Page 14 - Catalogue - cuvettes and solid-state calibration standards

Handling and cleaning cells

General handling

 Cells must be kept scrupulously clean. Optical surfaces should not be touched, as oil smudges are difficult
to remove. Lens paper is the best thing to clean the cells with, anything else may scratch them.

Cleaning

 Cleaning cuvettes carefully after use will ensure that their transmission characteristics remain fairly
constant. Improper use or poor cleaning will result in staining or etching of surfaces thus reducing
transmission and increasing light scattering. We recommend using a FireflySci cell washer, for example the
FF-P65D for two cuvettes illustrated below, as the best and easiest way to clean your cuvettes. Please
note that the FireflySci washers do not include the vacuum flask.

Solvents to use

 The purity of solvents used for sample and for cleaning is important for the protection of cells. Only distilled
water or spectrophotometric grade (highly pure) solvents should be used.

Cleaning agents to use

 Depending on the type of sample you are testing, you may decide to clean the cells with a mild agent (such
as dilute Hydrochloric acid) as soon as possible after each use. After an acid rinse, distilled water should
be used to remove all traces of acid.

For organic materials

 If you use mild detergents, we recommend that their pH value is as close to neutral as possible. These
detergents should also be free of any suspended material containing lanolin or oils. You may also use
dilute Hydrochloric acid. Rinse with the same solvent you originally used with the cell or with distilled water.

Stubborn contaminants

 To remove stubborn contaminants, cells can be soaked for a few minutes in mild sulfuric acid. Dichromate
cleaning solution is also very effective. Heavy metal salts may be removed by rinsing in concentrated nitric
acid or aqua regia (a mixture of hydrochloric acid and nitric acid). Reminder: After an acid rinse, distilled
water should be used to remove all traces of acid.

Drying cells

 Don’t dry cells with compressed air. Speed up evaporation by using the cell washer as a means of suction.

Warning

 Acids should never remain in the cells for longer than one hour. Never allow cells to soak in concentrated
acids, alkalines, or other agents which may etch polished optical surfaces. Also, we do not recommend the
use of ultra-sonic cleaners.

Cleaning cells with very small path lengths

Use a syringe to introduce the cleaning solvent to the corners and difficult to reach areas of the cell.

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