- Structure
- Nomenclature
- Properties
- Physical state
- Molecular weight
- Solubility
- Chemical properties
- Other properties
- Obtaining
- Uses in medicine
- Ear infections
- Skin diseases
- Other uses
- Discontinued use
- Damaging effects
- References
The aluminum acetate is an organic compound consisting of an aluminum ion to the 3+ and acetate ions three CH 3 COO -. Its chemical formula is Al (CH 3 COO) 3. It is also known as aluminum triacetate. It is a slightly hygroscopic white solid and soluble in water.
To obtain this compound, totally anhydrous conditions must be used, that is, free from water, otherwise the aluminum diacetate Al (OH) (CH 3 COO) 2 tends to form.
Aluminum triacetate Al (CH 3 COO) 3. Author: Marilú Stea.
Aluminum acetate solutions have antibacterial and antifungal properties, which is why since the 19th century they have been used to treat infections especially of the ears.
The best known is Burow's solution, devised by a German doctor. However, its use has occasionally led to damage to the middle ear.
This solution has also been used to treat skin problems like itching and rashes. It is even used as a sunburn reliever.
Aluminum acetate and its derivatives are used to obtain very small structures or particles of Al 2 O 3 alumina. These structures or nanoparticles can be in the form of leaves, flowers or nanotubes.
Structure
Aluminum triacetate is made up of an Al 3+ aluminum cation and three CH 3 COO - acetate anions. It is the aluminum salt of acetic acid CH 3 COOH.
Aluminum is bound to acetate anions through their oxygen. In other words, it is attached to three oxygens. These bonds are ionic.
Ionic structure of aluminum acetate. N4TR! UMbr. Source: Wikimedia Commons.
Nomenclature
- Aluminum acetate
- Aluminum triacetate
- Aluminum ethanoate
- Burow's solution (translation from English Burow's solution): It is a solution of aluminum acetate.
Properties
Physical state
Solid white.
Molecular weight
204.11 g / mol
Solubility
Soluble in water.
Chemical properties
In aqueous solution, aluminum triacetate is dissolved and tends to form diacetate Al (OH) (CH 3 COO) and sometimes monoacetate Al (OH) 2 (CH 3 COO). It all depends on the pH and the amount of acetic acid CH 3 COOH present in the solution.
Al (CH 3 COO) 3 + H 2 O ⇔ Al (OH) (CH 3 COO) 2 + CH 3 COOH
Al (CH 3 COO) 3 + 2 H 2 O ⇔ Al (OH) 2 (CH 3 COO) + 2 CH 3 COOH
Other properties
Aluminum acetate is slightly hygroscopic, that is, it tends to absorb water from the air.
Obtaining
The aluminum acetate is preferably obtained under strictly anhydrous conditions, that is, in the total absence of water. This also includes the absence of air, as it can contain moisture.
A mixture of glacial acetic acid CH 3 COOH and acetic anhydride (CH 3 CO) 2 O is heated under conditions such as to remove all the water present. Anhydrous solid aluminum chloride AlCl 3 (without water) is added to this hot mixture.
A white solid of Al (CH 3 COO) 3 forms.
AlCl 3 + 3 CH 3 COOH → Al (CH 3 COO) 3 + 3 HCl
The total absence of water is important to avoid the formation of salts of aluminum monoacetate Al (OH) 2 (CH 3 COO) and aluminum diacetate Al (OH) (CH 3 COO) 2.
It can also be obtained by reacting aluminum hydroxide Al (OH) 3 and acetic acid CH 3 COOH.
Uses in medicine
Ear infections
Aluminum acetate has been used since the 19th century to treat otitis, which is an inflammation of the outer or middle ear usually accompanied by infection. Its use is due to its antibacterial and antifungal effect.
It has been used in the form of a 13% aluminum acetate solution, originally devised by the German physician Karl August von Burow, which is why it is called Burow's solution.
It has been found to inhibit the growth of microorganisms commonly found in external or media otitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, and Proteus mirabilis.
Ear infections have been treated for many years with aluminum acetate. Author: Ulrike Mai. Source: Pixabay.
However, there are those who report that these solutions can be harmful to the ear. Some animal studies investigate its toxic effects on the ear but have reported conflicting results.
Some researchers recommend not using aluminum acetate when the tympanic membrane is perforated, as it has been observed to exert an inflammatory effect on the middle ear.
It is not advisable to treat otitis media (bluish area in the figure) with aluminum acetate. BruceBlaus. Source: Wikimedia Commons.
Skin diseases
Burow's solution is used as an antiseptic, astringent, and as a topical solution to treat severe rashes, dermatitis, inflammation, itching, burning, and sunburn. It has a calming and irritation reducing effect.
