Nitrogen ( ) is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.

Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen dominates nitrogen chemistry, causing difficulty for both organisms and industry in breaking the bond to convert the into useful compounds, but at the same time causing release of large amounts of often useful energy when the compounds burn, explode, or decay back into nitrogen gas.

Nitrogen occurs in all living organisms, and the nitrogen cycle describes movement of the element from the air into the biosphere and organic compounds, then back into the atmosphere. Synthetically produced nitrates are key ingredients of industrial fertilizers, and also key pollutants in causing the eutrophication of water systems. Nitrogen is a constituent element of amino acids and thus of proteins and nucleic acids (DNA and RNA). It resides in the chemical structure of almost all neurotransmitters, and is a defining component of alkaloids, biological molecules produced by many organisms. The human body contains about 3% by weight of nitrogen, a larger fraction than all elements save oxygen, carbon, and hydrogen.

History

Nitrogen is formally considered to have been discovered by Daniel Rutherford in 1772, who called it ''noxious air'' or ''fixed air''. The fact that there was an element of air that does not support combustion was clear to Rutherford. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as ''burnt air'' or ''phlogisticated air''. Nitrogen gas was inert enough that Antoine Lavoisier referred to it as "mephitic air" or ''azote'', from the Greek word (''azotos'') meaning "lifeless". In it, animals died and flames were extinguished. Lavoisier's name for nitrogen is used in many languages (French, Polish, Russian, etc.) and still remains in English in the common names of many compounds, such as hydrazine and compounds of the azide ion.

The English word nitrogen (1794) entered the language from the French ''nitrogène,'' coined in 1790 by French chemist Jean Antoine Chaptal (1756–1832), from "nitre" + Fr. ''gène'' "producing" (from Gk. -γενής means "forming" or "giving birth to."). The gas had been found in nitric acid. Chaptal's meaning was that nitrogen gas is the essential part of nitric acid, in turn formed from saltpetre (potassium nitrate), then known as nitre. However, this word in the more ancient world originally described sodium salts that did not contain nitrate, and is a cognate of natron and nitron.

Nitrogen compounds were well known during the Middle Ages. Alchemists knew nitric acid as ''aqua fortis'' (strong water). The mixture of nitric and hydrochloric acids was known as ''aqua regia'' (royal water), celebrated for its ability to dissolve gold (the ''king'' of metals). The earliest military, industrial, and agricultural applications of nitrogen compounds involved uses saltpetre (sodium nitrate or potassium nitrate), the most notable in gunpowder, and later as fertilizer. In 1910, Lord Rayleigh discovered that an electrical discharge in nitrogen gas produced "active nitrogen", an allotrope considered to be monatomic. The "whirling cloud of brilliant yellow light" produced by his apparatus reacted with quicksilver to produce explosive mercury nitride.

Properties

Nitrogen is a nonmetal, with an electronegativity of 3.04. It has five electrons in its outer shell and is, therefore, trivalent in most compounds. The triple bond in molecular nitrogen () is the strongest. The resulting difficulty of converting into other compounds, and the ease (and associated high energy release) of converting nitrogen compounds into elemental , have dominated the role of nitrogen in both nature and human economic activities.

At atmospheric pressure molecular nitrogen condenses (liquefies) at 77 K (−195.79 °C) and freezes at 63 K (−210.01 °C) into the beta hexagonal close-packed crystal allotropic form. Below 35.4 K (−237.6 °C) nitrogen assumes the cubic crystal allotropic form (called the alpha-phase). Liquid nitrogen, a fluid resembling water in appearance, but with 80.8% of the density (the density of liquid nitrogen at its boiling point is 0.808 g/mL), is a common cryogen.

Unstable allotropes of nitrogen consisting of more than two nitrogen atoms have been produced in the laboratory, like and . Under extremely high pressures (1.1 million atm) and high temperatures (2000 K), as produced using a diamond anvil cell, nitrogen polymerizes into the single-bonded cubic gauche crystal structure. This structure is similar to that of diamond, and both have extremely strong covalent bonds. is nicknamed "nitrogen diamond."

Other (as yet unsynthesized) allotropes include hexazine (, a benzene analog) and octaazacubane (, a cubane analog). The former is predicted to be highly unstable, while the latter is predicted to be stable, for reasons of orbital symmetry.

