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Culture of Denmark

The culture of Denmark has a rich artistic and scientific heritage. The fairy tales of Hans Christian Andersen (1805–1875), the philosophical essays of Søren Kierkegaard (1813–1855), the short stories of Karen Blixen, penname Isak Dinesen, (1885–1962), the plays of Ludvig Holberg (1684–1754), modern authors such as Herman Bang and Nobel laureate Henrik Pontoppidan and the dense, aphoristic poetry of Piet Hein (1905–1996), have earned international recognition, as have the symphonies of Carl Nielsen (1865–1931). From the mid-1990s, Danish films have attracted international attention, especially those associated with Dogme 95 like those of Lars Von Trier. Denmark has had a strong tradition of movie making and Carl Theodor Dreyer has been recognised as one of the world's greatest film directors. The astronomical discoveries of Tycho Brahe (1546–1601), Ludwig A. Colding's (1815–1888) neglected articulation of the principle of conservation of energy, and the foundational contributions to atomic physics of Niels Bohr (1885–1962); in this century Lene Vestergaard Hau (born 1959) in quantum physics involving the stopping of light, advances in nano-technology, and contributions to the understanding of Bose-Einstein Condensates, demonstrate the range and endurance of Danish scientific achievement.

Culture and the arts thrive as a result of the proportionately high amount of government funding they receive, much of which is administered by local authorities so as to involve citizens directly. Thanks to a system of grants, Danish artists are able to devote themselves to their work while museums, theatres, and the film institute receive national support.

Copenhagen, the capital, is home to many famous sites and attractions, including Tivoli Gardens, Amalienborg Palace (home of the Danish monarchy), Christiansborg Palace, Copenhagen Cathedral, Rosenborg Castle, Opera House, Frederik's Church (Marble Church), Thorvaldsens Museum, Rundetårn, Nyhavn and The Little Mermaid sculpture.

Hygge
Similar to other Scandinavian cultures, a fundamental aspect of Danish culture is hygge. Hygge, meaning "snug"; is a concept that evokes a "cosiness" that cannot be easily described due to being more of a mood, particularly when relaxing with good friends or loved ones. Christmas time is a true moment of hygge, as is grilling a pølse (Danish sausage) and drinking a beer on a long summer evening. It is suspected the concept of hygge is part of the reason Danes and other Scandinavians score high on happiness.

Danish Christmas
The Danish word for the Christmas holiday is Jul, from the Old Norse jól, the term for "midwinter", itself cognate with the English word, yule. Midwinter celebrations were an important part of Scandinavian culture since prehistoric times, and the term was retained to refer to "Christmas" after Christianization. In many countries Christmas is celebrated on 25 December, but in Denmark, and in the other Scandinavian countries, the most important day for celebrations is Christmas Eve on the 24th when the family comes together. The morning can be spent in various ways but most often it is the time when preparations are made for the evening. Juleaften (Danish for Christmas Eve) or Yule Eve starts around 6 p.m. when a traditional dinner (Julemiddag) is served. Afterwards, the candles on the Christmas tree are lit and the family dance around it singing Christmas songs and carols and subsequently exchange presents.

Folklore

Danish folklore is made up of folk tales, legends, songs, music, dancing, popular beliefs and traditions, mostly communicated by the inhabitants of towns and villages across the country. Many of these were passed on from generation to generation by word of mouth. As in neighbouring countries, interest in folklore grew with an emerging feeling of national consciousness in 19th-century Denmark. Researchers travelled across the country collecting innumerable folktales, songs and sayings while observing traditional dress in the various regions. Folklore today is part of the national heritage, represented in particular by national and local traditions, songs, folk dances and literature.

Today's folk dancing in Denmark dates back to the beginning of the 20th century, when there was renewed interest in the national heritage. A number of groups began to revive the music, dances and costumes of past generations. In 1901, the Society for the Promotion of Danish Folk Dancing (Foreningen til Folkedansens Fremme) was founded in Copenhagen, leading to local dancing societies throughout the country. Today there are more than 12,000 folk dancers in 219 local clubs, providing courses in music, dancing and dressmaking.

The traditional costumes of Denmark, though varying from region to region, date back roughly to the period between 1750 and 1900 when clothes were often home-made from yarn spun from wool or flax. In rural communities, the fabrication of garments for both family members and servants was an important part of everyday life. The artist Frederik Christian Lund, who had travelled across Denmark as a soldier in the First Schleswig War, took an interest in sketching people in local costumes in various parts of the country. He completed his collection of 31 coloured sketches in 1864, publishing them as coloured lithographs in Danske Nationaldragter (Danish National Costumes).

Numerous Danish folktales contain a range of mythical figures such as trolls, elves, goblins and wights as well as figures from Nordic mythology like giants and lygtemænd (hobby lanterns). The nisse is a particularly well known legendary figure in Danish folklore, apparently dating back to pre-Christian times when it was believed there were household gods. Traditionally each farm had its own nisse living on the loft or in a stable. Dressed in grey with a pointed red cap, he was no taller than a 10-year-old boy. The nisse would be helpful if treated well, for instance by offering him a bowl of porridge with a clump of butter at night, but, failing good treatment, he could become quite troublesome and mean.

Today, nisser are associated with Christmas, with some of them being portrayed as Santa Claus's helpers on Greendland. Whilst the superstition regarding the nisse has faded, it is still traditional for households with children to pretend that a nisse lives in the attic, or elsewhere in the house, and to offer it porridge in December. The parents will then, for the duration of the month, play mischievous, but harmless, jokes on the children. The nisse also provides daily gifts, that are laid in a sock, which is hung op on a wall at the start of the month.

Cuisine

Perhaps the most typically Danish contribution to the meals of the day is the traditional lunch or smørrebrød consisting of open sandwiches, usually on thinly sliced rugbrød. The meal usually begins with seafood such as marinated herring, smoked eel, crab, or breaded plaice filets with remoulade and moves on with slices of roast pork or beef, frikadeller (meatballs), hams and liver pâté. The sandwiches are richly garnished with onion rings, radish slices, cucumbers, tomato slices, parsley, remoulade or mayonnaise. The meal is mostly accompanied by beer, on occasion also by shots of ice-cold snaps or akvavit.

In the evening, hot meals are usually served. Traditional dishes include fried fish, roast pork with red cabbage, pot-roasted chicken, pot-roast and slow cooked beef, meat balls, or pork chops. Game is sometimes served in the autumn. Steaks are now increasingly popular, but is a modern addition.

A popular traditional Danish dessert, especially around Christmas, consists of æbleskiver, rather like small pancake doughnuts which are fried in butter in a special pan and are served hot with jam and sugar. Traditionally, they were made with small pieces of apple in the middle which is why they are called æbleskiver, literally "apple slices".

In recent years, development of the New Danish cuisine based on the rediscovery of local ingredients presented in interesting new recipes has led to a significant number of new, highly acclaimed restaurants in Copenhagen and the provinces, several with Michelin stars. This in turn has led to new developments in food production with a series of new products based on organic farming.

Sports
Sports are popular in Denmark, and its citizens participate in and watch a wide variety. The national sport is football (soccer), with the most notable results being qualifying for the European Championships six times in a row (1984–2004) and winning the Championship in 1992. Other significant achievements include winning the Confederations Cup in 1995 and reaching the quarter-final of the 1998 World Cup.

Denmark's numerous beaches and resorts are popular locations for fishing, canoeing, kayaking and a broad-range of other water-themed sports.

In speedway racing Denmark has won several world championships, including the Speedway World Cup in 2006 and 2008. Other popular sports include golf, mostly popular among the older demographic; tennis, in which Denmark is successful on a professional level; Danish Rugby Union, which dates back to 1950; and indoor sports such as badminton, handball and various forms of gymnastics.

, the national handball team are the current reigning European champions and the team with most medals won in European championship history on the men's side with a total of five medals, those being two gold medals (2008, 2012), and three bronze medals (2002, 2004 & 2006). And in 2016 Denmark's handball team won the gold medal for men at the Olympics in Rio.

Cycling

In recent years, Denmark has made a mark as a strong cycling nation, with Bjarne Riis winning Tour de France in 1996, and Michael Rasmussen reaching King of the Mountains status, in the Tour 2005 and 2006. The Tour d’France has been won for two consecutive years (2022 and 2023) by Jonas Vingegaard.

Most Danes are active cyclists, often using their bikes to commute to work or to go off on trips at the weekend. With its well-engineered cycle paths, Copenhagen is especially suited to city cycling. Every day 1.3 million km are cycled in the city, with 36% of all citizens commuting to work, school or university by bicycle. Cycling is generally perceived as a healthier, environmentally friendlier, cheaper and often quicker way around town than by public transport or car and it is therefore municipal policy for the number of commuters by bike to go up to 40% by 2012 and 50% by 2015.

Odense has been named the "bicycle city of the year" because of the great number of bicycle lanes in the city. A complete network of 350 km all-weather serviced lanes exists in the town.

During the summer months, there are free "City Bikes" stationed at various spots in the downtown area of Copenhagen, Aarhus and Aalborg. The idea is that anyone can take a bike from one of the spots, ride it to one of the other spots and leave it there for the next person. There are many National and regional bicycle routes throughout Denmark. They are all marked and include rest areas with benches and other necessities.

