Gas chromatography–mass spectrometry

From Wikipedia, the free encyclopedia

Example of a GC-MS instrument

 

Gas chromatography–mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation, and identification of unknown samples, including that of material samples obtained from planet Mars during probe missions as early as the 1970s. GC-MS can also be used in airport security to detect substances in luggage or on human beings. Additionally, it can identify trace elements in materials that were previously thought to have disintegrated beyond identification. Like liquid chromatography–mass spectrometry, it allows analysis and detection even of tiny amounts of a substance.

GC-MS has been regarded as a "gold standard" for forensic substance identification because it is used to perform a 100% specific test, which positively identifies the presence of a particular substance. A nonspecific test merely indicates that any of several in a category of substances is present. Although a nonspecific test could statistically suggest the identity of the substance, this could lead to false positive identification.

History

The first on-line coupling of gas chromatography to a mass spectrometer was reported in 1959. The development of affordable and miniaturized computers has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1964, Electronic Associates, Inc. (EAI), a leading U.S. supplier of analog computers, began development of a computer controlled quadrupole mass spectrometer under the direction of Robert E. Finnigan. By 1966 Finnigan and collaborator Mike Uthe's EAI division had sold over 500 quadrupole residual gas-analyzer instruments. In 1967, Finnigan left EAI to form the Finnigan Instrument Corporation along with Roger Sant, T. Z. Chou, Michael Story, and William Fies. In early 1968, they delivered the first prototype quadrupole GC/MS instruments to Stanford and Purdue University. When Finnigan Instrument Corporation was acquired by Thermo Instrument Systems (later Thermo Fisher Scientific) in 1990, it was considered "the world's leading manufacturer of mass spectrometers".

Instrumentation

The insides of the GC-MS, with the column of the gas chromatograph in the oven on the right.

 

The GC-MS is composed of two major building blocks: the gas chromatograph and the mass spectrometer. The gas chromatograph utilizes a capillary column which depends on the column's dimensions (length, diameter, film thickness) as well as the phase properties (e.g. 5% phenyl polysiloxane). The difference in the chemical properties between different molecules in a mixture and their relative affinity for the stationary phase of the column will promote separation of the molecules as the sample travels the length of the column. The molecules are retained by the column and then elute (come off) from the column at different times (called the retention time), and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately. The mass spectrometer does this by breaking each molecule into ionized fragments and detecting these fragments using their mass-to-charge ratio.

GC-MS schematic

 

These two components, used together, allow a much finer degree of substance identification than either unit used separately. It is not possible to make an accurate identification of a particular molecule by gas chromatography or mass spectrometry alone. The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. Flame ionization detector) cannot differentiate between multiple molecules that happen to take the same amount of time to travel through the column (i.e. have the same retention time), which results in two or more molecules that co-elute. Sometimes two different molecules can also have a similar pattern of ionized fragments in a mass spectrometer (mass spectrum). Combining the two processes reduces the possibility of error, as it is extremely unlikely that two different molecules will behave in the same way in both a gas chromatograph and a mass spectrometer. Therefore, when an identifying mass spectrum appears at a characteristic retention time in a GC-MS analysis, it typically increases certainty that the analyte of interest is in the sample.

Purge and trap GC-MS

For the analysis of volatile compounds, a purge and trap (P&T) concentrator system may be used to introduce samples. The target analytes are extracted by mixing the sample with water and purge with inert gas (e.g. Nitrogen gas) into an airtight chamber, this is known as purging or sparging. The volatile compounds move into the headspace above the water and are drawn along a pressure gradient (caused by the introduction of the purge gas) out of the chamber. The volatile compounds are drawn along a heated line onto a 'trap'. The trap is a column of adsorbent material at ambient temperature that holds the compounds by returning them to the liquid phase. The trap is then heated and the sample compounds are introduced to the GC-MS column via a volatiles interface, which is a split inlet system. P&T GC-MS is particularly suited to volatile organic compounds (VOCs) and BTEX compounds (aromatic compounds associated with petroleum).

A faster alternative is the "purge-closed loop" system. In this system the inert gas is bubbled through the water until the concentrations of organic compounds in the vapor phase are at equilibrium with concentrations in the aqueous phase. The gas phase is then analysed directly.

Types of mass spectrometer detectors

The most common type of mass spectrometer (MS) associated with a gas chromatograph (GC) is the quadrupole mass spectrometer, sometimes referred to by the Hewlett-Packard (now Agilent) trade name "Mass Selective Detector" (MSD). Another relatively common detector is the ion trap mass spectrometer. Additionally one may find a magnetic sector mass spectrometer, however these particular instruments are expensive and bulky and not typically found in high-throughput service laboratories. Other detectors may be encountered such as time of flight (TOF), tandem quadrupoles (MS-MS) (see below), or in the case of an ion trap MSⁿ where n indicates the number mass spectrometry stages.

GC-tandem MS

When a second phase of mass fragmentation is added, for example using a second quadrupole in a quadrupole instrument, it is called tandem MS (MS/MS). MS/MS can sometimes be used to quantitate low levels of target compounds in the presence of a high sample matrix background.

The first quadrupole (Q1) is connected with a collision cell (Q2) and another quadrupole (Q3). Both quadrupoles can be used in scanning or static mode, depending on the type of MS/MS analysis being performed. Types of analysis include product ion scan, precursor ion scan, selected reaction monitoring (SRM) (sometimes referred to as multiple reaction monitoring (MRM)) and neutral loss scan. For example: When Q1 is in static mode (looking at one mass only as in SIM), and Q3 is in scanning mode, one obtains a so-called product ion spectrum (also called "daughter spectrum"). From this spectrum, one can select a prominent product ion which can be the product ion for the chosen precursor ion. The pair is called a "transition" and forms the basis for SRM. SRM is highly specific and virtually eliminates matrix background.

Ionization

After the molecules travel the length of the column, pass through the transfer line and enter into the mass spectrometer they are ionized by various methods with typically only one method being used at any given time. Once the sample is fragmented it will then be detected, usually by an electron multiplier, which essentially turns the ionized mass fragment into an electrical signal that is then detected. 

The ionization technique chosen is independent of using full scan or SIM. 

Block diagram for gas chromatography using electron ionization for collecting mass spectrum.

Electron ionization

By far the most common and perhaps standard form of ionization is electron ionization (EI). The molecules enter into the MS (the source is a quadrupole or the ion trap itself in an ion trap MS) where they are bombarded with free electrons emitted from a filament, not unlike the filament one would find in a standard light bulb. The electrons bombard the molecules, causing the molecule to fragment in a characteristic and reproducible way. This "hard ionization" technique results in the creation of more fragments of low mass-to-charge ratio (m/z) and few, if any, molecules approaching the molecular mass unit. Hard ionization is considered by mass spectrometrists as the employ of molecular electron bombardment, whereas "soft ionization" is charge by molecular collision with an introduced gas. The molecular fragmentation pattern is dependent upon the electron energy applied to the system, typically 70 eV (electron Volts). The use of 70 eV facilitates comparison of generated spectra with library spectra using manufacturer-supplied software or software developed by the National Institute of Standards (NIST-USA). Spectral library searches employ matching algorithms such as Probability Based Matching and dot-product matching that are used with methods of analysis written by many method standardization agencies. Sources of libraries include NIST, Wiley, the AAFS, and instrument manufacturers.

