Laboratories often use many glass instruments, such as beakers, conical flasks, burettes, cylinders, measuring cups, etc. Whether the glass instruments are clean usually affects the reliability and accuracy of the analysis results, so it is essential to ensure they are clean.
Wash glass instruments should be based on the requirements of the experiment, the nature of the dirt, and the degree of pollution to choose.

1. Brush with water

A. Empty the bottle of liquid
B. Remove all labels on the containers and keep the surface of the bottles bright and clean
C. Rinse the glassware 3 times with natural water to ensure that it is thoroughly clean and free of residue
D. Invert the glassware and allow it to dry.

2. Acid washing

If there is still residue on the surface of the glassware after rinsing it once with water, acid washing is the choice. The two commonly used acid-washing methods are as follows:

Method 1:

If you have an Acid Steam Cleaning System (if not, see Method 2 directly), the procedure is as follows:

  1. Empty the bottle of liquid
  2. Place the glassware in the Acid Steam Cleaning System. Ensure that the surface of the vessel is fully exposed to the vapor.
  3. Select the appropriate cleaning program, usually Acid Steam Cleaning.
  4. Start the cleaning program and allow the steam to act for some time.
  5. After cleaning, remove the glassware. (If the machine does not come with drying, it is necessary to dry the glassware after removing it).

Method 2:

  1. Soak the glassware in the Liqui-Nox bath for at least 2 hours.
  2. Rinse the inside and outside of the vial 3 times with tap water. (Wear protective equipment and do not touch directly with your hands.)
  3. If there is no visible residue on the glassware, rinse the glassware thoroughly and allow it to dry
  4. If there is any visible residue inside the glassware:
    a. Soak the glassware in an acid bath (~10% HCl) for at least 1 hour. Ensure that the inner surface of the glassware is wholly submerged in the acid (no bubbles).
    b. Remove the glassware directly from the acid bath and place it in the wash bucket. Drain as much acid as possible back into the acid bath. (Be careful not to drip or splash acid outside the acid bath)
    c. Rinse the inside and outside of the vial 3 times with tap water, rinse the glassware thoroughly, and allow it to dry.