Painting

Danish painting goes back hundreds of years. Earlier work is often manifested in churches, for example in the form of frescos such as those from the 16th-century artist known as the Elmelunde Master. But it was not until the beginning of the 19th century that the Golden Age of Danish Painting emerged with a marked increase in truly Danish art inspired by the country itself with its lifestyle and traditions. Christoffer Wilhelm Eckersberg was an important influence on the following generation's study of nature, in which landscape painting came to the fore. He had many successful students, including Wilhelm Bendz (1804–1832), Christen Købke (1810–48), Martinus Rørbye (1803–1848), Constantin Hansen (1804–1880), Jørgen Roed (1808–1888), Wilhelm Marstrand (1810–1873), C. A. Jensen (1792–1870), J. Th. Lundbye (1818–1848), and P. C. Skovgaard (1817–1875).

Some years later, a number of painters including P. S. Krøyer (1851–1909) and Michael (1849–1927) and Anna Ancher (1859–1935) moved to Skagen in the far north of Jylland to paint the natural surroundings and local people. In due course, the town developed into an artists' colony. A little later, a similar phenomenon developed on Fyn with artists such as Johannes Larsen (1867–1961). Vilhelm Hammershøi is another known painter.

Collections of modern art enjoy unusually attractive settings at the Louisiana Museum north of Copenhagen, at the North Jylland Art Museum in Aalborg and at the ARoS art museum in Aarhus. The National Museum of Art and the Glyptotek, both in Copenhagen, contain treasures of Danish and international art.

Sculpture

Danish sculpture as a nationally recognized art form can be traced back to 1752 when Jacques Saly was commissioned to execute King Frederick V of Denmark while on horseback. While Bertel Thorvaldsen (1770–1844) was undoubtedly the country's most prominent contributor of his time, many other sculptors also produced notable works in the areas of Neoclassicism, Realism, and Historicism, the latter resulting from a growing consciousness of a national identity. From modern times, many notable works of Surrealism and Modernism has been produced, inspired by European trends, especially those from Paris. Present notable Danish sculptors includes Michael Kvium, Hein Heinsen and Bjørn Nørgaard, but the field holds many skilled practitioners and the styles has diversified greatly.

Literature
The principal contributors to Danish literature are undoubtedly Hans Christian Andersen (1805–1875) with his fairy tales, the philosopher Søren Kierkegaard (1813–1855), storyteller Karen Blixen (1885–1962), playwright Ludvig Holberg (1684–1754), and modern authors such as Henrik Pontoppidan and Herman Bang.

Among today's Danish writers, probably the best-known to international readers is Peter Høeg (Smilla's Sense of Snow; Borderliners). Benny Andersen writes poems, short stories, and music. Poems by both writers have been translated into English by the Curbstone Press. Klaus Rifbjerg has published over 100 novels as well as poetry, short stories and TV plays. Two of his works have been translated into English: Witness to the Future and War. Kirsten Thorup's novel Baby, winner of the 1980 Pegasus Prize, is published in English by the University of Louisiana Press. The psychological thrillers of Anders Bodelsen also appear in English as do some of the novels of intrigue by Leif Davidsen. Suzanne Brøgger and Vita Andersen focus largely on the changing roles of women in society.

Architecture
The architecture of Denmark has changed and evolved since prehistoric times, but the oldest buildings to have survived the ravages of time dates to the early Middle Ages when bricks was introduced as building material around 1150 AD and the first Romanesque, then Gothic churches and cathedrals sprang up across the country. Brick is still a locally produced, affordable, durable and widely used building material in today's architecture of Denmark. Inspired by French castles and with the assistance of Dutch designers, architecture during the Renaissance flourished with magnificent royal palaces. Neoclassicism came to Denmark from France and, in the 19th century, slowly merged into the National Romantic style when Danish designers came into their own. It was, however, not until the last half of the 20th century that Danish architects entered the world scene with their highly successful Functionalism. This, in turn, has evolved into more recent world-class designers such as Johann Otto von Spreckelsen who designed the Grande Arche in Paris. Internationally, perhaps the most celebrated of all is the architect who designed the iconic Sydney Opera House, Jørn Utzon, but within Danish borders, it is the architect Arne Jacobsen who is perhaps held in highest esteem for developing the 'Danish Modern' style and furniture/interior design, such as the now world-famous and much sought-after Swan and Egg chairs. A new wave of young Danish architects are rising into international prominence, like Bjarke Ingels with works such as the Danish National Pavilion at the Shanghai 2010 Expo.

Photography

Photography in Denmark has developed from strong participation and interest in the very beginnings of the art in 1839 to some of the strongest contemporary photography in Europe today. Pioneers such as Mads Alstrup and Georg Emil Hansen paved the way for a rapidly growing profession during the last half of the 19th century while both artistic and press photographers have since made internationally recognised contributions. Today Danish photographers such as Astrid Kruse Jensen and Jacob Aue Sobol are active both at home and abroad, participating in key exhibitions around the world.

Design

Danish design is a term often used to describe a style of functionalistic design and architecture that was developed in mid-20th century, originating in Denmark. Danish design is typically applied to industrial design, furniture and household objects, which have won many international awards.

The Danish Porcelain Factory ("Royal Copenhagen"), including Bing & Grøndahl, is famous for the quality of its ceramics and export products worldwide. Danish design is also a well-known brand, often associated with world-famous designers and architects such as Børge Mogensen (1914–1972), Finn Juhl (1912–1989), Hans Wegner (1914–2007), Arne Jacobsen (1902–1971), Poul Kjærholm (1929–1980), Poul Henningsen (1894–1967) and Verner Panton (1926–1998). Georg Jensen (1866–1935) is known the world over for modern design in silver.

Other designers of note include Kristian Solmer Vedel (1923–2003) in the area of industrial design, Jens Harald Quistgaard (1919–2008) for kitchen furniture and implements and Ole Wanscher (1903–1985) who had a classical approach to furniture design.

The Danish Museum of Art & Design in Copenhagen exhibits the best in Danish design.

Music
Denmark's most famous composer of classical music is Carl Nielsen who is best known outside of Denmark for his six symphonies, but whose melodies for popular songs are cherished among Danes. Other well-known pieces of his are the incidental music for Adam Oehlenschläger's drama Aladdin (Nielsen), the operas Saul og David and Maskarade, the concertos for flute, violin, and clarinet, the Wind Quintet, and the Helios Overture, which depicts the passage of the sun in the sky from dawn to nightfall. The Royal Danish Ballet specializes in the work of Danish choreographer August Bournonville (1805–79). Hans Abrahamsen, Per Nørgård and Poul Ruders are successful composers of contemporary classical music. Danish interest in classical music is exemplified by the prestigious Opera House completed in 2000. Strategically set on Copenhagen's waterfront, it has presented operas and musicals to full houses ever since its opening.

Danes have also distinguished themselves in rhythmical music, with world-famous jazz musicians such as Svend Asmussen, Niels-Henning Ørsted Pedersen, Niels Lan Doky and Marilyn Mazur. The Copenhagen Jazz Festival has acquired an international reputation.

The modern pop and rock scene has produced some bands of note like Aqua, Dizzy Mizz Lizzy, D-A-D, The Raveonettes, Michael Learns to Rock, Alphabeat, Medina, Oh Land, Kashmir, Mew, Outlandish and Dúné. All together, Lars Ulrich, drummer of the band Metallica, has become the first Danish musician to be inducted into the Rock and Roll Hall of Fame.

Cinema
In recent years, Danish films have gained increasing recognition at home and abroad. Gabriel Axel's film based on Karen Blixen's Babette's Feast was awarded an Oscar in 1987. In 1988, Bille August also received an Oscar with Pelle the Conqueror based on the novel by Martin Andersen Nexø. In 1992, August went on to win the Palme d'Or in Cannes with Ingmar Bergman's autobiography, The Best Intentions.

Since the late 1990s, the Dogme movement and figures such as Lars von Trier, Thomas Vinterberg, Søren Kragh-Jacobsen and Lone Scherfig have continued to contribute to the international success of Danish cinema. In 2011, Susanne Bier's In a Better World won the Academy Award for Best Foreign Language Film.

Theatre
The theatre in Denmark continues to thrive thanks to the many theatres across the country which put on a wide variety of Danish and foreign performances. The flagship Royal Danish Theatre presents drama, opera, ballet and music. Since the 18th century, Danish playwrights have been successful in attracting wide public interest.

Ludvig Holberg (1684–1754) is considered by many to be the founder of the Danish theatre. Satirical comedies such as Jean de France and Jeppe of the Hill are still performed today.

Adam Oehlenschläger (1779–1850) introduced romanticism to the Danish theatre. Especially successful was his Earl Hakon the Mighty, premiered in 1808.

The Norwegian Henrik Ibsen (1828–1906) also travelled to Copenhagen where he produced numerous plays such as A Doll's House (1879).

In recent years, there has been something of a revival in Danish theatre. Many new playwrights and producers have appeared including Astrid Saalbach (born 1955), winner of the Nordic Drama Award in 2004, and Peter Asmussen (born 1957), who wrote the film script for Lars von Trier's Breaking the Waves. Danish musicals have also been a particularly successful feature of the modern theatre. Knud Christensen, commonly known as Sebastian, was particularly successful with Cyrano (1992), based on Rostand's play and Klokkeren fra Notre Dame (The Hunchback of Notre Dame) (2001). Bent Fabricius-Bjerre's musical Matador (2007) is based on a successful TV series of the same name.

