Quartz Cuvettes for UV vis IR Spectroscopy: 500 Items for Easy Ordering
Our quartz cuvettes below are used to contain samples for spectroscopic research in the UV and visible ranges. Cuvettes with two polished sides are suitable for absorption spectroscopy while cuvettes with four polished sides are for fluorescence spectroscopy.
QVARZ® offers a wide range of quartz cuvettes with a choice of path lengths for use with UV-Vis and UV-Vis-NIR systems, including rectangular cells, microcuvettes, and flow cells with various aperture sizes and geometries.
The stock quartz cuvettes (all cuvettes and cells) are suited for wavelengths ranging from 190 to 2500 nanometers. And for wavelengths ranging from 250nm to 3500nm, IR fused quartz cuvettes are available, as well as optical glass cuvettes for wavelengths ranging from 340nm to 2500nm. Our quartz cuvette sizes range from macro to semi-micro to micro volumes and path lengths from 0.1mm to 100mm.
Optical Components For UV/visible/NIR Spectroscopy
In this below product list, you will find our most popular Best Sellers that our customers use the most frequently. If you are unable to locate a suitable product in this selection, please contact us or use the cuvette finder on our website to locate the product of your choice. We will also be delighted to work with you to develop individual and tailored solutions for your measurement requirements.
In addition to the UV quartz cuvettes that are currently in stock, custom orders are welcome. Please discuss your material and dimension needs with a sales representative at your earliest opportunity. With your tailored requirement, we will be delighted to assist you.
- Fused Quartz Cuvettes with Guaranteed High Transmission
- Path Lengths From 0.1 to 100mm Door to Door Shipping
- Extremely High Windows Parallelism with Tolerance of 0.01mm
- Optical Windows Surface Flatness of 0.01mm
- Quartz Transmission Spectrum of 190nm-2500nm
- Pair Variation of 0.1% for Reproducible Measurement Results
- Chemical Resistance and High-Temperature Stability
- Spectrophotometer and Fluorometer Use with 2/4 Clear Windows
- Customizable Ultra Micro, Micro, and Macro Cuvettes with Capacities Ranging from 70µL to 35mL
Quartz Cuvette Transmission
- Fabricated from High Transmission UV Quartz for the 190 nm – 2.5 µm Spectrum Range
- Two or Four Optical Polished Windows for UV/Vis/IR Spectroscopic Measurements
- Ultra Micro, Micro, and Macro Cuvettes with Capacities Ranging from 70µL to 35mL
- Standard 0.2mm – 100mm Optical Path Lengths and 12.5x(2.7 – 102.5)mm Square Footer
- Available with PTFE Closures or Airtight Stoppers / Screw Threaded Caps
Qvarz® cuvettes are high-quality cells designed to contain liquid samples for spectroscopic measurements. In addition to UV light, these quartz cuvettes are also compatible with visible and infrared light spectrums up to 2500 nm. Absorption and fluorescence spectroscopy require cuvettes with two or four optical polished sides which are available in stock or customization. Optical polished sides may be cleaned using standard cleaning methods. Additionally, PTFE tops are available in three different types: PTFE lids to block dust and other particles, PTFE stoppers or screw caps to keep liquid from evaporating, and for airtight applications.
Most spectrophotometers and our Cuvette Holder and Mounts can use Qvarz® cuvettes because of their typical 12.5mm square outer diameter and 10mm optical path length through the sample. Single-piece pricing is available for all of our sizes (see the tables below for further details). Enhanced chemical resistance is offered for all standard cuvettes from 70 µL to 35mL cells. The letter “Q” is laser etched on the outside of all quartz cuvettes to indicate that they are made of quartz.
Bonded cuvettes with sub- or ultra-micro volumes are assembled with glue for either two or four transparent windows. Molded type quartz cuvettes and cells are built by heating the quartz to a high temperature and then pressing the pieces together, while fused cuvettes have a quartz powder put to the edges before heating. Both molded and fused quartz cuvettes have enhanced chemical resistance. You can find more details on the different types of cuvettes for bonded, fused, or molded types.
