Criiical Reviews in Food Science and Nutrition. 46:365-377 (2006)

Copyright (C> Taylor and Francis Group, LLC

ISSN: 1040-B398

DOI: 10.1080/10408690590957322

Taylor Si FrancisTaylor 6> Fraricis Croup

Absinthe—A Review

DIRK W. LACHENMEIER and STEPHAN G. WALCHChemisches und Veterinaruntersuchungsamt (CVLJA) Karlsruhe. WeiBenburger Str. 3, D-76187 Karlsruhe, Germany

STEPHAN A. PADOSCHUniversiiatsklinikum Heidelberg, Klinik flirAnasthesiologie, Im Neuenheimer Feld 110, D-69120 Heidelberg. Germany

LARS U. KRONERinstilut fiir Rechtsmedizin der Universitat zu Koln, MelaiengUrtel 60-62. D-50823 Koln. Germany

The alcoholic beverage absinthe i.s recently experiencing a revival after a yearlong prohibition. This review article providesinformation on all uspects of this hitter spirit and its major components, especially wormwood (Artemisia absinthium L),which contains rhc to.uc monoierpene thitjone. Over WO references on historic and current literature are provided. Thetopics comprise the history of the alcoholic drink starting from its invention in the eighteenth century. Historical and modernrecipes are discussed in the cotitext of different equality categories and possibilities to reduce the content ofthujone are given.The analytical techniques used to verify compliance with the maximum limit of thujone as well as further possibilities forquality control of absinthe are discussed. The toxicology of absinthe is reviewed with regard to the cause of a syndrome called"absinthism," which was described after chronic abuse ofthe spirit in the nineteenth century. Finally, a food regulatoryand food chemical evaluation is provided and minimum requirements for absinthe are suggested. Absinthe should have arecognizable wormwood flavor and after dilution with water the characteristic clouding should arise (louche-effect). Products,which are advertized as being of premium grade should be made by distillation, should have an alcoholic strength of at least

l. and should not contain artiftcial dye.

Keywords absinthe, wormwood, Artemisia absinthium L.. thujone. absinthin. spirit drink

INTRODUCTION

The currently en-vogue beverage absinthe, a mostly greencolored spiril drink of distinct bitter taste, is recently experienc-ing a revival, after nearly 70 years of prohibition. It has founda way of distribution througb the Internet, a wide variety is alsofound in retail trade.

Beeause ofthe yearlong prohibition, no official requirementsor actual legal definitions exist, which explain or define howa spirit drink that is called absinthe should be like. Nowadays,a wide variety of absinthe variations are offered, which are allsubject to the official food control. In this context, a numberof substandard products, which do not show any organolepticcharacteristics ofthe wormwood plant, were recently found onthe market.' In this atlicle, all essential literature concerningabsinthe is combined to provide an extensive tool in the eval-uation of products for food control as well as for spirit drinkmanufaeturers. After a historical survey of absinthe, a summary

Address correspondence to Dr. Dirk W. Lachenmeicr. Chemisches undVeteriniinintersuchungsami (CVUA) Karlsruhe. WeiKenburger Sir. 3, D-76i87Karlsruhe, Germany. B-mail: Lachennieier@web.de

of the analytical and toxicological facts is given. Minimum re-quirements for products, which enter the market as absinthe, areproposed.

WORMWOOD—XRTEMISIX ABSINTHIUM L

The wormwood plant {Artemisia absinthium L.), which ispart ofthe family of composites (Asteraceae)-'^ has given ab-sinthe its name and is, besides aleohol, the main component ofthis spirit drink. Wormwood is a half-shrub which is local inCentral Europe and Asia with silvery grey, pinnatipartite. felty-haired leaves. The small, light yellow and globular fiowers arearranged in end standing panicles (Figure !).•* The plant partsabove ground are harvested in anthesis and after drying are usedfor the manufacturing of spirit drinks.'̂ Besides Artemisia ab-sinthium L.. the Roman or petite wormwood (Artemisia ponticaL.) is sometimes used, especially for coloration.

Wormwood contains an oil (0.2-1.5%) of a color rangingfrom dark-green or brown to blue. It is of a scratchingly ad-stringent bitter taste and smells rather strong.^ The bieyclic

365

366 D. W. LACHENMEIER ET AL.

Figure 1 Wurmwood, ArH-mi\iii ahsinlhhim L.. drawing of plant, flowers,seeds and fruils (drawing by W.Miiller. ISS5)."' Wormwood is the characteristicaromatic component of absinthe.

monoterpene thujone was often described as the main com-ponent of wormwood oil (40-90% of the essential oil). Onedistinguishes between the two isomeric components a- and ^-thujone. in dependence on the stereo chemistry ofthe C-4 methylgroup (Figure 2)? The concentration of j6-thujone is usuallyhigher than the one of o-thujone (/i-thujone: 70-90% of thetotal thujone content).** However, besides the /^-tbujone chemo-type ofthe wormwood plant further chemotypes were described,which contain (7.s-chrysanthenyl acetat, r/,v-chrysanthenol. cis-expoxyocimene, sabinyl acetate or bornyl acetate as principalcomponent.^"'-'' In the west alpine area above 1000 m the cis-epoxyocimen type is predominant, while the /f-thujone typerather exists in the lower zones.'- In wormwood oil from theTuscany'* or the Pyrenees'" neither a- nor /i-thujone could bedetected.

Further characteristic components of wormwood are ter-pene lactone bitter substances such as absinthin (0.20-0.28%)and artabsin (0.04-0.16%),' while the sesquiterpene lactoneabsinthin (Figure 2) is the organoleptieally dominant bitter

a-thujone (i-thujone

OH

H

O

absinthin

Figure 2 Structure of «- und ^-Ihujone and absinthin. the principal compo-nent.s of wormwood [Artemisia absinthium L.)

principle.'^ The concentration is seasonally different. The high-est content of bitter compounds can be found in September.while the highest content of essential oil can be observed fromJune to July.'^

HISTORICAL FACTS ABOUT ABSINTHE

Plinius already mentioned a wine called "absinthites" pre-pared by adding the herb of wormwood.'''•^'^ Wine containingbeverages, with watery wormwood extracts are still availableunder the label vermouth. The spirit drink known as absinthewas created in French-speaking Switzerland in the late eigh-teenth century. The herb of wormwood, used as medicine sinceantiquity, was mixed for the first time with further herba! in-gredients for flavoring and after the addition of alcohol distilledand distributed as foodstuff. The origin of this recipe is Couvet,in the Val-de-Travers (Neuchatel, Switzeriand) and both. Dr.Pierre Ordinaire,^'"^'^ and Henriette Henriod"" -'̂ were creditedwith its invention. However, it is proven, that the recipe got intothe possession of Henry-Louis Pernod, who founded a distilleryin Pontarlier (France) in I8O5.-"----'^

In the Wars of French Algeria (1844-1847). alcoholic bev-erages containing wormwood were given to the soldiers as aprophylaxis against miscellaneous diseases (such as malaria andhelminthiasis) and to raise the fighting .spirit.""-^ After the war,the homecoming soldiers made absinthe popular in their owncountries.'^-^ A further reason for the wide spreading of ab-sinthe in the nineteenth century, could be attributable to the factthat grave losses in vindemiation lead to rising wine prices, whilethe prices for absinthe were falling.-'̂ In the late nineteenth cen-tury, absinthe, in the meantime called "green fairy" ('"fee verte"),was the most popular spirit drink in Europe.-^

The green colored drink was consumed by the populationof all social levels. Especially in the bars and cafes of Paris,the "green hour" ('Theure verte") was a steady element of the

ABSINTHE—A REVIEW 367

Figure 3 ViiiueiU van Gogh; Slill Life uiih ubsinthe (Paris 18K7). The pictureshows one of the countless cafes in Paris, in which absinthe was served. Next tothe glasvs filled with absinthe, a water bottle is illustrated, which was necessarytor the drinking ritual.

daiiy routine. Absinthe also found its way into ihe spheres ofartists and intellectuals. Degas" "The Absinthe," van Gogh's''Still Life" (Figure 3), Picassos' "The Absinthe Drinker" andToulouse-Lautrec's portrait of his colleague van Gogh, markedby absinthe use and probabiy psychiatric symptoms, give proofof the disastrous addiction of so many.~- The biography ofVincent van Gogh is seen by many as the classic example ofcontinuous absinthe consume."" '̂**"'"

Pontarlier became the capital of absinthe. In 1905. 25 dis-tilleries had existed with approximately 3000 workers and anannual production of 10 million litres ot absinthe."''

