Water-accommodated Fraction
Water-accommodated Fraction - Related Videos
08:17
Chemical Analysis of Water-accommodated Fractions of Crude Oil Spills Using TIMS-FT-ICR MS
0 Views •
Cited by 10 •
2017
The low-energy water-accommodated fraction (LEWAF) of crude oil is a challenging system to analyze, because over time, this complex mixture undergoes chemical transformations. This protocol illustrates methods for the preparation of the LEWAF sample and for performing photo-irradiation and chemical analysis by trapped ion mobility spectrometry–FT-ICR MS.
10:09
Fractional Distillation
0 Views •
2023
Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation...
07:57
Using the GELFREE 8100 Fractionation System for Molecular Weight-Based Fractionation with Liquid Phase Recovery
0 Views •
Cited by 17 •
2009
The accompanying video describes the use of the GELFREE 8100 Fractionation System, which partitions complex protein samples on the basis of molecular weight and recovers the fractions in liquid phase. The video describes how the technology works, how it is used, and provides resultant data, with polyacrylamide gel electrophoresis analysis of fractionated bovine liver homogenate.
05:14
Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher
0 Views •
Cited by 9 •
2018
We present an efficient method of studying lens accommodation by using a manual lens stretcher. The protocol mimics physiological accommodation by pulling the zonules connected around the lens capsule, thereby, stretching the lens.
08:27
Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
0 Views •
Cited by 2 •
2023
VisualEyes2020 (VE2020) is a custom scripting language that presents, records, and synchronizes visual eye movement stimuli. VE2020 provides stimuli for conjugate eye movements (saccades and smooth pursuit), disconjugate eye movements (vergence), accommodation, and combinations of each. Two analysis programs unify the data processing from the eye tracking and accommodation recording systems.
FAQs
Mixing allows constituents from a poorly water-soluble substance to transfer into the surrounding water. After mixing, the aqueous phase contains compounds that entered solution along with stable water-dispersed components. The intensity and control of mixing therefore help determine which parts of a complex material become available for aquatic exposure, while larger undissolved material can be excluded during separation.
The separated phase retains dissolved compounds and stable components that remain dispersed in water. Undissolved portions of the original substance are removed rather than treated as part of the aqueous exposure preparation. This distinction matters biologically because aquatic organisms are evaluated against the water-associated portion of the material, not against the entire bulk substance placed into the system.
It allows investigators to examine the combined aquatic presence of constituents in materials whose individual components may be difficult to isolate or characterize. Rather than reducing a petroleum product, oil, or chemical mixture to selected compounds, the preparation preserves a water-associated exposure that can better represent how the material enters an aquatic test environment.
Preparation begins by combining the poorly water-soluble substance with water under controlled stirring or mixing. The mixture is then allowed to provide an aqueous phase containing transferred and stably dispersed components, while undissolved material remains separate. Investigators collect the water-associated phase for subsequent biological or ecotoxicological assessment rather than testing the unseparated mixture.
This approach is useful when the test material is a complex petroleum product, oil, or chemical mixture and its individual constituents are difficult to isolate or characterize. Studying the prepared aqueous phase can provide a more practical representation of exposure from the whole material, helping researchers evaluate effects without requiring complete separation of every component.
In aquatic biology and environmental toxicology, the preparation supplies a controlled water-associated exposure for studies involving aquatic organisms. It is especially relevant when poorly soluble materials would otherwise be difficult to introduce into water consistently. Results can help assess the biological effects associated with petroleum products, oils, and chemical mixtures under conditions that reflect their aqueous presence.