Solvent Compatibility
To avoid cuvettes leaking, bonded quartz cuvettes should not be used with benzene, toluene, aqua regia, ethanol, corrosive solutions, or other similar compounds. Aqua regia is compatible with the fused and molded cuvettes with improved chemical resistance.
| 1 | 2 | 3 | 4 | ||
|---|---|---|---|---|---|
| *Molded | *Fused | *Bonded / Glued | |||
| UV vis ( 190- 2500 nm) | Yes | Yes | Yes | ||
| Transmission Matched | On Request | No | No | ||
| Transmission > 80% | Yes | Yes | Yes | ||
| Resistant to Acids and Bases (except hydrofluoric acid) | Yes | Yes | No | ||
| Resistant to Organic Solvents | Yes | Yes | No | ||
| Usable upto 600°C (1112°F) | Yes | Yes | Yes | ||
| Usable upto 1200°C (2192°F) | Yes | No | No | ||
| 0 Variations Reading | On Request | No | No | ||
| Fabrication | Molded | Assembled with Quartz Powder | Assembled with Glue | ||
| Adhesives | No | No | Yes | ||
| Storage | Short Term Storage | Clean After Use | Clean After Use | ||
| Available Material | Fused Quartz Material | ||||
| Note | Molded and fused cuvettes and cells are assembled by direct fusion without the use of adhesives throughout the production process. This guarantees resistance against corrosive chemicals and high temperature. Each quartz cuvette and cell has excellent transmission from 190nm to 2500nm. | ||||
- “Molded” Cuvettes: The quartz pieces that make up these quartz cuvettes are finely polished before heating. After being heated to a high temperature, pressure is applied to adhere the pieces together.
- “Fused” Cuvettes: A quartz powder is applied to the edges of the quartz pieces. Then, the quartz is heated to a high temperature and pressure is applied to adhere the pieces together.
- “Bonded” Cuvettes: The ultra micro quartz cuvettes with aperture windows and semi cuvettes with black walls and some customized cuvettes are assembled with glue. Use with aqueous samples only.
Quartz Cuvettes for Spectrophotometers
Reading more about Comprehensive Guide to Spectrophotometer Cuvettes
Cuvettes with Open Top, 2 Polished Windows
- Two Optical Clear Windows for UV-vis Absorption Spectroscopy
- PTFE Lid (some no lids) with Each Cuvette to Block Dust or Other Particles
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capabilities from 2µL to 35mL, Customizable
- Flexible Optical Path Lengths from 0.2mm to 100mm
- Fused and Molded Quartz Cuvettes with Enhanced Chemical Resistance
- Z Dimensions of 8.5mm, 15mm, and 20mm suitable for Various Manufacturers
For absorption spectroscopy research, our UV Fused Quartz Cuvettes include two polished sides, as well as two frosted sides, for easy handling. Surfaces that aren’t being utilized are blacked to decrease light scattering in the ultramicro and semi-micro cuvettes (350 to 700 and 1050 to 1400 µL). Polished sides may be cleaned using standard optics cleaning methods. These quartz cuvettes are not suitable for fluorescence spectroscopy since they only have two polished windows, which means they cannot be used to measure fluorescence at right angles to the beam. Cuvettes with four polished sides are also available from Qvarz®.
Semi Micro Quartz Cuvettes
Further Reading: Semi Micro Cuvette: The Key to Precise and Reliable Data Analysis
0.2 – 100 mm Path Lengths Quartz Cuvettes
Our quartz cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 70 ul to 35 ml. In addition to ordinary “Fused” type quartz cuvettes (ie. VAOFIB), short or long path lengths (0.2, 0.5, 1, 2, 3, 5, 10, 20, 30, 40, 50, 100mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VAOMK). All these quartz cuvettes come with a PTFE lid to avoid contamination from dust and other particles, and each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
Cuvette Racks & Inserts
Racks or inserts are required for short path length cells that have less than 12.5 mm depth, to ensure secure mounting in a standard cell holder. We offers black spacers and racks for use with 1, 2, and 5 mm path length cells.