But as early as in 1850, it was observed that the regularconsume of absinthe caused a syndrome called "absinthism."However, only as a result of the mass consumption in the be-ginning of the twentieth century, absinthe was blamed for allkinds of diseases and ils prohibition was demanded. In 1905,absinthe was prohibited in Belgium, followed by Switzerlandin 1908, the Netherlands in 1910, the USA in 1912 and Italyin 1913.~^''^ In France absinthe was prohibited in 1915, be-cause of the misuse by the French military during the First

World War.•̂ '̂ "̂ Finally in 1923, absinthe was also prohibited inGermany.-'-'

While absinthe was banned throughout Europe for more than70 years, Spain and the Czech Republic were exceptions to therule. Because of an obscure legal situation, a continuous produc-tion in countless distilleries existed in these countries. In France,the big absinthe manufacturers invented substitute products (so-called Imitation Absinthes) without wormwood, such as Pernod,Ricard. or Pastis.^

According to the Council Directive 88/388/EEC on the ap-proximation of the laws of the Member States relating to flavor-ings for use in foodstuffs and to source materials for their produc-tion, ihc addition of thujone containing plants or flavorings pre-pared from natural raw materials was re-allowed in the EuropeanUnion.̂ "̂ After the obligatory adoption of the Directive by themember states in the early 1990s, absinthe was marketable againwithin the entire European Union. For bitter spirit drinks, suchas absinthe, a thujone maximum limit of 35 mg/kg a-Z/i-thujonewas Introduced in the Directive. Over 10 years after the lift ofthe prohibition, more than a hundred absinthe types are cutrentlysold, which are tnainly distributed as en-vogue drinks via the In-ternet. In bars, absinthe is served as a cocktail or long drink.̂ -̂

In Switzerland, absinthe's country of origin, the prohibitionwas recently ilfted '̂̂ with the satnc maximum iimits as in theEU."*̂ which makes it possible, that high-grade absinthe prod-ucts manufactured according to traditional Swiss recipes mayshow up oti the market in the future. Switzerland also proposedto introduce protected geographic denominations of origin andprotected geographic indications on the labelling of absinthe.Further requirements for Swiss absinthe, such as the ban of ar-titicial dyes are currently in discussion.

ABSINTHE PRODUCTION

Following traditional recipes for distilled absinthes, in thefirst step wormwood and other dried herbs (e.g. anise, fennel) aremacerated. The macerate ot the wormwood herb is of a greenish-brown color, smells aromatic, like al! Artemisia species, and re-minds one of the composites, like camomile. The taste is lightlystinging, strongly bitter, and camphoric.^ The following dis-tillation of the macerate results in a distillate that is reducedof the bitter compounds, which are relatively non-volatile. Thecharacteristic, light volatile, tine aromatic components of thewormwood aroma appear in the tirst fraction between 80 and6i.)%\o\. while the middle fractions posses a cinnamon or clove-like aroma.''

In a second step, wormwood (usuaWy Artemisiapontica) andother herbs are added to the colorless distillate. This is done toaccomplish the characteristic green coloring by chlorophyll andto achieve a mild bitter taste, as well as to extract other aro-matic compounds. Because of the easy denaturation of chloro-phyll through light and warmth, the characteristic color of atraditionally produced absinthe is only pale green. Afterwardsthe beverage is diluted with water until the drinking strength isreached.

368 D. W. LACHENMEIER ET AL,

Swiss Absinthe ofPontarlier

Absinthe ordinairefrom extracts

Wormwood (2.5 kg)Anise (5 kg)Fennel (5 kg)

Alcohol (95 1, 85%vol)

Maceration 12 hours

Add water (45 1)

1

Distillation

ColorlessDistillate (95 1)

Coloration withRoman Wormwood (1 kg)

Hyssop (1 kg)Lemon Balm (500 g)

Wormwood extract (30 g)Star-anise extract (50 g)

Anise extract (10 g)Fennel extract (10 g)

Alcohol (51 1, 90%vol)

Add water (49 1)

Mix ing

r

Coloration withfood dye and

caramel

Dilution with waterto 100 1 ^''

Absinthe74%vol

ing

rAbsinthe46%vol

Figure 4 Procedure for the manufacliiring of absinthe iifier historiciil recipes. The Swiss abiinihe from Poniarlicr from Ref.""' is given as example for ii premiumquality prtxtuci. The absinthe ordinaire manufactured from extracts according to Ref.̂ *̂ is indicative of a kiwer grade product.

Typical historic recipes are given in Figure 4. The compo-sition of herbs u.sed next to wormwood differs from recipe torecipe. *̂ ""̂ ' For the improvement of the taste, or for further col-oring ani.se, star anise, lemon balm, hyssop, juniper, nutmeg.veronica, angelica root, melissa. coriander, camomile, or parsleyare added.'''--•'"' In every country, own types of ab.sinthe wereintroduced. For example in the Czech Republic, peppermint wasadded, but no anise and fennel. In Switzerland, melissa. hys.sopor angelica root were used, while in France coriander was added.The Swiss alpine wormwood is a valued ingredient, because ofhis strong aroma.^

The absinthe recipes of nowadays are kept as corporate se-crets. Besides wonnwood, other plants are used for the macerate.The colour is greenish or yellowish and clear.

The drying process has a considerable influence on the qualityofthe essential oils ofthe plants. Tateo and Riva"*̂ observed thateven the drying with only lightly heated air (25-39C) leads to

an unacceptable change ofthe organoleptic quality ofthe worm-wood oil. To achieve a good quality, the drying process shouldbe performed with or without artificial air at room temperature.The drying and storing process has no influence on the bittercompound absinthin.'^ Tateo"̂ ^ also found that the extraction ofArtemi.sia varieties can be enhanced using enzymatic treatmentwith hemicellulase.

The top grade products are stili manufactured with regardto the traditional recipes without the addition of dye or otheradditives. Some products are made of herbal distillates and aredifferentiated by a mild flavor. Because such products are col-orless, they are sold as "Blanche" or "La Bleue." Types with alower alcoholic strength and added sugar are sold as absinthe-liqueurs. Independent ofthe traditional recipes many productssold nowadays are made with readily bought finished extractsof wormwood or other plants, which are blended with ethylalcohol of agricultural origin. For the coloring, artificial dye

ABSINTHE—A REVIEW 369

is used, especially mixtures of tartrazin (El02. FD&C YellowNo. 5) and patent blue V {EI3I). or brilliant blue FCF (E133).Deteriorated products contain no herbal extracts and are madesolely by Ihe blending of artificial flavors, coloring, and ethylalcohol.

In cases like this, sometimes even the macerated herbs arenot distilled but only filtrated, diluted to drinking strength andbottled. These products have a strong pronounced taste of worm-wood and a very strong, nearly unpleasant bitter touch. Euiiherfalsification is possible with the addition of extracts of otherthujone containing plants (e.g. Thuja occidentalis L.. Salvia of-ficinaiis L.).

Even in the nineteenth century inferior and falsified productswere known.~' Instead of the traditional production by distil-lation, absinthe could be made using herbal essences.•'**"'" So-called absinthe extracts were also commercially available at thattime, which had only to be dissolved in alcohol and colored withfooddyc.-'^ As food adulteration, the light green color of chloro-phyll was sometimes enhanced with copper sulphate, copper ac-etate, indigo, aniline green, curcuma or extracts of spinach.**-^Another form of adulteration was the addition of antimony chlo-ride to generate the clouding which arises in the dilution processwith water.2̂ -2̂ -̂ -̂̂ ^

But the genera! problem at that time was that heads and tail-ings, which were separated from the product fractions duringthe distillation by legal manufacturers, were purchased by ille-gal manufacturers and used as a main component for the adul-terated products. Even inedible mixtures of methanol and fuselalcohol could be made drinkable by masking the bitter worm-wood taste.'''••'^

TYPES OF ABSINTHE AND THE DRINKING RITUAL

Traditionally in the class of premium grade absinthe, it isdistinguished according to the alcoholic strength, between "ab-sinthe ordinaire"' with 45-50%vol, the "absinthe demi-tine" with50-68%vol and the "absinthe fine" with 68-72%vol. The "ab-sinthe suisse" (68-72%vol) showed the highest quality and con-sists of pure herbal distillate, while in case of the other types thedistillate was diluted with ethyl alcohol.~~'̂ *'~'*'

Nowadays, this type of quality grading is varied and the ma-jority of the products are sold with 70 or 55%vol. In compar-ison to other spirit drinks, the elevated alcoholic strength isnecessary to enhance the solubility of the lipophilic essentialoils.

