Spectrophotometer UV Vis
Instruments for UV Vis Spectroscopic Workflows
With a small footprint and no warm up time required, full spectrum scans take just one second. Our spectrophotometers utilize a combination of array technology and a long-lasting xenon lamp, leading to significantly reduced maintenance costs. Enjoy the flexible operation of a standalone instrument, or power your bench with LabX® PC software to ensure data integrity (FDA 21 CFR Part 11). You can also build multi-parameter systems connecting to other METTLER TOLEDO instruments.
Small, Fast, Simple and Reliable
METTLER TOLEDO'S UV/VIS Excellence Spectrophotometers offer a range of benefits to optimize and simplify your spectrophotometric analysis workflow. Watch the video and learn more about our outstanding UV Vis instruments.
Our spectrophotometers measure the intensity of light before and after passing through a sample solution in a cuvette, based on array technology. The main components included are a light source (e.g. xenon lamp), a sample holder, a dispersive device to separate the different wavelengths of the light, and a suitable detector, for example a photo diode detector. Watch our video below to learn more.
The working principle of our spectrophotometers is based on the following steps:
Blank measurement, which measures the intensity of light transmitted through the solvent:
- The solvent (e.g. water or alcohol) is added into a suitable transparent and non-light absorbing container – a cuvette.
- A light beam emitted by the light source passes through the cuvette with the solvent.
- The intensity of the transmitted light at different wavelengths is then measured by a detector positioned behind the cuvette and recorded.
After blank measurement, sample is measured:
- A sample is dissolved into the solvent and added into the cuvette.
- A light beam emitted by the light source passes through the cuvette with the sample.
- When passing through the cuvette, the light is partially absorbed by the sample molecules in the solution.
- The transmitted light is then measured by the detector.
- The light intensity changes at different wavelengths and is calculated by dividing the transmitted intensity of the sample solution by the corresponding values of the blank. This ratio is then stored by a recorder.
UV Vis instruments provide a great contribution to both qualitative and quantitative analytical processesand are needed to control the purity and dosage of an Active Pharmaceutical Ingredient (API) in drug products. For example, ibuprofen's API analysis can be quickly performed using a UV Vis spectrophotometer to determine the extinction coefficient at 264 and 273 nm for both the standard and the sample. The differences between the standard and the sample in relation to the percentage of the extinction coefficients acts as the quality control criteria, which according to U.S. Pharmacopeia (USP) monograph must be less than 3.0 %.
UV Vis Spectrophotometry is a standard method used on a daily basis in biotech laboratories. It can be used to determine the concentration of nucleic acids and protein (e.g. using the absorbance A260 and A280), or to check the purity of DNA (e.g. using the ratio of absorbance 260/280). Using other wavelengths on the visible spectrum, such as 595 nm for the Bradford assay and 750 nm for the Lowry assay, protein content in biological samples can be quantified.
Moreover, the optical density of a cell culture sample measured at a wavelength of 600 nm, namely OD600, is measured by UV spectroscopy to estimate the number of bacteria or other cells (e.g. Escherichia coli).
Food and beverage industry
UV Vis spectroscopy is used to monitor and improve product quality. For example, olive oil is determined by observing the absorbance behavior of a 1% solution in isopropanol between 200 and 400 nm, because elevated levels of absorbance in this range indicate oxidized oil and thus degraded quality.
Contaminations such as bacterial growth in wine may result in a change of the wine's color, which can be evaluated with UV Vis spectroscopy.
Spectrophotometry measurements are also commonly used at beer brewing companies for monitoring quality control. Color, bitterness, iso-alpha and alpha acids, total carbohydrates, free amino nitrogen (FAN) are often measured.
UV absorption spectroscopy is one of the best methods for the determination of the purity of organic solutions. An example in the chemical industry is the control of alcohol purity, which can be contaminated by benzene. Benzene absorbs light at 280 nm, whereas alcohol absorbs at 210 nm, an extra peak at 280 nm on the spectrum can indicate benzene contamination.
