We are currently facing an issue with the cleaning process of the reflector discs for the TXRF analysis. We have been following the following procedure:

1. Dipping the reflector discs in acid water for 12 hours at 150°C.

2. After the 12-hour duration, removing the water and adding distilled water. Boiling the discs for an additional 2 hours.

3. Pouring out the water and allowing the discs to dry.

However, even after diligently following this procedure, we are unable to achieve satisfactory cleanliness. As a result, we kindly request suggestions from experts to help resolve this matter.