How Spectrophotometry Works & How Our Program Saves You Time & Money
Excedr is able to source all instrument types and can accommodate any model preferences your end-user might have. Request an estimate today and see how a lease can reduce your spectrophotometer price.
All equipment brands/models are available
The Advantages of Excedr’s Spectrophotometer Leasing Program:
- Eliminates the upfront cost of purchasing equipment by spreading its cost over time
- Minimizes equipment downtime with included complete repair coverage and preventive maintenance
- Takes advantage of potentially 100% tax deductible* payments, providing you significant cash-savings
- Expedites the administrative work needed for instrument procurement and logistics
- Conserves working capital, enabling you to reinvest in your core business and operations (staffing, inventory, marketing/sales, etc.)
- Accommodates all manufacturer and model preferences
*Please consult your tax advisor to determine the full tax implications of leasing equipment.
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.
It is more specific than the general term electromagnetic spectroscopy in that it deals with visible light, near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.
Spectrophotometry uses photometers that can measure a light beam’s intensity as a function of its color (wavelength). Important features of these instruments are spectral bandwidth (the range of colors it can transmit through the test sample), the percentage of sample-transmission, the logarithmic range of sample-absorption, and sometimes a percentage of reflectance measurement.
A common spectrophotometer use includes the measurement of transmittance or reflectance in solutions and solids. These models measure gases as well. However, spectrophotometers are also designed to measure the diffusivity on any of the listed light ranges that cover around 200 nm – 2500 nm, using different controls and calibrations. Within these ranges of light, calibrations are needed on the machine using standards that vary in type depending on the wavelength of the photometric determination.
An example of an experiment in which spectrophotometry is used is the determination of the equilibrium constant of a solution. A certain chemical reaction within a solution may occur in a forward and reverse direction where reactants form products and products break down into reactants. At some point, this chemical reaction will reach a point of balance called an equilibrium point. In order to determine the respective concentrations of reactants and products at this point, the light transmittance of the solution can be tested using spectrophotometry. The amount of light that passes through the solution is indicative of the concentration of certain chemicals that do not allow light to pass through.
Application & Types
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology. They are widely used in many industries including semiconductor, laser, and optical manufacturing, and printing and forensic examination. Furthermore, they are utilized in laboratories for the study of chemical substances. Ultimately, these tools are able to determine, depending on the control or calibration, what substances are present in a target and exactly how much through calculations of observed wavelengths.
More specifically, spectrophotometry is an important technique used in many biochemical experiments that involve DNA, RNA, and protein isolation, enzyme kinetics, and biochemical analyses. A brief explanation of the procedure includes comparing the absorbency of a blank sample that does not contain a colored compound to a sample that contains a colored compound. The spectrophotometer is used to measure colored compounds in the visible region of light (between 350 nm and 800 nm), thus it can be used to find more information about the substance being studied. In biochemical experiments, a chemical and/or physical property is chosen and the procedure that is used is specific to that property in order to derive more information about the sample, such as the quantity, purity, enzyme activity, etc. It is also a helpful procedure for protein purification and can also be used as a method to create optical assays of a compound. Because the reader measures the wavelength of a compound through its color, a dye-binding substance can be added so that it can undergo a color change and be measured.
These instruments have been developed and improved over the decades and have been widely used among chemists. It is considered to be a highly accurate instrument that is also very sensitive and therefore extremely precise, especially in determining color change. This method is also convenient for use in laboratory experiments because it is an inexpensive and relatively simple process.
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The most common spectrophotometers are used in the ultraviolet and visible regions of the spectrum, and some of these instruments also operate into the near-infrared region as well.
Visible region 400–700 nm spectroscopy is used extensively in colorimetry science. It is a known fact that it operates best at the range of 0.2-0.8 O.D. Ink manufacturers, printing companies, textiles vendors, and many more, need the data provided through colorimetry. They take readings in the region of every 5–20 nanometers along the visible region, and produce a spectral reflectance curve or a data stream for alternative presentations. These curves can be used to test a new batch of colorant to check if it makes a match to specifications, e.g., ISO printing standards.
Traditional visible region spectrophotometers cannot detect if a colorant or the base material has fluorescence. This can make it difficult to manage color issues if for example one or more of the printing inks is fluorescent. Where a colorant contains fluorescence, a bi-spectral fluorescent system is used. There are two major setups for visual spectrum machines, d/8 (spherical) and 0/45. The names are due to the geometry of the light source, observer and interior of the measurement chamber. Scientists use this instrument to measure the amount of compounds in a sample. If the compound is more concentrated more light will be absorbed by the sample; within small ranges, the Beer-Lambert law holds and the absorbance between samples vary with concentration linearly. In the case of printing measurements two alternative settings are commonly used- without/with UV filter to control better the effect of UV brighteners within the paper stock.
Samples are usually prepared in cuvettes; depending on the region of interest, they may be constructed of glass, plastic (visible spectrum region of interest), or quartz (far UV spectrum region of interest).