Cold electron ionization

The "hard ionization" process of electron ionization can be softened by the cooling of the molecules before their ionization, resulting in mass spectra that are richer in information. In this method named cold electron ionization (cold-EI) the molecules exit the GC column, mixed with added helium make up gas and expand into vacuum through a specially designed supersonic nozzle, forming a supersonic molecular beam (SMB). Collisions with the make up gas at the expanding supersonic jet reduce the internal vibrational (and rotational) energy of the analyte molecules, hence reducing the degree of fragmentation caused by the electrons during the ionization process. Cold-EI mass spectra are characterized by an abundant molecular ion while the usual fragmentation pattern is retained, thus making cold-EI mass spectra compatible with library search identification techniques. The enhanced molecular ions increase the identification probabilities of both known and unknown compounds, amplify isomer mass spectral effects and enable the use of isotope abundance analysis for the elucidation of elemental formulae.

Chemical ionization

In chemical ionization a reagent gas, typically methane or ammonia is introduced into the mass spectrometer. Depending on the technique (positive CI or negative CI) chosen, this reagent gas will interact with the electrons and analyte and cause a 'soft' ionization of the molecule of interest. A softer ionization fragments the molecule to a lower degree than the hard ionization of EI. One of the main benefits of using chemical ionization is that a mass fragment closely corresponding to the molecular weight of the analyte of interest is produced. 

In positive chemical ionization (PCI) the reagent gas interacts with the target molecule, most often with a proton exchange. This produces the species in relatively high amounts.

In negative chemical ionization (NCI) the reagent gas decreases the impact of the free electrons on the target analyte. This decreased energy typically leaves the fragment in great supply.

Analysis

A mass spectrometer is typically utilized in one of two ways: full scan or selective ion monitoring (SIM). The typical GC-MS instrument is capable of performing both functions either individually or concomitantly, depending on the setup of the particular instrument. 

The primary goal of instrument analysis is to quantify an amount of substance. This is done by comparing the relative concentrations among the atomic masses in the generated spectrum. Two kinds of analysis are possible, comparative and original. Comparative analysis essentially compares the given spectrum to a spectrum library to see if its characteristics are present for some sample in the library. This is best performed by a computer because there are a myriad of visual distortions that can take place due to variations in scale. Computers can also simultaneously correlate more data (such as the retention times identified by GC), to more accurately relate certain data. Deep learning was shown to lead to promising results in the identification of VOCs from raw GC-MS data.

 

Another method of analysis measures the peaks in relation to one another. In this method, the tallest peak is assigned 100% of the value, and the other peaks being assigned proportionate values. All values above 3% are assigned. The total mass of the unknown compound is normally indicated by the parent peak. The value of this parent peak can be used to fit with a chemical formula containing the various elements which are believed to be in the compound. The isotope pattern in the spectrum, which is unique for elements that have many natural isotopes, can also be used to identify the various elements present. Once a chemical formula has been matched to the spectrum, the molecular structure and bonding can be identified, and must be consistent with the characteristics recorded by GC-MS. Typically, this identification is done automatically by programs which come with the instrument, given a list of the elements which could be present in the sample.

A “full spectrum” analysis considers all the “peaks” within a spectrum. Conversely, selective ion monitoring (SIM) only monitors selected ions associated with a specific substance. This is done on the assumption that at a given retention time, a set of ions is characteristic of a certain compound. This is a fast and efficient analysis, especially if the analyst has previous information about a sample or is only looking for a few specific substances. When the amount of information collected about the ions in a given gas chromatographic peak decreases, the sensitivity of the analysis increases. So, SIM analysis allows for a smaller quantity of a compound to be detected and measured, but the degree of certainty about the identity of that compound is reduced.

Full scan MS

When collecting data in the full scan mode, a target range of mass fragments is determined and put into the instrument's method. An example of a typical broad range of mass fragments to monitor would be m/z 50 to m/z 400. The determination of what range to use is largely dictated by what one anticipates being in the sample while being cognizant of the solvent and other possible interferences. A MS should not be set to look for mass fragments too low or else one may detect air (found as m/z 28 due to nitrogen), carbon dioxide (m/z 44) or other possible interference. Additionally if one is to use a large scan range then sensitivity of the instrument is decreased due to performing fewer scans per second since each scan will have to detect a wide range of mass fragments.

Full scan is useful in determining unknown compounds in a sample. It provides more information than SIM when it comes to confirming or resolving compounds in a sample. During instrument method development it may be common to first analyze test solutions in full scan mode to determine the retention time and the mass fragment fingerprint before moving to a SIM instrument method.

Selective ion monitoring

In selective ion monitoring (SIM) certain ion fragments are entered into the instrument method and only those mass fragments are detected by the mass spectrometer. The advantages of SIM are that the detection limit is lower since the instrument is only looking at a small number of fragments (e.g. three fragments) during each scan. More scans can take place each second. Since only a few mass fragments of interest are being monitored, matrix interferences are typically lower. To additionally confirm the likelihood of a potentially positive result, it is relatively important to be sure that the ion ratios of the various mass fragments are comparable to a known reference standard.

Applications

Environmental monitoring and cleanup

GC-MS is becoming the tool of choice for tracking organic pollutants in the environment. The cost of GC-MS equipment has decreased significantly, and the reliability has increased at the same time, which has contributed to its increased adoption in environmental studies.

Criminal forensics

GC-MS can analyze the particles from a human body in order to help link a criminal to a crime. The analysis of fire debris using GC-MS is well established, and there is even an established American Society for Testing and Materials (ASTM) standard for fire debris analysis. GCMS/MS is especially useful here as samples often contain very complex matrices and results, used in court, need to be highly accurate.

Law enforcement

GC-MS is increasingly used for detection of illegal narcotics, and may eventually supplant drug-sniffing dogs.^[1] A simple and selective GC-MS method for detecting marijuana usage was recently developed by the Robert Koch-Institute in Germany. It involves identifying an acid metabolite of tetrahyhydrocannabinol (THC), the active ingredient in marijuana, in urine samples by employing derivatization in the sample preparation. GC-MS is also commonly used in forensic toxicology to find drugs and/or poisons in biological specimens of suspects, victims, or the deceased. In drug screening, GC-MS methods frequently utilize liquid-liquid extraction as a part of sample preparation, in which target compounds are extracted from blood plasma.

Sports anti-doping analysis

GC-MS is the main tool used in sports anti-doping laboratories to test athletes' urine samples for prohibited performance-enhancing drugs, for example anabolic steroids.

Security

A post–September 11 development, explosive detection systems have become a part of all US airports. These systems run on a host of technologies, many of them based on GC-MS. There are only three manufacturers certified by the FAA to provide these systems, one of which is Thermo Detection (formerly Thermedics), which produces the EGIS, a GC-MS-based line of explosives detectors. The other two manufacturers are Barringer Technologies, now owned by Smith 's Detection Systems, and Ion Track Instruments, part of General Electric Infrastructure Security Systems.