Eor the purpose of drinking, a dilution is necessary developingitself as a part of a drinking ritual.

The increase of the water proportion liberates the herbal bou-quet and leads to a clouding of the beverage and a separationof the solution. Within the drinking ritual, this observed effectis called "louche"-effect caused by the dilution of the absinthewith water.'^-'* Tbe traditional and historic ritual demands, thata perforated spoon with sugar should be held over a glass filledwith cold absinthe while water is cast drop by drop over it (di-

lution approximately 5:1).̂ ^ ^̂ A Czech tradition demands thatthe sugar spoon should be dipped into absinthe, held over theglass while the sugar is ignited. First, the sugar drops into theglass and later the rest is stirred into the solution.

POSSIBILITIES TO REDUCE THE THUJONE CONTENT

Today's manufacturers face the problem that they have togenerate a distinctive wormwood taste, without exceeding thethujone maximum limit of 35 nig/kg. The selective enrichmentof the bitter and flavor compounds, while keeping the thujoneconcentration low. was extensively investigated.'*''

Tegtmeier et al."̂ '' compared a water extraction to an alco-hol extraction method. By the percolation with water or alcohol(30%vol) no thujone could be extracted, because the solubilityof thujone in water is poor. Only by the application of ethanol90%vol, it was possible to extract 0.18 mg thujone per g worm-wood herb. When the method of digestion with ethanol 30%volwas applied. 0.17 mg thujone per g wormwood herb could beextracted. The largest yields were obtained, whenever the mac-erate of the wormwood herb was distilled (0.24 mg thujone/g).The use of hot and highly concentrated alcohol for the extractionshould therefore be avoided to obtain extracts with a low contentof thujone. Because the percolation with pure water might leadto a loss of microbiological quality, the percolation with ethanol30%vol is regarded as the method of choice. This method isdescribed as being easy to handle and economic. Gambelungheand Melai."*̂ verified these results. Wormwood macerated withethanol 20%vol for 30 days contained only 0.2 mg/l of thujone.while the maceration of wormwood with ethanol 959c\o\ for6 months contained 62 mg/l of thujone. The consequence forthe absinthe manufactures is that traditional recipes and meth-ods have to be modified, in order to avoid thujone contents,which exceed the limit. The maceration should be done withlow concentrations of alcohol and the wormwood herb shouldbe separated before the distillation.

A possibility for the continuation of traditional recipes is toremove the thujone from the wormwood herb before the mac-eration. Stah! and Gerard"*** observed, that the extraction withliquid or supercritical carbon dioxide provides a fast, selectiveand quantitative method for the separation of thujone from thewormwood herb. Absinthin, which is responsible for the highbitter value of wormwood, remains in the herb. It is thereforepossible to generate nearly thujone free wormwood herb and touse it for the manufacturing of absinthe. However, the applica-tion of this method for the manufacturing of spirit drinks wasnever described.

The most elegant alternative to avoid the toxic thujone maybe the use of thujone-free wormwood herb, which is availablein certain cultivation areas."^-'^ and appears to be perfect for theuse in the spirit drink producing industry. With those chemo-types, it would be possible to produce absinthe with wormwoodquantities on the basis of the traditional recipes, without themanufacturer facing the risk of exceeding the thujone limit.

370 D. W. LACHENMEIER ET AL.

ANALYT/CAL METHODS

Thujone

Historically applied methods for the determination of thujonein absinthe are based upon iodometric titration. color reactions orpaper chromatography and sometimes provided only detectionlimits as high as e.g. 20 mg/1 and were therefore unfit tor thesensitive detection of .small quantities.'̂ ''"-'̂ - At the beginning ofthe nineteenth century the most modem methods were basedupon the reaction of thujone with sodium nitroprusside. sodiumhydroxide and acetic acid and provided a limit of detection of5 mg/i.^^"''^ However, this color reaction was highly unspecificand therefore other essential oils, aldehydes, and ketones led to asimilar reaction as thujone. Even by the u.se of improved samplepreparation, it was not possible to avoid these interferences.A positive reaction in case of the thujone analysis could notautomatically be interpreted in such a way as to say that the spiritdrink in question was made with wormwood herb. However,a negative result was regarded as a proof for the absence ofwormwood oil.̂ ^ '''̂

The .sensitive and selective determination of thujone inspirit drinks was only made possible by the use of modernchromatographic methods. The majority of these methods de-scribed in the literature, for the quantitative determination ofthujone in absinthe, use gas chromatographic separation (Ta-ble 1)/•''''̂ '̂ -<'*^ Besides, a qualitative screening method usingthin layer chromatography (TLC)*^ and liquid chromatographicmethods with fluorescence detection''^^^ were described. AUready in 1976, a gas chromatographic method (GC) with flameionization detector (FID) for the determination of thujone in al-

coholic beverages was developed by Merat et al ." The sam-ple preparation included a distillation of the samples and afollowing extraction (Table 1). Similar GC-FID methods wereproposed by the "international Organization of the FlavorTndustry" '̂̂ and in the Manuel Suisse des Denrees Alimentaires(MSDA)."

The first gas chromatographic method with mass spectro-metric detection (GC/MS) was described by Galli et al. in1984.''** The samples were neutralized and extracted with di-ethyl ether. The organic extract was concentrated and directlyinjected into the gas chromatograph. Tetraline was used as aninternal standard, because it shows an intensive molecular peakin the mass spectra and possesses similar retention time as theanalyte.

Sample preparation has an essential influence on the selec-tivity of the analysis. Adam and Postel^ observed that bitterliqueurs can contain up to 200 different components after thepreparation by distillation. It can happen that other componentscan co-eluate with a- and ^-thujone. pretending higher con-tents if GC-FID is u.sed. Emmert et al.*''̂ described that evenafter preparation by solid-phase extraction and following gaschromatographic separation, the peak of linalool could interferewith the a-thujone peak. It is therefore not advisable to do with-out mass spectrometric detection. Przyborski et al.^' as well asRapp et al.**- were able to lower the limit of detection 200-250fold to 0.005 mg/l or 0.002 mg/l respectively by liquid-liquidextraction, especially in comparison to the direct injection of thebeverage (Table I). '

The sample preparation is in parts of extremely high com-plexity. Therefore Lang et al.** proposed the use of a headspace(HS) method, which avoids an extensive sample prepara-

T^ble I Overview about methods for (he determinalion of thujone in spiril drinks

Sample preparation Meihod Internal standard

Limit of

detection [mg/l] Ref.

Distillation. LLE(dielhyl ether: pentane 2-1-1. v/v)LLE {diethyl ether)Distillation. LLE (isooctane)LLE (Pentane:

Dichioromelhane 2-1-1. v/v)DislitlationDistillation

Direct or LLH (Pentane:

Dichloromethane 2+1, v/v)LLE (kaltron)

DilutionSPE (C18)

Headspace-GCLLE (Diethyl elher)SPE(CIS)

HS-SPMF

GC-FID

GC-MSGC-FIDTLC

GC-FIDGC-FID.GC-MSGC-MS

GC-FID.GC-MSHPLC

HPLCGC-FIDGC-MSGC-FIDGC-MSGC-MS

n-Tndecan

Tetralin2-Decani)ne. Methyl-iindeca—

—

Pelargonic aciti methyl ester

Pyrogallol tri-methy! ether.i.so-Satrol

2.6-Dimethyl-3-hetpen-2-ol.

Decanol-3. Undecanol-I—

Dansylhydrazine

Pelargonic acid methyl estern.d.a.Standard Addition

Cvcloiieuanone

0.01

D.d.a.

0.28

0.01GC-FID: 0.05

GC MS: 0.01Direct: 1

LLE: 0.005

Direct: 0..S

LLE: 0.002

0.5

n.d.a.0.2

n.d.a.01

1100071

ss3966

63

60

61

67

6S

S47

69

LLE: iiquid-liquid-cxtraciioii. GC: jias chromatography. FID: fiame ioni/ation detector. MS: mass spectromelry. n.d.a.: no data available. TLC: thin layerchroniatugraphy, SPE: solid-phase extraction. HS-SPMH: headspace .solid-phase itiicroextraction.