- Spacers allow 1, 2, and 5 mm path length cells (with less than 12.5 mm depth) to be securely mounted in a standard cell holder (for 12.5 x 12.5 mm cells)
- Required when there is no path length adjustment facility in the cell holder
- Quartz rack can also be used instead of spacers – they provide more flexibility as each insert provides two different pathlengths selected by rotating through 90 degrees.
Ultra Micro Cuvettes (<300uL)
The ultra micro cuvettes with aperture windows and semi cuvettes with black walls are assembled with glue, which can be destroyed by benzene or other solutions with strong corrosive characteristics. These glued cuvettes are described as “Bonded” in the item description. These quartz cuvettes are not recommended for use with benzene, toluene, aqua regia ethanol or other corrosive liquids because they may damage the bonding between the parts and cause the cuvette to leak.
Below the sub micro quartz cuvettes have very small apertures that the Z dimensions should be considered before ordering.
And “Fused” cuvettes have quartz powder applied to the edges before heating. “Molded” cuvettes are assembled by first heating the quartz to a high temperature and then applying pressure to adhere the pieces together, eliminating the need for glue which is adhesive free, direct fusion bonding. “Fused” and “Molded” fabrication method allows the cuvette with enhanced chemical resistance to hold sample solutions with corrosive properties, similar to those of nitrohydrochloric acid (aqua regia), without being damaged.
Customized Open Top Quartz Cuvettes
Cuvettes with PTFE Stopper, 2 Polished Windows
- Two Optical Clear Windows for UV-vis Absorption Spectroscopy
- PTFE Stopper Included with Each Cuvette to for Airtight Seal
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capibilities from 100µL to 35mL, Customizable
- Flexible Optical Path Lengths from 1mm to 100mm
- Fused and Molded Cuvettes with Enhanced Chemical Resistance
- Z Dimension of 8.5mm, 15mm, and 20mm suitable for Various of Manufacturers
For absorption spectroscopy research, our UV Fused Quartz Cuvettes include two polished sides, as well as two frosted sides, for easy handling. Surfaces that aren’t being utilized are blacked to decrease light scattering in the ultramicro and semi-micro quartz cuvettes (350 to 700 and 1050 to 1400 µL). Polished sides may be cleaned using standard optics cleaning methods. These quartz cuvettes are not suitable for fluorescence spectroscopy since they only have two polished windows, which means they cannot be used to measure fluorescence at right angles to the beam. Cuvettes with four polished sides are also available from Qvarz®.
Our cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 100 microliters to 35 milliliters. In addition to ordinary “Fused” type cuvettes (ie. VAPFE), short or long path lengths (1, 2, 100mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VAPMG). All these quartz cuvettes come with a PTFE stopper to avoid contamination from dust and other particles, and for airtight sealing purposes. Each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
The ultra micro cuvettes with aperture windows and semi cuvettes with black walls are assembled with glue (ie. VAPBH1, VAPB100), which can be destroyed by benzene or other solutions with strong corrosive characteristics. These glued cuvettes are described as “Bonded” in the item description. These cuvettes are not recommended for use with benzene, toluene, aqua regia ethanol, or other corrosive liquids because they may damage the bonding between the parts and cause the cuvette to leak.