Chemical warfare agent detection

As part of the post-September 11 drive towards increased capability in homeland security and public health preparedness, traditional GC-MS units with transmission quadrupole mass spectrometers, as well as those with cylindrical ion trap (CIT-MS) and toroidal ion trap (T-ITMS) mass spectrometers have been modified for field portability and near real-time detection of chemical warfare agents (CWA) such as sarin, soman, and VX. These complex and large GC-MS systems have been modified and configured with resistively heated low thermal mass (LTM) gas chromatographs that reduce analysis time to less than ten percent of the time required in traditional laboratory systems. Additionally, the systems are smaller, and more mobile, including units that are mounted in mobile analytical laboratories (MAL), such as those used by the United States Marine Corps Chemical and Biological Incident Response Force MAL and other similar laboratories, and systems that are hand-carried by two-person teams or individuals, much ado to the smaller mass detectors. Depending on the system, the analytes can be introduced via liquid injection, desorbed from sorbent tubes through a thermal desorption process, or with solid-phase micro extraction (SPME).

Chemical engineering

GC-MS is used for the analysis of unknown organic compound mixtures. One critical use of this technology is the use of GC-MS to determine the composition of bio-oils processed from raw biomass.

Food, beverage and perfume analysis

Foods and beverages contain numerous aromatic compounds, some naturally present in the raw materials and some forming during processing. GC-MS is extensively used for the analysis of these compounds which include esters, fatty acids, alcohols, aldehydes, terpenes etc. It is also used to detect and measure contaminants from spoilage or adulteration which may be harmful and which is often controlled by governmental agencies, for example pesticides.

Astrochemistry

Several GC-MS have left earth. Two were brought to Mars by the Viking program. Venera 11 and 12 and Pioneer Venus analysed the atmosphere of Venus with GC-MS. The Huygens probe of the Cassini–Huygens mission landed one GC-MS on Saturn's largest moon, Titan. The material in the comet 67P/Churyumov–Gerasimenko will be analysed by the Rosetta mission with a chiral GC-MS in 2014.

Medicine

Dozens of congenital metabolic diseases also known as inborn errors of metabolism (IEM) are now detectable by newborn screening tests, especially the testing using gas chromatography–mass spectrometry. GC-MS can determine compounds in urine even in minor concentration. These compounds are normally not present but appear in individuals suffering with metabolic disorders. This is increasingly becoming a common way to diagnose IEM for earlier diagnosis and institution of treatment eventually leading to a better outcome. It is now possible to test a newborn for over 100 genetic metabolic disorders by a urine test at birth based on GC-MS. 

In combination with isotopic labeling of metabolic compounds, the GC-MS is used for determining metabolic activity. Most applications are based on the use of ¹³C as the labeling and the measurement of ¹³C-¹²C ratios with an isotope ratio mass spectrometer (IRMS); an MS with a detector designed to measure a few select ions and return values as ratios.

Absinthe

From Wikipedia, the free encyclopedia

Absinthe

Reservoir glass with naturally coloured verte absinthe and an absinthe spoon
Type	Spirit
Country of origin	Switzerland
Alcohol by volume	45–74%
Proof (US)	90–148
Colour	Green
Flavour	Anise
Ingredients	Wormwood Anise Fennel

Albert Maignan's Green Muse (1895): a poet succumbs to the Green Fairy

 

An absinthe frappé, a common way to serve absinthe with simple syrup, water, and crushed ice

 

Absinthe is historically described as a distilled, highly alcoholic beverage (45–74% ABV / 90–148 U.S. proof). It is an anise-flavoured spirit derived from botanicals, including the flowers and leaves of Artemisia absinthium ("grand wormwood"), together with green anise, sweet fennel, and other medicinal and culinary herbs.

Absinthe traditionally has a natural green colour, but may also be colourless. It is commonly referred to in historical literature as "la fée verte" (the green fairy). It is sometimes mistakenly referred to as a liqueur, but it is not traditionally bottled with added sugar and is, therefore, classified as a spirit. Absinthe is traditionally bottled at a high level of alcohol by volume, but it is normally diluted with water prior to being consumed. 

Absinthe originated in the canton of Neuchâtel in Switzerland in the late 18th century. It rose to great popularity as an alcoholic drink in late 19th- and early 20th-century France, particularly among Parisian artists and writers. The consumption of absinthe was opposed by social conservatives and prohibitionists, partly due to its association with bohemian culture. Absinthe drinkers included Ernest Hemingway, James Joyce, Charles Baudelaire, Paul Verlaine, Arthur Rimbaud, Henri de Toulouse-Lautrec, Amedeo Modigliani, Pablo Picasso, Vincent van Gogh, Oscar Wilde, Marcel Proust, Aleister Crowley, Erik Satie, Edgar Allan Poe, Lord Byron and Alfred Jarry. 

Absinthe has often been portrayed as a dangerously addictive psychoactive drug and hallucinogen. The chemical compound thujone, which is present in the spirit in trace amounts, was blamed for its alleged harmful effects. By 1915, absinthe had been banned in the United States and in much of Europe, including France, the Netherlands, Belgium, Switzerland, and Austria-Hungary, yet it has not been demonstrated to be any more dangerous than ordinary spirits. Recent studies have shown that absinthe's psychoactive properties have been exaggerated, apart from that of the alcohol.

A revival of absinthe began in the 1990s following the adoption of modern European Union food and beverage laws which removed long-standing barriers to its production and sale. By the early 21st century, nearly 200 brands of absinthe were being produced in a dozen countries, most notably in France, Switzerland, Austria, Germany, Netherlands, Spain, and the Czech Republic.

Etymology

The French word absinthe can refer either to the alcoholic beverage or, less commonly, to the actual wormwood plant, with grande absinthe being Artemisia absinthium, and petite absinthe being Artemisia pontica. The Latin name artemisia comes from the Greek ἀρτεμισία "wormwood" and the latter from Artemis, the ancient Greek goddess of the hunt. Absinthe is derived from the Latin absinthium, which in turn comes from the Greek ἀψίνθιον apsínthion, "wormwood". The use of Artemisia absinthium in a drink is attested in Lucretius' De Rerum Natura (I 936–950), where Lucretius indicates that a drink containing wormwood is given as medicine to children in a cup with honey on the brim to make it drinkable. Some claim that the word means "undrinkable" in Greek, but it may instead be linked to the Persian root spand or aspand, or the variant esfand, which meant Peganum harmala, also called Syrian Rue—although it is not actually a variety of rue, another famously bitter herb. That Artemisia absinthium was commonly burned as a protective offering may suggest that its origins lie in the reconstructed Proto-Indo-European root *spend, meaning "to perform a ritual" or "make an offering". Whether the word was a borrowing from Persian into Greek, or from a common ancestor of both, is unclear. Alternatively, the Greek word may originate in a pre-Greek substrate word, marked by the non-Indo-European consonant complex νθ (-nth). Alternative spellings for absinthe include absinth, absynthe and absenta. Absinth (without the final e) is a spelling variant most commonly applied to absinthes produced in central and eastern Europe, and is specifically associated with Bohemian-style absinthes.