Sometimes sunburns can be treated with an aluminum acetate solution. Author: Tumisu. Source: Pixabay.
Other uses
Aluminum triacetate and its derivatives are used for many qualitative and quantitative chemical experiments.
A derivative of aluminum triacetate, Al (OH) (CH 3 COO) 2 diacetate also called aluminum hydroxide acetate, is used as a precursor to obtain nanostructures of gamma-alumina (γ-Al 2 O 3).
In this case, precursor means that the γ-Al 2 O 3 nanostructures are prepared from aluminum diacetate (obtained in a particular way), and this is achieved by heating it to very high temperatures.
Nanostructures are very small particles that can be observed only through special microscopes such as electron microscopes. With aluminum acetate as a precursor, γ-Al 2 O 3 nanostructures have been obtained that resemble leaves, flowers, fibers and even nanotubes.
Alumina nanofibers can be made using a derivative of aluminum acetate. Aleksei tr. Source: Wikimedia Commons.
Discontinued use
At the beginning of the 20th century, aluminum acetate was used as a preservative in foods such as canned sausages.
An aluminum acetate solution was prepared by mixing aluminum sulfate Al 2 (SO 4) 3, calcium carbonate CaCO 3, acetic acid CH 3 COOH and water H 2 O, and added to the food.
When this solution comes into contact with the meat, the aluminum is fixed in its constituents in the form of a compound that is insoluble in boiling water, but that dissolves in gastric juices approximately 80%.
As early as 1904 it was known that aluminum salts slow digestion, both in the stomach and in the intestines. Therefore, it is an undesirable practice to add aluminum acetate solutions to canned food.
In the past, aluminum acetate has been used as a preservative for canned hot dogs. It is currently known to be harmful and is no longer used for it. Author: Changlc. Source: Wikimedia Commons.
Damaging effects
Since there are studies that report that aluminum acetate can be toxic, tests have been done in which laboratory mice have been injected with aluminum acetate.
The results indicate that this compound causes damage to the spinal column of these animals, as well as damage to the chromosomes and sperm of the animals. In other words, it is genotoxic.
This alerts you to the possible health hazards that could be caused by overexposure to aluminum acetate and to the care that should be taken during its use.
References
- Mac-Kay Chace, E. (1904). The use of basic aluminum acetate as a preservative in sausage. Journal of the American Chemical Society 1904, 26, 6: 662-665. Recovered from pubs.acs.org.
- Hood, GC and Ihde, AJ (1950). Aluminum Acetates and Propionates - Their Preparation and Composition. Journal of the American Chemical Society 1950, 72, 5: 2094-2095. Recovered from pubs.acs.org.
- Pitaro, J. et al. (2013). Ototoxicity of Aluminum Acetate / Benzenethonium Chloride Otic Solution in the Chinchilla Animal Model. Laryngoscope, 2013; 123 (10): 2521-5. Recovered from ncbi.nlm.nih.gov.
- Thorp, MA et al. (2000). Burow's solution in the treatment of active mucosal chronic suppurative otitis media: determining an effective dilution. The Journal of Laryngology & Otology, June 2000, Vol. 114, pp. 432-436. Recovered from ncbi.nlm.nih.gov.
- D'Souza, Mr. P. et al. (2014). Assessment of genotoxicity of aluminum acetate in bone marrow, male germ cells and fetal liver cells of Swiss albino mice. Mutation Research 766 (2014) 16-22. Recovered from ncbi.nlm.nih.gov.
- Basal, Y. et al. (2015). The Effects of Topical Burow's and Castellani's Solutions on the Middle Ear Mucosa of Rats. J. Int Adv Otol 2015; 11 (3): 253-6. Recovered from advancedotology.org.
- US National Library of Medicine. (2019). Aluminum acetate. Recovered from pubchem.ncbi.nlm.nih.gov.
- Buttaravoli, P. and Leffler, SM (2012). Sunburn. What To Do. In Minor Emergencies (Third Edition). Recovered from sciencedirect.com.
- Thompson, E. and Kalus, A. (2017). Acute Skin Reactions and Bacterial Infections. Treatment. In The Travel and Tropical Medicine Manual (Fifth Edition). Recovered from sciencedirect.com.
- Kim, T. et al. (2010). Morphology Controllable Synthesis of gamma-Alumina Nanostructures via an Ionic Liquid-Assisted Hydrothermal Route. Crystal Growth & Design, Vol. 10, No. 7, 2010, pp. 2928-2933. Recovered from pubs.acs.org.
- Rajala, JW et al. (2015). Core-Shell Electrospun Hollow Aluminum Oxide Ceramic Fibers. Fibers 2015, 3, 450-462. Recovered from mdpi.com.