This example gives

General Procedure and Tips for UV-Vis Absorption Measurements

1. Turn on the instrument and provide ample time for the lamp to warm up and

become stable (usually 10 minutes).

2. Find one cuvette to use for all measurements. Note the orientation, so you can

consistently place it in the sample holder.

3. Rinse the cuvette multiple times with water and then fill it with the blank

solution. We will use distilled water as the blank for this experiment.

4. Make sure the cuvette walls are free of interfering species (water drops,

fingerprints, scratches, etc.)

5. Make sure the solution is clear. Remember: In chemistry a clear solution

means one that is homogenous and free from solids or gas bubbles. The

presence of solids or gas bubbles will scatter light and interfere with

measurements. Cloudy is the opposite of clear. If your solution appears cloudy,

you must make it clear before taking the measurement.

6. Place the cuvette into the instrument and blank the instrument. Make sure the

orientation is correct.

7. Rinse the cuvette multiple times with the new solution that will be measured

and then fill it with that solution.

8. Make sure the cuvette walls are free of interfering species (water drops,

fingerprints, scratches, etc.).

9. Make sure the solution is clear. A green solution can be clear because clear

does NOT mean colorless. See the note above in point 5.

10. Place the cuvette into the instrument and measure the absorbance. Make sure

the orientation is correct.

Safety Considerations

Wear eye protection and wash hands regularly to avoid having harmful material

come into contact with your eyes.

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