History

Henri Privat-Livemont's 1896 poster

 

The precise origin of absinthe is unclear. The medical use of wormwood dates back to ancient Egypt and is mentioned in the Ebers Papyrus, c. 1550 BC. Wormwood extracts and wine-soaked wormwood leaves were used as remedies by the ancient Greeks. Moreover, there is evidence of a wormwood-flavoured wine in ancient Greece called absinthites oinos.

The first evidence of absinthe dates to the 18th century in the sense of a distilled spirit containing green anise and fennel. According to popular legend, it began as an all-purpose patent remedy created by Dr. Pierre Ordinaire, a French doctor living in Couvet, Switzerland around 1792 (the exact date varies by account). Ordinaire's recipe was passed on to the Henriod sisters of Couvet, who sold it as a medicinal elixir. By other accounts, the Henriod sisters may have been making the elixir before Ordinaire's arrival. In either case, a certain Major Dubied acquired the formula from the sisters in 1797 and opened the first absinthe distillery named Dubied Père et Fils in Couvet with his son Marcellin and son-in-law Henry-Louis Pernod. In 1805, they built a second distillery in Pontarlier, France under the company name Maison Pernod Fils. Pernod Fils remained one of the most popular brands of absinthe until the drink was banned in France in 1914.

Growth of consumption

An advertising poster for Absinthe Beucler

 

Absinthe's popularity grew steadily through the 1840s, when it was given to French troops as a malaria preventive, and the troops brought home their taste for it. Absinthe became so popular in bars, bistros, cafés, and cabarets by the 1860s that the hour of 5 p.m. was called l'heure verte ("the green hour"). It was favoured by all social classes, from the wealthy bourgeoisie to poor artists and ordinary working-class people. By the 1880s, mass production had caused the price to drop sharply, and the French were drinking 36 million litres per year by 1910, compared to their annual consumption of almost 5 billion litres of wine.

Absinthe was exported widely from France and Switzerland and attained some degree of popularity in other countries, including Spain, Great Britain, USA, and the Czech Republic. It was never banned in Spain or Portugal, and its production and consumption have never ceased. It gained a temporary spike in popularity there during the early 20th century, corresponding with the Art Nouveau and Modernism aesthetic movements.

New Orleans has a cultural association with absinthe and is credited as the birthplace of the Sazerac, perhaps the earliest absinthe cocktail. The Old Absinthe House bar on Bourbon Street sold absinthe since the first half of the 19th century. Its Catalan lease-holder Cayetano Ferrer named it the Absinthe Room in 1874 because of the popularity of the drink, which was served in the Parisian style. It was frequented by Mark Twain, Oscar Wilde, Franklin Delano Roosevelt, Aleister Crowley, and Frank Sinatra.

Bans

Absinthe became associated with violent crimes and social disorder, and one modern writer claims that this trend was spurred by fabricated claims and smear campaigns, which he claims were orchestrated by the temperance movement and the wine industry. One critic claimed:

Absinthe makes you crazy and criminal, provokes epilepsy and tuberculosis, and has killed thousands of French people. It makes a ferocious beast of man, a martyr of woman, and a degenerate of the infant, it disorganizes and ruins the family and menaces the future of the country.

L'Absinthe, by Edgar Degas, 1876

 

Edgar Degas's 1876 painting L'Absinthe can be seen at the Musée d'Orsay epitomising the popular view of absinthe addicts as sodden and benumbed, and Émile Zola described its effects in his novel L'Assommoir. Swiss farmer Jean Lanfray murdered his family in 1905 and attempted to take his own life after drinking absinthe. Lanfray was an alcoholic who had consumed considerable quantities of wine and brandy prior to drinking two glasses of absinthe, but that was overlooked or ignored, placing the blame for the murders solely on absinthe. The Lanfray murders were the tipping point in this hotly debated topic, and a subsequent petition collected more than 82,000 signatures to ban it in Switzerland. A referendum was held on 5 July 1908. It was approved by voters, and the prohibition of absinthe was written into the Swiss constitution. 

In 1906, Belgium and Brazil banned the sale and distribution of absinthe, although these were not the first countries to take such action. It had been banned as early as 1898 in the colony of the Congo Free State. The Netherlands banned it in 1909, Switzerland in 1910, the United States in 1912, and France in 1914.

The prohibition of absinthe in France would eventually lead to the popularity of pastis, and to a lesser extent, ouzo, and other anise-flavoured spirits that do not contain wormwood. Following the conclusion of the First World War, production of the Pernod Fils brand was resumed at the Banus distillery in Catalonia, Spain (where absinthe was still legal), but gradually declining sales saw the cessation of production in the 1960s. In Switzerland, the ban served only to drive the production of absinthe underground. Clandestine home distillers produced colourless absinthe (la Bleue), which was easier to conceal from the authorities. Many countries never banned absinthe, notably Britain, where it had never been as popular as in continental Europe.

Modern revival

British importer BBH Spirits began to import Hill's Absinth from the Czech Republic in the 1990s, as the UK had never formally banned it, and this sparked a modern resurgence in its popularity. It began to reappear during a revival in the 1990s in countries where it was never banned. Forms of absinthe available during that time consisted almost exclusively of Czech, Spanish, and Portuguese brands that were of recent origin, typically consisting of Bohemian-style products. Connoisseurs considered these of inferior quality and not representative of the 19th century spirit. In 2000, La Fée Absinthe became the first commercial absinthe distilled and bottled in France since the 1914 ban, but it is now one of dozens of brands that are produced and sold within France. 

Modern absinthes. Vertes at left; blanches at right. A prepared glass is in front of each.

 

In the Netherlands, the restrictions were challenged by Amsterdam wineseller Menno Boorsma in July 2004, thus confirming the legality of absinthe once again. Similarly, Belgium lifted its long-standing ban on January 1, 2005, citing a conflict with the adopted food and beverage regulations of the Single European Market. In Switzerland, the constitutional ban was repealed in 2000 during an overhaul of the national constitution, although the prohibition was written into ordinary law instead. That law was later repealed and it was made legal on March 1, 2005. 

The drink was never officially banned in Spain, although it began to fall out of favour in the 1940s and almost vanished into obscurity. The Catalan region has seen significant resurgence since 2007 when one producer established operations there. Absinthe has never been illegal to import or manufacture in Australia, although importation requires a permit under the Customs (Prohibited Imports) Regulation 1956 due to a restriction on importing any product containing "oil of wormwood". In 2000, an amendment made all wormwood species prohibited herbs for food purposes under Food Standard 1.4.4. Prohibited and Restricted Plants and Fungi. However, this amendment was found inconsistent with other parts of the preexisting Food Code, and it was withdrawn in 2002 during the transition between the two codes, thereby continuing to allow absinthe manufacture and importation through the existing permit-based system. These events were erroneously reported by the media as it being reclassified from a prohibited product to a restricted product.