Another popular Danish theatrical tradition is the revue which has been thriving since the mid-19th century. Today revues are performed every summer to full houses in theatres across Denmark, poking fun at the politics of the day and even the monarchy. Among the most popular are Circusrevyen in Copenhagen with Lisbet Dahl, and the Nykøbing Revy directed by Flemming Krøll in Nykøbing Falster.

To this day, Denmark also has a large tradition for children and youth theater, as it hosts the largest annual children and youth theater event in the world, Aprilfestivallen, every year.

Television
Danish television has also contributed to drama with a number of successful series since the 1970s. Perhaps the most notable domestic and international successes have been the political drama Borgen and the three series of Forbrydelsen (The Killing, 2007–2012). Forbrydelsen attracted more than a 30% audience share, when originally broadcast in Denmark and both series have been widely sold around the world.

Science
Denmark has a long tradition for scientific engagement in all fields, often with fundamental discoveries. The intelligentsia was involved in the European scientific revolution of the renaissance early on, with prominent scientists such as Tycho Brahe (1546–1601), Ole Worm (1588–1655), Nicolas Steno (1638–1686) and Ole Rømer (1644–1710).

The contributions to science has steadily continued through the ages, with the fundamental discoveries of Hans Christian Ørsted (1777–1851), the contributions to linguistics by Rasmus Rask (1787–1832), the neglected articulation of the principle of conservation of energy by Ludwig A. Colding's (1815–1888), Vilhelm Thomsen (1842–1927), Otto Jespersen (1860–1943) and others, into modern times with the brilliant contributions to atomic physics of Niels Bohr (1885–1962).

Niels Bohr founded several institutions in relation to quantum physics and both attracted and stimulated an important international and lasting scientific milieu in the country. This has since produced many important discoveries and advancements in physics, astrophysics, chemistry, mathematics and engineering, particularly in the areas of quantum physics, quantum optics and lately nano-technology. Although an international environment, notable Danish scientists from this milieu includes Bengt Strömgren (1908–1987), Aage Bohr (1922–2009), Holger Bech Nielsen (born 1941) and Lene Vestergaard Hau (born 1959).

The sciences of geology and geophysics has benefited from Danish scientists who have been - and are - heavily involved in the description and understanding of the geology of Greenland, one of the most important regions in the world to study the geological evolution of Earth. The Geological Survey of Denmark and Greenland (GEUS) was founded in 1888 and Inge Lehmann (1888–1993) revealed that Earth have a solid inner core in 1936, by the use of seismology. In the 1960s, Willi Dansgaard was the first to understand and describe how to use ice core drills to gain knowledge about Earth's paleoclimate, now a widely used method to understand climate changes. Lately, Greenland-born geologist Minik Rosing and his team, unravelled groundbreaking knowledge about the early evolution of life through studies of Greenland's geology in the 2000s.

The young science of archaeology, has also benefited from many Danish contributions, with prominent scholars such as Sophus Müller (1846-1934), Georg F.L. Sarauw, J.J.A. Worsaae and Peter Glob. The contributions have often been of a fundamental nature, such as the discoveries of kitchen middens or bog bodies and their great potential for advancing archaeology. Christian Jürgensen Thomsen refined and introduced the now universally recognized three-age system, dividing eras of prehistory into the well-known Stone Age, Bronze Age and Iron Age respectively. Danish archaeologists have contributed with many defining archaeological discoveries, such as the Kongemose culture, Maglemosian culture and the Ertebølle culture of the Nordic Stone Age and of course the Viking Age. With a great international engagement and a long tradition for interdisciplinary collaborations with anthropologists, geologists, zoologists, botanists, antiquarians and historians, Danish archaeologists have been, and still are, involved with all kinds of cultural archaeology around the globe, including the Middle East (Peter Glob, Peter Rowley-Conwy), the Mediterranean region (Peter Oluf Brøndsted, Jörgen Zoega) the Americas (Peter Wilhelm Lund, Frans Blom, Rane Willerslev) and the Arctic region (Therkel Mathiassen, Erik Holtved, Eigil Knuth).

Danes have made significant contributions to the field of computer science. Some notable figures include: Per Brinch Hansen, known for concurrent programming theory; Bjarne Stroustrup, who invented the C++ programming language; Janus Friis, the co-inventor of Skype; Jens and Lars Rasmussen, the co-founders of Google Maps; and Peter Naur, a contributor to ALGOL 60 and a recipient of the Turing Award.

LGBT
Social equality, including sexual equality, is relatively high in modern Denmark. Danes are somewhat tolerant towards sexual minorities.

Public displays of affection between gay partners are less likely to provoke disapproval, even as compared to other liberal Western countries. As such, Copenhagen is a popular destination for homosexual and bisexual travellers. The main gay and lesbian festivals of the year are the Copenhagen Pride Parade and the Gay & Lesbian Film Festival. Copenhagen has been host to the 2009 World Outgames.

In 1989 Denmark became the first country in the world to offer same-sex couples most of the same legal rights as heterosexual couples, in the form of "registered partnerships.". In March 2009 adoption was legalized for same-sex couples. Same-sex marriage became legal in 2012, after both the parliament and the Church of Denmark voted for it.

title: Culture of Denmark


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Aletsch Glacier

The Aletsch Glacier (Aletschgletscher, ) or Great Aletsch Glacier (Grosser Aletschgletscher) is the largest glacier in the Alps. It has a length of about 23 km (2014), a volume of 15.4 km3 (2011), and covers about 81.7 km2 (2011) in the eastern Bernese Alps in the Swiss canton of Valais. The Aletsch Glacier is composed of four smaller glaciers converging at Konkordiaplatz, where its thickness was measured by the ETH to be still near 1 km. It then continues towards the Rhône valley before giving birth to the Massa. The Aletsch Glacier is – like most glaciers in the world today – a retreating glacier. As of 2016, since 1980 it lost 1.3 km of its length, since 1870 3.2 km, and lost also more than 300 m of its thickness.

The whole area, including other glaciers is part of the Jungfrau-Aletsch Protected Area, which was declared a UNESCO World Heritage Site in 2001.

Geography
The Aletsch Glacier is one of the many glaciers located between the cantons of Bern and Valais on the Bernese Alps located east of the Gemmi Pass. The whole area is considered to be the largest glaciated area in western Eurasia. The Fiescher and Aar Glaciers lying on the east have similar extensions.

Except the Finsteraarhorn, all the highest summits of the Bernese Alps are located within the drainage basin of the glacier. The Jungfrau and Mönch constitute the northern boundary; the Gross Fiescherhorn and Gross Wannenhorn lie on its east side; finally the culminating point, the Aletschhorn (4193 m) is located on the west side.

Before reaching the maximum flow, four smaller glaciers converge at Konkordiaplatz:

 * From the western mouth flows the Grosser Aletschfirn, which runs along the northern foot of the Aletschhorn and Dreieckhorn. The Grosser Aletschfirn is supplied from the north by three notable firns: the Äbeni Flue-Firn, the Gletscherhornfirn, and the Kranzbergfirn. All of these firns have their starting points at around 3800 m. From the Äbeni Flue-Firn to the Konkordiaplatz, the Grosser Aletschfirn is 9 km long and is on average about 1.5 km wide. On the west, the Grosser Aletschfirn connects with the Langgletscher over the 3158 m high glacier pass, the Lötschenlücke, into the Lötschental.
 * From the northwestern mouth flows the Jungfraufirn. This firn in fact represents the straight continuation of the Aletsch Glacier, yet is the shortest of the four tributary glaciers. It has its origin on the southern flank of the Mönch and at the eastern flank of the Jungfrau with the Jungfraujoch in-between. Up to the Konkordiaplatz, the Jungfraufirn is a scarce 7 km long, and returns to flank the Kranzberg in the west and the Trugberg in the east. At its highest point, it is 2 km wide, and further down it is still a good 1 km wide.
 * From the northern mouth flows the Ewigschneefäld ("Eternal snow field"), where its starting point takes the east flank of the Mönch. In an elbow, it flanks from Trugberg in the west and the Gross Fiescherhorn and Grünhorn in the east, flowing on to the Konkordiaplatz. Up to here, it is about 8 km long and averages about 1.2 km wide. The mouth at the Konkordiaplatz it follows over a rise with a descent from 25 to 30 percent; here, the glacier is sharply split. Against the north is the Ewigschneefäld over the snow-covered pass of the Unners Mönchsjoch (3518 m), connected with the catchment area of the Ischmeer (Wallis German for "Ice Sea"). Through the Obere Mönchsjoch (3624 m) between the Mönch and the Trugberg stands a connection to the Jungfraufirn.
 * From the east, the smallest firn arrives at the Konkordiaplatz: the Grüneggfirn. Its northern arm begins below the Grünegghorn (3860 m). The southern arm collects its snow and ice in the pot flanked by the Wyssnollen, Fiescher Gabelhorn (3866 m), and the Chamm. Between the peaks Wyssnollen and Grünhörnli another glacier pass, the Grünhornlücke (3279 m), connects to the Fieschergletscher. The Grüneggfirn enters the Konkordiaplatz in a gap between the mountainsides Grünegg to the north and the Fülberg to the south. On the western side of the Fülberg the Konkordia hut (mountain hut) overlooks the whole Konkordiaplatz at an altitude of 2850 m.