Isotopes

There are two stable isotopes of nitrogen: ¹⁴N and ¹⁵N. By far the most common is ¹⁴N (99.634%), which is produced in the CNO cycle in stars. Of the ten isotopes produced synthetically, ¹³N has a half-life of ten minutes and the remaining isotopes have half-lives on the order of seconds or less. Biologically mediated reactions (e.g., assimilation, nitrification, and denitrification) strongly control nitrogen dynamics in the soil. These reactions typically result in ¹⁵N enrichment of the substrate and depletion of the product.

A small part (0.73%) of the molecular nitrogen in Earth's atmosphere is the isotopologue ¹⁴N¹⁵N, and almost all the rest is ¹⁴N₂.

Radioisotope ¹⁶N is the dominant radionuclide in the coolant of pressurized water reactors or boiling water reactors during normal operation. It is produced from ¹⁶O (in water) via (n,p) reaction. It has a short half-life of about 7.1 s, but during its decay back to ¹⁶O produces high-energy gamma radiation (5 to 7 MeV).

Because of this, the access to the primary coolant piping in a pressurized water reactor must be restricted during reactor power operation. ¹⁶N is one of the main means used to immediately detect even small leaks from the primary coolant to the secondary steam cycle.

In similar fashion, access to any of the steam cycle components in a boiling water reactor nuclear power plant must be restricted during operation. Condensate from the condenser is typically retained for 10 minutes to allow for decay of the ¹⁶N. This eliminates the need to shield and restrict access to any of the feed water piping or pumps.

Electromagnetic spectrum

Molecular nitrogen (¹⁴N₂) is largely transparent to infrared and visible radiation because it is a homonuclear molecule and, thus, has no dipole moment to couple to electromagnetic radiation at these wavelengths. Significant absorption occurs at extreme ultraviolet wavelengths, beginning around 100 nanometers. This is associated with electronic transitions in the molecule to states in which charge is not distributed evenly between nitrogen atoms. Nitrogen absorption leads to significant absorption of ultraviolet radiation in the Earth's upper atmosphere and the atmospheres of other planetary bodies. For similar reasons, pure molecular nitrogen lasers typically emit light in the ultraviolet range.

Nitrogen also makes a contribution to visible air glow from the Earth's upper atmosphere, through electron impact excitation followed by emission. This visible blue air glow (seen in the polar aurora and in the re-entry glow of returning spacecraft) typically results not from molecular nitrogen but rather from free nitrogen atoms combining with oxygen to form nitric oxide (NO).

Nitrogen gas also exhibits scintillation.

Reactions

In general, nitrogen is unreactive at standard temperature and pressure. N₂ reacts spontaneously with few reagents, being resilient to acids and bases as well as oxidants and most reductants. When nitrogen reacts spontaneously with a reagent, the net transformation is often called nitrogen fixation.

Nitrogen reacts with elemental lithium. Lithium burns in an atmosphere of N₂ to give lithium nitride:

: 6 Li + N₂ → 2 Li₃N

Magnesium also burns in nitrogen, forming magnesium nitride.

: 3 Mg + N₂ → Mg₃N₂

N₂ forms a variety of adducts with transition metals. The first example of a dinitrogen complex is [Ru(NH₃)₅(N₂)]²⁺ (see figure at right). Such compounds are now numerous, other examples include IrCl(N₂)(PPh₃)₂, W(N₂)₂(Ph₂PCH₂CH₂PPh₂)₂, and [(η⁵-C₅Me₄H)₂Zr]₂(μ₂, η²,η²-N₂). These complexes illustrate how N₂ might bind to the metal(s) in nitrogenase and the catalyst for the Haber process. A catalytic process to reduce N₂ to ammonia with the use of a molybdenum complex in the presence of a proton source was published in 2005.

The starting point for industrial production of nitrogen compounds is the Haber process, in which nitrogen is fixed by reacting and over an iron(III) oxide () catalyst at about 500 °C and 200 atmospheres pressure. Biological nitrogen fixation in free-living cyanobacteria and in the root nodules of plants also produces ammonia from molecular nitrogen. The reaction, which is the source of the bulk of nitrogen in the biosphere, is catalyzed by the nitrogenase enzyme complex that contains Fe and Mo atoms, using energy derived from hydrolysis of adenosine triphosphate (ATP) into adenosine diphosphate and inorganic phosphate (−20.5 kJ/mol).

