Impurity Effects
Impurity Effects - Related Videos
09:14
Glovebox and Impurity Sensors
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2023
Source: Tamara M. Powers, Department of Chemistry, Texas A&M University The glovebox provides a straightforward means to handle air- and moisture-sensitive solids and liquids. The glovebox is what it sounds like: a box with gloves attached to one or more sides, which allows the user to perform manipulations within the glovebox under an inert atmosphere. For manipulations under inert atmospheres, chemists can choose between Schlenk or high-vacuum techniques and a glovebox. Schlenk and...
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
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Cited by 14 •
2015
This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.
01:19
Pharmaceutical Alternatives: Excipients and Impurities-Related Therapeutic Nonequivalence
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2025
Pharmaceutical products contain more than just the active drug; they also contain various excipients such as binders, solubilizers, stabilizers, preservatives, and other elements. In some cases, impurities or contaminants might be present. Traditionally, quality control in pharmaceuticals has primarily focused on the analysis of the active drug, often overlooking the impact of these additional components. The recent issue with heparin contamination by over-sulfated chondroitin sulfate, a...
11:23
Purifying the Impure: Sequencing Metagenomes and Metatranscriptomes from Complex Animal-associated Samples
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Cited by 30 •
2014
Using the cystic fibrosis airway as an example, the manuscript presents a comprehensive workflow comprising a combination of metagenomic and metatranscriptomic approaches to characterize the microbial and viral communities in animal-associated samples.
02:19
Buffer Effectiveness
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2020
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised. The buffer capacity is the amount of acid or base that can be added to a given volume...
FAQs
An impurity can change the composition of a reacting system, altering the concentrations that help determine equilibrium. It may also interfere with an existing reaction pathway or introduce competing chemical behavior, so the observed outcome no longer reflects the intended reactants alone. Monitoring these changes helps chemists distinguish genuine reaction performance from results caused by contamination.
Impurities can interfere with measurements by changing the composition or properties of the sample being analyzed. As a result, the measured concentration or other reported value may not accurately represent the intended substance. Identifying and controlling these substances improves measurement accuracy and helps researchers interpret unexpected analytical results without confusing contamination with a real chemical difference.
Impurities may change melting point, boiling point, solubility, or conductivity, allowing physical measurements to reveal differences from the intended material. These changes can provide evidence that a sample is not compositionally pure, although the particular property affected depends on the chemical system. Comparing observed properties with expected behavior supports assessment of sample quality.
A practical approach is to examine unexpected composition, measurements, reaction outcomes, or physical properties for signs of contamination. Chemists can then use impurity information to guide the development of suitable purification methods and reassess the material afterward. This process supports more reliable experiments because it connects sample preparation and quality control with the behavior actually observed.
Impurity profiles are useful when evaluating reaction efficiency, product quality, and safety during chemical synthesis or manufacturing. The profile shows which unintended substances accompany the desired material and helps determine whether the process produces a consistent result. Reviewing it can also indicate whether purification is adequate before a chemical proceeds to later stages of production or use.
In pharmaceutical production and advanced-materials work, controlling unintended substances helps maintain consistent chemical composition and performance. Impurity information supports decisions about purification, product quality, and safety, while physical-property changes can signal variation between samples. Applying these checks across development and manufacturing helps researchers connect material composition with reliable outcomes rather than relying only on nominal formulation.