Cuvettes with Screw Caps, 2 Polished Windows
- Two Optical Clear Windows for UV-vis Absorption Spectroscopy
- PTFE Screw Threaded Cap Included with Each Cuvette to for Airtight Seal
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capabilities from 350µL to 3.5mL, Customizable
- Flexible Optical Path Lengths from 1mm to 10mm
- Fused and Molded Cuvettes with Enhanced Chemical Resistance
- Suitable for Various of Manufacturers
For absorption spectroscopy research, our UV Fused Quartz Cuvettes include two polished sides, as well as two frosted sides, for easy handling. Surfaces that aren’t being utilized are blacked to decrease light scattering in the ultramicro and semi-micro cuvettes (350 to 700 and 1050 to 1400 µL). Polished sides may be cleaned using standard optics cleaning methods. These cuvettes are not suitable for fluorescence spectroscopy since they only have two polished windows, which means they cannot be used to measure fluorescence at right angles to the beam. Cuvettes with four polished sides are also available from Qvarz®.
Our cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 350 microliters to 3.5 milliliters. In addition to ordinary “Fused” type cuvettes (ie. VASF1), short or long path lengths (2, 5mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VASM7). All these quartz cuvettes come with a PTFE screw-threaded cap each to avoid contamination from dust and other particles and are the airtight sealed. Each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
Quartz Cuvettes for Fluorometers
Cuvettes with Open Top, 4 Polished Windows
- Four Optical Clear Windows for Fluorescence Spectroscopy
- PTFE Lid (some no lids) with Each Cuvette to Block Dust or Other Particles
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capabilities from 20µL to 125mL, Customizable
- Flexible Optical Path Lengths from 1mm to 50mm
- Fused and Molded Cuvettes with Enhanced Chemical Resistance
- Z Dimension of 8.5mm, 15mm, and 20mm suitable for Various of Manufacturers
These cuvettes have 3/4 optical polished windows for fluorescence spectroscopy research. The four polished windows allow fluorescence measurements at right angles to the beam path. Standard optics cleaning procedures can be used to clean the cuvettes. The through beam windows of these quartz cuvettes can be utilized for different spectroscopic applications, despite the fact that they are built for fluorescence. Cuvettes with two polished and two frosted sides are also available from Qvarz® for these other spectroscopic measurements (see above).
Our cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 20 mL to 125 mL. In addition to ordinary “Fused” type cuvettes (ie. VFOFO3), short or long path lengths (1, 2, 3, 5, 20, 40, 50mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VFOMQ). All these quartz cuvettes come with a PTFE lid to avoid contamination from dust and other particles, and each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
0.2 – 100 mm Dual Path Lengths Cuvettes
These quartz cuvettes are available in two different optical path lengths, each of which offers significant cost and usage savings. Furthermore, it is possible to measure the fluorescence with respect to the length of each optical path. It is no longer necessary to switch cells, which saves time because the all quartz dual path length quartz cuvettes can simply be turned 90 degrees.
Cuvette Racks & Inserts
Racks or inserts are required for short path length cells that have less than 12.5 mm depth, to ensure secure mounting in a standard cell holder. We offers black spacers and racks for use with 1, 2, and 5 mm path length cells.
- Spacers allow 1, 2, and 5 mm path length cells (with less than 12.5 mm depth) to be securely mounted in a standard cell holder (for 12.5 x 12.5 mm cells)
- Required when there is no path length adjustment facility in the cell holder
- Quartz rack can also be used instead of spacers – they provide more flexibility as each insert provides two different pathlengths selected by rotating through 90 degrees.
Semi Micro Narrow Width Fluorescence Cuvettes
Ultra Micro (<350uL) Fluorescence Cuvettes
The ultra micro quartz cuvettes with aperture windows and some narrow-width cuvettes are assembled with glue, which can be destroyed by benzene or other solutions with strong corrosive characteristics. These glued cuvettes are described as “Bonded” in the item description. These quartz cuvettes are not recommended for use with benzene, toluene, aqua regia ethanol or other corrosive liquids because they may damage the bonding between the parts and cause the cuvette to leak.