South of Konkordiaplatz, the glacier runs towards the valley of the Oberwallis (Upper Valais); on the east side, near Bettmeralp, lies a small glacier lake, Märjelensee (2301 m); from the western side used to enter the Mittelaletschgletscher, but since the end of the 20th century the connection with the Aletsch Glacier has been lost. Further down, until about 1880, the Oberaletschgletscher did also enter the Aletsch Glacier at its mouth. But since then both glaciers have been retreating so far that they do not connect anymore (the Upper Aletsch Glacier did retreat about 1.3 km from its connecting point with the Aletsch Glacier), but both serve now only as the source of the river Massa. The river flows through the Lake Gibidum (a reservoir, and coincidentally representing the glacier's mouth region in the 19th century, which is a retreat of more than 4 km) and a gorge of the same name before reaching the Rhône near Brig.

Tourism
The area of the Aletsch Glacier and some surrounding valleys is on the UNESCO World Heritage list, thus it is protected and the facilities are mostly restricted to the external zones. The region between Belalp, Riederalp and Bettmeralp (which is called Aletsch Region) in Valais gives access to the lower part of the glacier. The Bettmerhorn and Eggishorn are popular view points and are accessible by cable car. The Massa river can be crossed since 2008 by a suspension bridge, thus allowing hikes between the left and the right part of the glacier.

The Jungfraujoch railway station (3,450 m) gives a direct access to the upper Aletsch Glacier as well as the normal route to the Jungfrau. It can be reached only from Interlaken in the canton Bern. Hiking paths pass the Konkordia Hut or the Hollandia Hut, eventually reaching other glaciers in the massif.

On the Riederfurka, at 2,065 metres between Riederalp and the glacier, is located the historic Villa Cassel, former summer residence of many famous and influential guests from the worlds of politics and finance. The house is now one of the centers of the environmental organization Pro Natura, which hosts a permanent exhibition about the site.

Panorama
Also at the mouth of the Konkordiaplatz from the east is the small but important Grüneggfirn (3 km long and averaging 600 m wide). This firn is connected in the over the glacier pass Grünhornlücke (3280 m high) to the Fiescher Glacier in the east.

From the Konkordiaplatz, the Aletsch Glacier has a width of approximately 1.5 km and moves at a rate of 180 m per year to the southeast on course with the Rhône valley, bordering the Dreieckhorn in the west and the great Wannenhorn in the east. It then takes a great right turn and bends ever closer to the southwest, running through the edge of the Eggishorn and Bettmerhorn of the Rhône valley. The lowest part of the great Aletsch Glacier is largely covered with detritus of the lateral and medial moraines. The glacier's toe currently lies about 1560 m high, far beneath the local tree line. From it springs the Massa stream, which flows through the Massa Canyon and is used to generate hydroelectric power. It continues through the upper half of the Brig, eventually entering into the Rhône.

The great Aletsch Glacier shows considerable ice cover. At the Konkordiaplatz, it has an ice cover of more than 900 m, but as it moves to the south, the greater part of the ice melts, gradually decreasing the cover to around 150 m.

The characteristically dark medial moraine, situated almost in the middle of the glacier, runs protracted in two bands from the Konkordiaplatz along the whole length to the glacier's toe-zone. This medial moraine is collected from the ice of three large ice fields, which all run together. The westernmost medial moraine has been named the Kranzbergmoräne, and the easternmost carries the name Trugbergmoräne.

Formation and evolution
The Aletsch Glacier resulted from the accumulation and compaction of snow. Glaciers generally form where snow and ice accumulation exceed snow and ice melt. As the snow and ice thicken it reaches a point where it begins to move due to a combination of gravity and pressure of the overlying snow and ice.

During the last glacial periods, the Aletsch Glacier was much larger than now. 18,000 years ago the lower part of the ridge, between Riederalp and the glacier, was completely covered by ice. Only the summits of the Bettmerhorn, Eggishorn and the Fusshörner were above the glacier. After an important retreat, the glacier again advanced 11,000 years ago during the last glacial period. The glacier reached the Rhône valley, and its ice the Riederfurka. Remaining moraines are still visible in the Aletsch Forest.

Since the last glaciation, the glacier generally retreated. However slight climatic changes happened and, in 1860, the glacier was 3 km longer and the ice level 200 m higher.

As for many other glaciers, records show a major longer-term retreat trend. The Aletsch Glacier receded by 3.2 km since 1870, including 1.3 km since 1980. A record retreat of 114.6 m happened in 2006 alone.

Since the end of the Little Ice Age in 1850 the glacier has lost 20 percent of its ice mass, considerably less than other glaciers in Switzerland, which have lost up to 50 percent. This is explained with the large size of the Aletsch Glacier, which reacts much slower to climate change than smaller glaciers. It is however estimated that, by 2100, the glacier will have only one tenth of its 2018 ice mass.

Photo opportunity
On August 18, 2007, photographer Spencer Tunick used hundreds of naked people in a "living sculpture" on the Aletsch Glacier in a photo shoot which he said was intended to draw attention to global warming and the shrinking of the world's glaciers. The temperature was about 10 °C (50 °F) at the time of the photo shoot. The 600 participants on the shrinking glacier said that they had volunteered for Tunick (a collaboration with Greenpeace) to let the world know about the effects of global warming on the melting Swiss glaciers.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Aletsch Glacier


text:
Mass spectrometry

Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures.

A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds.

In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated according to their mass-to-charge ratio, for example by accelerating them and subjecting them to an electric or magnetic field: ions of the same mass-to-charge ratio will undergo the same amount of deflection. The ions are detected by a mechanism capable of detecting charged particles, such as an electron multiplier. Results are displayed as spectra of the signal intensity of detected ions as a function of the mass-to-charge ratio. The atoms or molecules in the sample can be identified by correlating known masses (e.g. an entire molecule) to the identified masses or through a characteristic fragmentation pattern.

History of the mass spectrometer

In 1886, Eugen Goldstein observed rays in gas discharges under low pressure that traveled away from the anode and through channels in a perforated cathode, opposite to the direction of negatively charged cathode rays (which travel from cathode to anode). Goldstein called these positively charged anode rays "Kanalstrahlen"; the standard translation of this term into English is "canal rays". Wilhelm Wien found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with perpendicular electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (Q/m). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist J. J. Thomson later improved on the work of Wien by reducing the pressure to create the mass spectrograph.

The word spectrograph had become part of the international scientific vocabulary by 1884. Early spectrometry devices that measured the mass-to-charge ratio of ions were called mass spectrographs which consisted of instruments that recorded a spectrum of mass values on a photographic plate. A mass spectroscope is similar to a mass spectrograph except that the beam of ions is directed onto a phosphor screen. A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an oscilloscope. The use of the term mass spectroscopy is now discouraged due to the possibility of confusion with light spectroscopy. Mass spectrometry is often abbreviated as mass-spec or simply as MS.

Modern techniques of mass spectrometry were devised by Arthur Jeffrey Dempster and F.W. Aston in 1918 and 1919 respectively.

Sector mass spectrometers known as calutrons were developed by Ernest O. Lawrence and used for separating the isotopes of uranium during the Manhattan Project. Calutron mass spectrometers were used for uranium enrichment at the Oak Ridge, Tennessee Y-12 plant established during World War II.

In 1989, half of the Nobel Prize in Physics was awarded to Hans Dehmelt and Wolfgang Paul for the development of the ion trap technique in the 1950s and 1960s.

In 2002, the Nobel Prize in Chemistry was awarded to John Bennett Fenn for the development of electrospray ionization (ESI) and Koichi Tanaka for the development of soft laser desorption (SLD) and their application to the ionization of biological macromolecules, especially proteins.

Parts of a mass spectrometer

A mass spectrometer consists of three components: an ion source, a mass analyzer, and a detector. The ionizer converts a portion of the sample into ions. There is a wide variety of ionization techniques, depending on the phase (solid, liquid, gas) of the sample and the efficiency of various ionization mechanisms for the unknown species. An extraction system removes ions from the sample, which are then targeted through the mass analyzer and into the detector. The differences in masses of the fragments allows the mass analyzer to sort the ions by their mass-to-charge ratio. The detector measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present. Some detectors also give spatial information, e.g., a multichannel plate.

Theoretical example
The following describes the operation of a spectrometer mass analyzer, which is of the sector type. (Other analyzer types are treated below.) Consider a sample of sodium chloride (table salt). In the ion source, the sample is vaporized (turned into gas) and ionized (transformed into electrically charged particles) into sodium (Na+) and chloride (Cl−) ions. Sodium atoms and ions are monoisotopic, with a mass of about 23 daltons (symbol: Da or older symbol: u). Chloride atoms and ions come in two stable isotopes with masses of approximately 35 u (at a natural abundance of about 75 percent) and approximately 37 u (at a natural abundance of about 25 percent). The analyzer part of the spectrometer contains electric and magnetic fields, which exert forces on ions traveling through these fields. The speed of a charged particle may be increased or decreased while passing through the electric field, and its direction may be altered by the magnetic field. The magnitude of the deflection of the moving ion's trajectory depends on its mass-to-charge ratio. Lighter ions are deflected by the magnetic force to a greater degree than heavier ions (based on Newton's second law of motion, F = ma). The streams of magnetically sorted ions pass from the analyzer to the detector, which records the relative abundance of each ion type. This information is used to determine the chemical element composition of the original sample (i.e. that both sodium and chlorine are present in the sample) and the isotopic composition of its constituents (the ratio of 35Cl to 37Cl).

