Gooch crucible
Encyclopedia
A Gooch crucible, named after Frank Austen Gooch
, is a filtration device for laboratory use (and was also called a Gooch filter). It is convenient for collecting a precipitate directly within the vessel in which it is to be dried, possibly ashed, and finally to be weighed in gravimetric analysis
.
The device was originally a standard platinum
laboratory crucible with a perforated base into which asbestos
pulp was placed to form the filter mat. The crucible was then heated in an oven to dry out until it attained constant weight The use of these materials meant that after filtration, the crucible and its contents could be subjected to high temperature to dry the filtrate and possible oxidize, or ash it to minimum weight. However, because of the high cost of platinum, versions made of porcelain
were introduced in 1882. Some Gooch crucibles, such as the one in the drawing, permit two layers of asbestos to be used, separated by a perforated porcelain plate.
Other inorganic fibers, notably glass, have been used in place of asbestos. Gooch crucibles made of borosilicate glass with fritted glass bases are more common today. Platinum may still be required for the most corrosive materials, and porcelain ones are used where ashing at high temperature is required, but the borosilicate glass ones are adequate for drying.
They may also be used for collection and processing of biological tissue samples within the same container.
Frank Austen Gooch
Frank Austen Gooch was a chemist and engineer. He was born to Joshua G. & Sarah Gates Gooch in Watertown, Massachusetts...
, is a filtration device for laboratory use (and was also called a Gooch filter). It is convenient for collecting a precipitate directly within the vessel in which it is to be dried, possibly ashed, and finally to be weighed in gravimetric analysis
Gravimetric analysis
Gravimetric analysis describes a set of methods in analytical chemistry for the quantitative determination of an analyte based on the mass of a solid...
.
The device was originally a standard platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
laboratory crucible with a perforated base into which asbestos
Asbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
pulp was placed to form the filter mat. The crucible was then heated in an oven to dry out until it attained constant weight The use of these materials meant that after filtration, the crucible and its contents could be subjected to high temperature to dry the filtrate and possible oxidize, or ash it to minimum weight. However, because of the high cost of platinum, versions made of porcelain
Porcelain
Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between and...
were introduced in 1882. Some Gooch crucibles, such as the one in the drawing, permit two layers of asbestos to be used, separated by a perforated porcelain plate.
Other inorganic fibers, notably glass, have been used in place of asbestos. Gooch crucibles made of borosilicate glass with fritted glass bases are more common today. Platinum may still be required for the most corrosive materials, and porcelain ones are used where ashing at high temperature is required, but the borosilicate glass ones are adequate for drying.
They may also be used for collection and processing of biological tissue samples within the same container.