Short Height (<45mm) Fluorescence Cuvettes
Customized Fluorescence Quartz Cuvettes
Long Mouth Cuvettes
Large Tank Quartz Cuvettes
And “Fused” quartz cuvettes have quartz powder applied to the edges before heating. “Molded” quartz cuvettes are assembled by first heating the quartz to a high temperature and then applying pressure to adhere the pieces together, eliminating the need for glue which is adhesive-free, direct fusion bonding. “Fused” and “Molded” fabrication method allows the cuvette with enhanced chemical resistance to hold sample solutions with corrosive properties, such as those of nitrohydrochloric acid (aqua regia), without being damaged.
Cuvettes with PTFE Stoppers, 4 Polished Windows
- Four Optical Clear Windows for Fluorescence Spectroscopy
- PTFE Stopper Included with Each Cuvette to for Airtight Seal
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capabilities from 350µL to 3.5mL, Customizable
- Flexible Optical Path Lengths from 1mm to 10mm
- Fused and Molded Cuvettes with Enhanced Chemical Resistance
- Suitable for Various Manufacturers
These quartz cuvettes have 4 optical polished windows for fluorescence spectroscopy experiments. The four polished windows allow fluorescence measurements at right angles to the beam path. Standard optics cleaning procedures can be used to clean the quartz cuvettes. The through-beam windows of these cuvettes can be utilized for different spectroscopic applications, despite the fact that they are built for fluorescence. Cuvettes with two polished and two frosted sides are also available from Qvarz® for these other spectroscopic measurements (see above).
Our quartz cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 350 microliters to 3.5 milliliters. In addition to ordinary “Fused” type cuvettes (ie. VFPFA), short or long path lengths (1, 2mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VFPM5). All these quartz cuvettes come with a PTFE stopper to avoid contamination from dust and other particles and for airtight sealing purposes. Each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
“Fused” quartz cuvettes have quartz powder applied to the edges before heating. “Molded” cuvettes are assembled by first heating the quartz to a high temperature and then applying pressure to adhere the pieces together, eliminating the need for glue which is adhesive-free, direct fusion bonding. “Fused” and “Molded” fabrication method allows the cuvette with enhanced chemical resistance to hold sample solutions with corrosive properties, such as those of nitrohydrochloric acid (aqua regia), without being damaged.
Cuvettes with Screw Caps, 4 Polished Windows
- Four Optical Clear Windows for Fluorescence Spectroscopy
- PTFE Screw Threaded Cap Included with Each Cuvette to for Airtight Seal
- Fabricated from High Transmission UV Fused Quartz (190nm – 2.5µm)
- Various Volume Capabilities from 700µL to 3.5mL, Customizable
- Flexible Optical Path Lengths from 2mm to 10mm
- Fused and Molded Cuvettes with Enhanced Chemical Resistance
- Suitable for Various Manufacturers
These cuvettes have 4 optical polished windows for fluorescence spectroscopy research. The four polished windows allow fluorescence measurements at right angles to the beam path. Standard optics cleaning procedures can be used to clean the quartz cuvettes. The through-beam windows of these cuvettes can be utilized for different spectroscopic applications, despite the fact that they are built for fluorescence. Cuvettes with two polished and two frosted sides are also available from Qvarz® for these other spectroscopic measurements (see above).
Our quartz cuvettes feature a 12.5 mm square outside diameter, a 10 mm transmitted path length through the sample, and capacities ranging from 700 microliters to 3.5 milliliters. In addition to ordinary “Fused” type cuvettes (ie. VFSF2), short or long path lengths (2, 5, 32mm) cuvettes are offered in a “Molded” type for increased chemical resistance(ie. VFSM41). All these quartz cuvettes come with a PTFE screw cap to avoid contamination from dust and other particles and are the airtight sealed. Each cuvette is laser etched with a letter “Q” that denotes its quartz construction on the light transmission side.
