Cleaning of Platinum/Silica Crucibles

1.0 OBJECTIVE

To lay down the procedure for cleaning Platinum / Silica Crucibles.

2.0    SCOPE

This procedure is applicable to all Platinum / Silica Crucibles used in the Quality Control Laboratory .

3.0 RESPONSIBILITIES

QC Executive/Officer/designee shall be responsible for Cleaning of Platinum/Silica Crucibles.

Head-QC/Designee shall be responsible for the ensuring overall compliance of the Standard Operating Procedure.

4.0 DISTRIBUTION

Master copy                :           Quality Assurance Department

            Controlled copy – 1     :           Quality Control Department

5.0       PROCEDURE

• The platinum / silica crucible shall be washed with water thoroughly.
  • The crucibles shall be checked visually before use. The crucibles should be visually clean and free from strains.
  • To remove the stain, small quantity of anhydrous sodium carbonate shall be taken and fused. The residue shall be dissolved in water and discarded. Carefully add small volume of concentrated hydrochloric acid and warm gently, the operation shall be repeated till stains are removed.
  • To remove Iron stains, the crucible shall be heated with 1 to 2 gm of ammonium chloride.
  • The crucibles shall be washed thoroughly as per the above procedure after every analysis.
  • Never cover the crucibles while heating.
  • Platinum crucibles shall be handled carefully to prevent deformation and denting.
  • PRESERVATION:
    • Preserve all the crucibles in their original boxes or special wooden boxes.  

• In case the crucibles are deshaped due to dents, they should be sent for restoration