In 2007, the French Lucid brand became the first genuine absinthe to receive a COLA (Certificate of Label Approval) for importation into the United States since 1912, following independent efforts by representatives from Lucid and Kübler to overturn the long-standing US ban. In December 2007, St. George Absinthe Verte produced by St. George Spirits of Alameda, California became the first brand of American-made absinthe produced in the United States since the ban. Since that time, other micro-distilleries have started producing small batches in the US. 

The 21st century has seen new types of absinthe, including various frozen preparations which have become increasingly popular. The French Absinthe Ban of 1915 was repealed in May 2011 following petitions by the Fédération Française des Spiritueux which represents French distillers.

Production

Green anise, one of three main herbs used in production of absinthe

Grande wormwood, one of three main herbs used in production of absinthe

 

Sweet fennel, one of three main herbs used in production of absinthe

 

Most countries have no legal definition for absinthe, whereas the method of production and content of spirits such as whisky, brandy, and gin are globally defined and regulated. Therefore, producers are at liberty to label a product as "absinthe" or "absinth" without regard to any specific legal definition or quality standards. 

Producers of legitimate absinthes employ one of two historically defined processes to create the finished spirit: distillation, or cold mixing. In the sole country (Switzerland) that does possess a legal definition of absinthe, distillation is the only permitted method of production.

Distilled absinthe

Distilled absinthe employs a method of production similar to that of high quality gin. Botanicals are initially macerated in distilled base alcohol before being redistilled to exclude bitter principles, and impart the desired complexity and texture to the spirit.

Absinthe distillation, ca. 1904

 

The distillation of absinthe first yields a colourless distillate that leaves the alembic at around 72% ABV. The distillate may be reduced and bottled clear, to produce a Blanche or la Bleue absinthe, or it may be coloured to create a verte using natural or artificial colouring. 

Traditional absinthes obtain their green colour strictly from the chlorophyll of whole herbs, which is extracted from the plants during the secondary maceration. This step involves steeping plants such as petite wormwood, hyssop, and melissa (among other herbs) in the distillate. Chlorophyll from these herbs is extracted in the process, giving the drink its famous green colour. 

This step also provides a herbal complexity that is typical of high quality absinthe. The natural colouring process is considered critical for absinthe ageing, since the chlorophyll remains chemically active. The chlorophyll serves a similar role in absinthe that tannins do in wine or brown liquors.

After the colouring process, the resulting product is diluted with water to the desired percentage of alcohol. The flavour of absinthe is said to improve materially with storage, and many pre-ban distilleries aged their absinthe in settling tanks before bottling.

Cold mixed absinthe

Many modern absinthes are produced using a cold mix process. This inexpensive method of production does not involve distillation, and is regarded as inferior in the same way that cheaper compound gin is regarded as inferior to distilled gin. The cold mixing process involves the simple blending of flavouring essences and artificial colouring in commercial alcohol, in similar fashion to most flavoured vodkas and inexpensive liqueurs and cordials. Some modern cold mixed absinthes have been bottled at strengths approaching 90% ABV. Others are presented simply as a bottle of plain alcohol with a small amount of powdered herbs suspended within it. 

The lack of a formal legal definition for absinthe in most countries enables some cold mixing producers to falsify advertising claims, such as referring to their products as "distilled", since the base alcohol itself was created at some point through distillation. This is used as justification to sell these inexpensively produced absinthes at prices comparable to more authentic absinthes that are distilled directly from whole herbs. In the only country that possesses a formal legal definition of absinthe (Switzerland), anything made via the cold mixed process cannot be sold as absinthe.

Ingredients

Anise seeds

 

Absinthe is traditionally prepared from a distillation of neutral alcohol, various herbs, spices and water. Traditional absinthes were redistilled from a white grape spirit (or eau de vie), while lesser absinthes were more commonly made from alcohol from grain, beets, or potatoes. The principal botanicals are grande wormwood, green anise, and florence fennel, which are often called "the holy trinity." Many other herbs may be used as well, such as petite wormwood (Artemisia pontica or Roman wormwood), hyssop, melissa, star anise, angelica, peppermint, coriander, and veronica.

One early recipe was included in 1864's The English and Australian Cookery Book. It directed the maker to "Take of the tops of wormwood, four pounds; root of angelica, calamus aromaticus, aniseed, leaves of dittany, of each one ounce; alcohol, four gallons. Macerate these substances during eight days, add a little water, and distil by a gentle fire, until two gallons are obtained. This is reduced to a proof spirit, and a few drops of the oil of aniseed added."

Alternative colouring

Adding to absinthe's negative reputation in the late 19th and early 20th centuries, unscrupulous makers of the drink omitted the traditional colouring phase of production in favour of adding toxic copper salts to artificially induce a green tint. This practice may be responsible for some of the alleged toxicity historically associated with this beverage. Many modern day producers resort to similar (but non-deadly) shortcuts, including the use of artificial food colouring to create the green colour. Additionally, at least some cheap absinthes produced before the ban were reportedly adulterated with poisonous antimony trichloride, reputed to enhance the louching effect.

Absinthe may also be naturally coloured pink or red using rose or hibiscus flowers. This was referred to as a rose (pink) or rouge (red) absinthe. Only one historical brand of rose absinthe has been documented.

Bottled strength

Absinthe was historically bottled at 45-74% percent ABV. Some modern Franco–Suisse absinthes are bottled at up to 83.2% ABV, while some modern, cold-mixed bohemian-style absinthes are bottled at up to 89.9% ABV.

Kits

The modern day interest in absinthe has spawned a rash of absinthe kits from companies that claim they produce homemade absinthe. Kits often call for soaking herbs in vodka or alcohol, or adding a liquid concentrate to vodka or alcohol to create an ersatz absinthe. Such practices usually yield a harsh substance that bears little resemblance to the genuine article, and are considered inauthentic by any practical standard. Some concoctions may even be dangerous, especially if they call for supplementation with potentially poisonous herbs, oils and/or extracts. In at least one documented case, a person suffered acute kidney injury after drinking 10 ml of pure wormwood oil—a dose much higher than that found in absinthe.

Alternatives

In baking, Pernod Anise is often used as a substitute if absinthe is unavailable. In preparing the classic New Orleans-style Sazerac cocktail, various substitutes such as Pastis, Pernod, Ricard, and Herbsaint have been used to replace absinthe.

Preparation

Preparing absinthe using the traditional method, which does not involve burning.

 

Absinthe spoons are designed to perch a sugar cube atop the glass, over which ice-cold water is dripped to dilute the absinthe. The lip near the centre of the handle lets the spoon rest securely on the rim of the glass.

 

The traditional French preparation involves placing a sugar cube on top of a specially designed slotted spoon, and placing the spoon on a glass filled with a measure of absinthe. Iced water is poured or dripped over the sugar cube to mix the water into the absinthe. The final preparation contains 1 part absinthe and 3-5 parts water. As water dilutes the spirit, those components with poor water solubility (mainly those from anise, fennel, and star anise) come out of solution and cloud the drink. The resulting milky opalescence is called the louche (Fr. opaque or shady, IPA [luʃ]). The release of these dissolved essences coincides with a perfuming of herbal aromas and flavours that "blossom" or "bloom," and brings out subtleties that are otherwise muted within the neat spirit. This reflects what is perhaps the oldest and purest method of preparation, and is often referred to as the French Method.