ABSINTHE—A REVIEW 371

100

c

hujo

A

c

lUJO

h-

\

a

nor

S•§oO

_ . A11.50 12.00 12.50 13.00

Time [mini13.50 14.00

Figure 5 Chiiracteristk- HS-SPME/GC/MS-SIM-chromaiogram of authentic absinthe sample (55%vol) containing 3.3 mg/l of w-thujone and 46.7 mg/l of

/f-thujone; method according to Ref.''*" ithujone; m// 152, 110. 92; cyclodecanone: m// 154. i l l . 98).

tion. Samples are diluted to the alcoholic stretigth of I5%voland are diluted 1:5 with ethanol (I5%vol). This solution isused directly for the headspace gas chromatographic analy-sis. The limit of detection is 0.2 mg/l. which is compara-tively high but i.s sufficient for the control of the limit of35 mg/kg.

The headspace solid-phase microextraction (SPME) can beused as an alternative method for the sample preparation. Thismethod has proven itself in the analysis of terpenoids.™ A to-tally automated HS-SPME method with cyclodecanone as in-ternal standard, was proposed by Kroner et al.̂ ^ The absorp-tion of thujone was achieved by a polydimethylsiloxan-coatedSPME-fibre. which is exposed to the headspace above the sam-ple for the reason of enrichment of the analyte. After this solventfree extraction, desorption is achieved by the penetration of Ihefiber into the hot injector of the GC/MS. For the simultane-ous determination of a- and /i-thujone in bitter spirit drinks,a limit of detection of 0.7 fig/l was achieved. The high sen-sitivity of the HS-SPME/GC/MS method even allows a de-termination of thujone in blood samples.''-^ Matrix effects arediminished by the extraction out of the headspace. A typicalHS-SPME chromatogram of an absinthe sample is given inFigure 5.

Absinthin

A method of determination forthe flavor dominant bitter com-pound absinthin in absinthe spirit drinks has yet to be developed.TLC and photometric methods for the determination of artab-sin and absinthin used for the identification of wormwood herbare summarized by Schneider and Mielke, '̂ '** Another methodis described in the European Pharmacopoeia.^' By comparingTLC and HPLC profiles, the origin of wormwood extracts couldbe determined by Yashiro et al.^- as the aerial parts of Anemisiaah.sinihiiini. Modern instrumental analytical methods for the de-termination of bitter compounds in the spirit drink itself arecurrently in development.

Alcohol and Volatile Congeners

Within the work of the official food control the determina-tion of alcoholic strength is the most important parameter in theexamination of spirit drinks. The CVUA Karlsruhe, part of theGerman official food control system, had to object 15% of all ex-amined absinthe samples because of a too low alcoholic strength.For the analysis of alcohol either the reference method {distil-lation, followed by pycnometric determination of the density)̂ -̂or a recently developed screening method can be used.̂ "̂

In the nineteenth century, the alcohol quality of absinthewas determined using a colour reaction of fusel oil with sali-cylaldehyde and sulphuric acid.̂ "" Today, higher alcohols andby-products of the fermentation are usually determined by gascbromatography with flame ionisation detector. A distillationcan be used as a sample preparation or the samples can be anal-ysed by Headspace GC.^''

Skopp et al.''^ investigated the alcoholic congeners of 56 ab-sintbe brands and reported that these spirit drinks were predom-inantly made on the basis of ethyl alcohol of agricultural originaccording to the European Regulation 1576/89.̂ ** Further, a cer-tain country specificity was observed. !n the absinthe of Aus-trian, Swiss, or Spanish origin no other congeners but methanolwere detected, while the brands from Bulgaria were very richin congeners. Seven of the 56 analyzed absinthe brands con-tained exclusively ethanol, while the other samples containedat least methanol as a congener. Only 10 brands contained ad-ditional congener alcohols. All of them contained iso-butanol.l-propanol and 2-methylbutanol-l were detected in 7 types, 3-methylbutanol-1 in 8 types. Butanol-2 was not detected in anyof the samples, while butanol-l was detected in one absinthe ofCzech origin.^^

Use of Artificial Food Dyes

To determine artificial food dye in absinthe within the scopeof the official food control is of special importance (see section

372 D. W. LACHENMEIER ET AL.

absinthe production). Own tests showed that some samples, es-pecially ot" Czech or Spanish origin lacked the necessary la-belling ofthe use of dye. In single cases, the products containeda diiferent dye from the one indicated on the labelling. Un-til now. 41% of all absinthe samples, which were tested at theCVUA Karlsruhe, were objected, because of deficiencies in thedye labelling. The colouring is usually analysed by TLC andconfirmed by UV/VIS spectroscopy.^*

TOXICOLOGY Of ABSINTHE

The chronic abuse in the zenith of absinthe in the nineteenthand twentieth century was made responsible for a syndromecalled "absinthism" and was described to cause the followingsymptoms: after consuming absintbe. at first the well-being hadbeen stimulated, later hallucinations bad arisen followed by adepressive phase. Prolonged drinking of absinthe had causedconvulsions, blindness, hallucinations, and mental deteriora-tion. In the advanced state, signs of degeneration could be ob-served, which couid cause convulsions that even resulted in

For quite a long time, thujone was held responsible for ab-sinthism. Today's point of view is more differentiated. Otherfactors or an interaction of different factors must be held re-sponsible for causing absinthism.̂ "^

In the opinion of Strang et al.*̂ -* absinthism can be tracedback to a chronic alcohol intoxication causing similar symp-toms. Pollmer'̂ '* describes the adulteration of absinthe wilh toxicplants, such as sweet calamus {Acorus calamus L.) or tansy{Tanacetum vulgare L.). or adulteration with antimony chlo-ride and copper sulphate as a possible cause of absinthism. Es-pecially copper, whose resorption is amplified in combinationwith a massive alcohol ingestion. may cause alcoholic cirrhosisin alcoholics.̂ "* Also the use of inferior alcohol should be keptin mind as a possibility, because it explains symptoms such asimpaired vision. The symptoms having been reported about vanGogh could also be explained by a digitalis poisoning, or theabuse or accidental ingestion of solvents or turpentine.-̂ •̂ '•* '̂̂The possibility that van Gogb's xanthopsia may be caused bysantonin from Artemisiu pontica L. was already dismissed byArnold etal.^^

The thujone content of historic absinthe is largely unknownand speculated to be as high as 260 mg/kg."̂ ""̂ - Hutton points outthat the thujone content could be overestimated because of theinsufficient analytical methods that were available at the time.**"Wilson estimated in 1936 that absinthe made from essences con-tained 1.8 to 45 mg/1, and absinthe made with wonnwood herbcontained 2 to 34 mg/1 of thujone.'''' In recent analyses, historicabsinthes contained less thujone than current products (Table 2),which validated Hutton's hypothesis. Schaefer et al.*̂ ^ found solow thujone concentrations analysing a legal French absinthedating of 1904 that the authors even proposed the "toxicologicalrehabilitation" of absinthe.

The German federal institute for risk assessment**^ holds theview tbat, even if the legai limit of 35 mg/kg is significantly

Table 2 Thttjone contents of historic absinthes

Absinthe

French 1904Pernod tils circa lyOOPernod Tarragona 1930

Thujone[mg/ll

<0.0l6

Year ofanalysis

199420023004

Method

GCGC

GC/MS

Ref.

69

exceeded, the consumer does not ingest health threateningamounts of thujone. Because ofthe high alcoholic strength it isadvised against a continuous and massive consume. Threaten-ing thujone concentration can only occur if beverages are madefollowing recipes retrieved from the Internet, which suggest tbeuse of huge amounts of wormwood oil. Some absinthe typeswith a content of 100 mg/kg thujone were legally available in tbeCzech Republic until its recent integration into the EU. Weisbordet al.**'' described a case of accidental tbujone intoxication in aman after having consumed a large dose of wormwood oil underthe erroneous belief it had been absinthe. The symptoms wereseizures, rhabdomyolysis. and acute renal failure. The worm-wood oil was ordered from a website that sold essential oils foraromatherapy. This inadequate control of access to potentiallyunsafe herbal products is seen as an unacceptable health risk toconsumers."*"

In comparison to ^-thujone. a-thujone is believed to be2.3fold more toxic.^' Until today, only little valid data is avail-able concerning the effect of ff-/^-thujone. especially in regardto the influence on the central nervous system after absintheconsumption. A recent study of Dettling el al.̂ -' showed tbatthe administration of alcohol containing a high concentrationof thujone {100 mg/1) had a negative effect on attention perfor-mance. When the subjects were under the influence of alcoholor were administered hoth alcohol and low thujone concentra-tions (10 mg/1). these effects were not observed. Similarly, it wasfound tbat only high concentrations of thujone can temporarilycounteract the anxiolytic effect of alcohol.

