Uv Light Absorption
Uv Light Absorption - Related Videos
05:09
A Riboflavin and UV Light Treatment of Platelet Products to Eliminate Bacteria
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2025
This video demonstrates the riboflavin and UV light-based pathogen reduction process against high-titer bacterial contamination in human platelet products. This process could help to lower the risk of severe adverse transfusion events associated with bacterial contamination.
10:32
Treatment of Platelet Products with Riboflavin and UV Light: Effectiveness Against High Titer Bacterial Contamination
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Cited by 19 •
2015
The storage conditions of platelet products create an ideal environment for bacterial contaminants to multiply to dangerous levels. The goal of this study was to use a colony forming assay to evaluate a riboflavin based pathogen reduction process against high titer bacterial contamination in human platelet products.
11:34
Scattering And Absorption of Light in Planetary Regoliths
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Cited by 12 •
2019
Numerical and experimental methods are presented for multiple scattering of light in discrete random media of densely-packed particles. The methods are utilized to interpret the observations of asteroid (4) Vesta and comet 67P/Churyumov-Gerasimenko.
04:55
UV-Vis Spectroscopy of Dyes - Concepts
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2020
Absorbance When light interacts with a substance, a portion of the light is absorbed while the rest is either reflected or transmitted through it. Substances that we perceive as having a color reflect light in the visible range. The color of the substance that we are able to see depends on which wavelength of light is reflected. A substance that we perceive as blue reflects light in the blue range (430 – 480 nm) of the visible spectrum. According to the color wheel, the same substance absorbs...
09:52
UV-Vis Spectroscopy of Dyes - Student Protocol
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2020
Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA Absorbance Wavelength ComparisonExpand In the first part of the lab, you'll use ultraviolet and visible light absorption spectroscopy, or UV-Vis absorption spectroscopy, to analyze the absorption characteristics of fluorescein, β-carotene, and indigo dye. To perform UV-Vis spectroscopy, you'll place a solution between a light source and a photodetector. The molecules will absorb light at...
FAQs
The absorbed wavelength reflects the energy gap between molecular orbitals. A photon can promote an electron only when its energy matches an allowed transition, such as movement from a bonding or nonbonding orbital into an antibonding orbital. Consequently, the absorption pattern provides evidence about electronic structure rather than merely indicating that radiation was present.
Conjugation changes the electronic structure of a molecule, so conjugated systems and chromophores can produce characteristic absorption wavelengths. A chromophore is the part of a molecule associated with an observable absorption feature. Examining where these features occur helps chemists compare compounds and relate spectral behavior to structural differences.
Changes in a molecule’s chemical environment can alter its absorption pattern, even when the absorbing region remains associated with the same general chromophore. For this reason, UV light absorption can support interpretation of molecular structure and molecular interactions. The spectrum is therefore useful as chemical information, not simply as a signal of light intensity.
A researcher records the sample’s absorption pattern across relevant ultraviolet wavelengths, then examines the positions and intensities of its features. Those observations can be compared with expected molecular electronic behavior to identify compounds or assess chemical environment. Repeating measurements during a reaction allows changes in the spectrum to track chemical progress.
The Beer-Lambert law links measured absorbance with concentration, allowing a UV-visible measurement to move beyond qualitative identification. When a sample’s absorbance is determined, the relationship provides a basis for estimating how much of the absorbing compound is present. This quantitative role is useful when chemical analysis requires concentration information rather than structure alone.
In pharmaceutical analysis, absorption measurements can help identify compounds and determine their concentrations. Environmental testing uses the same spectroscopic information to examine chemical samples, while reaction studies follow changing absorption patterns as transformations occur. The method also supports investigations of molecular structure and interactions, connecting measurable spectral features with broader chemical behavior.