In the chemical industry, color measurement using spectrophotometer is widely employed. For instance, the platinum cobalt (Pt/Co) scale for clear liquids, described by ASTM D1209 method, is applicable for the visual measurement of the color of chemicals and petro-chemicals such as glycerin, plasticizers, solvents, carbon tetrachloride and petroleum spirits.
A spectrophotometer is the ideal instrument for water and wastewater photometric analysis in utility companies and institutions. It can measure hundreds of parameters with high accuracy (e.g. COD, ammonium, hardness, chlorine, etc.) and provide quick results to ensure timely quality control.
Moreover, many power plants are required to monitor the ppb level of ions (e.g. iron, silicate), which can be performed by a spectrometer without the need for boiler correction.
UV Vis spectrophotometers can be classified into two categories according to the geometry of the components building up the optical system for the recording of spectra:
- Scanning spectrophotometer
- Array spectrophotometer
The spectrum of a scanning UV Vis device is obtained by continuously changing the wavelength of the light (i.e. scanning), which separately passes through the sample by rotating a reflection grating, as shown in the figure below. In an array spectrophotometer, the light of a full wavelength passing through a sample is diffracted by a reflection grating located after the cuvette, it is then received by an array detector (e.g. CCD sensor).This allows for the simultaneous measurement of all wavelengths of the light in a short amount of time. As a result, array spectrophotometer can deliver the spectrum of a full scan (e.g. 200 – 800 nm) within several seconds, whereas a scanning spectrophotometer needs a minimum of several minutes to complete the same task.
The mechanically rotating elements of a scanning spectroscopy instrument can impact the accuracy and reproducibility of a wavelength. In order to avoid that, it requires a regular re-calibration and the involved maintenance costs. An array spectrophotometer does not have any moving optical parts, which means wavelength deviations due to mechanical imprecisions do not occur.
An additional advantage of an array spectroscopy instrument is its immunity to ambient light due to its optical design, which means it does not require a closed sample compartment, rendering sample changing easier.
A tungsten halogen lamp is the most common light source used in spectrophotometers. It consists of a tungsten filament enclosed in a glass bulb and a halogen portion included to recover the evaporated tungsten. It provides a usable wavelength range from 330 to 1100 nm in the visible to near-infrared region and has a lifetime of about 3000 hours.
A deuterium lamp is a discharge light source with gaseous deuterium sealed in a bulb. A deuterium lamp covers the ultraviolet region from 190 to 450 nm with a smooth light intensity distribution and has a lifetime of about 1000 hours.
The above two lamps are often combined to cover a full range of UV and Vis light.
A xenon lamp is a discharge light source with xenon gas sealed in a quartz glass bulb. It produces a continuous spectrum from the ultraviolet to the near-infrared, ranging from 190 to 1100 nm. Xenon flash lamps generate light by pulsed ignition, which is integrated over a defined time span to achieve a complete spectrum scan, they require no warm-up time. The pulsed light generation produces little heat and the lifetime is long, lasting up to 5,500 hours and corresponds to 50 Hz flashes at constant operation. The usage of xenon lamps means less needed maintenance and a longer lamp lifetime.
FastTrack™ Technology by METTLER TOLEDO consists of a xenon flash lamp, quartz glass fibers and an array setup.
The UV5 spectrophotometer is simple to use and fast, delivering spectrum scans within one second. There are two measurement options to select from, direct measurements and methods, which operate via the intuitive One Click™ touch screen. Our spectrophotometer can is fast, saving you time in your UV Vis analytical workflows for quality control, water testing and color measurement.
The UV7 has the features what the UV5 provides; however it is tested according to European and US Pharmacopeia and has a number of pre-programmed methods. It provides advanced automation possibilities for performance qualification based on METTLER TOLEDO's established methods suiting strictly regulated industries, such as the pharmaceutical industry. It supports 21 CFR Part 11 and data integrity compliance with the LabX Software.
Watch the video below to learn more about the two modes: Direct measurement and methods.
