Why is platinum preferred material for labware?

The precious metal platinum is frequently used as a material to make various products for analysis purposes. We explain the choice for this by highlighting the physical and chemical characteristics.

Physical properties precious metal

Precious metal has the following physical characterisctics;

  • A good machinability, hardly any limits have to be set on the design of the most complicated products and yet it is sufficiently hard to give the products the necessary strength.
  • Good mechanical properties at high temperatures and resistance to fatigue caused by numerous temperature changes and prolonged heating.
  • A high melting point. Melting points of platinum, platinum combinations and other precious metals;
Chemical symbolMetalMelting point
Pt/Au 95/5%Platinum / gold1670°C
Pt/Ir 97/3%Platinum / iridium1772°C
Pt/Ir 90/10%Platinum / iridium1780°C
Pt/Ir 80/20%Platinum / iridium1815°C
Pt/Rh 90/10%Platinum / rhodium1850°C
Pt/Rh 80/20%Platinum / rhodium1900°C
Au/Pt 90/10%Gold / platinum1120°C

Precious metal chemical properties

Precious metal has the following chemical characterisctics;

  • Resistance to the corrosion/oxidation caused by a large number of acids, gases and corrosive salts or mixtures.
  • Resistance to high temperatures, it does not flake, discolor or significantly change weight.

Usage of platinum for labware

The elements that combine most of these properties are the metals of the platinum group. With the exception of osmium and palladium. Osmium oxidizes at normal temperatures and palladium oxidizes at about 400°C.  Palladium is also affected by certain mineral acids in particular, such as nitric acid.

Although the mechanical properties and heat resistance of iridium and ruthenium are better than those of platinum and rhodium, it is the hardness and high melting point that make them difficult to process.

Pure iridium products are only used for special applications. In addition, iridium and ruthenium are metals which oxidize relatively easily, necessitating an inert and reducing atmosphere.

Platinum is preferred over the three other metals; rhodium, palladium and osmium. This because of its physical and chemical properties, which make it ideally suited for applications in laboratory equipment. The properties can however be adjusted by adding certain other metals.

Check out our platinum in laboratory prodicts;

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