What is the maximum operating temperature for the UV-Cuvettes?

 A small transparent tube or container with specific optical properties. The chemical composition of the container determines the vessel's use, such as Pyrex glass for examining materials in the visible spectrum or silica for those in the ultraviolet range. It is used in laboratory research and analyses, such as photometric evaluations, colorimetric determinations, and turbidity studies.

A cuvette is a small tube of circular or square cross section, sealed at one end, made of plastic, glass, or fused quartz (for UV light) and designed to hold samples for spectroscopic experiments. The best cuvettes are as clear as possible, without impurities that might affect a spectroscopic reading. Like a test tube, a cuvette may be open to the atmosphere on top or have a cap to seal it shut. Parafilm can also be used to seal it.

Inexpensive cuvettes are round and look similar to test tubes. Disposable plastic cuvettes are often used in fast spectroscopic assays, where speed is more important than high accuracy.

Some cuvettes will be clear only on opposite sides, so that they pass a single beam of light through that pair of sides; often the unclear sides have ridges or are rough to allow easy handling. Cuvettes to be used in fluorescence spectroscopy[ must be clear on all four sides because fluorescence is measured at a right-angle to the beam path to limit contributions from beam itself. Some cuvettes, known as tandem cuvettes, have a glass barrier that extends 2/3 up inside, so that measurements can be taken with two solutions separated, and again when they are mixed. Typically, cuvettes are 10 mm (0.39 in) across, to allow for easy calculations of coefficients of absorption.

Cuvettes to be used in circular dichroism experiments should never be mechanically stressed, as the stress will induce birefringence[ in the quartz and affect the measurements made.

 Types of cuvettes

There are three different types of cuvettes commonly used, with different usable wavelengths:

Glass, with a wavelength from 380 to 780 nm (visible spectrum).

Plastic, with a wavelength from 380 to 780 nm (visible spectrum).

Fused quartz, with a wavelength below 380 nm (ultraviolet spectrum).

UV quartz has a usable wavelength of around 185 nm, and a matching tolerance of 1% at 220 nm.

ES quartz has a usable wavelength range of 190 to 2,000 nm, and a matching tolerance of 1% at 200 nm.

IR quartz has a usable wavelength range of 220 to 3,500 nm, and a matching tolerance of 1% at 2,730 nm.

What is the maximum operating temperature for the UV-Cuvettes?

The UV-Cuvettes can be used at temperatures up to 60 degrees Celsius for several hours.

I have selected the correct size UV-Cuvettes for my spectrophotometer, but still am not getting appropriate results. Why?

If you are using the appropriate window height (z-dimension) ultra-micro UV-Cuvette for your spectrophotometer, and are not getting appropriate results, it is likely due to one of two different problems.

Extremely dilute samples.

Because the proprietary plastic has a higher absorbance than quartz, extremely dilute samples may not differ substantially from background, so you may have no other choice than to use a quartz cuvette.

Light beam width.

Some spectrophotomers have abnormally wide light beams that can be refracted by the side walls of the cuvette. When using ultra-micro sized samples, these spectrophotometers require the use of black-masked quartz cuvettes to overcome this deficiency.

What is the difference between your PS, PMMA and UV-Cuvettes

Polystyrene (PS) cuvettes are the least expensive, however they have the lowest chemical resistance, and are only suitable for visible light applications, with a lower wavelength limit of around 340nm. Polymethyl methacrylate (PMMA or “acrylic”) cuvettes extend that range to about 300nm, or slightly into the near UV range, and have slightly greater chemical compatibility. BRAND UV-Cuvettes use a proprietary plastic to allow measurement as low as 220nm, and has resistance to many polar organics as well as many acids and bases.

What does “mold cavity matched” mean?

Cuvettes are injection molded plastic. No matter how close the tolerances are in the molds, there will be some variance. BRAND cuvettes are sorted during the manufacturing process so that each package of cuvettes contains only cuvettes made from the same mold, minimizing the cuvette-to-cuvette variance.

Do you sell four-clear-side flourimetry cuvettes?

No.

My results with your UV-Cuvettes are different than with quartz. What’s happening?

While our UV-Cuvettes allow enough light to pass to perform accurate spectrophotometry down to 220nm, they are not as transparent as quartz. When using UV-Cuvettes, any reference measurements should also be done with UV-Cuvettes.