![Quaternary ammonium cation](https://upload.wikimedia.org/wikipedia/commons/9/92/Quaternary_ammonium_cation.svg)
In
chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
, quaternary ammonium cations, also known as quats, are positively charged
polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zero. The term molecule may or may no ...
s of the structure , R being an
alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen.
The term ''alkyl'' is intentionally unspecific to include many possible substitutions.
An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloalk ...
group or an
aryl
In organic chemistry, an aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl. "Aryl" is used for the sake of abbreviation or generalization, and "Ar" is used as ...
group. Unlike the
ammonium ion
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...
() and the primary, secondary, or tertiary ammonium
cations
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by con ...
, the
quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...
ammonium cations are permanently charged, independent of the
pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in
oilfield
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations.
Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...
parlance) are
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
s of quaternary ammonium cations.
Polyquats are a variety of engineered
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
forms which provide multiple quat molecules within a larger molecule.
Quats are used in consumer applications including as
antimicrobials
An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals a ...
(such as
detergent
A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more ...
s and
disinfectant
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...
s),
fabric softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner that is applied to laundry during the rinse cycle in a washing machine to reduce harshness in clothes that are dried in air after machine washing. In con ...
s, and
hair conditioners. As an antimicrobial, they are able to inactivate
enveloped viruses (such as
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
). Quats tend to be gentler on surfaces than
bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...
-based disinfectants, and are generally fabric-safe.
Synthesis
Quaternary ammonium compounds are prepared by the
alkylation
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting ...
of
tertiary amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such ...
s with a
halocarbon
Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms (fluorine, chlorine, bromine or iodine – ) resulting in the formation of organofluorine compounds, organochlori ...
.
In older literature this is often called a
Menshutkin reaction
In organic chemistry, the Menshutkin reaction converts a tertiary amine into a quaternary ammonium salt by reaction with an alkyl halide. Similar reactions occur when tertiary phosphines are treated with alkyl halides.
The reaction is the meth ...
, however modern chemists usually refer to it simply as quaternization. The reaction can be used to produce a compound with unequal alkyl chain lengths; for example when making
cationic surfactants
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foa ...
one of the alkyl groups on the amine is typically longer than the others. A typical synthesis is for
benzalkonium chloride
Benzalkonium chloride (BZK, BKC, BAK, BAC), also known as alkyldimethylbenzylammonium chloride (ADBAC) and by the trade name Zephiran, is a type of cationic surfactant. It is an organic salt classified as a quaternary ammonium compound. ADBACs ha ...
from a long-chain alkyldimethylamine and
benzyl chloride
Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C6H5CH2Cl. This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block.
Preparation
Benzyl chloride is prepared indust ...
:
:CH
3(CH
2)
nN(CH
3)
2 + ClCH
2C
6H
5 →
3(CH2)''n''N(CH3)2CH2C6H5">H3(CH2)''n''N(CH3)2CH2C6H5sup>+Cl
−
Reactions
Quaternary ammonium cations are unreactive toward even strong
electrophile
In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carrie ...
s,
oxidant
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...
s, and
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
s. They also are stable toward most
nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...
s. The latter is indicated by the stability of the
hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. I ...
salts such as
tetramethylammonium hydroxide
Tetramethylammonium hydroxide (TMAH or TMAOH) is a quaternary ammonium salt with molecular formula N(CH3)4+ OH−. It is commonly encountered in form of concentrated solutions in water or methanol. TMAH in solid state and its aqueous soluti ...
and
tetrabutylammonium hydroxide
Tetrabutylammonium hydroxide is the chemical compound with the formula (C4H9)4NOH, abbreviated Bu4NOH with the acronym TBAOH or TBAH. This species is employed as a solution in water or alcohols. It is a common base in organic chemistry. Relative to ...
even at elevated temperatures. The halflife of Me
4NOH in 6M NaOH at 160 °C is >61 h.
Because of their resilience, many unusual anions have been isolated as the quaternary ammonium salts. Examples include
tetramethylammonium pentafluoroxenate, containing the highly reactive pentafluoroxenate () ion.
Permanganate
A permanganate () is a chemical compound containing the manganate(VII) ion, , the conjugate base of permanganic acid. Because the manganese atom is in the +7 oxidation state, the permanganate(VII) ion is a strong oxidizing agent. The ion is a tra ...
can be solubilized in
organic solvents, when deployed as its salt.
With exceptionally strong bases, quat cations degrade. They undergo
Sommelet–Hauser rearrangement and
Stevens rearrangement
The Stevens rearrangement in organic chemistry is an organic reaction converting quaternary ammonium salts and sulfonium salts to the corresponding amines or sulfides in presence of a strong base in a 1,2-rearrangement.