“Fused” cuvettes have quartz powder applied to the edges before heating. “Molded” quartz cuvettes are assembled by first heating the quartz to a high temperature and then applying pressure to adhere the pieces together, eliminating the need for glue which is adhesive-free, direct fusion bonding. “Fused” and “Molded” fabrication method allows the cuvette with enhanced chemical resistance to hold sample solutions with corrosive properties, similar to those of nitrohydrochloric acid (aqua regia), without being damaged.
Flow Through Quartz Cuvettes
For spectrophotometric experiments in which a continuously flowing sample can be passed through the observation chamber, we have a variety of flow through cells in various configurations available for purchase from us as listed below.
Tubing is used to connect flow through cells to their sample sources. Flow through cells allow the sample to pass through the cell while still being connected to the sample source. For this purpose, a pump, such as a sipper accessory, is required to draw the sample into the cell for measurement and then draw it out again. Manually filling quartz cuvettes reduces productivity by reducing sample measurement time as well as operator-induced errors that are associated with manual filling.
For automated analyses such as dissolution testing, our oval aperture cells combine low volume with excellent flow characteristics, making them a good choice. For low concentration samples, long path length flow cells are useful, and they require the long path length rectangular cell holder to hold them.
- Flow through cells are designed for use with a sipper to reduce sample measurement time and operator-induced errors associated with manually filling cuvettes
- 10 mm pathlength flow through cells fits any standard cell holder
- Flow through cells feature nontransmitting, self masking black walls which improve sensitivity by eliminating stray light from measurements
- Available with oval, round or rectangular apertures and 5.5, 8.5, 15, or 20 mm z dimensions for compatibility with various systems
- Exceptional accuracy in terms of optical path length and parallelism
- Unique surface flatness of the optical windows
- High-temperature stability and high chemical resistance
- Outstanding measurement reproducibility
- Guaranteed transmission of >80% from 190-3500 nm
- Flow-through cells do not include tubing/fittings (unless indicated otherwise)
Single Channel Flow Through Cuvettes
Bubble Free Flow Through Cuvettes
Flow Through Cuvettes with Sides Connectors
Flow Through Cuvettes with Top Connectors
These all-quartz flow-through cuvettes are ideally suited for tablet dissolution tests (TDA) and flow-through spectroscopic analysis.
Custom Design Quartz Cuvettes
In this above product catalog, you will find our most popular Best Sellers that our customers use the most frequently. If you are unable to locate a suitable product in this selection, please contact us or use the cuvette finder on our website to locate the product of your choice. We will be delighted to work with you to develop individual and tailored solutions for your measurement requirements.
We will be pleased to create custom-designed quartz cuvettes and cells according to your requirements and specifications, within the limits of technical feasibility. We make every effort to use standard cells as the basis for these whenever possible, primarily for cost reasons. If you are interested in custom designs, please submit a technical drawing to us for consideration. After that, you will be sent a quotation, and once you have given your approval, this drawing will be used as the agreed-upon specification for manufacturing to begin.
FAQs
Why is my choice of cuvette important for reliable measurements?
The cuvette used to measure a sample is part of the optical system of the spectrophotometer. As a result, the position, geometry, and quality of the cuvette can all affect the accuracy and precision of absorbance measurements and should be carefully monitored.
Why use quartz cuvettes over glass or plastic cuvettes in a spectrophotometer?
For the following 3 reasons, quartz material cuvettes are preferred for spectroscopic measurements:
1. Transparent to UV ranges
Depending on the wavelength, the cuvette’s material can cause its own absorption. Ordinary optical glass contains many substances other than silicon dioxide, which makes it translucent over the UV range, but quartz is practically pure silicon dioxide (silica), which makes quartz cuvettes transparent over the whole UV/Vis measurement range (190-2500nm). Disposable plastic cuvettes are frequently only transparent in the visible spectrum (320-2500nm).
Although ultraviolet waves are invisible to human senses, they have a shorter wavelength than visible light. When we use glass instead of quartz, the glass absorbs UV radiation, but quartz does not.