Creating ions

The ion source is the part of the mass spectrometer that ionizes the material under analysis (the analyte). The ions are then transported by magnetic or electric fields to the mass analyzer.

Techniques for ionization have been key to determining what types of samples can be analyzed by mass spectrometry. Electron ionization and chemical ionization are used for gases and vapors. In chemical ionization sources, the analyte is ionized by chemical ion-molecule reactions during collisions in the source. Two techniques often used with liquid and solid biological samples include electrospray ionization (invented by John Fenn ) and matrix-assisted laser desorption/ionization (MALDI, initially developed as a similar technique "Soft Laser Desorption (SLD)" by K. Tanaka for which a Nobel Prize was awarded and as MALDI by M. Karas and F. Hillenkamp ).

Hard ionization and soft ionization

In mass spectrometry, ionization refers to the production of gas phase ions suitable for resolution in the mass analyser or mass filter. Ionization occurs in the ion source. There are several ion sources available; each has advantages and disadvantages for particular applications. For example, electron ionization (EI) gives a high degree of fragmentation, yielding highly detailed mass spectra which when skilfully analysed can provide important information for structural elucidation/characterisation and facilitate identification of unknown compounds by comparison to mass spectral libraries obtained under identical operating conditions. However, EI is not suitable for coupling to HPLC, i.e. LC-MS, since at atmospheric pressure, the filaments used to generate electrons burn out rapidly. Thus EI is coupled predominantly with GC, i.e. GC-MS, where the entire system is under high vacuum.

Hard ionization techniques are processes which impart high quantities of residual energy in the subject molecule invoking large degrees of fragmentation (i.e. the systematic rupturing of bonds acts to remove the excess energy, restoring stability to the resulting ion). Resultant ions tend to have m/z lower than the molecular ion (other than in the case of proton transfer and not including isotope peaks). The most common example of hard ionization is electron ionization (EI).

Soft ionization refers to the processes which impart little residual energy onto the subject molecule and as such result in little fragmentation. Examples include fast atom bombardment (FAB), chemical ionization (CI), atmospheric-pressure chemical ionization (APCI), atmospheric-pressure photoionization (APPI), electrospray ionization (ESI), desorption electrospray ionization (DESI), and matrix-assisted laser desorption/ionization (MALDI).

Inductively coupled plasma

Inductively coupled plasma (ICP) sources are used primarily for cation analysis of a wide array of sample types. In this source, a plasma that is electrically neutral overall, but that has had a substantial fraction of its atoms ionized by high temperature, is used to atomize introduced sample molecules and to further strip the outer electrons from those atoms. The plasma is usually generated from argon gas, since the first ionization energy of argon atoms is higher than the first of any other elements except He, F and Ne, but lower than the second ionization energy of all except the most electropositive metals. The heating is achieved by a radio-frequency current passed through a coil surrounding the plasma.

Photoionization mass spectrometry
Photoionization can be used in experiments which seek to use mass spectrometry as a means of resolving chemical kinetics mechanisms and isomeric product branching. In such instances a high energy photon, either X-ray or uv, is used to dissociate stable gaseous molecules in a carrier gas of He or Ar. In instances where a synchrotron light source is utilized, a tuneable photon energy can be utilized to acquire a photoionization efficiency curve which can be used in conjunction with the charge ratio m/z to fingerprint molecular and ionic species. More recently atmospheric pressure photoionization (APPI) has been developed to ionize molecules mostly as effluents of LC-MS systems.

Ambient ionization
Some applications for ambient ionization include environmental applications as well as clinical applications. In these techniques, ions form in an ion source outside the mass spectrometer. Sampling becomes easy as the samples don't need previous separation nor preparation. Some examples of ambient ionization techniques are Direct Analysis in Real Time (DART),DESI, SESI, LAESI, desorption atmospheric-pressure chemical ionization (DAPCI), and desorption atmospheric pressure photoionization DAPPI among others.

Other ionization techniques
Others include glow discharge, field desorption (FD), fast atom bombardment (FAB), thermospray, desorption/ionization on silicon (DIOS), atmospheric pressure chemical ionization (APCI), secondary ion mass spectrometry (SIMS), spark ionization and thermal ionization (TIMS).

Mass selection
Mass analyzers separate the ions according to their mass-to-charge ratio. The following two laws govern the dynamics of charged particles in electric and magnetic fields in vacuum:

 * $$\mathbf{F} = Q (\mathbf{E} + \mathbf{v} \times \mathbf{B})$$ (Lorentz force law);

 * $$\mathbf{F}=m\mathbf{a}$$ (Newton's second law of motion in the non-relativistic case, i.e. valid only at ion velocity much lower than the speed of light).

Here F is the force applied to the ion, m is the mass of the ion, a is the acceleration, Q is the ion charge, E is the electric field, and v × B is the vector cross product of the ion velocity and the magnetic field

Equating the above expressions for the force applied to the ion yields:

 * $$(m/Q)\mathbf{a} = \mathbf{E}+ \mathbf{v} \times \mathbf{B}.$$

This differential equation is the classic equation of motion for charged particles. Together with the particle's initial conditions, it completely determines the particle's motion in space and time in terms of m/Q. Thus mass spectrometers could be thought of as "mass-to-charge spectrometers". When presenting data, it is common to use the (officially) dimensionless m/z, where z is the number of elementary charges (e) on the ion (z=Q/e). This quantity, although it is informally called the mass-to-charge ratio, more accurately speaking represents the ratio of the mass number and the charge number, z.

There are many types of mass analyzers, using either static or dynamic fields, and magnetic or electric fields, but all operate according to the above differential equation. Each analyzer type has its strengths and weaknesses. Many mass spectrometers use two or more mass analyzers for tandem mass spectrometry (MS/MS). In addition to the more common mass analyzers listed below, there are others designed for special situations.

There are several important analyzer characteristics. The mass resolving power is the measure of the ability to distinguish two peaks of slightly different m/z. The mass accuracy is the ratio of the m/z measurement error to the true m/z. Mass accuracy is usually measured in ppm or milli mass units. The mass range is the range of m/z amenable to analysis by a given analyzer. The linear dynamic range is the range over which ion signal is linear with analyte concentration. Speed refers to the time frame of the experiment and ultimately is used to determine the number of spectra per unit time that can be generated.

Sector instruments

A sector field mass analyzer uses a static electric and/or magnetic field to affect the path and/or velocity of the charged particles in some way. As shown above, sector instruments bend the trajectories of the ions as they pass through the mass analyzer, according to their mass-to-charge ratios, deflecting the more charged and faster-moving, lighter ions more. The analyzer can be used to select a narrow range of m/z or to scan through a range of m/z to catalog the ions present.

Time-of-flight
The time-of-flight (TOF) analyzer uses an electric field to accelerate the ions through the same potential, and then measures the time they take to reach the detector. If the particles all have the same charge, their kinetic energies will be identical, and their velocities will depend only on their masses. For example, ions with a lower mass will travel faster, reaching the detector first. Ions usually are moving prior to being accelerated by the electric field, this causes particles with the same m/z to arrive at different times at the detector. This difference in initial velocities is often not dependent on the mass of the ion, and will turn into a difference in the final velocity. This distribution in velocities broadens the peaks shown on the count vs m/z plot, but will generally not change the central location of the peaks, since the starting velocity of ions is generally centered at zero. To fix this problem, time-lag focusing/delayed extraction has been coupled with TOF-MS.

Quadrupole mass filter
Quadrupole mass analyzers use oscillating electrical fields to selectively stabilize or destabilize the paths of ions passing through a radio frequency (RF) quadrupole field created between four parallel rods. Only the ions in a certain range of mass/charge ratio are passed through the system at any time, but changes to the potentials on the rods allow a wide range of m/z values to be swept rapidly, either continuously or in a succession of discrete hops. A quadrupole mass analyzer acts as a mass-selective filter and is closely related to the quadrupole ion trap, particularly the linear quadrupole ion trap except that it is designed to pass the untrapped ions rather than collect the trapped ones, and is for that reason referred to as a transmission quadrupole. A magnetically enhanced quadrupole mass analyzer includes the addition of a magnetic field, either applied axially or transversely. This novel type of instrument leads to an additional performance enhancement in terms of resolution and/or sensitivity depending upon the magnitude and orientation of the applied magnetic field. A common variation of the transmission quadrupole is the triple quadrupole mass spectrometer. The "triple quad" has three consecutive quadrupole stages, the first acting as a mass filter to transmit a particular incoming ion to the second quadrupole, a collision chamber, wherein that ion can be broken into fragments. The third quadrupole also acts as a mass filter, to transmit a particular fragment ion to the detector. If a quadrupole is made to rapidly and repetitively cycle through a range of mass filter settings, full spectra can be reported. Likewise, a triple quad can be made to perform various scan types characteristic of tandem mass spectrometry.