The reactants can b ...
, as well as dealkylation under harsh conditions or in presence of strong nucleophiles, like thiolates. Quaternary ammonium cations containing N−C−C−H units can also undergo the
Hofmann elimination
Hofmann elimination is an elimination reaction of an amine to form alkenes. The least stable alkene (the one with the least number of substituents on the carbons of the double bond), called the Hofmann product, is formed. This tendency, known as ...
and
Emde degradation
The Emde degradation (also called Emde-reaction or Emde-reduction) is a method for the reduction of a quaternary ammonium cation to a tertiary amine with sodium amalgam:{{cite book , first1=M. B. , last1=Smith , first2=J. , last2=March , tit ...
.
Examples
*
Tetramethylammonium
Tetramethylammonium (TMA) or (Me4N+) is the simplest quaternary ammonium cation, consisting of four methyl groups attached to a central nitrogen atom, and is isoelectronic with neopentane. It is positively charged and can only be isolated in asso ...
ion: or
*
Tetraethylammonium
Tetraethylammonium (TEA), () or (Et4N+) is a quaternary ammonium cation consisting of four ethyl groups attached to a central nitrogen atom, and is positively charged. It is a counterion used in the research laboratory to prepare lipophilic salts ...
ion: or
*
Tetrapropylammonium ion: or
*
Tetrabutylammonium
Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more ...
ion: or
Applications
Quaternary ammonium salts are used as
disinfectant
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...
s,
surfactants
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...
,
fabric softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner that is applied to laundry during the rinse cycle in a washing machine to reduce harshness in clothes that are dried in air after machine washing. In con ...
s, and as
antistatic agent
An antistatic agent is a compound used for treatment of materials or their surfaces in order to reduce or eliminate buildup of static electricity. Static charge may be generated by the triboelectric effect or by a non-contact process using a high ...
s (e.g. in
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the ...
s). In
liquid
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...
fabric softeners, the
chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ...
salts are often used. In
dryer anticling strips, the
sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ar ...
salts are often used. Older aluminium
electrolytic capacitors
An electrolytic capacitor is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor. A solid, liquid, or gel ...
and
spermicidal jellies also contain quaternary ammonium salts. Quats are also used in contraception formulations, veterinary products, diagnostic testing, vaccine production, and nasal formulations.
Medicines
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Quaternary ammonium compounds have antimicrobial activity. Quaternary ammonium compounds, especially those containing long alkyl chains, are used as antimicrobials and
disinfectant
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...
s. Examples are
benzalkonium chloride
Benzalkonium chloride (BZK, BKC, BAK, BAC), also known as alkyldimethylbenzylammonium chloride (ADBAC) and by the trade name Zephiran, is a type of cationic surfactant. It is an organic salt classified as a quaternary ammonium compound. ADBACs ha ...
,
benzethonium chloride
Benzethonium chloride, also known as hyamine is a synthetic quaternary ammonium salt. This compound is an odorless white solid, soluble in water. It has surfactant, antiseptic, and anti-infective properties, and it is used as a topical antimicr ...
, methylbenzethonium chloride,
cetalkonium chloride
Cetalkonium chloride (CKC) is a quaternary ammonium compound of the alkyl-benzyldimethylammonium chloride family, the alkyl group having a chain length of C16 (16 carbons).
It is used in pharmaceutical products either as an excipient (Cationorm, ...
,
cetylpyridinium chloride
Cetylpyridinium chloride (CPC) is a cationic quaternary ammonium compound used in some types of mouthwashes, toothpastes, lozenges, throat sprays, breath sprays, and nasal sprays. It is an antiseptic that kills bacteria and other microorganisms ...
,
cetrimonium,
cetrimide
Cetrimide, or alkyltrimethylammonium bromide, is an antiseptic which is a mixture of three quaternary ammonium compounds: tetradonium bromide (TTAB or MITMAB), cetrimonium bromide (CTAB), and laurtrimonium bromide (DTAB or LTAB). It was first d ...
, dofanium chloride,
tetraethylammonium bromide
Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and ...
,
didecyldimethylammonium chloride
Didecyldimethylammonium chloride (DDAC) is a quaternary ammonium compound used as antiseptic/disinfectant. It causes the disruption of intermolecular interactions and the dissociation of lipid bilayers. The bacteriostatic (prevent growth) or bac ...
and domiphen bromide. Also good against
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
,
amoebas
An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopo ...
, and
enveloped viruses
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
(such as
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
),
quaternary ammonium compounds are believed to act by disrupting the
cell membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...
or
viral envelope
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes.
Numerous human pathogenic viruses in circulation are encase ...
. Quaternary ammonium compounds are lethal to a wide variety of organisms except
endospores
An endospore is a dormancy, dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore ...
and
non-enveloped virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's ...
es.