It is possible to explain tbese effects becau.se of an interac-tion of tt-thujone with /-amino butyric acid (GABA) dependentchloride channels^'-^'"^'' as well as a 5-HTi receptor activity**^was demonstrated.

Interestingly, the activation of human bitter taste receptorsby tc-thujone was recently proven by Behrens et al.''^ and it wasfound that the receptor is sufficiently sensitive to serve as pro-tection against tbe ingestion of toxic amounts of this substance.

Another hypothesis is that because of structural similari-ties between thujone and tetrahydrocannabinol (THC), the psy-choactive component of the bemp plant Cannahis saliva L..̂ **both substances might activate the same receptor in the cen-tral nervous system.'''̂ This theory could not be proven inexperiments.'*' Nevertheless absinthe is advertised on tbe In-ternet as having a cannabis-like effect. In some recent literaturethis thesis is also misleadingly proclaimed.""'""

Tbe sometimes observed porphyrinogenic effect of thujoneand other terpenoids is explained with the pathway of metabo-lization by the hepatic cytochrome P-450 system.''^*'"•'•"^

ABSINTHE—A REVIEW 373

Very few data exist about the pharmacology of thujone.pointed out that the typical 2 ^ mg of thujone, which

were consumed per drink were far below the level at whichacute pharmacological effects are observed. This is confirmed byHinkelbein,""' who states that by the consumption of absinthe,up to a blood alcohol concentration of 2.5 g/l. approximately3.5 mg of thujone are ingested (0.005 mg/kg body weight). In thisorder of magnitude it is highly improbable that centra! effectscan be caused by thujone.

A pilot drinking study by Kroner et al.^'' resulted in highblood alcohol concentration, but as expected no tbujone wasdetected. The probands examined did not show a central effectcaused by the terpenoids besides the effect ofthe alcohol. There-fore, the hallucinogenic potency of absinthe can be neglected,if the EU limit is obeyed. The feared return of absintbism. pro-claimed by Hein et al..-" Holstege et al.-"* and Muller'"' is tbere-fore exaggerated. The effects ofthe recent types of absinthe arepredominantly caused by the naturally high alcoholic strength(>50%vol). although it is possible to reach effective thujoneblood levels, if illegally produced and distributed absinthe isingested.

QUALITY CONTROL OF ABSINTHE

Absinthe is neither defined in the German definitions of spiritdrinks.'"^ nor in the regulation of tbe EU concerning spiritdrinks.̂ ** This causes problems in the food chemical and legaljudgement for the official food control. Only the Manuel Suissedes Denrees Alimentaires (MSDA)''^ provides specifications forabsinthe, regarding its thujone content. Referring to this defini-tion, a typical absinthe does not contain more than 15 mg/1 ofthujone. A content between 2 and 15 mg/1 hints towards the useof wormwood. Contents below 2 mg/1 can be neglected. How-ever, in the context of the different chemotypes of wormwoodand the various possibilities of production this grading after theMSDA appears to be a bit oversimplified. From our experience,there exists a correlation between tbe quality and tbe thujonecontent of absinthe. But especially absinthes regarded as to beof high-grade show a very large concentration range. Inferiorproducts, made only by maceration, can contain more thujonethan distilled ones. The MSDA's criteria is valid in regard to ab-sinthe that contains less than 2 mg/i of thujone and the questionarises if such a product contains wormwood at all. An officialobjection on tbe single reason of a low or missing thujone con-tent is seen as critical, because the presence of a potentially toxicsubstance cannot be made a requirement. Until more parametersfor the authentification of absinthe are available, the content oftbujone can only give a hint. An objection by the official foodcontrol department should always be based on further charac-teristics (such as organoleptical testing).

A further definition for absinthe, which may be used nowa-days, was provided by the Swiss Law for tbe prohibition ofabsinthe. According to this, every spirit drink without regardto the method of production that contains aromatic compounds

of wormwood herb in combination with other aromatic com-pounds derived from plants such as anise and fennel, is definedas absinthe."* At that time, thujone was also regarded as beingthe determining factor amongst tbe aromatic compounds."*^

As a further hint for the quality control of absinthe, it was pro-posed to check the ratio ofthe thujone isomers, because this al-lows conclusions concerning the origin ofthe thujone detected.*^Tbujone of wormwood origin usually can be recognized by apredominant /i-thujone content. In other cases it has to be dis-tinguished between seldomly found a-tbujone chemotypes ofwormwood and a food adulteration with cedar or other tbujonecontaining plants.

Table 3 presents tbe results of four recently conducted studiesof the thujone content of commercially available absinthe andincludes own results determined by the CVUA Karlsruhe.**^^^^In conclusion, it can be noted that the majority of tbe examinedsamples (95%) did not exceed the thujone EU maximum limit of35 mg/kg. Strikingly, more than half of the examined samples(55%) contained less than 2 mg/kg thujone.

Because 5% of the examined samples, which are actuallyavailable on the market exceeded the legal thujone limit, the an-alytical determination of thujone should still be a permanentparameter of the official food control. Most of the absinthemanufacturers and suppliers advertise the proclaimed thujonecontent of their products on their Internet pages. Slogans suchas "it contains tbe maximum allowed thujone concentration of35 mg/kg" should be critically judged by the appropriate au-thorities. If higher tbujone contents are proclaimed than can bedetected, these absinthes should be objected as a deception ofthe consumer.

Besides thujone. further characteristic compounds of the es-sential oil of wormwood (e.g. linalool, fenchone. sesquiter-penes) may be used for the authentification of absinthe. Othermarkers might be the bitter components or characteristic sub-stances like tetrahydrofuran lignanes. flavonic glucosides oroligo sac chad des.' There is a great need for further research inthe field of identification and characterization of typical markercomponents of wormwood. In doubtful cases, the official foodcontrol should take samples of the wormwood plant used for theproduction of absinthe and control the recipe, in regard to itswormwood content.

MINIMUM REQUIREMENTS FOR ABSINTHE

In a recent study of our group, the homepages of manufactur-ers and suppliers of absinthe were analyzed, with the intentionof providing a statement about the actual concept of commercefor the spirit drink.' In 2003. 89 absinthe brands were distributedin Germany via the Internet. Most brands are made in the CzechRepublic. Spain. France, and Germany. The alcoholic strengthvaries between 30 and 90'7rvol. 39 brands contain a declarationabout wormwood or bitter taste as well as a clouding with water.The predominant part ofthe products provided a correspondingtaste (90%) and clouding (77%). Tbe classic definitions, which

374 D. W. LACHENMEIER ET AL.

Table 3 Classilicalicin ot" absinihe sample.s in regard of their tliujdni: content

Totalthujone

content |mg/kg|

<22-10IO-3.*i> 35

16923

( n - 14)

533

(n = 16)

754

n

CVUA

531716

1

( n = 147)

813425

7

^.

5523175

State that absinthe contains aromatic compounds of the worm-wood plant (Artemisia ahsinlhium L.)''-''^—^i'"^ are still validin case of the nowadays purchasable products and can there-fore, still be used for their evaluation. If the sensory testing forwormwood is negative and neither thujone nor absinthin aredetectable, the recipe should be controlled on the spol, whileconducting a manufacturing control. It has to be demanded, thatevery product has at least a '•|ouche"-effect and certain worm-wood content. The color of most products is between yellow-green and olive, or clear. Some more exotic types show an un-usual red color. In case of 45 products, the origin of the color islabelled and609f of them are made without artificial dye. Espe-cially tbe Czecb products differ from tbe ordinary absinthe outof other countries (Switzerland. France and Germany). After theaddition of water, no milky clouding arises and the characteris-tic bitter taste of wormwood extracts is not present. Instead, asweet mint taste can be observed. The color of these products isturquoise, which is highly unusual for an absinthe and which isthe result of the use of artificial dye.