The UV5Bio is a cuvette spectrophotometer dedicated to life science applications. It has a pre-installed method library with 22 predefined bio-applications such as, Bradford assay, Lowry assay, OD600 and enzyme kinetics. The UV5Bio is compatible with a variety of accessories, such as temperature control units, which enable temperature-dependent analysis (e.g. protein denaturation, enzyme kinetics studies, DNA melting temperature, lipase activity, etc.).
The U5Nano also has pre-installed life science applications and is a micro-volume spectrophotometer, requiring only small volumes of samples (as low as 1 µL). The UV Vis measurements can be done on the micro-volume platform or in a cuvette.Highly concentrated samples, for instance up to 15,000 ng/µL of dsDNA, can also be measured without further dilution due to LockPath Technology integrated in the UV5Nano. The path length can be set at either 0.1 or 1 mm.
Watch the video below to learn more about Micro-volume UV/VIS spectroscopy — LockPath Technology.
- The METTLER TOLEDO UV5Nano and UV5Bio Spectrophotometers offer a large collection of life science methods, such as:
- Qualitative analysis of DNA, RNA and proteins
- Quantitative analysis of DNA, RNA and proteins
- BCA, Bradford, Lowry and other colorimetric protein assays
- Pre-configured dyes and option to add custom dyes
- Oligo calculator for the concentration determination of DNA and RNA oligos
- OD600 for live cells
- Qualitative analysis of DNA, RNA and proteins
- Additionally, the UV5Bio and UV7 Spectrophotometers offer kinetics methods for carrying out enzyme kinetics
- For more information on life science applications with METTLER TOLEDO spectrophotometers download the Life Science Toolbox.
Several pre-installed color scales such as APHA, Gardner, Saybolt, CIELAB, EBC and ASBC are included in METTLER TOLEDO's spectrophotometers making it an ideal solution for performing color measurements of transparent liquids.
The APHA color space (synonymous to Pt-Co and Hazen) as well as the Gardner color scale quantifies the yellowness of near-clear substances, and therefore serves to determine the purity and quality, or the degree of degradation of a substance.
CIELAB expresses color in three values: L* for lightness, a* for green to red and b* for blue to yellow. This color scale is employed to ensure a constant color of liquids, such as dyes, flavors, etc.
The Saybolt color scale is used for grading light colored petroleum products. The Saybolt color is an indicator of the quality or contamination degree of products such as gasoline, jet fuel, etc.
The EBC and ASBC color scales are used to determine the color of beer, which distinguishes beer types.
METTLER TOLEDO' thermostating unit expands the capabilities of spectrophotometer to applications that demand high temperature accuracy and reproducibility such as protein analysis, enzyme activity or DNA melting point. With this accessory, it is possible to control the temperature conditions of a sample within a range between 4 – 95ºC before, during or after the spectroscopic measurement.
UV Vis spectrophotometry provides fast, easy and accurate characterization and quantification of vaccine components such as nucleic acids (i.e. DNA/RNA), proteins, additives/preservatives, etc., as the components have characteristic absorption on the UV Vis spectra. Therefore, it can impact the time-to-result for both downstream and upstream processes, as well as quality control. Furthermore, it is an efficient tool for purity checks of vaccine components in each step of development.
METTLER TOLEDO offers a solution for spectrophotometer calibration in the form of the CertiRef™ and LinSet™ units, which automate the tests required to check whether your spectrophotometer complies with European and US pharmacopeias. Users can employ the CertiRef™ units, which contain certified reference materials (CRMs), to automatically perform tests for wavelength accuracy and repeatability, photometric accuracy and repeatability, resolution, stray light, photometric noise and drift, as well as baseline flatness.
METTLER TOLEDO LabX® software enables users to have higher flexibility by creating custom workflows exactly for the user's needs. Calculation and transcription errors are completely avoided. It also ensures data integrity with all information safely stored in a secure database, including all performance verifications and services. With security features such as electronic signatures and user management, it assists to comply with 21 CFR part 11 regulations from the FDA.