The Bohemian Method is a recent invention that involves fire, and was not performed during absinthe's peak of popularity in the Belle Époque. Like the French method, a sugar cube is placed on a slotted spoon over a glass containing one shot of absinthe. The sugar is pre-soaked in alcohol (usually more absinthe), then set ablaze. The flaming sugar cube is then dropped into the glass, thus igniting the absinthe. Finally, a shot glass of water is added to douse the flames. This method tends to produce a stronger drink than the French method. A variant of the Bohemian Method involves allowing the fire to extinguish on its own. This variant is sometimes referred to as "Cooking the Absinthe" or "The Flaming Green Fairy." The origin of this burning ritual may borrow from a coffee and brandy drink that was served at Café Brûlot, in which a sugar cube soaked in brandy was set aflame. Most experienced absintheurs do not recommend the Bohemian Method and consider it a modern gimmick, as it can destroy the absinthe flavour and present a fire hazard due to the unusually high alcohol content present in absinthe.

Slowly dripping ice water from an absinthe fountain

 

Burning the sugar

 

In 19th century Parisian cafés, upon receiving an order for an absinthe, a waiter would present the patron with a dose of absinthe in a suitable glass, sugar, absinthe spoon, and a carafe of iced water. It was up to the patron to prepare the drink, as the inclusion or omission of sugar was strictly an individual preference, as was the amount of water used. As the popularity of the drink increased, additional accoutrements of preparation appeared, including the absinthe fountain, which was effectively a large jar of iced water with spigots, mounted on a lamp base. This let drinkers prepare a number of drinks at once—and with a hands-free drip, patrons could socialise while louching a glass.

Although many bars served absinthe in standard glassware, a number of glasses were specifically designed for the French absinthe preparation ritual. Absinthe glasses were typically fashioned with a dose line, bulge, or bubble in the lower portion denoting how much absinthe should be poured. One "dose" of absinthe ranged anywhere around 2-2.5 fluid ounces (60-75 ml).

In addition to being prepared with sugar and water, absinthe emerged as a popular cocktail ingredient in both the United Kingdom and the United States. By 1930, dozens of fancy cocktails that called for absinthe had been published in numerous credible bartender guides. One of the most famous of these libations is Ernest Hemingway's "Death in the Afternoon" cocktail, a tongue-in-cheek concoction that contributed to a 1935 collection of celebrity recipes. The directions are as follows: "Pour one jigger absinthe into a Champagne glass. Add iced Champagne until it attains the proper opalescent milkiness. Drink three to five of these slowly."

Styles

The Absinthe Drinker by Viktor Oliva (1861–1928)

 

The Drinkers by Jean Béraud (1908)

 

Most categorical alcoholic beverages have regulations governing their classification and labelling, while those governing absinthe have always been conspicuously lacking. According to popular treatises from the 19th century, absinthe could be loosely categorised into several grades (ordinaire, demi-fine, fine, and Suisse—the latter does not denote origin), in order of increasing alcoholic strength and quality. Many contemporary absinthe critics simply classify absinthe as distilled or mixed, according to its production method. And while the former is generally considered far superior in quality to the latter, an absinthe's simple claim of being 'distilled' makes no guarantee as to the quality of its base ingredients or the skill of its maker.

• Blanche absinthe ("white" in French, also referred to as la Bleue in Switzerland) is bottled directly following distillation and reduction, and is uncoloured (clear). The name la Bleue was originally a term used for Swiss bootleg absinthe (which was bottled colourless so as to be visually indistinct from other spirits during the era of absinthe prohibition), but has become a popular term for post-ban Swiss-style absinthe in general. Blanches are often lower in alcohol content than vertes, though this is not necessarily so; the only truly differentiating factor is that blanches are not put through a secondary maceration stage, and thus remain colourless like other distilled liquors.
• Verte absinthe ("green" in French, sometimes called la Fée Verte) begins as a blanche. The blanche is altered by a secondary maceration stage, in which a separate mixture of herbs is steeped into the clear distillate. This confers a peridot green hue and an intense flavour. Vertes represent the prevailing type of absinthe that was found in the 19th century. Vertes are typically more alcoholic than blanches, as the high amounts of botanical oils conferred during the secondary maceration only remain miscible at lower concentrations of water, thus vertes are usually bottled at closer to still-strength. Artificially coloured green absinthes may also be claimed to be verte, though they lack the characteristic herbal flavours that result from maceration in whole herbs.
• Absenta ("absinthe" in Spanish) is sometimes associated with a regional style that often differed slightly from its French cousin. Traditional absentas may taste slightly different due to their use of Alicante anise, and often exhibit a characteristic citrus flavour.
• Hausgemacht (German for home-made, often abbreviated as HG) refers to clandestine absinthe (not be confused with the Swiss La Clandestine brand) that is home-distilled by hobbyists. It should not be confused with absinthe kits. Hausgemacht absinthe is produced in tiny quantities for personal use and not for the commercial market. Clandestine production increased after absinthe was banned, when small producers went underground, most notably in Switzerland. Although the ban has been lifted in Switzerland, some clandestine distillers have not legitimised their production. Authorities believe that high taxes on alcohol and the mystique of being underground are likely reasons.
• Bohemian-style absinth is also referred to as Czech-style absinthe, anise-free absinthe, or just "absinth" (without the "e"), and is best described as a wormwood bitters. It is produced mainly in Czechia, from which it gets its designation as Bohemian or Czech, although not all absinthes from Czechia are Bohemian-style. Bohemian-style absinth typically contains little or none of the anise, fennel, and other herbal flavours associated with traditional absinthe, and thus bears very little resemblance to the absinthes made popular in the 19th century. Typical Bohemian-style absinth has only two similarities with its authentic, traditional counterpart: it contains wormwood and has a high alcohol content. The Czechs are credited with inventing the fire ritual in the 1990s, possibly because Bohemian-style absinth does not louche, which renders the traditional French preparation method useless. As such, this type of absinthe and the fire ritual associated with it are entirely modern fabrications, and have little to no relationship with the historical absinthe tradition.

Storage

Absinthe that is artificially coloured or clear is aesthetically stable, and can be bottled in clear glass. If naturally coloured absinthe is exposed to light or air for a prolonged period, the chlorophyll gradually becomes oxidised, which has the effect of gradually changing the colour from green to yellow green, and eventually to brown. The colour of absinthe that has completed this transition was historically referred to as feuille morte ("dead leaf"). In the pre-ban era, this natural phenomenon was favourably viewed, for it confirmed the product in question was coloured naturally, and not artificially with potentially toxic chemicals. Predictably, vintage absinthes often emerge from sealed bottles as distinctly amber in tint due to decades of slow oxidation. Though this colour change presents no adverse impact to the flavour of absinthe, it is generally desired to preserve the original colour, which requires that naturally coloured absinthe be bottled in dark, light resistant bottles. Absinthe intended for decades of storage should be kept in a cool (room temperature), dry place, away from light and heat. Absinthe should not be stored in the refrigerator or freezer, as the anethole may polymerise inside the bottle, creating an irreversible precipitate, and adversely impacting the original flavour.