According to the statement of an importer, (he described com-position is characteristic for a Czech absinthe and is complyingwitb the local concept of commerce. It is the opinion of the au-thors, that this deviation at least should be made recognizable.

The overview of the market of absinthe provided informa-tion about the concept of commerce, from which tbe minimumrequirements for an absinthe are derived and given in Table4. The result of the sensory testing should be a recognizablewormwood flavor and hitter taste. After dilution with water, thecharacteristic clouding should arise. Products, which are ad-vertised as being of premium grade (e.g. "'made after historicrecipes"), should be made by distillation, should have an alco-holic strength of at least 45*^ vol. and should not contain artificialdye.

Table 4 Minimum requirements of absinthe

Minimum requirements• Characteristic aromatic flavour and tiilter laste caused by natural exlracts

or distillates of wormwood {Artemisia absinthium L. |• Colour: uncoloured or greenish• Characteristic clouding if diluted with water ("louche-effect")• Standard chemolypes: ^-thujone > tf-thujone

Further requirements for premium grade products• No artificial dye (colouring achieved only wilh wormwood and olher

herbs)• Disiillutive manuiacluring• Minimum alcoholic strength 45'?f-vol

On the background of the high number of deteriorated prod-ucts found on the market, the initiative of Switzerland for thespecial labelling of authentic products would be very welcometo facilitate the consumers' decision.

CONCLUSION

The over 100 cited references show a great difference in sci-entific quality. Some papers should focus more on real analyti-cal and toxicological facts instead of resuming all the facloidalmyths and legends of former years. However, the authors wantedto give a complete guide to absinthe and let the knowledgeablereader judge on his own.

In our opinion, absinthe poses less of a problem for healthprotection of the consumers than initially assumed. Absinthe isextensively control led by the official food control and the thujonelimit is obeyed by most products. Even when it slightly exceedsthe limit, no toxicological eftects can be expected. Therefore,absinthe is not a problem because of the thujone content, butlike all spirit drinks because of the possible excessive alcoholconsumption. Besides this, the current major problem in theevaluation of absinthe is the protection of the consumer againstdeception from deteriorated products without wormwood, wbicbare sold at exaggerated prices. Because of a missing official def-inition of absinthe, a legal uncertainty exists, which is exploitedby many manufacturers for the distribution of inferior products.To protect the consumer from deception and in the interest of astandardized evaluation, absinthe should be uniformly definedwithin the EU. In tbe opinion of tbe authors, it is a mandatorydemand that real absinthe must be produced with wormwoodherb using maceration and distillation. Regrettably, a proposallor sucb an Europe-wide regulation initiated by Germany basrecently failed.^

REFERENCES

\ 11 Lachenmeier, D.W., Frank. W., Athanasiikis. C . Patlosch. S.A.. Madea.B.. Rolhschild. M.A.. and Kroner, L.LT. 2004. Absinth—ein Getrankkommt wieder in Mode: toxikologisch-analytische und lebensmittel-rechtliche Betrachluiigen. Dtsch. Lehensm.-Rundsch.. 100:117-129.

[2] Frohne. D. 1984. Wermulkraut. In TeeJrogen. Wichtl. M,. Ed. pp. 363-365. Wissenschaftliche Verlagsgesellschafl. Stutlgart. Germany.

[3| Deans. S.G.. and Kennedy. A.I. 2002. Artemisia ahsimhium. Med. Arum.Plants hid. Pwfik-s. 18:79-X9.

[4] Thome. O.W. 1885. Flora von Deulschiand, Osterreich und der Schweiz,Kohler. Gera, Germany.

ABSINTHE—A REVIEW 375

[5] Strohmer. G. 2002. Rohstnft'e und Huibfabrikate 7Ut Herslellung vonLikoren. In Spirituosen-Technalogic. Kolb, E.. Ed. pp. 161-343. Behr'sVerlag, Hamburg, Germany.

J61 Goettier, H. 1958. Lexikon der Spiriiuosen- und alkohollVeien Gelranke-Industrie. Carl Knoppke Gruncr Verlag. Berlin, Germany.

[7) Albcn-Puleo. M. 1978. Mythabolany. pharmacology, and chemistry ofIhujone-cnniaining plants and derivatives. Econ. Boi.. 32:65-74.

|8] Lang. M., Fauhl. C . and Wittkowski. R. 2002. Belastungssitua-tion von Absinth niit Thujon (BgVV-Hefte OK/2002). Burdesinstitutflir ge.sundheitlJL-hen Verbraucherschutz und VeteHnarmedizin, Berlin.Germany.

[9] Camat.A.-P..Madesdaire,M.,Chavignon.O..andLamaison.J.-L. 1992.cis-Chrysanthenol, a main component in essential oil ai Arwmiaia ab-sinthium L. growing in Auvergne (Massif Central). France. J. EssetU. OilRf.v.. 4:487-490.

[10] Arino, A.. Arberas, 1.. Renobales, G.. Arriaga. S.. and Domiiiguez. J.B.1999. Essential oil of Arlemisia ahsiiuhium L. from the Spanish Pyrenees./ Esseni. OH Res.. 11:182-184.

[111 Mucciarelli, M.. Caramiello, R.. and Maffei. M. 1995. Essential Oilsfrom some Artemisia species growing spontaneously in North-West Italy.Flavour Fragr. J.. 10:25-32.

[12] Chialva, R, Liddle, P.A.P., ami Doglia. G. 1983. Cheniotaxonomy of

wormwood {Ariemisia ahsiiuhium L.I I. Composition ofthe essenllal oilof .several chemoiypes. Z. Leheiism. ViUer.s. Forscli.. 176:363-366.

(13] Vostrow.sky. 0.. B rose he. T. Ihm. H., ZIntl. R.. and Knobloch. K. 1981.Uber die Komponenien des atherischen Ols aus Ariemisia ahsinlliiiim L.Z. Naturforsch., 36c:369-377.

[14] Pino, J.A.. Rosado, A., and Fuenies. V. 1997. Chemical composition ofthe essential oil of Arli'misiu absinlhiiim L. from Cuba. 7. Esscni. Oil Res..9:87-89.

[15] Sacco. T.. and Chi;ilva. F. 1988. Chemical characteristics of the oil fromArtemisia ahsiiitliiiim collected in Paiagony (Argentina). Planki Med..54:93. •

[16] Nin. S.. Arfaioli, P.. and Boselto. M. 1995. Quantitative determination ofsome essential oil components of selected Ariemisia ab.mithium planls./ Essent. Oil Res.. 7:271-277.

[17] Schneider. G.. and Mielke, B. 1979- Zur Aiialyiik der Bitterstoffe Ab-sinthin. Arlabsin und Matrizin aus Artemisia absinthium L. Teil II:Lsolierung und Gehaltsbestimmungen. Wf.vr/i. Apoiii. Zig.. 119:977-982.

[18! Schneider, G.. and Mielke. B. 1978. Zur Analytik der Bittersloffe Ab-sinthin. Artabsin und Mairi/_in aus Artemisia absinthium L. Teil I: Nach-

weis in der Droge und Dunnschichtchromatographie. Df^ch. Apoth. Zii;.,118:469-472.

[]9[ Arnold. W.N. 1989. Absinthe. 5W. Am., 260:112-117.[20] Hein, J., Lobbedey, L., and Neumiirker, K.J. 2(X)1. Absinth—Neue Mode.

alte Probleme. Dl. Ar-jebi. 98:A27I6-A2724.[21] Vogt. D.D. 1981. Absinthium: a nineteenth-cenlury drug of abuse. /

Etimopiianmicoi. 4:337-342.[22] Vogt. D.D.. and Montagne. M. 1982. Absinthe: Behind the emerald ma,sk.

hit. J. Aiiilici.. 17:1015-1029.[23] Haines,J-D. 1998. Absinthe—return of the green fairy../. Okiti. Slalc Med.

As.wc. 91:406-401. '[24] Holstege. C.R, Baylor, M.R., and Rusyniak. D.E- 2002. Absinthe: return

ofthe Green Fairy. St'iniii. Nciirol.. 22:89-93.[25] Melcher, S. 2002. Absinthe—history before 1915. www.absinthe.lu.[26] Aronson, S.M. 1999. Absinthe makes the hearl grow fonder. Med. Health

/;./.. 82:80-81.[27] Alcohol in France 1906. Lcmvel. 168:1531.[28] Hemphill, R.E. 1961. The illness of Vincent Van Gogh. Rn>c. R. Soc.