Occurrence

Nitrogen is the largest single constituent of the Earth's atmosphere (78.082% by volume of dry air, 75.3% by weight in dry air). It is created by fusion processes in stars, and is estimated to be the seventh most abundant chemical element by mass in the universe.

Molecular nitrogen and nitrogen compounds have been detected in interstellar space by astronomers using the Far Ultraviolet Spectroscopic Explorer. Molecular nitrogen is a major constituent of the Saturnian moon Titan's thick atmosphere, and occurs in slightly appreciable to trace amounts in other planetary atmospheres.

Nitrogen is present in all living organisms, in proteins, nucleic acids, and other molecules. It typically makes up around 4% of the dry weight of plant matter, and around 3% of the weight of the human body. It is a large component of animal waste (for example, guano), usually in the form of urea, uric acid, ammonium compounds, and derivatives of these nitrogenous products, which are essential nutrients for all plants that cannot fix atmospheric nitrogen.

Nitrogen occurs naturally in many minerals, such as saltpetre (potassium nitrate), Chile saltpetre (sodium nitrate) and sal ammoniac (ammonium chloride). Most of these are uncommon, partly because of the minerals' ready solubility in water. See also Nitrate minerals and Ammonium minerals.

Compounds

The main neutral hydride of nitrogen is ammonia (), although hydrazine () is also commonly used. Ammonia is more basic than water by 6 orders of magnitude. In solution ammonia forms the ammonium ion (). Liquid ammonia (boiling point 240 K) is amphiprotic (displaying either Brønsted-Lowry acidic or basic character) and forms ammonium and the less common amide ions (); both amides and nitride () salts are known, but decompose in water. Singly, doubly, triply and quadruply substituted alkyl compounds of ammonia are called amines (four substitutions, to form commercially and biologically important quaternary amines, results in a positively charged nitrogen, and thus a water-soluble, or at least amphiphilic, compound). Larger chains, rings and structures of nitrogen hydrides are also known, but are generally unstable.

Other classes of nitrogen anions (negatively charged ions) are the poisonous azides (), which are linear and isoelectronic to carbon dioxide, but which bind to important iron-containing enzymes in the body in a manner more resembling cyanide. Another molecule of the same structure is the colorless and relatively inert anesthetic gas Nitrous oxide (dinitrogen monoxide, ), also known as laughing gas. This is one of a variety of nitrogen oxides that form a family often abbreviated as NOx. Nitric oxide (nitrogen monoxide, NO), is a natural free radical used in signal transduction in both plants and animals, for example, in vasodilation by causing the smooth muscle of blood vessels to relax. The reddish and poisonous nitrogen dioxide contains an unpaired electron and is an important component of smog. Nitrogen molecules containing unpaired electrons show a tendency to dimerize (thus pairing the electrons), and are, in general, highly reactive. The corresponding acids are nitrous and nitric acid , with the corresponding salts called nitrites and nitrates.

The higher oxides dinitrogen trioxide , dinitrogen tetroxide and dinitrogen pentoxide , are unstable and explosive, a consequence of the chemical stability of . Nearly every hypergolic rocket engine uses as the oxidizer; their fuels, various forms of hydrazine, are also nitrogen compounds. These engines are extensively used on spacecraft such as the space shuttle and those of the Apollo Program because their propellants are liquids at room temperature and ignition occurs on contact without an ignition system, allowing many precisely controlled burns. Some launch vehicles such as the Titan II and Ariane 1 through 4 also use hypergolic fuels, although the trend is away from such engines for cost and safety reasons. is an intermediate in the manufacture of nitric acid , one of the few acids stronger than hydronium and a fairly strong oxidizing agent.

Nitrogen is notable for the range of explosively unstable compounds that it can produce. Nitrogen triiodide is an extremely sensitive contact explosive. Nitrocellulose, produced by nitration of cellulose with nitric acid, is also known as guncotton. Nitroglycerin, made by nitration of glycerin, is the dangerously unstable explosive ingredient of dynamite. The comparatively stable, but more powerful explosive trinitrotoluene (TNT) is the standard explosive against which the power of nuclear explosions are measured.

Nitrogen can also be found in organic compounds. Common nitrogen functional groups include: amines, amides, nitro groups, imines, and enamines. The amount of nitrogen in a chemical substance can be determined by the Kjeldahl method.

