UV/Vis spectroscopy is a common analytical laboratory technique relying on light in the ultraviolet and visible spectrum, ranging from 200–400 nm for ultraviolet light and 400–800 nm for visible light. The basic principle of the technique is based on the UV/visible light being absorbed by a sample. When energy from this light is absorbed by a sample’s molecules, these molecules transition from a low-energy ground state to a higher-energy excited state. The wavelength of light being absorbed is related to the difference in energy between the ground and excited state.

Absorbance of light provides the basis for analysis by UV/Vis spectroscopy. The Beer-Lambert Law is often utilized to relate absorbance and concentration of a species. The typical readout of a UV/Vis instrument is a plot of absorbance versus wavelength. This plot can provide clues to the types of bonds in a molecule and its general structure, but not a definitive structure as factors such as sample solvent and sample temperature can affect absorbance.

UV/Vis spectrometers come in a variety of sizes and configurations. The most common type is a double-beam instrument. As the name implies, these types of instruments split the light source into two beams: one that is directed at the sample cell and another that is directed at a reference cell. This is different from single-beam instruments, which are more common as teaching tools or in industrial labs. Double-beam instruments offer the advantage of quicker analysis and are less sensitive to changes in the light source or temperature since the reference is measured at the same time as the sample.

Double-beam UV/Vis spectrometers can be found in numerous laboratories, particularly for general, pharmaceutical and biotech applications. Reaction kinetics, quantitative analysis of pharmaceuticals, purity and molecular structure can all be analyzed utilizing double-beam UV/Vis instruments. With a wide application base, it is not surprising that these instruments are so common in laboratories.

The three largest vendors of double-beam UV/Vis instruments are PerkinElmer with its LAMBDA product line, Thermo Fisher Scientific with its GENESYS and Evolution products, and Shimadzu’s UV products. All three vendors offer a wide variety of systems within their product lines, including some systems tailored towards the pharma/bio sector. Some recent developments include a new series of GENESYS instruments from Thermo Fisher and the release of the UV-1900 from Shimadzu. The double-beam market is highly fragmented with many other vendors occupying the market including Agilent Technologies, Analytik Jena, Hitachi High-Technologies and JASCO.

The total market for double-beam UV/Vis instruments was about $200 million in 2017, and is expected to experience low to mid-single digit growth through 2022. Double-beam instruments have the largest share out of the whole UV/Vis market, and this is not expected to change any time soon. Growth in demand is expected to come from expanding general and biopharma testing worldwide.

Double-beam UV/Vis Spectroscopy at a Glance:

Leading Vendors

• PerkinElmer
• Shimadzu
• Thermo Fisher Scientific

Largest Markets

• General and Environmental Testing
• Biotechnology
• Pharmaceutical

Instrument Cost

• $3,000–$20,000