Phase transfer catalysts
In organic chemistry, quaternary ammonium salts are employed as
phase transfer catalyst
In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the transition of a reactant from one phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of heterogeneous catalysis. Ionic rea ...
s (PTCs). Such catalysts accelerate reactions between reagents dissolved in immiscible solvents. The highly reactive reagent
dichlorocarbene
Dichlorocarbene is the reactive intermediate with chemical formula CCl2. Although this chemical species has not been isolated, it is a common intermediate in organic chemistry, being generated from chloroform. This bent diamagnetic molecule rapidly ...
is generated via PTC by reaction of
chloroform
Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...
and aqueous
sodium hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions .
Sodium hydroxide is a highly caustic base and alkali ...
.
Fabric softeners and hair conditioners
In the 1950s,
distearyldimethylammonium chloride
Dimethyldioctadecylammonium chloride also commonly distearyl dimethyl ammonium chloride is an organic compound classified as quaternary ammonium salt. The nitrogen center substituted with two methyl groups and two stearyl groups. The combinatio ...
(DHTDMAC), was introduced as a
fabric softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner that is applied to laundry during the rinse cycle in a washing machine to reduce harshness in clothes that are dried in air after machine washing. In con ...
. This compound was discontinued because the cation biodegrades too slowly. Contemporary fabric softeners are based on salts of quaternary ammonium cations where the fatty acid is linked to the quaternary center via ester linkages; these are commonly referred to as
betaine
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group, such as a quaternary ammonium or phosphonium cation (generally: onium ions) that bears no hydrogen atom and with a negatively charge ...
-esters or ester-quats and are susceptible to degradation, e.g., by
hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
. Characteristically, the cations contain one or two long
alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen.
The term ''alkyl'' is intentionally unspecific to include many possible substitutions.
An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloalk ...
chains derived from fatty acids linked to an
ethoxylate
Ethoxylation is a chemical reaction in which ethylene oxide adds to a substrate. It is the most widely practiced alkoxylation, which involves the addition of epoxides to substrates.
In the usual application, alcohols and phenols are converted i ...
d ammonium salt. Other cationic compounds can be derived from
imidazolium
Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non-a ...
,
guanidinium
Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine predominantly in patients experie ...
, substituted amine salts, or quaternary
alkoxy
In chemistry, the alkoxy group is an alkyl group which is singularly bonded to oxygen; thus . The range of alkoxy groups is vast, the simplest being methoxy (). An ethoxy group () is found in the organic compound ethyl phenyl ether (, also ...
ammonium salts.
File:C18x2Me2Cl.png, Distearyldimethylammonium chloride
Dimethyldioctadecylammonium chloride also commonly distearyl dimethyl ammonium chloride is an organic compound classified as quaternary ammonium salt. The nitrogen center substituted with two methyl groups and two stearyl groups. The combinatio ...
, an early generation fabric softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner that is applied to laundry during the rinse cycle in a washing machine to reduce harshness in clothes that are dried in air after machine washing. In con ...
with low biodegradability
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...
that was phased out.
File:Redrawn diesterquat salt (methanesulfonate anion) related to fabric softeners.png, Another diesterquat, a contemporary fabric softener.
File:AltDiesterquatCl.png, Diethyl ester dimethyl ammonium chloride used as a fabric softener.
File:DiesterCl.png, Another diesterquat used as a fabric softener.
The antistatic qualities that make quaternary ammonium salts useful as fabric softeners also make them useful in
hair conditioners and
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the ...
s. The idea was pioneered by
Henkel with a 1984 patent. Examples include
cetrimonium chloride and
behentrimonium chloride
Behentrimonium chloride, also known as docosyltrimethylammonium chloride or BTAC-228, is a yellow waxlike organic compound with chemical formula , used as an antistatic agent and, sometimes, a disinfectant. It is commonly found in cosmetics su ...
.
Plant growth retardants
Cycocel (chlormequat chloride) reduces plant height by inhibiting the production of
gibberellin
Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of p ...
s, the primary plant hormones responsible for cell elongation. Therefore, their effects are primarily on stem, petiole and flower stalk tissues. Lesser effects are seen in reductions of leaf expansion, resulting in thicker leaves with darker green color.
Natural occurrence
Glycine betaine
Trimethylglycine is an amino acid derivative that occurs in plants. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because, in the 19th century, it was discovered in sugar beets. It has a sweet and umami ...
, found in
osmolyte
Osmolytes are low-molecular weight organic compounds that influence the properties of biological fluids. Their primary role is to maintain the integrity of cells by affecting the viscosity, melting point, and ionic strength of the aqueous solution. ...
s, stabilizes osmotic pressure in cells.