Health effects

Édouard Manet, The Absinthe Drinker, 1859

 

Absinthe has been frequently and improperly described in modern times as being hallucinogenic. No peer-reviewed scientific study has demonstrated absinthe to possess hallucinogenic properties. The belief that absinthe induces hallucinogenic effects is at least partly rooted in the fact that following some ten years of experiments with wormwood oil in the 19th century, the French psychiatrist Valentin Magnan studied 250 cases of alcoholism, and claimed that those who drank absinthe were worse off than those drinking ordinary alcohol, having experienced rapid-onset hallucinations. Such accounts by opponents of absinthe (like Magnan) were cheerfully embraced by famous absinthe drinkers, many of whom were bohemian artists or writers.

Two famous artists who helped popularise the notion that absinthe had powerful psychoactive properties were Toulouse-Lautrec and Vincent van Gogh. In one of the best-known written accounts of absinthe drinking, an inebriated Oscar Wilde described a phantom sensation of having tulips brush against his legs after leaving a bar at closing time.

Notions of absinthe's alleged hallucinogenic properties were again fuelled in the 1970s, when a scientific paper suggested that thujone's structural similarity to THC, the active chemical in cannabis, presented the possibility of THC receptor affinity. This theory was conclusively disproven in 1999.

The debate over whether absinthe produces effects on the human mind in addition to those of alcohol has not been conclusively resolved. The effects of absinthe have been described by some as mind opening. The most commonly reported experience is a "clear-headed" feeling of inebriation—a form of "lucid drunkenness". Chemist, historian and absinthe distiller Ted Breaux has claimed that the alleged secondary effects of absinthe may be caused by the fact that some of the herbal compounds in the drink act as stimulants, while others act as sedatives, creating an overall lucid effect of awakening. The long-term effects of moderate absinthe consumption in humans remain unknown, although herbs traditionally used in the production of absinthe are reported to have both painkilling and antiparasitic properties. 

Today it is known that absinthe does not cause hallucinations. It is widely accepted that reports of hallucinogenic effects of absinthe were attributable to the poisonous adulterants being added to cheaper versions of the drink in the 19th century, such as oil of wormwood, impure alcohol, and poisonous colouring matter (e.g. copper salts).

Controversy

It was once widely promoted that excessive absinthe drinking caused effects that were discernible from those associated with alcoholism, a belief that led to the coining of the term absinthism. One of the first vilifications of absinthe followed an 1864 experiment in which Magnan simultaneously exposed one guinea pig to large doses of pure wormwood vapour, and another to alcohol vapours. The guinea pig exposed to wormwood vapour experienced convulsive seizures, while the animal exposed to alcohol did not. Magnan would later blame the naturally occurring (in wormwood) chemical thujone for these effects.

Thujone, once widely believed to be an active chemical in absinthe, is a GABA antagonist, and while it can produce muscle spasms in large doses, there is no direct evidence to suggest it causes hallucinations. Past reports estimated thujone concentrations in absinthe as being up to 260 mg/kg. More recently, published scientific analyses of samples of various original absinthes have disproved previous estimates, and demonstrated that only a trace of the thujone present in wormwood actually makes it into a properly distilled absinthe when historical methods and materials are employed to create the spirit. As such, most traditionally crafted absinthes, both vintage and modern, fall within the current EU standards.

Tests conducted on mice to study toxicity showed an oral LD₅₀ of about 45 mg thujone per kg of body weight, which represents far more absinthe than could be realistically consumed. The high percentage of alcohol in absinthe would result in mortality long before thujone could become a factor. In documented cases of acute thujone poisoning as a result of oral ingestion, the source of thujone was not commercial absinthe, but rather non-absinthe-related sources, such as common essential oils (which may contain as much as 50% thujone).

One study published in the Journal of Studies on Alcohol concluded that high doses (0.28 mg/kg) of thujone in alcohol had negative effects on attention performance in a clinical setting. It delayed reaction time, and caused subjects to concentrate their attention into the central field of vision. Low doses (0.028 mg/kg) did not produce an effect noticeably different from the plain alcohol control. While the effects of the high dose samples were statistically significant in a double blind test, the test subjects themselves were unable to reliably identify which samples contained thujone. For the average 65 kg (143 lb) man, the high dose samples in the study would equate to 18.2 mg of thujone. The EU limit of 35 mg/L of thujone in absinthe means that given the highest permitted thujone content, that individual would need to consume approximately 0.5 litres of high proof (e.g. 50%+ ABV) spirit before the thujone could be metabolized in order to display effects detectable in a clinical setting, which would result in a potentially lethal BAC more than 0.4%.

Regulations

Most countries (except Switzerland) at present do not possess a legal definition of absinthe (unlike Scotch whisky or cognac). Accordingly, producers are free to label a product "absinthe" or "absinth", whether or not it bears any resemblance to the traditional spirit.

Australia

Absinthe is readily available in many bottle shops. Bitters may contain a maximum 35 mg/kg thujone, while other alcoholic beverages can contain a maximum 10 mg/kg. The domestic production and sale of absinthe is regulated by state licensing laws. 

Until July 13, 2013, the import and sale of absinthe technically required a special permit, since "oil of wormwood, being an essential oil obtained from plants of the genus Artemisia, and preparations containing oil of wormwood" were listed as item 12A, Schedule 8, Regulation 5H of the Customs (Prohibited Imports) Regulations 1956 (Cth). These controls have now been repealed, and permission is no longer required.

Brazil

Absinthe was prohibited in Brazil until 1999 and was brought by entrepreneur Lalo Zanini and legalised in the same year. Presently, absinthe sold in Brazil must abide by the national law that restricts all spirits to a maximum of 54.0% ABV. While this regulation is enforced throughout channels of legal distribution, it may be possible to find absinthe containing alcohol in excess of the legal limit in some restaurants or food fairs.

Canada

In Canada, liquor laws concerning the production, distribution, and sale of spirits are written and enforced by individual provincial government monopolies. Each product is subject to the approval of a respective individual provincial liquor board before it can be sold in that province. Importation is a federal matter, and is enforced by the Canada Border Services Agency. The importation of a nominal amount of liquor by individuals for personal use is permitted, provided that conditions for the individual's duration of stay outside the country are satisfied.

• British Columbia, New Brunswick: no established limits on thujone content
• Alberta, Ontario: 10 mg/kg
• Manitoba: 6–8 mg
• Quebec: 15 mg/kg
• Newfoundland and Labrador: absinthe sold in provincial liquor store outlets
• Nova Scotia: absinthe sold in provincial liquor store outlets
• Prince Edward Island: absinthe is not sold in provincial liquor store outlets, but one brand (Deep Roots) produced on the island can be procured locally.
• Saskatchewan: Only one brand listed in provincial liquor stores, although an individual is permitted to import one case (usually twelve 750 ml bottles or eight one-litre bottles) of any liquor.