Production and applications

Nitrogen gas is an industrial gas produced by the fractional distillation of liquid air, or by mechanical means using gaseous air (i.e., pressurized reverse osmosis membrane or Pressure swing adsorption). Commercial nitrogen is often a byproduct of air-processing for industrial concentration of oxygen for steelmaking and other purposes. When supplied compressed in cylinders it is often called OFN (oxygen-free nitrogen).

Nitrogen gas has a variety of applications, including serving as an inert replacement for air where oxidation is undesirable;

As a modified atmosphere, pure or mixed with carbon dioxide, to preserve the freshness of packaged or bulk foods (by delaying rancidity and other forms of oxidative damage)

In ordinary incandescent light bulbs as an inexpensive alternative to argon.

The production of electronic parts such as transistors, diodes, and integrated circuits

Dried and pressurized, as a dielectric gas for high-voltage equipment

The manufacturing of stainless steel

Used in military aircraft fuel systems to reduce fire hazard, (see inerting system)

On top of liquid explosives as a safety measure

Filling automotive and aircraft tires due to its inertness and lack of moisture or oxidative qualities, as opposed to air. Growing in popularity for consumer vehicles due to ability to enhance fuel efficiency, increase tire longevity, and provide more safety and stability .

Used as a propellant for draught wine, and as an alternative to or together with carbon dioxide for other beverages.

Nitrogen is commonly used during sample preparation procedures for chemical analysis. To be specific, it is used to concentrate and reduce the volume of liquid samples. Directing a pressurized stream of nitrogen gas perpendicular to the surface of the liquid allows the solvent to evaporate while leaving the solute(s) and un-evaporated solvent behind.

Nitrogen tanks are also replacing carbon dioxide as the main power source for paintball guns. The downside is that nitrogen must be kept at higher pressure than CO₂, making N₂ tanks heavier and more expensive.

Nitrogenated beer

A further example of its versatility is its use as a preferred alternative to carbon dioxide to pressurize kegs of some beers, in particular, stouts and British ales, due to the smaller bubbles it produces, which make the dispensed beer smoother and headier. A modern application of a pressure sensitive nitrogen capsule known commonly as a "widget" now allows nitrogen charged beers to be packaged in cans and bottles.

A mixture of nitrogen and carbon dioxide can be used for this purpose as well, to maintain the saturation of beer with carbon dioxide.

Liquid nitrogen

Liquid nitrogen is a cryogenic liquid. At atmospheric pressure, it boils at −195.8 °C. When insulated in proper containers such as Dewar flasks, it can be transported without much evaporative loss.

Like dry ice, the main use of liquid nitrogen is as a refrigerant. Among other things, it is used in the cryopreservation of blood, reproductive cells (sperm and egg), and other biological samples and materials. It is used in the clinical setting in cryotherapy to remove cysts and warts on the skin. It is used in cold traps for certain laboratory equipment and to cool X-ray detectors. It has also been used to cool central processing units and other devices in computers that are overclocked, and that produce more heat than during normal operation.

Applications of nitrogen compounds

Molecular nitrogen (N₂) in the atmosphere is relatively non-reactive due to its strong bond, and N₂ plays an inert role in the human body, being neither produced nor destroyed. In nature, nitrogen is converted into biologically (and industrially) useful compounds by lightning, and by some living organisms, notably certain bacteria (i.e. nitrogen fixing bacteria – see ''Biological role'' below). Molecular nitrogen is released into the atmosphere in the process of decay, in dead plant and animal tissues.

The ability to combine, or fix, molecular nitrogen is a key feature of modern industrial chemistry, where nitrogen and natural gas are converted into ammonia via the Haber process. Ammonia, in turn, can be used directly (primarily as a fertilizer, and in the synthesis of nitrated fertilizers), or as a precursor of many other important materials including explosives, largely via the production of nitric acid by the Ostwald process.

