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The analytical
laboratory is a vital part of all industrial plants and research establishments.
the techniques employed therein have developed rapidly in recent years, but the
fundamentals upon which many of these techniques are based have remained
constant and the majority demand the use of high-purity inert materials. In this
category platinum has properties that make it an ideal choice. It has a high
degree of chemical inertness and yet can readily fabricated into a wide variety
of articles.
Metals
used for laboratory apparatus must have the following properties;
Platinum and its alloys possess these qualities and is therefore
the most widely used metal for analytical laboratory apparatus.
Platinum (Pt)
Platinum is best known and least rare of the platinum
group metals. Its high melting point, 1773 degrees Celsius, ductility and
excellent resistance to chemical attack by acids and fusion mixtures makes it
very suitable for laboratory ware.
Platinum 5% Gold (Pt/Au)
Universally accepted material of Choice for crucible and
casting moulds for spectrographic analysis by x-ray fluorescence (XRF). The
alloy has higher temperature strength than pure platinum and has a "non-wetting"
property, which results in easy removal of the sample after fusion and allows
for many reproducible assays.
Platinum 3.5% Rhodium (Pt/Rh)
The rhodium alloys have higher hardness and high
temperature strength making it suitable for more aggressive conditions.
Platinum 10% Rhodium (Pt/Rh) This alloy
has a melting point of 1850 degrees Celsius; it has greater hardness and higher
strength than other platinum alloys. It is capable of maintaining its shape
under the hottest furnace conditions.
Platinum Gold Rhodium (87/3/10)
This alloy combines the "non-wetting" property of the
Pt/Au alloy and the extra strength and durability of Pt/Rh alloys.
Other Metals
Gold (Au)
Gold can be used in labware. Its most common application
is for hydrofluoric acid treatment of siliceous materials.
Silver (Ag)
Pure Silver can be used for fusion with alkali hydroxides.
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