Nitrogen Isotherm Analysis
Nitrogen Isotherm Analysis - Related Videos
10:41
Carbon and Nitrogen Analysis of Environmental Samples
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2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University Elemental Analysis is a method used to determine elemental composition of a material. In environmental samples such as soils, scientists are particularly interested in the amounts of two ecologically important elements, nitrogen and carbon. Elemental analysis by the flash combustion technique works by oxidizing the sample with a catalyst through combustion in a high-temperature chamber. The products of combustion are...
13:31
Soil Nutrient Analysis: Nitrogen, Phosphorus, and Potassium
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2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University In this experiment, three soil macronutrients are chemically extracted, combined with color-based reagents, then analyzed using color to determine the nutrient concentration present in the soil sample. Nitrogen, phosphorus, and potassium are the main components of soil fertilizer. These methods isolate each nutrient from the soil into a solution that can be analyzed using turbidity and color to determine the...
07:49
On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes
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Cited by 14 •
2016
A method combining comprehensive two-dimensional gas chromatography with nitrogen chemiluminescence detection has been developed and applied to on-line analysis of nitrogen containing compounds in a complex hydrocarbon matrix.
07:14
Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx
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Cited by 21 •
2016
Previous work suggests that the nitrogen isotopic composition of atmospheric nitrogen oxides might distinguish the influence of different sources in the environment. We report on an automated, mobile, field-based method for the high collection efficiency of atmospheric NOx for N isotopic analysis at an hourly time resolution.
01:49
The Nitrogen Cycle
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2019
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
FAQs
As pressure changes, the amount of nitrogen adsorbed by the solid changes according to available surface and pore space. Recording this response produces adsorption and desorption isotherms that describe how the material interacts with the gas. Comparing these curves helps chemists distinguish differences in surface area, pore structure, and overall porosity among solid samples.
The method typically uses nitrogen at 77 K so adsorption can be measured under controlled, low-temperature conditions. This temperature provides the stated basis for collecting the adsorption and desorption data used in surface characterization. Keeping the measurement condition consistent also supports meaningful comparisons of surface area and pore-related properties between materials.
Brunauer–Emmett–Teller, or BET, analysis converts part of the nitrogen adsorption data into an estimate of specific surface area. That value expresses the available surface relative to the amount of material, allowing samples to be compared quantitatively. In chemistry, it helps connect surface texture with adsorption capacity, reactivity, and related material performance.
Pore-size calculations organize the material’s internal space into micropores and mesopores while also estimating total pore volume. These measures provide complementary information: pore categories describe the size characteristics of accessible spaces, whereas total pore volume summarizes their overall capacity. Together, they help relate a solid’s pore structure to adsorption and separation behavior.
A typical workflow records how much nitrogen adsorbs onto a solid as pressure changes, then collects the corresponding desorption data as conditions are reversed. The resulting adsorption and desorption isotherms are analyzed with BET and pore-size calculations. This sequence yields estimates of specific surface area, pore-size characteristics, and total pore volume.
Chemists apply the measurements to catalysts, activated carbons, zeolites, porous polymers, and other porous solids. The same general data set supports comparison of their surface areas and pore structures, even when their chemical uses differ. Such comparisons help determine how textural differences may influence adsorption capacity, reactivity, separation performance, or storage behavior.
The results provide quantitative textural information that can be linked with a material’s chemical function. For catalysts, surface area and pore structure can be compared with reactivity; for activated carbons, zeolites, and porous polymers, the measurements help assess relationships with adsorption, separation, or storage. These connections guide comparison of materials based on measurable porosity rather than composition alone.