Uv-visible Detector
Uv-visible Detector - Related Videos
09:21
Ultraviolet-Visible (UV-Vis) Spectroscopy
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2023
Source: Laboratory of Dr. B. Jill Venton - University of Virginia Ultraviolet-visible (UV-Vis) spectroscopy is one of the most popular analytical techniques because it is very versatile and able to detect nearly every molecule. With UV-Vis spectroscopy, the UV-Vis light is passed through a sample and the transmittance of light by a sample is measured. From the transmittance (T), the absorbance can be calculated as A=-log (T). An absorbance spectrum is obtained that shows the absorbance of a...
02:51
UV-Visible Spectroscopy for Monitoring Fibrin Clot Formation
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2025
This video demonstrates the use of a UV-visible spectrophotometer for monitoring insoluble fibrin clot formation as a function of the change in the solution turbidity. The UV-visible spectrophotometer measures the solution’s absorbance over time, which represents the turbidity change due to the insoluble fibrin clot formation.
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Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
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2024
Ultraviolet–visible (UV–visible or UV–Vis) spectroscopy is an analytical technique that investigates the interaction between matter and UV–Vis light within the electromagnetic spectrum. This method is widely used for its versatility, simplicity, and relatively quick data acquisition, making it valuable for both qualitative and quantitative analysis. When UV–Vis radiation passes through a material, molecules absorb light depending on the energy required for electronic transitions. As a result...
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 Beer-Lambert law provides the basis for relating measured absorbance to the concentration of a compound. As the detector records the optical change produced by the sample, the resulting absorbance can be interpreted quantitatively when the compound responds suitably. This relationship allows chemistry researchers to move beyond detection and estimate how much analyte is present.
A compound must contain a suitable chromophore to produce a useful response in the ultraviolet or visible region. Chromophores provide the optical feature that permits the detector to distinguish and measure the compound. Consequently, compound selection and method suitability depend on whether the sample components generate an appropriate absorbance signal for identification or quantification.
These measurement modes describe different optical changes that can produce a detector response. Absorption reflects light taken up by the sample, transmission reflects light remaining after passage through it, and emission reflects light released by the sample. Selecting the relevant signal helps match the measurement to the sample behavior and the intended chemical analysis.
In spectrophotometry, light is directed through the sample and the detector records the resulting optical change. The measurement can then be expressed as absorbance and related to concentration through the Beer-Lambert law. This workflow supports assessment of sample composition and provides a reproducible basis for routine chemical measurements.
A reaction can be followed by measuring changes in its optical response over time. If reactants or products contain suitable chromophores, their changing signals provide information about reaction progress. This application allows chemists to assess how sample composition changes during the reaction rather than relying only on a final measurement.
Coupling with liquid chromatography allows compounds separated in the chromatographic process to be detected and measured when they contain suitable chromophores. The detector therefore contributes both identification and quantification information for components in a sample. This combination is useful for evaluating composition while supporting sensitivity and reproducibility in routine analytical measurements.