AOAC Official Thujone Detection Method

Excerpt from

Official Methods of Analysis of the
Association of Official Analytical Chemists


It is not expected that the average reader will have either the expertise, resources, or inclination to perform this operation; it is provided for educational purposes only.

It should be noted that this method only detects the presence of thujone, with margin of error of 10ppm. Although there are much more accurate means now available to measure thujone content, the current regulations hinge on the margin of error for this particular method, hence, 10ppm is considered to be "thujone free".


9.129 Thujone (25)ยน Official First Action

    To 500 mL sample add 1 mL freshly distilled aniline and 1 mL H3P04, and reflux 30 min on steam bath.   Distill two 100 mL portions; reject first and test second for thujone as follows:

    Add 0.5 g semicarbazide hydrochloride and 0.6g anhyd NaOAc (or 1.0 g crystd salt) and let mixt. stand overnight. Distil off alcohol at min. pressure.  Steam distil to remove essential oils and other volatile material; collect and reject first ca 15 mL distillate . Wash down condenser with little alcohol and with H20.  Cool sample, add 1 mL H2S04 (1 + 1), and again steam distil, collecting 20 mL distillate in cylinder.  Pour distillate into small separator, and add 20 mL ether, using receiver as measure.  Shake and sep. ether soln. Add 10 mL 65% alcohol and let ether evap. spontaneously.   After all ether evaps, note odor of residue. Odor of thujone will be apparent if  > .2 mg is present in soln, provided it is not masked by presence of other odoriferous substances.  Make modified Legal test as follows:

    To soln obtained as above, add 1 mL 10% ZnS04 soln and 0.25 mL freshly prepd aq. Na nitroprusside soln (0.1 g/mL). Slowly, with const stirring, add 2 mL 5% NaOH soln. Let stand 1-2 min. Add 1.5 mL HOAc and mix. Ppt of raspberry red color (resembling alcohol ppt of red fruit juice) shows presence of thujone. Neg. test is shown by similar ppt having appearance similar to that of alcohol ppt from apple jelly or other light colored fruit. 

A Classic Cocktail

Yellow Daisy Cocktail

(Serves 6)

2 glasses gin
2 glasses French vermouth
1 glass Grand Marnier
1 dash of absinthe

Shake with ice. Strain into 6 cocktail glasses.

Not only the favourite drink, but also the one made famous, if not invented, by Richard William ("Deadwood Dick") Clark, recently deceased.*
Onetime Custer scout, Pony Express rider, Deadwood Gulch stage coach guard, inspiration for all the Deadwood Dick novels of E. L. Wheeler, friends of Wild Westerners, Wild Bill Hickok, Buffalo Bill, Poker Alice Tubbs, Calamity Jane, Madame Mustache and Diamond Dick Turner of Norfolk, Nebraska.  Clark is buried on Sunrise Mountain, overlooking Deadwood Gulch, South Dakota.

*Recently in 1930 -ed.

Savoy Cocktail Book, 1930 

Wormwood Society Gear

Available in our CafePress store with white or full color seal on a range of colored shirts. Mens, womens, hoodies & more.

Absinthe Tasting Journal

front cover th
The WS Absinthe Tasting Journal

With room for over 200 tastings, provides novices and experts with a primer in absinthe history and facts, as well as instructions on how to conduct scorings and blind tastings.

Real-Time Global Visitors