A Guide to Cleaning Platinum Crucibles
Platinum crucibles are frequently exposed to extremely harsh environments. These environments can decrease the lifetime of the product and its accuracy of measurement. This article will act as a brief overview of how to clean crucibles correctly.
The Benefits of Platinum Crucibles
Platinum is a popular material for crucibles as it has excellent chemical resistance even at extremely high temperatures. Platinum is not subject to attack by any acid and cannot be oxidized at any temperature. This is why platinum crucibles are so well suited to sample preparation of fusion samples and wet chemical digestions.
High-performance platinum crucibles are known for a long length of service and high repeatability due to their extreme chemical resistance.
The Importance of Cleaning Laboratory Crucibles Correctly
There are a few ways that platinum crucibles can be cleaned and they are fairly simple. However, platinum crucibles must be cleaned meticulously so that there is no transfer of materials when starting another experiment.
Cleaning Platinum Crucibles with Hydrofluoric Acid
One way of cleaning platinum crucibles is by soaking them in diluted hydrofluoric acid for at least 24 hours, then boiling for three hours. Once the platinum crucible is cool, it should be rinsed carefully with water and then if necessary it should be cleaned mechanically in an ultrasonic bath.
After this, the laboratory crucibles should be rinsed again and boiled in distilled water to remove the hydrofluoric acid completely. It should then be baked at 900°C for one hour.
Citric Acid for Cleaning Platinum Crucibles
Platinum crucibles should be put in an ultrasonic bath in a tailor-made holder to make sure no cross-contamination takes place. The citric acid (20%) should then be placed inside the bath and it should be set to vibrate at 50C for ten minutes to remove any adhering flux. The citric acid solution must be regularly replaced and then the labware should be dried using a clean air stream or it could be placed in a drying oven.
Cleaning Platinum Crucibles with Fused Potassium Bicarbonate
The first step of this cleaning method is to manually scrape any residue from experiments from the platinum crucible. Then the crucible is filled with potassium bicarbonate in its solid form, past the residual line of remaining material from experiments.
Following this, the crucible is placed on a burner and heated until the bicarbonate melts. The melt should then be frequently stirred until a layer of red potassium salt appears on the surface. The melt should then be poured out of the platinum crucible and then it should be rinsed with hot water. Following this is must be dried with a clean cloth and allowed to cool.
Platinum Crucibles from XRF Scientific