Additional applications of ultraviolet-visible spectroscopy include: Estimating dissolved organic carbon concentration, measuring specific ultraviolet absorption for metric of aromaticity, and Bial’s Test for concentration of pentoses.
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The spectrophotometers designed for the infrared region are quite different because of the technical requirements of measurement in that region. One major factor is the type of photosensors that are available for different spectral regions, but infrared measurement is also challenging because virtually everything emits IR light as thermal radiation, especially at wavelengths beyond about 5 μm.
Another complication is that quite a few materials such as glass and plastic absorb infrared light, making it incompatible as an optical medium. Ideal optical materials are salts, which do not absorb strongly. Samples prepped for IR may be smeared between two discs of potassium bromide or ground with potassium bromide and pressed into a pellet. Where aqueous solutions are to be measured, insoluble silver chloride is used to construct the cell.
We cover a range of spectrophotometry devices in our spectrophotometer blog post. If you’re interested in learning about the different types, follow the link! It’s important to understand the differences between ultraviolet-visible, infrared, near-infrared, or Raman spectrophotometry. Knowing the specific model you need to perform a task is critical to the success of your lab.
Have you ever wondered what the difference between a spectrometer and a spectrophotometer is? Check out our blog post! Whether you’re interested in leasing a spectrophotometer or UV-VIS/NIR spectrometer, we can help. Contact us today at (510) 982-6552 or fill out our contact form and we can discuss your financing options.
Customized Spectrophotometer Leases to Meet Your Needs
This off-balance sheet financing structure provides three options at the end of the term. The lessee has the option to return the equipment to the lessor, renew at a discounted rate, or purchase the instrument for the fair market value. Monthly payments are also 100% tax deductible which yields additional cash savings.
If you recently purchased equipment, Excedr can offer you cash for your instrument and convert your purchase into a long-term rental. This is called a sale leaseback. If you’ve paid for equipment within the last ninety days, we can help you recoup your investment and allow you to make low monthly payments. This also frees up cash in your budget rather than tying it down to the instrument.
Spectrophotometer Manufacturers & Models on the Market
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Thermo Fisher Scientific:
SPECTRONIC 200, GENESYS 30 Vis, GENESYS 40 Vis/50 UV-Vis, GENESYS 140 Vis/150 UV-Vis, GENESYS 180 UV-Vis, Evolution™ 350 UV-Vis, Evolution™ 260 Bio UV-Vis, Evolution™ 201/220 UV-Vis, BioMate™ 160 UV-Vis, Nanodrop™ 2000/2000c, Nandrop™ One/OneC Microvolume UV-Vis, Nanodrop™ 8000, Nanodrop™ 3300 Fluorospectrometer
Cole-Parmer UV-Visible Spectrophotometer, Visible Spectrophotometer, Scanning UV-Visible Spectrophotometers
UV-1280 UV-Vis Spectrophotometer, BioSpec-nano Micro-volume UV-Vis, UV-1900i UV-Vis, UV-2600i UV-Vis, UV-2700i UV-Vis, UV-3600i Plus UV-Vis-NIR, SolidSpec-3700i/3700i DUV UV-Vis-NIR
iHR Series, iHR320, iHR550, MicroHR series, MicroHR Auto, Lumetta,TRIAX Series, TRIAX 180, VS70-PDA, VS70-CCD-HD, VS70-CCD-HS, FHR 1000, FHR 640, Gemini 180
LAMBDA 1050+ UV-Vis-NIR, LAMBDA 850+ UV-Vis, LAMBDA 365 UV-Vis, LAMBDA 465 UV-Vis, LAMBDA 265 UV-Vis
BioPhotometer D30, BioSpectrometer basic, BioSpectrometer kinetic, BioSpectromter fluorescence
Cary 60 UV-Vis, Cary 3500 UV-Vis, Cary 4000 UV-Vis, Cary 5000 UV-Vis, Cary 6000i UV-Vis-NIR, Cary 7000 UMS
6300, 6320D, 6305, 7200, 7300, 7305, 7310, 7315, 7410, 7415, 6700, 6705, 6715, 6850, Genova Bio, Genova Plus, Genova Nano, 7415 Nano
NanoPhotometer, Cuvette, NP80, N60, N50, C40, DiluPhotometer, OD600
V-730 , V750, V-760, V-770, V-780, MV-3000 Series, MV-3100, MV-3150, MV-3200, MV-3250, MV-3300, MV-3350
V-1200, UV-1600PC, UV-3100PC, V-3000PC, VWR Double Beam, UV-6300PC
DR1900 Portable, DR3900 Laboratory, DR6000 UV-Vis Laboratory
ioDrop Duo+, BioDrop uLite+, WPA Biowave, WPA Biowave II, WPA Lightwave II, WPA S1200+, WPA S800+, WPA CO8000, Libra S80, Libra S80PC, Libra S70, Libra S70PC, Libra S60., Libra S60PC, Libra S50, Libra S50PC, Libra S50PC, Libra S22, Libra S21, Libra S6+, Libra S4+
UV5, UV7, UV, UV5Bio, UV5Nano