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UV-Vis spectroscopy compares a sample to a reference or blank sample to determine how much discrete wavelengths of visible or ultraviolet light are absorbed or transmitted through the sample.
Different amounts of light are absorbed according to the light’s wavelength and the molecule’s structure.
The concentration of the absorbing substance can be calculated by determining the absorption spectrum of light at various wavelengths, and unidentified substances can be determined.
Information Obtained From UV-Vis Spectroscopy
Data from UV-vis spectroscopy can provide quantitative and qualitative relevant information about a specific substance or molecule.
Utilizing a reference cell makes for a more complex UV-Vis spectrometer. The reference cell uses the same substance as the sample cell and is made entirely of solvent.
In essence, it is used to reset the instrument, correcting for any light that may have been absorbed or reflected by the cell and solvent. It is crucial to use a reference cell, regardless of whether quantitative or qualitative information is required.
The molecule or atom being studied can be recognized using UV-Vis spectroscopy, which can also be used to measure the concentration of a specific substance.
A substance appears colored when it absorbs light from the visible light spectrum. Consider the chlorophyll in plants, which gives them their vibrant green color.
The preparation of diluted solutions ensures enough light can pass through them and be recorded by the detector or recorder.
It might be necessary to dilute materials whose very high absorption limits the amount of light that can reach the recording device.
Also, it is necessary to dilute opaque solutions, like milk, for light to pass through and be measured easily.
2. Other UV-Vis Spectroscopy Applications
In analytical chemistry, numerous analytes or samples, including transition metals, biological macromolecules, and highly conjugated organic chemicals, are commonly quantified using UV-Vis spectroscopy.
This methodology is widely known because it is reasonably affordable and simple to use in a variety of practical and theoretical applications, including:
- Analysis of DNA and RNA
- In the beverage industry
- Pharmacological evaluation
- Bacterial cultivation
- Amount of hemoglobin absorbed
- Quantitative and purity evaluations of nucleic acids
- Analysis of food authenticity
- Air quality observation
In some more highly specialized research, UV-Vis spectroscopy is also substantively beneficial. Not to mention, this technique has numerous and seemingly endless applications.
3. Strengths of UV-Vis Spectroscopy
UV-Vis spectroscopy is not an exception to the rule that no technique is flawless. However, the method has a few key advantages, which are listed below, that help to explain its recognition:
- UV-Vis spectroscopy is a flexible technique with many potential applications.
- It is non-destructive, allowing sample reusability or continued processing or analysis.
- Measurements are made quickly, making it uncomplicated to incorporate into test procedures.
- UV-Vis instruments require very little user training before use and are easy to understand and utilize.
- Since data analysis typically involves little processing, there is also little need for user education.
- This technique is simple. It doesn’t call for elaborate equipment and is comparatively simple to learn.
- Since the instrument involved in UV-Vis spectroscopy is typically inexpensive to purchase, many laboratories can use it.
4. Limitations of UV-Vis Spectroscopy
Despite the overwhelming advantages of this method, there are some drawbacks or restrictions:
- It can only be utilized to evaluate solutions; it cannot be used to measure samples of solids or gasses.
- This technique can only examine substances that absorb the electromagnetic spectrum’s ultraviolet or visible light.
- Only substances with known mass attenuation coefficients can be measured using this method to determine concentrations.
- UV-Vis spectroscopy is sensitive to variations in pressure and temperature.
- For accurate results, samples must be maintained at a constant temperature and tension for accurate results.
- Improperly fitted instrument compartments or stray light from the environment could result in significant measurement errors.
- The bubbles in the cuvette or sample will spread light and produce inconsistent results.
5. UV-Visible Spectrophotometer
A UV-Vis spectrophotometer is the device used in ultraviolet-visible spectroscopy. When light passes through a sample, its intensity is measured afterward and compared to its intensity before passing through the sample.
By manipulating the analysis wavelength of light and the signaling pathway, UV-Vis spectrophotometers can estimate the concentration of particular components in a microvolume.
The future of UV-Vis spectroscopy
The field of UV-Vis spectroscopy will continue to grow due to expert discoveries and technological advancements.
Generally, the need for food analysis, technological advancements, the growing use of UV-visible spectroscopy in the biotechnology and pharmaceutical industries, and other factors contribute to UV-Vis spectroscopy’s growth.
The development of this technology will be towards being more portable, easy to use, and has more applications in the future.
Additionally, the future of the UV-VIS spectrophotometer will change due to all evolutions, especially the advancement of the light source.
This presents a chance to advance the conventional UV-VIS spectrophotometer and the handheld spectrophotometer’s product potential, resulting in new applications.
These technologies are on the way and will be available soon.
References:
https://www.mrclab.com/all-you-need-to-know-about-uv-vis-spectrophotometer