Three-dimensional quadrupole ion trap
The quadrupole ion trap works on the same physical principles as the quadrupole mass analyzer, but the ions are trapped and sequentially ejected. Ions are trapped in a mainly quadrupole RF field, in a space defined by a ring electrode (usually connected to the main RF potential) between two endcap electrodes (typically connected to DC or auxiliary AC potentials). The sample is ionized either internally (e.g. with an electron or laser beam), or externally, in which case the ions are often introduced through an aperture in an endcap electrode.

There are many mass/charge separation and isolation methods but the most commonly used is the mass instability mode in which the RF potential is ramped so that the orbit of ions with a mass $a > b$ are stable while ions with mass b become unstable and are ejected on the z-axis onto a detector. There are also non-destructive analysis methods.

Ions may also be ejected by the resonance excitation method, whereby a supplemental oscillatory excitation voltage is applied to the endcap electrodes, and the trapping voltage amplitude and/or excitation voltage frequency is varied to bring ions into a resonance condition in order of their mass/charge ratio.

Cylindrical ion trap
The cylindrical ion trap mass spectrometer (CIT) is a derivative of the quadrupole ion trap where the electrodes are formed from flat rings rather than hyperbolic shaped electrodes. The architecture lends itself well to miniaturization because as the size of a trap is reduced, the shape of the electric field near the center of the trap, the region where the ions are trapped, forms a shape similar to that of a hyperbolic trap.

Linear quadrupole ion trap
A linear quadrupole ion trap is similar to a quadrupole ion trap, but it traps ions in a two dimensional quadrupole field, instead of a three-dimensional quadrupole field as in a 3D quadrupole ion trap. Thermo Fisher's LTQ ("linear trap quadrupole") is an example of the linear ion trap.

A toroidal ion trap can be visualized as a linear quadrupole curved around and connected at the ends or as a cross-section of a 3D ion trap rotated on edge to form the toroid, donut-shaped trap. The trap can store large volumes of ions by distributing them throughout the ring-like trap structure. This toroidal shaped trap is a configuration that allows the increased miniaturization of an ion trap mass analyzer. Additionally, all ions are stored in the same trapping field and ejected together simplifying detection that can be complicated with array configurations due to variations in detector alignment and machining of the arrays.

As with the toroidal trap, linear traps and 3D quadrupole ion traps are the most commonly miniaturized mass analyzers due to their high sensitivity, tolerance for mTorr pressure, and capabilities for single analyzer tandem mass spectrometry (e.g. product ion scans).

Orbitrap

Orbitrap instruments are similar to Fourier-transform ion cyclotron resonance mass spectrometers (see text below). Ions are electrostatically trapped in an orbit around a central, spindle shaped electrode. The electrode confines the ions so that they both orbit around the central electrode and oscillate back and forth along the central electrode's long axis. This oscillation generates an image current in the detector plates which is recorded by the instrument. The frequencies of these image currents depend on the mass-to-charge ratios of the ions. Mass spectra are obtained by Fourier transformation of the recorded image currents.

Orbitraps have a high mass accuracy, high sensitivity and a good dynamic range.

Fourier-transform ion cyclotron resonance

Fourier-transform mass spectrometry (FTMS), or more precisely Fourier-transform ion cyclotron resonance MS, measures mass by detecting the image current produced by ions cyclotroning in the presence of a magnetic field. Instead of measuring the deflection of ions with a detector such as an electron multiplier, the ions are injected into a Penning trap (a static electric/magnetic ion trap) where they effectively form part of a circuit. Detectors at fixed positions in space measure the electrical signal of ions which pass near them over time, producing a periodic signal. Since the frequency of an ion's cycling is determined by its mass-to-charge ratio, this can be deconvoluted by performing a Fourier transform on the signal. FTMS has the advantage of high sensitivity (since each ion is "counted" more than once) and much higher resolution and thus precision.

Ion cyclotron resonance (ICR) is an older mass analysis technique similar to FTMS except that ions are detected with a traditional detector. Ions trapped in a Penning trap are excited by an RF electric field until they impact the wall of the trap, where the detector is located. Ions of different mass are resolved according to impact time.

Detectors

The final element of the mass spectrometer is the detector. The detector records either the charge induced or the current produced when an ion passes by or hits a surface. In a scanning instrument, the signal produced in the detector during the course of the scan versus where the instrument is in the scan (at what m/Q) will produce a mass spectrum, a record of ions as a function of m/Q.

Typically, some type of electron multiplier is used, though other detectors including Faraday cups and ion-to-photon detectors are also used. Because the number of ions leaving the mass analyzer at a particular instant is typically quite small, considerable amplification is often necessary to get a signal. Microchannel plate detectors are commonly used in modern commercial instruments. In FTMS and Orbitraps, the detector consists of a pair of metal surfaces within the mass analyzer/ion trap region which the ions only pass near as they oscillate. No direct current is produced, only a weak AC image current is produced in a circuit between the electrodes. Other inductive detectors have also been used.

Tandem mass spectrometry
A tandem mass spectrometer is one capable of multiple rounds of mass spectrometry, usually separated by some form of molecule fragmentation. For example, one mass analyzer can isolate one peptide from many entering a mass spectrometer. A collision cell then stabilizes the peptide ions while they collide with a gas, causing them to fragment by collision-induced dissociation (CID). A further mass analyzer then sorts the fragments produced from the peptides. Tandem MS can also be done in a single mass analyzer over time, as in a quadrupole ion trap. There are various methods for fragmenting molecules for tandem MS, including collision-induced dissociation (CID), electron capture dissociation (ECD), electron transfer dissociation (ETD), infrared multiphoton dissociation (IRMPD), blackbody infrared radiative dissociation (BIRD), electron-detachment dissociation (EDD) and surface-induced dissociation (SID). An important application using tandem mass spectrometry is in protein identification.

Tandem mass spectrometry enables a variety of experimental sequences. Many commercial mass spectrometers are designed to expedite the execution of such routine sequences as selected reaction monitoring (SRM), precursor ion scanning, product ion scanning, and neutral loss scanning.

 * In SRM, the first analyzer allows only a single mass through and the second analyzer monitors for multiple user-defined fragment ions over longer dwell-times than could be achieved in a full scan. This increases sensitivity.

 * In product ion scans, the first mass analyzer is fixed to select a particular precursor ion ("parent"), while the second is scanned to find all the fragments ("products", or "daughter ions") to which it can be fragmented in the collision cell.

 * In precursor ion scans, the second mass analyzer is fixed to select a particular fragment ion ("daughter"), while the first is scanned to find all possible precursor ions that could give rise to this fragment.

 * In neutral loss scans, the two mass analyzers are scanned in parallel, but separated by the mass of a molecular subunit of interest to the analyst. Ions are detected if they lose that fixed mass during fragmentation. This can be used to look for any chemical that is capable of losing a particular neutral group, for example a sugar residue. Together, neutral loss and precursor ion scans can be used to hunt for chemicals with particular motifs.

Another type of tandem mass spectrometry used for radiocarbon dating is accelerator mass spectrometry (AMS), which uses very high voltages, usually in the mega-volt range, to accelerate negative ions into a type of tandem mass spectrometer.

The METLIN Metabolite and Chemical Entity Database is the largest repository of experimental tandem mass spectrometry data acquired from standards. The tandem mass spectrometry data on over 930,000 molecular standards (as of January 2024) is provided to facilitate the identification of chemical entities from tandem mass spectrometry experiments. In addition to the identification of known molecules it is also useful for identifying unknowns using its similarity searching/analysis. All tandem mass spectrometry data comes from the experimental analysis of standards at multiple collision energies and in both positive and negative ionization modes.

Common mass spectrometer configurations and techniques
When a specific combination of source, analyzer, and detector becomes conventional in practice, a compound acronym may arise to designate it succinctly. One example is MALDI-TOF, which refers to a combination of a matrix-assisted laser desorption/ionization source with a time-of-flight mass analyzer. Other examples include inductively coupled plasma-mass spectrometry (ICP-MS), accelerator mass spectrometry (AMS), thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry (SSMS).

Certain applications of mass spectrometry have developed monikers that although strictly speaking would seem to refer to a broad application, in practice have come instead to connote a specific or a limited number of instrument configurations. An example of this is isotope-ratio mass spectrometry (IRMS), which refers in practice to the use of a limited number of sector based mass analyzers; this name is used to refer to both the application and the instrument used for the application.

Separation techniques combined with mass spectrometry
An important enhancement to the mass resolving and mass determining capabilities of mass spectrometry is using it in tandem with chromatographic and other separation techniques.

Gas chromatography

A common combination is gas chromatography-mass spectrometry (GC/MS or GC-MS). In this technique, a gas chromatograph is used to separate different compounds. This stream of separated compounds is fed online into the ion source, a metallic filament to which voltage is applied. This filament emits electrons which ionize the compounds. The ions can then further fragment, yielding predictable patterns. Intact ions and fragments pass into the mass spectrometer's analyzer and are eventually detected. However, the high temperatures (300°C) used in the GC-MS injection port (and oven) can result in thermal degradation of injected molecules, thus resulting in the measurement of degradation products instead of the actual molecule(s) of interest.