Choline Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but r ...
is a precursor for the neurotransmitter
acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Part ...
. Choline is also a constituent of
lecithin, which is present in many plants and animal organs.
It is found in
phospholipids. For example,
phosphatidylcholines
Phosphatidylcholines (PC) are a class of phospholipids that incorporate choline as a headgroup.
They are a major component of biological membranes and can be easily obtained from a variety of readily available sources, such as egg yolk or soybean ...
, a major component of
biological membrane
A biological membrane, biomembrane or cell membrane is a selectively permeable membrane that separates the interior of a cell from the external environment or creates intracellular compartments by serving as a boundary between one part of the ce ...
s, are a member of the
lecithin group of fatty substances in animal and plant tissues.
Carnitine
Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids into mitochondria to be oxidized for energy production, an ...
participates in the
beta-oxidation of fatty acids.
Health effects
Quaternary ammonium compounds can display a range of health effects, amongst which are mild skin and respiratory irritation up to severe caustic burns on skin and the
gastrointestinal wall (depending on concentration), gastrointestinal symptoms (e.g., nausea and vomiting), coma, convulsions, hypotension and death.
They are thought to be the chemical group responsible for
anaphylactic reaction
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follo ...
s that occur with use of
neuromuscular blocking drug
Neuromuscular-blocking drugs block neuromuscular transmission at the neuromuscular junction, causing paralysis of the affected skeletal muscles. This is accomplished via their action on the post-synaptic acetylcholine (Nm) receptors.
In c ...
s during
general anaesthesia
General anaesthesia (UK) or general anesthesia (US) is a medically induced loss of consciousness that renders the patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general ...
in
surgery
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
.
Quaternium-15
Quaternium-15 (systematic name: hexamethylenetetramine chloroallyl chloride) is a quaternary ammonium salt that has been used as a surfactant and preservative. It acts as an antimicrobial agent because it slowly releases formaldehyde, which is ...
is the single most often found cause of allergic
contact dermatitis
Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes are ...
of the hands (16.5% in 959 cases).
Possible reproductive effects in laboratory animals
Quaternary ammonium-based disinfectants (Virex and Quatricide) were tentatively identified as the most probable cause of jumps in birth defects and fertility problems in caged lab mice. The quat ingredients in the disinfectants include
alkyl dimethyl benzyl ammonium chloride (ADBAC) and
didecyl dimethyl ammonium chloride (DDAC).
A similar link was tentatively identified in nurses. The studies contradict earlier toxicology data reviewed by the U.S. Environmental Protection Agency (U.S. EPA) and the EU Commission.
Quantification
The quantification of
quaternary ammonium compounds in environmental and biological samples is problematic using conventional chromatography techniques because the compounds are highly soluble in water. Analysis by
liquid chromatography coupled tandem mass spectrometry has found that they follow an exception rule. Under standard
electrospray ionization
Electrospray ionization (ESI) is a technique used in mass spectrometry to produce ions using an electrospray in which a high voltage is applied to a liquid to create an aerosol. It is especially useful in producing ions from macromolecules becaus ...
(ESI) conditions, mono- and di-quaternary ammonium compounds form molecular ions with the formula of ' rather than . Formation of is observed for di-quaternary ammonium compounds (like
diquat) as precursor ion and as product ion due to the loss of one of the quaternary charge during CID. In di-quaternary ammonium compounds, this process can also result in the formation of fragment ions with higher mass as compared to their precursor ion.
Hydrophilic interaction liquid chromatographic separation has been reported to demonstrate a successful separation of quaternary ammonium compounds for their quantification in ESI-MS/MS with higher precision.
See also
*
Ammonium
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...
*
Benzyltrimethylammonium fluoride
*
Iminium
In organic chemistry, an iminium cation is a polyatomic ion with the general structure . They are common in synthetic chemistry and biology.
Structure
Iminium cations adopt alkene-like geometries. The central C=N unit is nearly coplanar with al ...
References
External links
Toxicities of quaternary ammonium* {{cite journal, first1=Chang , last1=Zhang , first2=Fang , last2=Cui , first3=Guang-ming , last3=Zeng , first4=Min , last4=Jiang , first5=Zhong-zhu , last5=Yang , first6=Zhi-gang , last6=Yu , first7=Meng-ying , last7=Zhu , first8=Liu-qing , last8=Shen , title=Quaternary ammonium compounds (QACs): A review on occurrence, fate and toxicity in the environment , journal= Science of the Total Environment, volume=518–519 , date=15 June 2015 , pages=352–362 , doi=10.1016/j.scitotenv.2015.03.007, pmid=25770948 , bibcode=2015ScTEn.518..352Z
Disinfectants
Food safety
de:Quats