An Erlenmeyer flask, also known as a conical flask (

British English British English is the set of Variety (linguistics), varieties of the English language native to the United Kingdom, especially Great Britain. More narrowly, it can refer specifically to the English language in England, or, more broadly, to ...

) or a

titration Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of Quantitative research, quantitative Analytical chemistry, chemical analysis to determine the concentration of an identified analyte (a substance to be ...

flask, is a type of

laboratory flask Laboratory flasks are vessels or containers that fall into the category of laboratory equipment known as glassware. In laboratory and other scientific settings, they are usually referred to simply as flasks. Flasks come in a number of shapes an ...

with a flat bottom, a conical body, and a cylindrical neck. It is named after the German chemist

Emil Erlenmeyer Richard August Carl Emil Erlenmeyer (28 June 1825 – 22 January 1909), known simply as Emil Erlenmeyer, was a German chemist known for contributing to the early development of the theory of chemical structure and formulating the Erlenmeyer rul ...

(1825–1909), who invented it in 1860. Erlenmeyer flasks have wide bases and narrow necks. They may be graduated, and often have spots of

ground glass Ground glass is glass whose surface has been ground to produce a flat but rough ( matte) finish, in which the glass is in small sharp fragments. Ground glass surfaces have many applications, ranging from ornamentation on windows and table glass ...

or enamel where they can be labeled with a

pencil A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage and keeps it from marking the user's hand. Pencils create marks by physical abrasion, leaving a trail of ...

. It differs from the beaker in its tapered body and narrow neck. Depending on the application, they may be constructed from glass or plastic, in a wide range of volumes. The mouth of the Erlenmeyer flask may have a beaded lip that can be stoppered or covered. Alternatively, the neck may be fitted with

or other connector for use with more specialized stoppers or attachment to other apparatus. A Büchner flask is a common design modification for

filtration Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filte ...

under vacuum.

Uses

In chemistry

The slanted sides and narrow neck of this flask allow the contents of the flask to be mixed by swirling, without risk of spillage, making them suitable for titrations by placing it under the buret and adding solvent and the indicator in the Erlenmeyer flask. Such features similarly make the flask suitable for boiling liquids. Hot vapour condenses on the upper section of the Erlenmeyer flask, reducing

solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

loss. Erlenmeyer flasks' narrow necks can also support filter funnels. The final two attributes of Erlenmeyer flasks make them especially appropriate for recrystallization. The sample to be purified is heated to a boil, and sufficient solvent is added for complete dissolution. The receiving flask is filled with a small amount of solvent, and heated to a boil. The hot solution is filtered through a fluted filter paper into the receiving flask. Hot vapors from the boiling solvent keep the filter funnel warm, avoiding the premature

crystallization Crystallization is a process that leads to solids with highly organized Atom, atoms or Molecule, molecules, i.e. a crystal. The ordered nature of a crystalline solid can be contrasted with amorphous solids in which atoms or molecules lack regu ...

. Like beakers, Erlenmeyer flasks are not normally suitable for accurate volumetric measurements. Their stamped volumes are approximate within about 5% accuracy.

In biology

Erlenmeyer flasks are also used in

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

for the preparation of

microbial culture A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diag ...

s. Erlenmeyer flasks used in

cell culture Cell culture or tissue culture is the process by which cell (biology), cells are grown under controlled conditions, generally outside of their natural environment. After cells of interest have been Cell isolation, isolated from living tissue, ...

are sterilized and may feature vented closures to enhance gas exchange during incubation and shaking. The use of minimal liquid volumes, typically no more than one fifth of the total flask volume, and baffles molded into the flask's internal surface both serve to maximize gas transfer and promote chaotic mixing when the flasks are orbitally shaken. The oxygen transfer rate in Erlenmeyer flasks depends on the agitation speed, the liquid volume, and the shake-flask design. The shaking frequency has the most significant impact on oxygen transfer. Oxygenation and mixing of liquid cultures further depend on rotation of the liquid "in-phase", meaning the synchronous movement of the liquid with the shaker table. Under certain conditions the shaking process leads to a breakdown of liquid motion – called "out-of-phase phenomenon". This phenomenon has been intensively characterized for shake flask bioreactors. Out-of-phase conditions are associated with a strong decrease in mixing performance, oxygen transfer, and power input. Main factor for out-of-phase operation is the viscosity of the culture medium, but also the vessel diameter, low filling levels and/or a high number of baffles.

Legal restriction

To impede illicit

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

manufacturers, the state of

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

previously restricted the sale of Erlenmeyer flasks to those who have the requisite permits. On September 1, 2019, SB 616 amended the law so that permits are no longer required, but accurate inventory of this and certain other pieces of lab equipment must still be maintained, loss or theft must still be reported, and the owner must still allow audits of their records and equipment to be made.

Additional images

File:Matraz de Erlenmeyer - Diseño original.png, Original drawing of the Erlenmeyer flask File:Erlenmeyer flasks en.svg, Different styles of Erlenmeyer flask File:Erlenmeyer flask ben.jpg, Different sizes of Erlenmeyer flask File:Autoclaved sterile Erlenmeyer flasks.jpg, Autoclaved sterile Erlenmeyer flasks covered with aluminium foil

References

External links

* {{Authority control 1860 in science 1860 in the German Confederation German inventions Laboratory glassware Volumetric instruments