The organic and inorganic salts of nitric acid have been important historically as convenient stores of chemical energy. They include important compounds such as potassium nitrate (or saltpeter used in gunpowder) and ammonium nitrate, an important fertilizer and explosive (see ANFO). Various other nitrated organic compounds, such as nitroglycerin, trinitrotoluene, and nitrocellulose, are used as explosives and propellants for modern firearms. Nitric acid is used as an oxidizing agent in liquid fueled rockets. Hydrazine and hydrazine derivatives find use as rocket fuels and monopropellants. In most of these compounds, the basic instability and tendency to burn or explode is derived from the fact that nitrogen is present as an oxide, and not as the far more stable nitrogen molecule (N₂), which is a product of the compounds' thermal decomposition. When nitrates burn or explode, the formation of the powerful triple bond in the N₂ produces most of the energy of the reaction.

Nitrogen is a constituent of molecules in every major drug class in pharmacology and medicine. Nitrous oxide (N₂O) was discovered early in the 19th century to be a partial anesthetic, though it was not used as a surgical anesthetic until later. Called "laughing gas", it was found capable of inducing a state of social disinhibition resembling drunkenness. Other notable nitrogen-containing drugs are drugs derived from plant alkaloids, such as morphine (there exist many alkaloids known to have pharmacological effects; in some cases, they appear natural chemical defenses of plants against predation). Drugs that contain nitrogen include all major classes of antibiotics and organic nitrate drugs like nitroglycerin and nitroprusside that regulate blood pressure and heart action by mimicking the action of nitric oxide.

Biological role

Nitrogen is an essential building block of amino and nucleic acids, essential to life on Earth.

Elemental nitrogen in the atmosphere cannot be used directly by either plants or animals, and must be converted to a reduced (or 'fixed') state in order to be useful for higher plants and animals. Precipitation often contains substantial quantities of ammonium and nitrate, thought to result from nitrogen fixation by lightning and other atmospheric electric phenomena. This was first proposed by Liebig in 1827 and later confirmed. However, because ammonium is preferentially retained by the forest canopy relative to atmospheric nitrate, most fixed nitrogen reaches the soil surface under trees as nitrate. Soil nitrate is preferentially assimilated by tree roots relative to soil ammonium.

Specific bacteria (e.g., ''Rhizobium trifolium'') possess nitrogenase enzymes that can fix atmospheric nitrogen (see nitrogen fixation) into a form (ammonium ion) that is chemically useful to higher organisms. This process requires a large amount of energy and anoxic conditions. Such bacteria may live freely in soil (e.g., ''Azotobacter'') but normally exist in a symbiotic relationship in the root nodules of leguminous plants (e.g. clover, ''Trifolium'', or soybean plant, ''Glycine max''). Nitrogen-fixing bacteria are also symbiotic with a number of unrelated plant species such as alders (''Alnus'') spp., lichens, ''Casuarina'', ''Myrica'', liverworts, and ''Gunnera''.

As part of the symbiotic relationship, the plant converts the 'fixed' ammonium ion to nitrogen oxides and amino acids to form proteins and other molecules, (e.g., alkaloids). In return for the 'fixed' nitrogen, the plant secretes sugars to the symbiotic bacteria. Legumes maintain an anaerobic (oxygen free) environment for their nitrogen-fixing bacteria.

Plants are able to assimilate nitrogen directly in the form of nitrates that may be present in soil from natural mineral deposits, artificial fertilizers, animal waste, or organic decay (as the product of bacteria, but not bacteria specifically associated with the plant). Nitrates absorbed in this fashion are converted to nitrites by the enzyme ''nitrate'' reductase, and then converted to ammonia by another enzyme called ''nitrite'' reductase.

Nitrogen compounds are basic building blocks in animal biology as well. Animals use nitrogen-containing amino acids from plant sources as starting materials for all nitrogen-compound animal biochemistry, including the manufacture of proteins and nucleic acids. Plant-feeding insects are dependent on nitrogen in their diet, such that varying the amount of nitrogen fertilizer applied to a plant can affect the reproduction rate of insects feeding on fertilized plants.

Soluble nitrate is an important limiting factor in the growth of certain bacteria in ocean waters. In many places in the world, artificial fertilizers applied to crop-lands to increase yields result in run-off delivery of soluble nitrogen to oceans at river mouths. This process can result in eutrophication of the water, as nitrogen-driven bacterial growth depletes water oxygen to the point that all higher organisms die. Well-known "dead zone" areas in the U.S. Gulf Coast and the Black Sea are due to this important polluting process.

