Size Fractionation
Size Fractionation - Related Videos
08:38
Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions
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Cited by 8 •
2019
Combined size and density fractionation (CSDF) is a method to physically separate soil into fractions differing in texture (particle size) and mineralogy (density). The purpose is to isolate fractions with different reactivities towards soil organic matter (SOM), in order to better understand organo-mineral interactions and SOM dynamics.
10:09
Fractional Distillation
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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...
09:33
Asymmetrical Flow Field-Flow Fractionation for Sizing of Gold Nanoparticles in Suspension
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Cited by 6 •
2020
This protocol describes the use of Asymmetrical Flow Field-Flow Fractionation coupled with UV-vis detection for the determination of the size of an unknown gold nanoparticle sample.
01:25
The Anchoring-and-Adjustment Heuristic
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2020
In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000...
01:12
Adjusting a Traverse
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2025
In the site survey of a four-sided traverse, internal angles are essential to ensure geometric accuracy. The survey revealed that the sum of the measured internal angles was 359 degrees and 48 minutes, which is 12 minutes less than the expected 360 degrees. This discrepancy signals an error likely arising from measurement inaccuracies during the fieldwork.To rectify this error, the adjustment process involved distributing the 12-minute shortfall equally across the four internal angles. By...
FAQs
Separating material into size classes allows researchers to compare how fine and coarse particles transport, react, and distribute matter. These contrasts can show whether contaminants, organic matter, or nutrients are associated more strongly with particular fractions. The resulting comparisons help interpret particle mobility and clarify how physical structure contributes to environmental patterns in soils, sediments, and suspended material.
Sieves and filters separate samples using defined openings or pore sizes, whereas settling and centrifugation separate particles according to their size and behavior in a fluid. The first approach emphasizes passage through a physical barrier; the latter uses fluid-based particle behavior. Together, these options provide different ways to produce size classes from environmental materials for subsequent comparison.
Fine and coarse material can differ in contaminant associations, organic matter composition, nutrient cycling, and mobility. Measuring these fractions separately therefore reveals patterns that may be obscured in an unsorted sample. The comparison is especially useful when researchers need to determine whether an observed environmental property is distributed broadly across a sample or concentrated within particular particle-size groups.
Defined pore sizes establish the boundaries between collected size classes when filters or sieves are used. Because each fraction corresponds to a specified physical range, researchers can compare measurements consistently across portions of a sample. This standardization supports interpretation of contaminant, organic matter, nutrient, and mobility patterns without treating the entire environmental material as uniform.
Researchers begin with an environmental sample, such as soil, sediment, or suspended particles, and expose it to sieves or filters with defined openings. Depending on the separation approach, they may instead use settling or centrifugation in a fluid. The resulting size groups are then characterized and compared for composition, associations, nutrient cycling, or mobility.
The sample may consist of soil, sediment, suspended particles, or another environmental material. Separation equipment includes sieves or filters with defined pore sizes; settling and centrifugation provide fluid-based alternatives. These components determine how the sample is divided and create the size classes used for subsequent measurements, allowing researchers to focus their analysis on particle-size differences.
Researchers can use measurements from separate size classes to examine contaminant associations, organic matter composition, nutrient cycling, and particle mobility. In pollution studies, the comparisons help relate contaminants to the material carrying them. In ecosystem studies, they support analysis of how nutrients and organic matter are distributed across fine and coarse fractions, improving interpretation of environmental processes.