Why do we zero the spectrophotometer?

Why do we zero the spectrophotometer?

Why does a spectrophotometer need to be zeroed? Spectrophotometers and colorimeters are zeroed or “blanked” to reset the absorbance baseline to any background color in the sample that may absorb at the wavelength in question causing an interference.

Why does the cuvettes have two frosted sides?

Some plastic cuvettes have two clear sides and two frosted sides. This is important as rotating the cuvette by 180 degres can give a significantly different reading. The purpose of the frosted faces is to prevent light scattering out of the cuvette at the sides for certain types of samples.

Which way should the triangular mark on the cuvette be facing in the V Spec Spectrophotometer?

Make sure that the “V” symbol or indicator on the cuvette for the light path is facing forward. Securely Close lid after inserting cuvette(s).

How do you hold a cuvette?

Hold the cuvettes in such a manner that, opaque sides are held between two fingers & transparent sides are not being touched. 5. Before keeping the cuvettes inside the holders, always blot them (from all the sides) with tissue paper.

How do you fill a cuvette?

Cleaning and proper use of the cuvettes for the Spec 20

1. NEVER use a brush to clean the inside of the cuvette.
2. Rinse the tube with distilled water a few times.
3. Add about 1 mL of the solution to be measured.
4. Fill the cuvette about 3/4 full of the solution you wish to test.

What is a blank solution and why is it used?

A blank solution is a solution containing little to no analyte of interest, usually used to calibrate instruments such as a colorimeter.

What happens if there are 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.

Do fingerprints absorb light?

The presence of the finger prints will scatter the detector and absorb light causing higher absorbance and higher concentration results. yes because it is colorless, and does not absorb visible light and does not have a appreciable molar absorptivity.