Many saltwater fish manufacture large amounts of trimethylamine oxide to protect them from the high osmotic effects of their environment; conversion of this compound to dimethylamine is responsible for the early odor in unfresh saltwater fish. In animals, free radical nitric oxide (NO) (derived from an amino acid), serves as an important regulatory molecule for circulation.

Animal metabolism of NO results in production of nitrite. Animal metabolism of nitrogen in proteins, in general, results in excretion of urea, while animal metabolism of nucleic acids results in excretion of urea and uric acid. The characteristic odor of animal flesh decay is caused by the creation of long-chain, nitrogen-containing amines, such as putrescine and cadaverine, which are breakdown products of the amino acids ornithine and lysine, respectively, in decaying proteins.

Decay of organisms and their waste products may produce small amounts of nitrate, but most decay eventually returns nitrogen content to the atmosphere, as molecular nitrogen. The circulation of nitrogen from atmosphere, to organic compounds, then back to the atmosphere, is referred to as the nitrogen cycle.

Safety

Rapid release of nitrogen gas into an enclosed space can displace oxygen, and therefore represents an asphyxiation hazard. This may happen with few warning symptoms, since the human carotid body is a relatively slow and a poor low-oxygen (hypoxia) sensing system. An example occurred shortly before the launch of the first Space Shuttle mission in 1981, when two technicians lost consciousness (and one of them died) after they walked into a space located in the Shuttle's Mobile Launcher Platform that was pressurized with pure nitrogen as a precaution against fire. The technicians would have been able to exit the room if they had experienced early symptoms from nitrogen-breathing.

When inhaled at high partial pressures (more than about 4 bar, encountered at depths below about 30 m in scuba diving), nitrogen begins to act as an anesthetic agent. It can cause nitrogen narcosis, a temporary semi-anesthetized state of mental impairment similar to that caused by nitrous oxide.

Nitrogen also dissolves in the bloodstream and body fats. Rapid decompression (in particular, in the case of divers ascending too quickly, or astronauts decompressing too quickly from cabin pressure to spacesuit pressure) can lead to a potentially fatal condition called decompression sickness (formerly known as caisson sickness or ''the bends''), when nitrogen bubbles form in the bloodstream, nerves, joints, and other sensitive or vital areas. Other "inert" gases (those gases other than carbon dioxide and oxygen) cause the same effects from bubbles composed of them, so replacement of nitrogen in breathing gases may prevent nitrogen narcosis, but does not prevent decompression sickness.

Direct skin contact with liquid nitrogen will eventually cause severe frostbite (cryogenic "burns"). This may happen almost instantly on contact, or after a second or more, depending on the form of liquid nitrogen. Bulk liquid nitrogen causes less rapid freezing than a spray of nitrogen mist (such as is used to freeze certain skin growths in the practice of dermatology). The extra surface area provided by nitrogen-soaked materials is also important, with soaked clothing or cotton causing far more rapid damage than a spill of direct liquid to skin. Full "contact" between naked skin and large collected-droplets or pools of liquid nitrogen may be prevented for second or two, by a layer of insulating gas from the Leidenfrost effect. This may give the skin a second of protection from nitrogen bulk liquid. However, liquid nitrogen applied to skin in mists, and on fabrics, bypasses this effect, and causes local frostbite immediately.

See also

Industrial gas

Liquid nitrogen

Nitrogen asphyxiation

Nutrient

Reactive nitrogen species

Tetranitrogen

TKN

References

Further reading

External links

Etymology of Nitrogen

Why high nitrogen density in explosives?

WebElements.com – Nitrogen

It's Elemental – Nitrogen

Chemistry in its element podcast (MP3) from the Royal Society of Chemistry's Chemistry World: Nitrogen

Schenectady County Community College – Nitrogen

Nitrogen N2 Properties, Uses, Applications

Handling procedures for liquid nitrogen

Material Safety Data Sheet

Category:Nitrogen Category:Chemical elements Category:Coolants Category:Laser gain media Category:Biology and pharmacology of chemical elements Category:Dielectric gases Category:Pnictogens Category:Nonmetals

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name	Ferran Adrià
birth date	May 14, 1962
birth place	L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
restaurants	''El Bulli'' }}

Ferran Adrià i Acosta () is a Catalan Spanish chef born on May 14, 1962 in L'Hospitalet de Llobregat. He was the head chef of the ''El Bulli'' restaurant in Roses on the Costa Brava, and is considered one of the best chefs in the world.

