Cleaning your Precision Cells
Cell Cleaning Information
If the cells are cleaned carefully after use, their transmission characteristics will remain fairly constant. Improper use or poor cleaning will result in staining or etching of surfaces thus reducing transmission and increasing light scattering.
- Cells must be scrupulously clean. Optical surfaces should not be touched, as oil smudges are difficult to remove. Lens paper is the best kind to wipe the cells with. Anything else may scratch the cells.
- Purity of solvents used for sample and cleaning is important for 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, were commend that they’re pH is as close to neutral as possible. These detergents should also be free of any suspended material,containing no lanolin or oils. You might also use dilute Hydrochloric acid. You can rinse with the same solvent you originally used with the cell. We also recommend distilled water.
To remove stubborn contaminants, cells can be soaked for a few minutes in mild sulfuric acid. Dichromate cleaning solution is 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 the Cells
Avoid blowing cells with air to dry them. It is better to speed evaporation by using the cell washer as a means of suction.
At no time should acids 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.
Note About Small Path Lengths
A syringe may be used to introduce the cleaning solvent to the corners and difficult to reach areas within the cell.