If wavelengths in the ultraviolet region (below 300 nm) are utilized, cuvettes made of quartz glass or a special type of plastic with appropriate transparency in this range must be used.
2. Better Thermal Properties
The melting point of quartz is much higher than that of glass. Quartz cuvettes are more durable than plastic or glass cuvettes.
3. Better Chemical Compatibility
Quartz material chemical compatibility is stronger than glass, allowing it to handle a wider variety of substances that would melt or harm a glass cuvette.
What are typical samples of spectroscopy?
The vast majority of UV/Vis spectroscopy samples are solutions put in a cuvette for measurement. Cuvettes are tiny glass or quartz containers with a rectangular shape. The laser beam is usually intended to travel a distance of 10 mm through the contents, however, the light path length might range from 0.1 or 0.2 mm to 100 mm. The sample quartz cuvettes usually contain a very dilute solution of the chemical you’re measuring. Cuvettes with a long optical path length are typically used to test highly dilute sample solutions. According to Beer’s Law, the greater the sensitivity of analysis, the longer the sample path length should be.
The solvent is decided so that no substantial quantity of light in the wavelength range of interest is absorbed by it. The quartz cuvettes in most instruments are intended to fit inside a 10 mm square container.
Other non-solution sample types are commonly measured in high-performance UV/Vis/NIR types of equipment. Solid materials, both transparent and opaque, can be assessed with the right diffuse reflectance accessory, such as an integrating sphere. Samples such as mirrors and optical coatings can be measured using specular reflection accessories.
What is the material difference between cuvettes?
At the measured wavelength, the cuvette fabrication material must have no absorption. Glass and quartz are two common materials for cuvettes. For disposable cells, polystyrene (PS) and polymethylmethacrylate (PMMA) are commonly chosen. The wavelengths for which the various types of cuvettes and cells can be employed are shown in the right figure. The detectable wavelength range varies from different cuvette materials.
The transmission spectra obtained for several types of cells using air as the measuring object are shown in the figure. There is no absorption by the cells in the measurement wavelength ranges indicated in the figure.
There’s also the issue of cuvette chemical resistance, in addition to desired wavelength measurement ranges. Glass and quartz are chemically resistant, with the exception of severely alkaline solutions. The chemical resistance of plastic disposable cuvettes, on the other hand, varies depending on the substance, thus while choosing a cell for measurement special care is required. Another thing to keep in mind is that the optical path lengths of individual disposable cuvettes, which are usually discarded after usage, vary slightly. This might result in quantitative value errors.
Glass cuvettes have a measuring range of around 320 nm to 2500 nm, which is narrower than quartz cuvettes since glass is opaque in the ultraviolet. They are, however, a practical and less expensive alternative to quartz cells provided measurements are not required in the ultraviolet wavelength range below roughly 320 nm. These cuvettes are frequently labeled “G.”
When glass or quartz cuvettes are used, a series of measurements are performed to remove variations in optical path lengths from cell to cell. Disposable cells are constructed of plastic and may be thrown away once they’ve been used. Unlike the glass and quartz cells mentioned above, each sample is placed in a separate disposable cell. Because differences in optical path length occur often from cell to cell, obtaining correct data is challenging. When great measurement precision is not necessary, disposable cells are used. They are helpful for measuring biological samples were washing the material out of the cell is difficult. Disposable cells are not capable of measuring samples that destroy plastics, such as organic solvents, because they are constructed of plastic. They are also opaque in the ultraviolet and near-infrared areas, only limited to observations in the visible light spectrum range.
Why are “short path length” cuvettes used? (for too concentrated samples)
When high-concentration samples are diluted, a 10 mm cuvette can be used to measure them. However, there are certain samples that are difficult to dilute. Diluting a sample, for example, may result in a change in absorbance because of the interaction with the solvent (i.e., a shift in the peak wavelengths).