Career

Ferran Adrià began his culinary career in 1980 during his stint as a dishwasher at the Hotel Playafels, in the town of Castelldefels. The ''chef de cuisine'' at this hotel taught him traditional Spanish cuisine. At 19 he was drafted into military service where he worked as a cook. In 1984, at the age of 22, Adrià joined the kitchen staff of El Bulli as a line cook. Eighteen months later he became the head chef.

Along with British chef Heston Blumenthal, Adrià is often associated with "molecular gastronomy," although like Blumenthal the Catalan chef does not consider his cuisine to be of this category. Instead, he has referred to his cooking as deconstructivist. Adrià's stated goal is to "provide unexpected contrasts of flavour, temperature and texture. Nothing is what it seems. The idea is to provoke, surprise and delight the diner." As he likes to say, "the ideal customer doesn't come to El Bulli to eat but to have an experience."

El Bulli is only open for about six months of the year (in 2010, the season is due to run from June 15 to December 20). Adrià spends the remaining six months of the year perfecting recipes in his workshop "El Taller" in Barcelona. He is famous for his thirty course gourmet menu.

He is also well known for creating "culinary foam". In his quest to enhance flavour, Adrià discards the use of cream and egg; foam is made exclusively of the main ingredient and "air" (combined in a siphon bottle equipped with N₂O cartridges). Adrià's foam creations include foamed espresso (Èspesso), foamed mushroom, and foamed beetroot, as well as foamed meats.

El Bulli has 3 Michelin stars and is regarded as one of the best restaurants in the world. In 2005, it ranked second in the ''Restaurant'' Top 50. It was awarded the first place in 2006, displacing The Fat Duck in Bray, England. El Bulli retained this title in 2007, 2008 and 2009, but in 2010 the title was awarded to Noma of Copenhagen, Denmark.

Adrià is the author of several cookbooks including ''A Day at El Bulli'', ''El Bulli 2003-2004'' and ''Cocinar en Casa'' (Cooking at Home). With his young assistant Daniel Picard, Adrià has made almonds into cheese and asparagus into bread with the help of natural ingredients.

Adrià has been a featured chef on ''Great Chefs'' television.

In the fall of 2010, Adrià and José Andrés will teach a culinary physics course at Harvard University.

In October 2010, Adrià announces an alliance with Telefónica.

Controversy

Adrià denounced his fellow 3-star Michelin cook Santi Santamaria who described his approach to cuisine as "pretentious". Traditionalist Santi Santamaria attacked Adrià's dishes in El Bulli as unhealthy, alleging that "Adrià's dishes are designed to impress rather than satisfy and used chemicals that actually put diners' health at risk". Top chefs, however, accused Santamaria, who runs the 3-star Can Fabes near El Bulli, of envy and "endangering the reputations of Spanish kitchens". The criticism has split top Spanish chefs into pro- and anti-Adrià camps. Unusual dishes that have been criticized include frozen whisky sour candy, white garlic and almond sorbet, tobacco-flavoured blackberry crushed ice and Kellogg's paella (Rice Krispies, shrimp heads and vanilla-flavoured mashed potatoes).

German food writer, Jörg Zipprick, accused Adrià of more or less poisoning his customers with the additives he uses in his cuisine and said that Adrià's menu should carry health warnings: "These colorants, gelling agents, emulsifiers, acidifiers and taste enhancers that Adrià has introduced massively into his dishes to obtain extraordinary textures, tastes and sensations do not have a neutral impact on health".

Domestic Commercialisation

Texturas is a range of products by Ferran Adrià, and his brother Albert Adrià. The products include the Sferificación, Gelificación, Emulsificación, Espesantes and Surprises lines are the result of a rigorous process of selection and experimentation. Texturas include products such as Xanthan and Algin which are packaged and labelled as Xantana Texturas and Algin Texturas respectively. Xanthan gum allows the user to use a very small amount to thicken soups, sauces and creams without changing the flavour. Algin is a key component of the "Spherification Kit" and is essential for every spherical preparation: caviar, raviolis, balloons, gnocchi, pellets, and mini-spheres.

