Suppliers of Platinum and Platinum Alloy Labware

Platinum (Pt) and many of its alloys are highly resistant to chemical attack. To get the greatest use and life out of your Pt ware you should observe the following:

• Avoid thermal and physical shock.
• Cleaning: For routine operation, place the Pt labware into a beaker of hot citric acid solution (concentration and temperature to suit). For a quick dry crucible clean, place about 1gm of lithium borate into the crucible, melt, place a grain of ammonium iodide and pour the melt to waste. Eg. A 500ml capacity steel crucible.

Other cleaning operations include:
Boiling with dilute hydrochloric acid (HCl) or fusing with potassium bisulphate prior to boiling with water normally suffices. There are procedures set out for specific material types in various standards e.g. ISO 9516 - 1992 for fusion XRF analysis of iron ores.

For a more aggressive clean, boil in nitric acid (HNO3 chlorine free). Whatever cleaning method is used, rinse thoroughly with clean water and dry thoroughly.

• Polish and reshape your Pt ware after use.
• Always maintain oxidising condition.
• When performing borate fusion on reducible matter, pre-oxidise first before fusing. In most cases, this can be done in situ e.g. using an oxidant such as sodium nitrate and sintering at 700°C. Eg. For the analysis of base metal sulphides. Organic material must be fully ashed before fusing.
• Avoid contact with most metals, e.g. Fe, Cr, Ni, Cu, Zn, Pb – particularly at elevated temperatures. If the metal particles are fine enough, they can be pre-oxidised as above.
• Do not carry out direct fusions with caustic alkalis, nitrates, cyanides or nitrides in Pt ware.
• Barium and lithium hydroxides react at red heat with platinum and fused alkali oxides and peroxides dissolve platinum.
• In general, reduce handling as much as possible. Ideally the Pt ware should only come in contact with tongs (titanium or Pt tipped steel tongs), balance pan and cradle used to hold the Pt ware. e.g. preheated/conditioned inconel cradles for fusion work and teflon cradles for cleaning/washing. Never place Pt ware on bench tops.

Contact APS about particular applications of platinum and its alloys.