Mf'./.. 54:1083-1088.[291 Albert-Puleo, M. 1981. Van Gogh's vision: ihujone intoxication. JAMA.

246:42.[30] Arnold. W.N. 1988. Vincent van Gogh and Ihe thujone connection. Y/̂ M ,̂

260:3042-3044.[31 [ Morrant, J.C. 1993. The wing of madness: the illness of Vincent van Gogh-

Can. J. F.mhiutiy. 38:480-484.

[32] Blumer. D. 2002. The illness of Vinceni van Gdgh. Am. J. P.sxchialry.159:519-526.

[33] Gesetziiberden Verkehr mit Absinth \923. Reicbsge.tetzhl. 1.251.[34[ European Council 1988. Council Direciive (EEC) No 88/388 on the ap-

proximation of the laws of the Member States relating to Havourings foruse in foodstuffs and lo source materials for their prixluction. Off. J. Europ.O>mw/..L184:6!-66.

[35] C/ajka. S. 2001. Die grunen Feen schwarmen wieder. Pharm. Ztg.,146:3948-3950.

[36] Bundesgesetz uber Lebensmittel und Gebrauchsgegenstande. Anderungvom l8.Juni20O4..Sff, 817.0.

[37[ Verordnung des EDI liber Fremd- und Inhaltsstoffe in Lebensmitieln 2002..W. 817.021.23.

[38] Duplais. P. 1882. Traite de !a fabrication des liqueurs el de la distillationdes alcools. Gauthier-Villars. Paris. France.

[39[ Fritsch, J. 1891. Nouveau traite de la fabrication des liqueurs d'apres lesprocedes les plus recents. G. Masson. Paris, France.

j40] Bedel, A. 1899. Traite complet de la fabrication des liqueurs. GarnierFreres, Paris, France.

[41] de Brevans. J. 1908. La fabrication des liqueurs. J.-B. Bailliere et tils,Paris. France.

[42] Tateo. F, and Riva. G. 199L Influence ofthe drying process on the qual-ity of essential oils in Artemisia absinthium. Mitt. Geh. Lehensm. //vjj..82:607-614.

[43] Tateo, F 1979. Useof en/ymes in the prixluction of vegetable food flavour-ing extracts. Enzyme Micwb. TechnoL. 1:282-286.

[44] Absinthism 1873. Lancet. 101:22.[45] Bielenberg. J. 2(K)2. Die griine Fee. Zentralnervose ElTekte durch Thujon.

Osten: Apath. Ztg.. 56:566-569.[46| Tegtmeier. M-. and Hamischfeger, G. 1994. Methods for Ihe reduction of

thujone content in pharmaceutical preparaiions of Artemisia. Salvia andThuja. Ear. 7. Phann. Biopharm., 40:337-340.

[47 [ Gambelunghe, C . and Melai, P. 2002. Absinthe: Enjoying anew popularity among young people? Forensic Sei. Int.. 130:183-186.

[48] Stahl, E., and Gerard. D. 1983. Hochdruek-Exiraktion von Naiurstoffenmit uberkrilischen und verflussigten Gasen. II. Mitt.: Entgiftung vonWermutkraut. Z. Lebensm. Vnier.s. Forsch.. 176:1-4.

[49] Balavoine. P. 1952. A propos de la thuyone dans les absinihes et sesimitations. M///. Geh. tu-bensm. Hyg.. 43:195-196.

[50] Cortina. B.R., and Monies, A.L. 1954. Nuevomelodoparainvestigartuy-ona en bebidas alcoholicas. Anales de Iu Asociacion Quimica Argentina,42:213-222.

[5I[ Auguet, A. 1914. Elude sur le dosage des essences dans les absinthes,liqueurs similaires et les solutions alcooliques d'huiles essentielles par lamethode oflicielle fran^aise. Annales des Falsijications et Jes Fraudes.6:385-396.

[52] Ronnei, L. 1911. Analyse des absinthes du commerce. Annales des Fal-sifications et des Fraudes. 3:477^79.

[53J Enz.H. 1911.ZumNachweisdesThujons im Absinth.Sir/jwci;. Wochschr.Chem. Pharm., 49:337-340.

[54] Philippe, E.. and Fellenberg, Th. 1911. Zur Arbeit von H. Enz "Uber denNachweis des Thujons im Absinth." Schweiz. Wockschr. Chem. Pharm.,49:418^20.

[55] Wilson. J.B. 1936. Determination of thujone in absinthe-type liqueurs. 7

[56[ Rocques, M.X. 1908. Caracterisation ei dosage de i'essence d'absinthedans les liqueurs. Annales de Chimie Analytique ei Revue de ChimieAnalytique Reunies, 13:227-232.

[.'57] Merat, E.. Martin, E., Duret. M., and Vogel, J. 1976. Extraction el dosagepar chromatographie en phase gazeuse de ^-asarone et de a- et /^-ihuyonedans les aperitifs. Trav. chim. aliment, hv^.. 67:521-526.

[58] Galli. C.L.. Galli, G., Tragni. E.. Caruso, D., and Fiecchi, A. 1984.Quantilalive analysis of a,/}-ihujone, pulegone. safrole, coumarin and/j-asarone in alcoholic beverages by selecled-ion monitoring. 7 Appl.Toxicol., 4:213-216.

376 D. W. LACHENMEIER ET AL.

[59] International Organi/,alionofthe Flavor Industry (1.O.F.I,) Recommended |7y|methods 1988. Z Lehensm. Unters. Forsch., 186:36-38. [8()|

[60] Adam, L.. and Posiel. W. 1992. Beslimmung von cf- und ^-Thujon. Safrol,Isosafrol. /!-Asaron und Cumarin in weinhalligen Getraenken uniJ Spiri- [S11tuosen, Brunntweinwirtsd)., 132:202-206.

[61] Pr/.yborski, H.. and Bandion, F, 1992. Zur Bestimmung von /i-Asaron. [82|Pulegon. Safrol. Sanionin und Thujon in Spiriluosen unil Wein. Mitt. [83|Klostemeuhur^, 42:171 -178,

[62| Rapp, A., Haslrich. H., Yavas. I., and Ullemeyer. H, 1994. Zur einfachen. [84|schnellen Anreicherung ("Kaltronmeihode") und quantitativen Bestim- [85|mung von fluchtigen Inhaltssloften aus Spirituosen: Bestimmung vonThujon. Safrol. Isosalrol. /J-Asaron. Pulegon und Cumarin. Branntwein- [86]H/mc/i., 134:286-289,

[63] Beslimmung des Thujons, gaschromalographisch 2000. In Manuei suissedes denrees alimentaires. 32/13. 1-3. Office federal de la sante publique. |87|Berne. Switzerland.

[64] Kroner. L,U,, Padosch, S.A.. Bruckner. M.S.. Lachenmeier. D.W.. [88]MuBhoff. F. and Madea, B. 2003. Optimierung einer HS-SPME/GC/MS-Melhode zur Beslimmung von Qr-//i-Thujon in alkohoiischen Getranken,LebensmitleUhenL.Sl.lH. [89]

[65] Kroner. L.. Padosch. S.A., Briickner. M.S.. and Madea. B. 2004. Deter-mination of thujone in alcoholic heverages and body Huids using HS-SPME/GC7MS, In XIII. GTFCh-Symposium: Ausgewahlte Aspekte der [90]Forensischen Toxikologic. Pragst, F and Ailerjan. R.. Eds. pp. 354-360,Veriag Dr. Dieter Helm, Heppenheim, Germany. [91 [

(66] Lander. V.. and Schreier, P !989. HPTLC-Schnelltest 7um Nachweisvon Asaron. Acorenon. Cumarin und Thujon in Wennut- und Trinkbran-ntwein. Lehensmittekhem. Gcrichtl. Chem.. 43:126-127.

[67] Micali. G.. and Lanuzza. F. 1995. HPLC determination of a- and fi- [92]thujone. potentially toxic components of natural flavourings, in alcoholicbeverages. Fkivour Fragr. J.. 10:329-333.

[68] Scott, PM.. Lawrence. G.A., and Lau, B.PY. 2004- Determina- [93]tion of thujone by derivatization with dansylhydra/ine and liq-uid chromatography. J. Liq. Chromatogr. Re!. Technol.. 27:1071- [94]1081.