In 2007, Canada's first genuine absinthe (Taboo Absinthe) was created by Okanagan Spirits Craft Distillery in British Columbia.

European Union

The European Union permits a maximum thujone level of 35 mg/kg in alcoholic beverages where Artemisia species is a listed ingredient, and 10 mg/kg in other alcoholic beverages. Member countries regulate absinthe production within this framework. The sale of absinthe is permitted in all EU countries unless they further regulate it.

Finland

The sale and production of absinthe was prohibited in Finland from 1919 to 1932; no current prohibitions exist. The government-owned chain of liquor stores (Alko) is the only outlet that may sell alcoholic beverages containing over 5.5% ABV, although national law bans the sale of alcoholic beverages containing over 60% ABV.

France

Despite adopting sweeping EU food and beverage regulations in 1988 that effectively re-legalised absinthe, a decree was passed that same year that preserved the prohibition on products explicitly labelled as "absinthe", while placing strict limits on fenchone (fennel) and pinocamphone (hyssop) in an obvious, but failed, attempt to thwart a possible return of absinthe-like products. French producers circumvented this regulatory obstacle by labelling absinthe as spiritueux à base de plantes d'absinthe ('wormwood-based spirits'), with many either reducing or omitting fennel and hyssop altogether from their products. A legal challenge to the scientific basis of this decree resulted in its repeal (2009), which opened the door for the official French re-legalisation of absinthe for the first time since 1915. The French Senate voted to repeal the prohibition in mid-April 2011.

Georgia

It is legal to produce and sell absinthe in Georgia, which has claimed to possess several producers of absinthe.

Germany

A ban on absinthe was enacted in Germany on 27 March 1923. In addition to banning the production of and commercial trade in absinthe, the law went so far as to prohibit the distribution of printed matter that provided details of its production. The original ban was lifted in 1981, but the use of Artemisia absinthium as a flavouring agent remained prohibited. On 27 September 1991, Germany adopted the European Union's standards of 1988, which effectively re-legalised absinthe.

Italy

The Fascist regime in 1926 banned the production, import, transport and sale of any liquor named "Assenzio". The ban was reinforced in 1931 with harsher penalties for transgressors, and remained in force until 1992 when the Italian government amended its laws to comply with the EU directive 88/388/EEC.

New Zealand

Although absinthe is not prohibited at national level, some local authorities have banned it. The latest is Mataura in Southland. The ban came in August 2008 after several issues of misuse drew public and police attention. One incident resulted in breathing difficulties and hospitalisation of a 17-year-old for alcohol poisoning. The particular brand of absinthe that caused these effects was bottled at an unusually high 89.9% ABV.

Sweden and Norway

The sale and production of absinthe has never been prohibited in Sweden or Norway. However, the only outlet that may sell alcoholic beverages containing more than 3.5% ABV in Sweden and 4.75% ABV in Norway, is the government-owned chain of liquor stores known as Systembolaget in Sweden and Vinmonopolet in Norway. Systembolaget and Vinmonopolet did not import or sell absinthe for many years after the ban in France; however, today several absinthes are available for purchase in Systembolaget stores, including Swedish made distilled absinthe. In Norway, on the other hand, one is less likely to find many absinthes since Norwegian alcohol law prohibits the sale and importation of alcoholic beverages above 60% abv, which eliminates most absinthes.

Switzerland

La fin de la Fée Verte (The End of the Green Fairy): Swiss poster criticising the country's prohibition of absinthe in 1910

 

In Switzerland, the sale and production of absinthe was prohibited from 1910 to March 1, 2005. This was based on a vote in 1908. To be legally made or sold in Switzerland, absinthe must be distilled, must not contain certain additives, and must be either naturally coloured or left uncoloured.

In 2014, the Federal Administrative Court of Switzerland invalidated a governmental decision of 2010 which allowed only absinthe made in the Val-de-Travers region to be labeled as absinthe in Switzerland. The court found that absinthe was a label for a product and was not tied to a geographic origin.

United States

In 2007, the Alcohol and Tobacco Tax and Trade Bureau (TTB) effectively lifted the long-standing absinthe ban, and it has since approved many brands for sale in the US market. This was made possible partly through the TTB's clarification of the Food and Drug Administration's (FDA) thujone content regulations, which specify that finished food and beverages that contain Artemisia species must be thujone-free. In this context, the TTB considers a product thujone-free if the thujone content is less than 10 ppm (equal to 10 mg/kg). This is verified through the use of gas chromatography-mass spectrometry. The brands Kübler and Lucid and their lawyers did most of the work to get absinthe legalized in the U.S., over the 2004-2007 time period. In the U.S., March 5 sometimes is referred to as "National Absinthe Day" as it was the day the 95-year ban on absinthe was finally lifted.

The import, distribution, and sale of absinthe is permitted subject to the following restrictions:

• The product must be thujone-free as per TTB guidelines,
• The word "absinthe" can neither be the brand name nor stand alone on the label, and
• The packaging cannot "project images of hallucinogenic, psychotropic, or mind-altering effects."

Absinthe imported in violation of these regulations is subject to seizure at the discretion of U.S. Customs and Border Protection.

Beginning in 2000, a product called Absente was sold legally in the United States under the marketing tagline "Absinthe Refined," but as the product contained sugar, and was made with southernwood (Artemisia abrotanum) and not grande wormwood (Artemisia absinthium) (prior to 2009), the TTB classified it as a liqueur.

Pablo Picasso, 1901-02, Femme au café (Absinthe Drinker), oil on canvas, 73 cm × 54 cm (29 in × 21 in), Hermitage Museum, Saint Petersburg, Russia

Vanuatu

The Absinthe (Prohibition) Act 1915, passed in the New Hebrides, has never been repealed, is included in the 2006 Vanuatu consolidated legislation, and contains the following all-encompassing restriction: "The manufacture, importation, circulation and sale wholesale or by retail of absinthe or similar liquors in Vanuatu shall be prohibited."

Cultural influence

Numerous artists and writers living in France in the late 19th and early 20th centuries were noted absinthe drinkers, and featured absinthe in their work. Some of these included Édouard Manet, Guy de Maupassant, Amedeo Modigliani, Arthur Rimbaud, Henri de Toulouse-Lautrec, Paul Verlaine, Vincent van Gogh, Oscar Wilde, and Émile Zola. Many other renowned artists and writers similarly drew from this cultural well, including Aleister Crowley, Ernest Hemingway, Pablo Picasso, August Strindberg and Erik Satie. 

The aura of illicitness and mystery surrounding absinthe has played into literature, movies, music, and television, where it is often portrayed as a mysterious, addictive, and mind-altering drink. Absinthe has served as the subject of numerous works of fine art, films, video, music, and literature since the mid-19th-century. Some of the earliest film references include The Hasher's Delirium (1910) by Émile Cohl, an early pioneer in the art of animation, as well as two different silent films, each entitled Absinthe, from 1913 and 1914 respectively.

On November 9, 2018, the alternative rock band I Don't Know How But They Found Me released a song titled "Absinthe" as part of their 1981 Extended Play.