UV-Visible Spectroscopy

Ultraviolet-visible (UV-Vis) spectroscopy is a widely used technique in many areas of science ranging from bacterial culturing, drug identification and nucleic acid purity checks and quantitation, to quality control in the beverage industry and chemical research. This article will describe

• What is UV-Vis spectroscopy.
• What are the main components of a spectrophotometer,
• what is the principle of UV-spectroscopy.
• what is UV-Spectroscopy used for
• How does UV Spectrophotometer works.
• What is the Beer’ low of UV-Visible.
• Why quartz cuvette used in UV.
• What are the application of UV-Visible Spectroscopy.
• What is working principle of double beam UV-Visible Spectrophotometer.
• What is the principle and working mechanism of spectrophotometer.
• What is the formula for spectrophotometer principle.
• Which light is used in spectrophotometer.
• What are the two light sourse of UV-Visible spectrophotometry.
• What are the difference between UV and UV-Visible spectrophotometer.
• Which detector used in UV.

What is UV-Vis spectroscopy

UV-Vis spectroscopy is an analytical technique that measures the amount of discrete wavelengths of UV or visible light that are absorbed by or transmitted through a sample in comparison to a reference or blank sample. This property is influenced by the sample composition, potentially providing information on what is in the sample and at what concentration. Since this spectroscopy technique relies on the use of light, let’s first consider the properties of light.

What are the main components of a spectrophotometer

A spectrophotometer consists of four general parts; light source, an optical system (monochromator), sample holder, and detector (photometer). Any spectrophotometer requires light of various wavelengths. Commonly tungsten lamp provides a visible spectrum of light in a spectrophotometer.

What is the principle of UV spectroscopy

UV Spectroscopy uses ultraviolet light to determine the absorbency of a substance. In simple terms, the technique maps the interaction between light and matter and measures. As matter absorbs light it undergoes either excitation or de-excitation, which generates what is known as a spectrum.

What is UV spectroscopy used for

UV-Vis Spectroscopy is a quantitative technique used to measure how much a chemical substance absorbs light. This is done by measuring the intensity of light that passes through a sample with respect to the intensity of light through a reference sample or blank.

How does a UV-VIS spectrophotometer work

Ultraviolet-visible (UV-Vis) spectrophotometers use a light source to illuminate a sample with light across the UV to the visible wavelength range (typically 190 to 900 nm). The instruments then measure the light absorbed, transmitted, or reflected by the sample at each wavelength.

What is the Beer’s law of UV-Vis

The law states that the concentration of a chemical is directly proportional to the absorbance of a solution. The relation may be used to determine the concentration of a chemical species in a solution using a colorimeter or spectrophotometer. The relation is most often used in UV-visible absorption spectroscopy.

Why quartz cuvette is used in UV

Historically, reusable quartz cuvettes were required for measurements in the ultraviolet range, because glass and most plastics absorb ultraviolet light, creating interference. Today there are disposable plastic cuvettes made of specialized plastics that are transparent to ultraviolet light. Glass, plastic and quartz cuvettes are all suitable for measurements made at longer wavelengths, such as in the visible light range.

“Tandem cuvettes” have a glass barrier medium that extends two-thirds of the way up in the middle, so that measurements can be taken with two solutions separated and again when they are mixed.

Cuvettes are made from quartz, and plastic (disposable) depending upon UV transmission requirements.

What are the Applications of UV-Visible Spectroscopy

UV-Visible spectroscopy is widely used in the field of analytical chemistry, especially during the quantitative analysis of a specific analyte. For example, the quantitative analysis of transition metal ions can be achieved with the help of UV-Visible spectroscopy. Furthermore, the quantitative analysis of conjugated organic compounds can also be done with the help of UV-Visible spectroscopy. It can also be noted that this type of spectroscopy can also be carried out on solid and gaseous analytes in some conditions.

What is the working principle of double beam UV-Vis spectrophotometer

Double beam spectrophotometers measure color in a sample by using two, or “double,” beams. One beam passes through the sample side, and the other beam passes through the reference side, so the reference and the sample can be read simultaneously with no need to recalibrate the instrument.

What is the principle and working mechanism of spectrophotometer

Spectrophotometry is a method to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solution. The basic principle is that each compound absorbs or transmits light over a certain range of wavelength

What is the formula for spectrophotometer principle

The amount of light absorbed by a solution is related to the analyte concentration by the Beer–Lambert law, which is expressed as follows: A = εbc, where ε is the molar absorptivity of the analyte, b is the path length (the distance the light travels through the solution), and c is the concentration of the analyte.

Which light is used in spectrophotometer

Halogen lamps are often used in general spectrophotometers but xenon lamps are used in cases where a high light intensity is required (such as spectrophotometers), due to their high brightness.

What are the two light sources for UV-Vis spectrophotometry

Two kinds of lamps, a Deuterium for measurement in the ultraviolet range and a tungsten lamp for measurement in the visible and near-infrared ranges, are used as the light sources of a spectrophotometer. A continuous spectrum of 300 – 3,000 nm is emitted.

What is the difference between UV and UV-VIS spectrophotometer

The UV-visible spectrophotometer is an instrument that uses the absorption spectroscopic techniques to quantify the analytes in a sample. There is no difference between UV and visible spectrophotometer because both names refer to the same analytical instrument.

Which detector used in UV

Photomultiplier tube is the popular detector nowadays used in UV-Vis spectrophotometers. It has an anode, cathode, and many dynodes. Photon when entering the tube, strikes the cathode, resulting in the emission of electrons.