[69] Bmmert, J., Sartor, G.. Sporer. F. and Gummersbach. J. 2004. Determi-nation of tt-//f-thujone and related terpenes in absinthe using solid phaseextraction and gas chromatography. Dtsch. lehensm.-tiundsch.. 100:352- [95 [356.

[70] Zabaras. D., and Wyllie. S.G. 2001- Quantitalive analysis ofterpenoids inthe gas phase using headspace soiid-phase microextraction (HS-SPME).F /o iwr f r a^ / : / , 16:411^16. [96]

[71] Wermulkraut Absinthii herba 1999. Ph. Em:. Navhtr. 2000:1510-1511.

[72] Yashiro. T., Sugimoto, N.. Sato. K., Yamazaki, T. and Tanamoto. K. 2004.Analysis of absinthin in absinlh extract bittering agent. Nippon Shokuhin [97]Kasakii Gakkai.^hi. 11:86-90.

[73] European Commission. 2(K)0. Commission Regulation (EC| No2870/2(K)0 laying down Community reference methods for the analysi.sof spirit.s drinks. Off. J. Europ. Ctmmi.. L333:20-16, [98[

[74[ Lachenmeier. D.W.. Sviridov, O.. Frank, W.. and Athanasakis. C. 2003.Schneilbestimmung des Alkoholgehaltes in Emulsionslikoren und an- [99]deren Spirituosen mittols Wasserdampfdestillation und Biegeschwinger,Disch. U-bensm.-RuiuLsch.. «)«):439-444.

[75] Fellenberg. Th. 1936. Nachweis und Bestimmung hiiherer AIko- [100]hole in Absinthimitationen. Mitt. Geh. Eebensm. Hyg.. 27:292-302.

[76] Frank, W. 2(X)2. Qualitiitssicherung. Organisation unci Analysenmetho- flOl]den. In Spirituosen-Technologie. Kolb. E., Ed. pp. 425-472. B. Behr'sVeriag, Hamburg, Germany. [102]

[77] Skopp, G.. Dettiing. A.. Pfilsch, L-, Schmitt, G., and Haffner. H.T [103]2(H)3. Begleitstoflprofile Absinth-haltiger Bitlerspirituosen. BliitalkohoL.40:287-293.

i7X[ European Council 1989. Council Regulation (EEC) No 1576/89 layingdown general rules on the delinition. description and presentation ol"spiritdrinks. O_ff. J. Eump. Comm., L160:1-17.

Absinthe and alcohol 1869. Lancet. 93:334.Magnan. V. 1874, On the comparative action of alcohol and absinthe.Liincet. 1M-AIO-A\2.Giebelmann, R. 2001. Kulturgcschichtliches zum Thujon. To.xichemKrimii-ch. 68:43-46.Hutton. I. 2002. Myth, reality and absinthe. Curr Driif> Di.scov.. 9:62-64,Strang. J.. Arnold. W.N., and Peters. T. 1999. Absinthe: what's your poi-son? BM7, 319:1590—1592,Pollmer, U. 1994. Absinth—wanun war er gittig'.' Ncitur. 66-68.Arnold. W.N., and Loftus, L.S. !99I. Xanthopsia and van Gogh"s yellowpalette. £vf. 5:503-510.Arnold, W.N.. Dalton. T P . Loftus. L.S.. and Conan, PA. 1991. A searchfor santonin in Artemisia pontica. the other wormwood of old absintlie.y.C/jf/H-£(/«(•.. 68:27-2S.Schaefer. I., Bindler, F. and Lugnier, A. 1994. Toxicological rehabilitationof absinthium liqueur. Taxicoi. Ei-tt.. 74(Suppl. I ):75.Fashionable beverage absinth: BfR advises consumers to exercise cau-tion with this product! 2003. Federal Institute for Risk Assessment Pressrelease 15/2003. Beriin, Germany.Weishord, S.D., Soule. J.B.. and Kimmel. PL. 1997, Poison on l i n e -acute renal failure caused by oil of wormwood purchased through theInternet. N. Eiigl. J. Med.. 337:825-827.De Smet. PA. 2(K)4. Health risks of herbal remedies: an update. Clin.Pharmacol. Ther., 76:1-17.Hold. K.M,, Siri.soma, N.S., Ikeda. T., Narahashi. T.. anil Casida, J.E.2000. or-Thujone (the active component of absinthet: y-aminobutyricacid type A receptor modulation and metabolic detoxification. Proc. NatlAcad. Sci. U. S. A. 97:3826-3831.Dettiing, A.. Grass. H., Schuff, A., Skopp, G., Strohbeck-Kuehner. P. andHaffner, H.T. 2(HM. Ab.sinthe: attention performance and mood under theinfluence of thujone. / Stud. Alcohol.. 65:573-581.OLsen. R.W. 2000. Absinthe and y-aminobutyric acid receptors. Proc.Natl. Acad. Sci. U. S. A. 97:4417-1418.Sirisoma. N.S., Hold, K.M., and Casida. J.E. 2001, a- and ^-Thujones(herbal medicines and fo(xi additives): synthesis and analysis of by-droxy and dehydro metabolites. / Agric. Food Chem.. 49:1915-1921.Hold. K.M.. Sirisoma, N.S., and Casida. J.E, 2001. Detoxification of «-and /J-Thujones (the active ingredients of absinthe): Site specificity andspecies differences in cytochrome P450 oxidation in vitro and in vivo.Chem. Res. Toxicoi. 14:589-595.Deiml. T., Haseneder. R.. Zieglglinsberger. W.. Rammes, G., Eisensamer.B.. Rupprecht. R.. and Hapfelmeier. G. 2004. or-thujone reduces 5-HT3receptor activity by an effect on the agonist-reduced desensitization. Neu-rophariuacology. 46:192-201,Behrens. M.. Brockhoff. A,. Kuhn. C . Bufe. B.. Winnig. M.. and Meyer-hof. W, 2004. The human laste receptor hTAS2R 14 responds to a variety ofdifferent bitter compounds. Biochem. Biophys. Res. Commiin.. 319:479-485.Lachenmeier, D.W, 2(HM. Hanfhaltige Lebensmittel—ein Problem?Dt.uh. Lebensm.-Rundsch., 100:481-190.del Castillo. J., Anderson. M,. and Rubottom. G.M. 1975. Mari-juana, absinthe and the central nervous system. Nature, 253:365-366.Meschler. J.P. and Howlett, A.C. 1999. Thujone exhibits low affinityfor cannabinoid receptors but fails to evoke cannabimimetic responses.Phanmicol. Biochem. Behav.. 62:473^80.MUller. 0. 2(H)2. Wermut - gefdhrliches Kraut in harmloser Verpackung.Zahndrztl. Mill.. 92:n.Werner, H. 2002. Absinth. Ullstein Veriag, Munchen. Germany.Bonkovsky, H.L., Cable. E.E.. Cable. J.W,. Donohue. S.E., White.F..C,. Greene. Y.J,. Lambrecht, R.W., Srivastava. K.K.. and Arnold.W,N, 1992. Porpbyrogenic properties of the terpenes camphor, pinene.and thujone (with a note on historic implications for absinthe andthe illness of Vincent van Gogh). Biochem. Pharmacol.. 43:2359-2368.

ABSINTHE—A REVIEW 377

[1041 He. X., and de Monlellano, P.R.O. 2004. Radical rebound mechanism |IO7| Begriflsbestimmungen fiir Spirituosen in der Fassung vom 24.6.1971in cytochromeP-450-catalyzedhydroxylalionoflhemultifaceIed radical 1971. Bund fur Lebensmittelrecht und Lebensmittelkunde. Hamburg,clocks alpba-and beia-lhujone. 7. Biol. Chem., 279:39479-39484. Germany.

|105] Max. B. 1990. This and tbat: Cheap drinks and expensive drugs. TiPS. [108] Bundesversammlung 1910. Bundesgeset/ betreffend J;is Absjnthverbot.11:56-60. Schweiz. Wochschr. Chem. F/irtrm.. 48:677-678.

1106] Hinkelhein. J. 2(K)4. Absinth—the renaissance of Ihe green fairy. Aktuel. 11091 Schweizer Bundesrat 1910. Vollziehungsgesetz zum Bundesgeset/ befre-ErnaehrMed..29:[i^-l4]. ffentidas Absinthveibot.Schweiz. Wockschr. Chem. Pharm.