Liquid chromatography

Similarly to gas chromatography MS (GC-MS), liquid chromatography-mass spectrometry (LC/MS or LC-MS) separates compounds chromatographically before they are introduced to the ion source and mass spectrometer. It differs from GC-MS in that the mobile phase is liquid, usually a mixture of water and organic solvents, instead of gas. Most commonly, an electrospray ionization source is used in LC-MS. Other popular and commercially available LC-MS ion sources are atmospheric pressure chemical ionization and atmospheric pressure photoionization. There are also some newly developed ionization techniques like laser spray.

Capillary electrophoresis–mass spectrometry
Capillary electrophoresis–mass spectrometry (CE-MS) is a technique that combines the liquid separation process of capillary electrophoresis with mass spectrometry. CE-MS is typically coupled to electrospray ionization.

Ion mobility
Ion mobility spectrometry-mass spectrometry (IMS/MS or IMMS) is a technique where ions are first separated by drift time through some neutral gas under an applied electrical potential gradient before being introduced into a mass spectrometer. Drift time is a measure of the collisional cross section relative to the charge of the ion. The duty cycle of IMS (the time over which the experiment takes place) is longer than most mass spectrometric techniques, such that the mass spectrometer can sample along the course of the IMS separation. This produces data about the IMS separation and the mass-to-charge ratio of the ions in a manner similar to LC-MS.

The duty cycle of IMS is short relative to liquid chromatography or gas chromatography separations and can thus be coupled to such techniques, producing triple modalities such as LC/IMS/MS.

Data representations
Mass spectrometry produces various types of data. The most common data representation is the mass spectrum.

Certain types of mass spectrometry data are best represented as a mass chromatogram. Types of chromatograms include selected ion monitoring (SIM), total ion current (TIC), and selected reaction monitoring (SRM), among many others.

Other types of mass spectrometry data are well represented as a three-dimensional contour map. In this form, the mass-to-charge, m/z is on the x-axis, intensity the y-axis, and an additional experimental parameter, such as time, is recorded on the z-axis.

Data analysis
Mass spectrometry data analysis is specific to the type of experiment producing the data. General subdivisions of data are fundamental to understanding any data.

Many mass spectrometers work in either negative ion mode or positive ion mode. It is very important to know whether the observed ions are negatively or positively charged. This is often important in determining the neutral mass but it also indicates something about the nature of the molecules.

Different types of ion source result in different arrays of fragments produced from the original molecules. An electron ionization source produces many fragments and mostly single-charged (1-) radicals (odd number of electrons), whereas an electrospray source usually produces non-radical quasimolecular ions that are frequently multiply charged. Tandem mass spectrometry purposely produces fragment ions post-source and can drastically change the sort of data achieved by an experiment.

Knowledge of the origin of a sample can provide insight into the component molecules of the sample and their fragmentations. A sample from a synthesis/manufacturing process will probably contain impurities chemically related to the target component. A crudely prepared biological sample will probably contain a certain amount of salt, which may form adducts with the analyte molecules in certain analyses.

Results can also depend heavily on sample preparation and how it was run/introduced. An important example is the issue of which matrix is used for MALDI spotting, since much of the energetics of the desorption/ionization event is controlled by the matrix rather than the laser power. Sometimes samples are spiked with sodium or another ion-carrying species to produce adducts rather than a protonated species.

Mass spectrometry can measure molar mass, molecular structure, and sample purity. Each of these questions requires a different experimental procedure; therefore, adequate definition of the experimental goal is a prerequisite for collecting the proper data and successfully interpreting it.

Interpretation of mass spectra

Since the precise structure or peptide sequence of a molecule is deciphered through the set of fragment masses, the interpretation of mass spectra requires combined use of various techniques. Usually the first strategy for identifying an unknown compound is to compare its experimental mass spectrum against a library of mass spectra. If no matches result from the search, then manual interpretation or software assisted interpretation of mass spectra must be performed. Computer simulation of ionization and fragmentation processes occurring in mass spectrometer is the primary tool for assigning structure or peptide sequence to a molecule. An a priori structural information is fragmented in silico and the resulting pattern is compared with observed spectrum. Such simulation is often supported by a fragmentation library that contains published patterns of known decomposition reactions. Software taking advantage of this idea has been developed for both small molecules and proteins.

Analysis of mass spectra can also be spectra with accurate mass. A mass-to-charge ratio value (m/z) with only integer precision can represent an immense number of theoretically possible ion structures; however, more precise mass figures significantly reduce the number of candidate molecular formulas. A computer algorithm called formula generator calculates all molecular formulas that theoretically fit a given mass with specified tolerance.

A recent technique for structure elucidation in mass spectrometry, called precursor ion fingerprinting, identifies individual pieces of structural information by conducting a search of the tandem spectra of the molecule under investigation against a library of the product-ion spectra of structurally characterized precursor ions.

Applications

Mass spectrometry has both qualitative and quantitative uses. These include identifying unknown compounds, determining the isotopic composition of elements in a molecule, and determining the structure of a compound by observing its fragmentation. Other uses include quantifying the amount of a compound in a sample or studying the fundamentals of gas phase ion chemistry (the chemistry of ions and neutrals in a vacuum). MS is now commonly used in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds. Quantitation can be relative (analyzed relative to a reference sample) or absolute (analyzed using a standard curve method).

As an analytical technique it possesses distinct advantages such as: Increased sensitivity over most other analytical techniques because the analyzer, as a mass-charge filter, reduces background interference, Excellent specificity from characteristic fragmentation patterns to identify unknowns or confirm the presence of suspected compounds, Information about molecular weight, Information about the isotopic abundance of elements, Temporally resolved chemical data.

A few of the disadvantages of the method is that it often fails to distinguish between optical and geometrical isomers and the positions of substituent in o-, m- and p- positions in an aromatic ring. Also, its scope is limited in identifying hydrocarbons that produce similar fragmented ions.

Isotope ratio MS: isotope dating and tracing

Mass spectrometry is also used to determine the isotopic composition of elements within a sample. Differences in mass among isotopes of an element are very small, and the less abundant isotopes of an element are typically very rare, so a very sensitive instrument is required. These instruments, sometimes referred to as isotope ratio mass spectrometers (IR-MS), usually use a single magnet to bend a beam of ionized particles towards a series of Faraday cups which convert particle impacts to electric current. A fast on-line analysis of deuterium content of water can be done using flowing afterglow mass spectrometry, FA-MS. Probably the most sensitive and accurate mass spectrometer for this purpose is the accelerator mass spectrometer (AMS). This is because it provides ultimate sensitivity, capable of measuring individual atoms and measuring nuclides with a dynamic range of ~1015 relative to the major stable isotope. Isotope ratios are important markers of a variety of processes. Some isotope ratios are used to determine the age of materials for example as in carbon dating. Labeling with stable isotopes is also used for protein quantification. (see protein characterization below)

Membrane-introduction mass spectrometry: measuring gases in solution
Membrane-introduction mass spectrometry combines the isotope ratio MS with a reaction chamber/cell separated by a gas-permeable membrane. This method allows the study of gases as they evolve in solution. This method has been extensively used for the study of the production of oxygen by Photosystem II.

Trace gas analysis
Several techniques use ions created in a dedicated ion source injected into a flow tube or a drift tube: selected ion flow tube (SIFT-MS), and proton transfer reaction (PTR-MS), are variants of chemical ionization dedicated for trace gas analysis of air, breath or liquid headspace using well defined reaction time allowing calculations of analyte concentrations from the known reaction kinetics without the need for internal standard or calibration.

Another technique with applications in trace gas analysis field is secondary electrospray ionization (SESI-MS), which is a variant of electrospray ionization. SESI consist of an electrospray plume of pure acidified solvent that interacts with neutral vapors. Vapor molecules get ionized at atmospheric pressure when charge is transferred from the ions formed in the electrospray to the molecules. One advantage of this approach is that it is compatible with most ESI-MS systems.

Atom probe
An atom probe is an instrument that combines time-of-flight mass spectrometry and field-evaporation microscopy to map the location of individual atoms.

Pharmacokinetics
Pharmacokinetics is often studied using mass spectrometry because of the complex nature of the matrix (often blood or urine) and the need for high sensitivity to observe low dose and long time point data. The most common instrumentation used in this application is LC-MS with a triple quadrupole mass spectrometer. Tandem mass spectrometry is usually employed for added specificity. Standard curves and internal standards are used for quantitation of usually a single pharmaceutical in the samples. The samples represent different time points as a pharmaceutical is administered and then metabolized or cleared from the body. Blank or t=0 samples taken before administration are important in determining background and ensuring data integrity with such complex sample matrices. Much attention is paid to the linearity of the standard curve; however it is not uncommon to use curve fitting with more complex functions such as quadratics since the response of most mass spectrometers is less than linear across large concentration ranges.

There is currently considerable interest in the use of very high sensitivity mass spectrometry for microdosing studies, which are seen as a promising alternative to animal experimentation.

Recent studies show that secondary electrospray ionization (SESI) is a powerful technique to monitor drug kinetics via breath analysis. Because breath is naturally produced, several datapoints can be readily collected. This allows for the number of collected data-points to be greatly increased. In animal studies, this approach SESI can reduce animal sacrifice. In humans, SESI-MS non-invasive analysis of breath can help study the kinetics of drugs at a personalized level.

