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What is a cuvette used for?

Cuvettes are designed to hold samples for spectroscopic measurement, where a beam of light is passed through the sample within the cuvette to measure the absorbance, transmittance, fluorescence intensity, fluorescence polarization, or fluorescence lifetime of the sample.

Why is it important to clean the surface of the cuvettes before performing an absorbance measurement?

Cleaning cuvettes Do not handle the lower portion of the cuvettes, because smudges or droplets of solution will affect the passage of the light beam through the cuvette. Wipe off the outside with an absorbent tissue before inserting the cuvette clamp holder.

Why is it important not to have fingerprints on the cuvette?

Wipe the cuvette with a Kimwipe to remove any liquid and fingerprints on the outside of the cuvette. Both of these will interfere with light transmission and will cause erroneous readings. This technique prevents scratching of the cuvette in those areas through which the light will pass.

Do fingerprints affect absorbance?

Concentration will stay the same since the fingerprints will only deflect the light slightly and not enough to affect the absorbance measurements.

What effect would a fingerprint left on the outside of the cuvette have on the measured absorbance?

How would your test results be affected if you left finger prints on the sides of the cuvette in line with the light path of the spectrometer (or colorimeter)? The presence of the finger prints will scatter the detector and absorb light causing higher absorbance and higher concentration results.

Why is it important not to leave fingerprints or scratch the sample cells in spectrophotometric measurements?

Why is it important not to leave fingerprints or scratch the sample cells in spectrophotometric measurements? Scratches and fingerprints make it difficult for the cell to be positioned properly in the spectrophotometer. Scratches and fingerprints on the surface of the cell can contaminate the sample.

Does volume affect absorbance?

The results show that the loaded sample volume (between 1 and 10 µL) and evaporation rates do not adversely affect the absorbance measurements collected.

How much liquid should be in the cuvette?

A standard volume cuvette holds a measuring volume of 3.5 mL. A semi micro cuvette volume holds samples of 0.35 mL – 1.7 mL. Among these types of short path length cuvettes may require cuvette mounts or spacers.

Why the cuvettes have two frosted sides?

Answer. Some plastic cuvettes have two clear sides and two frosted sides. The purpose of the frosted faces is to prevent light scattering out of the cuvette at the sides for certain types of samples. Cloudy samples tend to scatter light.

Why are fluorescence cuvettes clear on all sides?

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.

Why glass is not suitable for UV spectroscopy?

Glass cells are most common in school and college undergraduate laboratories because of their lower cost. However, glass absorbs strongly in UV region and its application is not recommended for wavelengths below 340 nm.

Why does quartz not absorb UV light?

Quartz will transmit UV from 180 nm to 400 nm. Since quartz is made of silicon dioxide, glasses made from a high proportion of this material will also readily transmit UV. One such glass is known as VYCOR, which is 96% silica. However, remember that the shortest UV is the most damaging to the skin and cells.

Can UVC pass through quartz glass?

Ordinary glass is not transparent to germicidal ultraviolet radiation wavelengths—quartz is. In order to provide disinfection, CRYSTAL CLEAR™ Quartz Sleeves allow precisely the right amount of radiation to pass through into the air or water.