Works

''El Bulli 1983-1993'' (with Juli Soler and Albert Adrià)

''El Bulli: el sabor del Mediterráneo'', 1993, ISBN 84-7596-415-X

''Los secretos de El Bulli'', 1997, ISBN 448710002

''El Bulli 1994-1997'' (with Juli Soler and Albert Adrià)

''Cocinar en 10 minutos con Ferran Adrià'', 1998, ISBN 84-605-7628-0

''Celebrar el milenio con Arzak y Adrià'' (with Juan Mari Arzak), 1999, ISBN 84-8307-246-7

''El Bulli 1998-2002'' (with Juli Soler and Albert Adrià), Conran Octopus, 2003, ISBN 1-84091-346-0; Ecco, 2005, ISBN 0-06-081757-7

''El Bulli 2003-2004'' (with Juli Soler and Albert Adrià), Ecco, 2006, ISBN 0-06-114668-4

''El Bulli 2005''

''A Day At El Bulli 2008

''FOOD for thought THOUGHT for food'' (El Bulli y Ferran Adrià), 2009 Actar Editorial, ISBN 978-84-96954-68-7

In October 2008, Ferran Adrià published ''A Day At El Bulli'' along with Juli Soler, and Albert Adrià. The book describes 24-hours at the El Bulli restaurant, with images, commentary, photographs and 30 recipes. Most of the recipes included are complex and require many out-of-the ordinary kitchen appliances, such as a Pacojet, freeze-dryer, liquid nitrogen tank, candyfloss machine and Perspex molds.

See also

Haute cuisine

References

External links

Great Chefs Biography

About.com Biography

Interview with The Guardian

Category:1962 births Category:Living people Category:Molecular gastronomy Category:Catalan chefs Category:Spanish chefs Category:Michelin Guide starred chefs

ca:Ferran Adrià Acosta de:Ferran Adrià es:Ferran Adrià eo:Ferran Adrià eu:Ferran Adria fr:Ferran Adrià gl:Ferrán Adrià it:Ferran Adrià he:פראן אדריה hu:Ferran Adrià nl:Ferran Adrià ja:フェラン・アドリア pt:Ferran Adrià ru:Адрия, Ферран fi:Ferran Adrià sv:Ferran Adrià

name	Harold McGee
occupation	Scientist and author
nationality
subject	Chemistry of food and cooking
notableworks	''On Food and Cooking''
website	http://www.curiouscook.com/cook/home.php
portaldisp	}}

Harold McGee is an American author who writes about the chemistry, technique and history of food and cooking and has written two seminal books on kitchen science. His first book, ''On Food and Cooking: The Science and Lore of the Kitchen'' was initially published in 1984. A greatly revised second edition was published in 2004. McGee has also written for ''Nature'', ''Health'', ''The New York Times'', the ''World Book Encyclopedia'', ''The Art of Eating'', ''Food & Wine'', ''Fine Cooking'', and ''Physics Today'' and lectured on kitchen chemistry at cooking schools, universities, The Oxford Symposia on Food, the Denver Natural History Museum and the Fermi National Accelerator Laboratory. McGee also consults for restaurants and manufacturers. Currently, he writes a regular column for the New York Times, The Curious Cook, which examines, and often debunks, conventional kitchen wisdom. Along with Dave Arnold and Nils Norén, he also teaches a three-day class at The French Culinary Institute in New York City entitled the Harold McGee Lecture Series.

Education

Prior to becoming a food science writer McGee was a literature and writing instructor at Yale. He attended the California Institute of Technology, originally intending to study Astronomy and Physics, but graduated with a B.S in Literature (1973), and later went on to receive a Ph.D from Yale University.

Influence

McGee's science-based approach to cooking has been embraced and popularized by chefs and authors such as Heston Blumenthal, Alton Brown, Shirley Corriher, Lynne Rossetto Kasper and Russ Parsons.

Books

''On Food and Cooking: The Science and Lore of the Kitchen'' (ISBN 0-684-80001-2, 2004)

''The Curious Cook: More Kitchen Science and Lore'' (ISBN 0-02-009801-4, 1990)

''Keys to Good Cooking: A Guide to Making the Best of Foods and Recipes'' (ISBN 0-34-096320-4, 2010), a compendium of practical information on food and cooking.

External links

Curious Cook

Organic Farming, talking at Google

On Food, NPR December 2004

Cooking with IEEE Spectrum: Harold McGee

Category:American food writers Category:California Institute of Technology alumni Category:Living people

es:Harold McGee pt:Harold McGee