Vapor Phase Extraction
Vapor Phase Extraction - Related Videos
02:39
Phase Transitions: Vaporization and Condensation
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2020
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
02:34
Vapor Pressure
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2020
When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally collide with the surface of the condensed phase, and in some cases, these collisions will result in the molecules re-entering the condensed phase. The change from the gas phase to the liquid is called condensation. When the rate of condensation becomes equal to the rate of vaporization, neither the amount of the liquid nor the amount of the vapor...
11:32
Vapor-liquid Equilibrium
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2023
Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Vapor-liquid equilibrium is paramount in engineering applications such as distillation, environmental modeling, and general process design. Understanding the interactions of components in a mixture is very important in designing, operating and analyzing such separators. The activity coefficient is an excellent tool for relating molecular interactions to mixture...
01:18
Vaporization
0 Views •
2019
The physical form of a substance changes by changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. For vaporization to occur, kinetic energy must be greater than the intermolecular forces that keep molecules bonded. The amount of energy needed to vaporize a quantity of liquid at a given pressure and a constant temperature is called the heat of vaporization. When...
08:28
Synthesis of Phase-shift Nanoemulsions with Narrow Size Distributions for Acoustic Droplet Vaporization and Bubble-enhanced Ultrasound-mediated Ablation
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Cited by 18 •
2012
Phase-shift nanoemulsions (PSNE) can be vaporized using high intensity focused ultrasound to enhance localized heating and improve thermal ablation in tumors. In this report, the preparation of stable PSNE with a narrow size distribution is described. Furthermore, the impact of vaporized PSNE on ultrasound-mediated ablation is demonstrated in tissue-mimicking phantoms.
FAQs
Compounds partition differently between the biological sample and its surrounding gas phase. More volatile analytes are more likely to move into the headspace, while affinity for the sample matrix or collection material influences how efficiently they are transferred and retained. These relationships determine which metabolites, signaling molecules, or exposures become available for subsequent instrumental analysis.
Incubation or controlled heating provides the conditions that allow analytes to redistribute between the biological matrix and the gas phase. The resulting headspace composition reflects both compound volatility and interactions with the sample and collection material. This step therefore affects which chemical signals are concentrated for analysis and enables comparisons among biological samples prepared under consistent conditions.
A sorbent captures analytes after they leave the biological sample and enter the gas phase. This collection step concentrates volatile and semi-volatile compounds and separates them from much of the original tissue, fluid, or culture-medium matrix. The retained compounds can then be released for instrumental analysis, supporting chemical profiling with reduced interference from complex biological samples.
The method transfers target compounds away from complex tissues, biological fluids, or culture media before instrumental measurement. Because the collected material comes from the headspace rather than the entire original matrix, unwanted sample components may contribute less interference. This separation is especially relevant when researchers need to compare chemical profiles or detect biological-state differences.
A typical workflow begins with a biological sample and an incubation or controlled-heating period that promotes analyte transfer into the headspace. A sorbent then captures the volatile or semi-volatile compounds present in that gas phase. Finally, the collected analytes are released and directed to instrumental analysis, often as part of chromatographic profiling.
Researchers may choose Vapor Phase Extraction when a study targets volatile or semi-volatile metabolites, signaling molecules, or chemical exposures in complex biological samples. It is relevant to metabolomics and biomarker research because it can concentrate chemical information while limiting matrix interference. The approach also supports environmental toxicology investigations involving biological exposure measurements.
The resulting chromatographic profiles can reveal differences in the volatile and semi-volatile chemical composition of biological samples. Researchers can compare profiles associated with distinct biological states, such as differing sample conditions or exposure contexts. These comparisons may help identify candidate metabolites, signaling compounds, or chemical exposure patterns for further biomarker or toxicology research.