Every chemistry lab, whether academic or professional, contains a lot of equipment, and, in most, you would find a stainless steel Buchner funnel.
The Buchner funnel is named after an industrial chemist, Ernst Buchner, and was invented in 1888. In general, it is used as a filtration device to remove unwanted moisture from solids.
How Does A Buchner Funnel Works?
Stainless steel Buchner funnels are normally set up with a Buchner flask, rubber bung, and vacuum line. The narrow part of the funnel is placed into a rubber bung that fits snug into a Buchner flask.
Attached to the side hole on the Buchner flask is a vacuum line that will suck the air out of the flask and provide a pressure gradient for the liquid to flow.
The Buchner funnel is typically equipped with a fitted piece of filter paper just slightly smaller than the diameter of the funnel. The filter paper is moistened with water or solvent depending on your sample to provide good adhesion to the funnel. Once the setup is complete, the filtration can begin.
Open the vacuum line to create a pressure gradient and then pour your solids/liquids mixture onto the filter paper. The solid particles will stick to the filter paper and the liquids) will flow directly into the flask. In general, gravity will create the same effect, but the advantage of the Buchner funnel is that this process will be exponentially faster.
Continue to stir the mixture allowing more of the liquid to be filtered through the paper. Then when the mixture has been sufficiently dried, stop the vacuum and remove the funnel from the flask.
The solids can be removed from the filter paper by scraping with a spatula or sharply hitting the sides of the funnel.
Applications For A Buchner Funnel
There are many uses for a stainless steel Buchner funnel across various scientific disciplines. However, it most typically used in organic chemistry to collect recrystallized solids out of solvents. Especially in the pharmaceutical industry.
Other uses include:
- Quality control labs in municipal waste plants
- Distillation and extraction processes in chemical processing plants
- Phase separation processes in chemical plants
- Steam jet ejector systems
- Filtration in a wine and spirits processing
Advantages Of A Stainless Steel Buchner Funnel
Buchner funnels can be made of porcelain, plastic, or stainless steel. Stainless steel Buchner funnels are the filtration media of choice in the pharmaceutical industry (compared to porcelain or plastic) as they will not chip crack or break under normal processing conditions.
Stainless steel is typically used in pharmaceutical plants due to ease of cleaning and maintenance, autoclavability.
Furthermore, it can easily adhere to cleanroom and other cleanliness standards. Another important characteristic of stainless steel is its chemical resistance to many organic and inorganic substances and media.
This provides a very versatile piece of equipment that in theory, could be used across various manufacturing lines without much worry. Since it can be autoclaved, the risk of CROSS contamination is very slim and highly desirable for the cleanroom processing environment.
Stainless steel Buchner funnels are an adaptable piece of equipment that can be utilized in any type of laboratory across a wide range of scientific disciplines. Their setup, use, and cleanup are simple and efficient and provide an easy filtration method for solids from liquids.