogenizer UP100H

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This tutorial explains what type of sonicator is best for your sample preparation tasks such as lysis, cell disruption, protein isolation, DNA and RNA fragmentation in laboratories, analysis, and research. Choose the ideal sonicator type for your application, sample volume, sample number and throughput. Hielscher Ultrasonics has the ideal ultrasonic homogenizer for you!

How to Find the Perfect Sonicator for Cell Disruption and Protein Extraction in Science and Analysis

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Find the Right Ultrasonicator for Your Cloud Point Extraction

Hielscher Ultrasonics offers various sophisticated ultrasonic solutions for an efficient, time-saving and user-friendly sample preparation for cloud point extraction and pre-analysis. Wether you want to sonicate single samples, multiple samples or microtiter / multi-well plates for cloud point extraction, we have the ideal ultrasonicator for your extraction procedure.
The table below gives you an overview over our ultrasonicators for sample preparation and extraction. Click at the device type to get more information on each ultrasonic homogenizer. Our well-trained and long-time experiences technical staff will be glad to help you choosing the most suitable ultrasonicator for your sample preparation!

Batch VolumeFlow RateRecommended Devices
up to 10 vials or tubesn.a.VialTweeter
multiwell / microtiter platesn.a.UIP400MTP
multiple tubes / vesselsn.a.CupHorn
1 to 500mL10 to 200mL/minUP100H
10 to 1000mL20 to 200mL/minUP200Ht, UP200St
10 to 2000mL20 to 400mL/minUP400St

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The video shows the ultrasonic sample preparation system UIP400MTP, which allows for the reliable sample preparation of any standard multi-well plates using high-intensity ultrasound. Typical applications of the UIP400MTP include cell lysis, DNA, RNA, and chromatin shearing as well as protein extraction.

Ultrasonicator UIP400MTP for multi-well plate sonication

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VialTweeter at the ultrasonic processor UP200ST

The VialTweeter is an ultrasonic multi-sample preparation unit for the simultaneous sonication of 10 test tubes.

High performance ultrasonics! Hielscher's product range covers the full spectrum from the compact lab ultrasonicator over bench-top units to full-industrial ultrasonic systems.

Hielscher Ultrasonics manufactures high-performance ultrasonic homogenizers from lab to industrial size.

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