Protein characterization
Mass spectrometry is an important method for the characterization and sequencing of proteins. The two primary methods for ionization of whole proteins are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). In keeping with the performance and mass range of available mass spectrometers, two approaches are used for characterizing proteins. In the first, intact proteins are ionized by either of the two techniques described above, and then introduced to a mass analyzer. This approach is referred to as "top-down" strategy of protein analysis. The top-down approach however is largely limited to low-throughput single-protein studies. In the second, proteins are enzymatically digested into smaller peptides using proteases such as trypsin or pepsin, either in solution or in gel after electrophoretic separation. Other proteolytic agents are also used. The collection of peptide products are often separated by chromatography prior to introduction to the mass analyzer. When the characteristic pattern of peptides is used for the identification of the protein the method is called peptide mass fingerprinting (PMF), if the identification is performed using the sequence data determined in tandem MS analysis it is called de novo peptide sequencing. These procedures of protein analysis are also referred to as the "bottom-up" approach, and have also been used to analyse the distribution and position of post-translational modifications such as phosphorylation on proteins. A third approach is also beginning to be used, this intermediate "middle-down" approach involves analyzing proteolytic peptides that are larger than the typical tryptic peptide.

Space exploration

As a standard method for analysis, mass spectrometers have reached other planets and moons. Two were taken to Mars by the Viking program. In early 2005 the Cassini–Huygens mission delivered a specialized GC-MS instrument aboard the Huygens probe through the atmosphere of Titan, the largest moon of the planet Saturn. This instrument analyzed atmospheric samples along its descent trajectory and was able to vaporize and analyze samples of Titan's frozen, hydrocarbon covered surface once the probe had landed. These measurements compare the abundance of isotope(s) of each particle comparatively to earth's natural abundance. Also on board the Cassini–Huygens spacecraft was an ion and neutral mass spectrometer which had been taking measurements of Titan's atmospheric composition as well as the composition of Enceladus' plumes. A Thermal and Evolved Gas Analyzer mass spectrometer was carried by the Mars Phoenix Lander launched in 2007.

Mass spectrometers are also widely used in space missions to measure the composition of plasmas. For example, the Cassini spacecraft carried the Cassini Plasma Spectrometer (CAPS), which measured the mass of ions in Saturn's magnetosphere.

Respired gas monitor
Mass spectrometers were used in hospitals for respiratory gas analysis beginning around 1975 through the end of the century. Some are probably still in use but none are currently being manufactured.

Found mostly in the operating room, they were a part of a complex system, in which respired gas samples from patients undergoing anesthesia were drawn into the instrument through a valve mechanism designed to sequentially connect up to 32 rooms to the mass spectrometer. A computer directed all operations of the system. The data collected from the mass spectrometer was delivered to the individual rooms for the anesthesiologist to use.

The uniqueness of this magnetic sector mass spectrometer may have been the fact that a plane of detectors, each purposely positioned to collect all of the ion species expected to be in the samples, allowed the instrument to simultaneously report all of the gases respired by the patient. Although the mass range was limited to slightly over 120 u, fragmentation of some of the heavier molecules negated the need for a higher detection limit.

Preparative mass spectrometry
The primary function of mass spectrometry is as a tool for chemical analyses based on detection and quantification of ions according to their mass-to-charge ratio. However, mass spectrometry also shows promise for material synthesis. Ion soft landing is characterized by deposition of intact species on surfaces at low kinetic energies which precludes the fragmentation of the incident species. The soft landing technique was first reported in 1977 for the reaction of low energy sulfur containing ions on a lead surface.

title: Mass spectrometry


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Lionel (given name)

Lionel is a given name which may refer to one of the following persons:

People

 * All male, unless otherwise noted.

 * Lionel (radio personality) (born 1958), an American radio talk show host
 * Lionel of Antwerp, 1st Duke of Clarence (1338–1368), son of King Edward III of England
 * Lionel Aingimea (born 1965), President of Nauru (2019–2022)
 * Lionel Algama (1935–2008), Sri Lankan Sinhala musician and composer
 * Lionel Antoine (1950–2021), American football player
 * Lionel Balagalle, general, Commander of the Sri Lanka Army from 2000 to 2004
 * Lionel Barber (born 1955), English journalist
 * Lionel Barrymore (1878–1954), American actor
 * Lionel Bart (1930–1999), British composer
 * Lionel Bender (1934–2008), American author and linguist
 * Lionel Blair (1928–2021), British dancer and actor
 * Lionel Bordeaux (1940–2022), Native American educator
 * Lionel Bowen (1922–2012), Australian politician
 * Lionel Bussey (1883–1969), British engineer and collector of women's shoes
 * Lionel Cohen (disambiguation), various people
 * Lionel Cox (disambiguation), various people
 * Lionel Herbert Clarke (1859–1921), Canadian businessman and Lieutenant Governor of Ontario
 * Lionel Cranfield (disambiguation), various people
 * Lionel Cust (1859–1929), British art historian, courtier and museum director
 * Lionel Dyck (born 1944), Rhodesian-born mercenary
 * Lionel Fleury (1912–1997), Canadian ice hockey administrator
 * Lionel Herbert Dahmer father of Jeffrey Dahmer
 * Lionel Henry Daiches (1911–1999), Scottish Queen's Counsel
 * Lionel Deraniyagala (1940–1994), Sri Lankan Sinhala cinema and theater actor
 * Lionel Dubray (1923–1944), member of French Resistance during World War II
 * Lionel Dunsterville (1865–1946), British general
 * Lionel Edirisinghe (1913–1988), Sri Lankan Sinhala musicologist
 * Lionel Grigson (1942–1994), British jazz musician and educator
 * Lionel Victor Gunaratna (1893–1971), Sri Lankan Sinhala army officer, educationist, municipal councilor
 * Lionel Hampton (1908–2002), American jazz musician, bandleader and actor
 * Lionel James (1962–2022), American football player
 * Lionel Jeffries (1926–2010), English actor, screenwriter and director
 * Lionel Johnson (1867–1902), English poet
 * Lionel Jospin (born 1937), French politician and Prime Minister of France (1997–2002)
 * Lionel Letizi (born 1973), French footballer
 * Lionel Logue (1880–1953), Australian speech therapist and friend of King George VI
 * Lionel Manuel (born 1962), American football player
 * Lionel Mapoe (born 1988), South African rugby union footballer
 * Lionel Messi (born 1987), Argentine footballer
 * Lionel Morgan (footballer) (born 1983), English footballer
 * Lionel Morgan (rugby league) (1938–2023), Australian rugby league footballer
 * Lionel de Moustier (1817–1869), French diplomat and politician
 * Lionel Newman (1916–1989), American film & television composer who worked for 20th Century Fox
 * Lionel de Nicéville (1852–1901), English entomologist and curator
 * Lionel Nshole Makondi (born 1995), Belgian footballer
 * Lionel Penrose (1898–1972), British psychiatrist, medical geneticist, mathematician and chess theorist
 * Lionel Power (c. 1370–1385–1445), English composer
 * Lionel Price (1927–2019), British basketball player
 * Lionel Ranwala (1939–2002), Sri Lankan folk musician
 * Lionel Richie (born 1949), American singer, songwriter, musician, record producer and actor
 * Lionel Rivera (born 1956), American politician
 * Lionel Robbins, Baron Robbins (1898–1984), British economist and academic
 * Lionel Rose (1948–2011), Australian boxer
 * Lionel Rothschild (disambiguation), various people
 * Lionel Royce (1891–1946), Austrian-American actor
 * Lionel Royer-Perreaut (born 1972), French politician
 * Lionel Sackville-West, 2nd Baron Sackville (1827–1908), British diplomat
 * Lionel Scaloni (born 1978), Argentine football manager and former player
 * Lionel Allen Sheldon (1828–1917), American politician and Governor of New Mexico Territory
 * Lionel Shriver (born 1957), female American author
 * Lionel Simmons (born 1968), American basketball player
 * Lionel Stander (1908–1994), American actor
 * Lionel Taylor (born 1935), American football player
 * Lionel Taylor (footballer) (born 1984), Samoan footballer
 * Lionel Tennyson, 3rd Baron Tennyson (1889–1951), English cricketer
 * Lionel Tiger (born 1937), British anthropologist
 * Lionel Tollemache (disambiguation), various earls and baronets
 * Lionel Trilling (1905–1975), American literary critic
 * Lionel Wendt (1900–1944), Sri Lankan pianist, photographer, literature collector, critic, and cinematographer
 * Lionel Woodville (1446/1447–1484), Bishop of Salisbury
 * Lionel Woodville (1446/1447–1484), Bishop of Salisbury

Fictional characters

 * Lion El'Jonson, a character in the Warhammer 40,000 universe, inspired by Lionel Johnson
 * Lionel Hutz, a recurring character in the television series The Simpsons
 * Lionel Lockridge, a character in the American soap opera Santa Barbara
 * Lionel Shrike, a character in the Now You See Me film series
 * Lionel Skeggins, a character in the New Zealand soap opera Shortland Street
 * Lionel Verney, the narrator in Mary Shelley's novel The Last Man
 * Sir Lionel, a knight of the Round Table in Arthurian legend
 * Lionel Jefferson, a character in the American sitcom The Jeffersons
 * Lionel, a Lion villager from the video game series Animal Crossing
 * Lionel Mane, a main character on the children's television show Between the Lions

title: Lionel (given name)