When the absorbance is high and dilution is difficult, a short path length cuvette can be used to measure the absorbance. Short path length cuvettes come in 0.2 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, and 5 mm optical path lengths. The findings of analyzing toluene using a 1-mm cell and a 10-mm cell are shown in the left figure. The 1 mm cell has far less absorption saturation (i.e., 0% transmittance) than the 10 mm cell.
Solution analysis in the near-infrared wavelength range is a well-known use of measurement employing short path length cuvettes. When a 10 mm cell is used for near-infrared measurements, saturation typically occurs due to solvent absorption, making it difficult to determine the sample’s absorption. To avoid absorption saturation caused by the solvent, a short path length cuvette is used.
The optical path length of the cell is decided by the size of the absorbance or transmittance in low- and high-concentration samples.
Spacers or inserts are required for short path length cells that have less than 12.5 mm depth, to ensure secure mounting in a standard cell holder. QVARZ® offers black spacers and quartz block inserts for use with 1, 2, and 5 mm path length cells
Why are “long path length” cuvettes used? (for too diluted samples)
Many different types of solution analysis use cuvettes with a 10 mm optical path length. However, if the sample concentration is low, a cell of this size may not be able to provide adequate absorbance. Although 10 mm cells may be used when concentrating the samples, concentration could be difficult if the material vaporizes or experiences a chemical change during the concentration process. In such instances, adopting a “long path length cuvette” for measuring is more effective. Long path length cuvettes are available in optical path lengths of 20 mm, 30 mm, 40 mm, 50 mm, and 100 mm. The absorbance rises in direct proportion to the cell’s optical path length. The results of testing a 10 mg/L potassium permanganate solution with a 10 mm path length cell and a 100 mm path length cell are shown in the figure on the right. The absorbance of the 100 mm cell is ten times that of the 10-mm cell, as can be observed.
The measuring of water turbidity is a well-known application of analysis utilizing long path length cuvettes. Low turbidity samples are often analyzed using 50 mm and 100 mm cells.
How do fingerprints on cuvettes affect absorbance?
When residuals, such as fingerprints or grease, are deposited on the cuvette windows, the absorbance increases due to the presence of extra absorbent components. This can be avoided by cleaning thoroughly before and after use. After the windows have been cleaned, extra caution must be exercised to prevent touching them.
How to clear fingerprints on cuvettes?
Wipe the outside of the cuvette with a Kimwipe to remove any fluids or fingerprints. This method prevents scratching of the cuvette in locations where the light will pass through. Scratches on the cuvette can result in inaccurate measurements.
How to clear the cuvettes?
This is a popular question for which there is no definitive solution. In fact, there is no specific published method of cleaning. And why?
The reason for this is due to the wide range of samples that are evaluated. A large number of cleaning procedures are necessary due to the wide variety of analytical samples. However, because detailing all ways is unrealistic, it does not contribute to the solution of the problem. As a result, we’ve included a handful of the most typical cleaning procedures below. These techniques can be divided into a few categories. The first group employs water as a solvent, whereas the second uses an organic solvent.
1) Using Water as a Solvent – Clean with purified water first, then ethanol, then dry. Soak cells in a commercial cleaning solution developed particularly for cleaning cells (for around 10 minutes at 30 to 50 °C) for more serious contamination. After that, rinse the cell with distilled water and immerse it in a dilute nitric acid and hydrogen peroxide solution (for about 30 minutes). Finally, rinse the cell with distilled water and place it in an airtight container.
2) Cleaning with Organic Solvents (Only Fused or Molded Types)- Clean with ethanol or acetone after cleaning with the organic solvent, and then clean using the same approach as mentioned above for the aqueous solution.
3) Scrub the cell softly with a cotton swab if the pollution is obstinate. Avoid alkaline cleaning solutions, which can disintegrate glass, and ultrasonic cleaning methods, which can harm the cell.