I N D U S T R I A L A X D ENGINEERING C H E M I S T R Y
March, 1925 Table VII-Analysis
of Indigo and Indirubin in Admixture 1 cc. TiCh = 0.006257 gram indigo N e t assay = 0.2000 gram Recoverv -...~ calcd.-as TiCla indigo Expt. cc. Per cent Purified indigo 1 31.92 99.85 2 31.87 99.70 3 31.90 99.77 Purified indigo plus 5% indirubin 4 31.90 99.77 5 31.87 99.72 6 31.84 99.65 ~~
No distinction is therefore possible between indigo and indirubin by this method, the latter being also quantitatively recovered. Conclusions Upon the data presented above, the optimum conditions for the determination of indigotin by the method under investigation may be stated as follows: Weigh 1.000 gram of the dry ground sample into a 30-cc. tall-form weighing bottle,
303
add 15 cc. of concentrated sulfuric acid, stopper, and place in an oven a t 60"-65" C. for one hour. Cool to room temperature, drown in 400 cc. of water and dilute to 500 CC. Pipet a 100-cc. aliquot into a 300-cc. Erlenmeyer flask, add 20 grams of crystallized sodium tartrate, connect to the carbon dioxide generator and boil for 3 to 5 minutes. Sweep with carbon dioxide and titrate hot with 0.05 N titanous chloride to the last distinct color change. The end point is readily determinable within one drop, the final color change being from green to yellow. From these data it is also evident that the results are not appreciably influenced by variations in technic. The amount and strength of the sulfonating acid, the duration and temperature of sulfonation, the volume of solution titrated, and the amount of sodium tartrate may all be varied within quite wide limits without detriment. The rate of titration is also without significance. The method is capable of yielding results accurate within 0.2 per cent, on the 100 per cent basis.
Identification of Sources of Vanilla Extracts' By C. B. Gnadinger MCLAUGHLIN GORMLBYKINGCo;,MINNEAPOLIS, MI".
IC'DER the present standards for flavoring extracts2 the term "vanilla extract" may properly be applied to the alcoholic extract made from the beans of any variety of Vanilla planifolia Andrews. The extract trade, however, distinguishes between the several varieties, Tahiti beans being considered the least desirable and therefore commanding a much lower price than Mexican or Bourbon beans. The extract of vanillons cannot legally be sold as vanilla extract, but supplies of vanillons are usually obtainable in this country. Since the extracts of the different varieties of beans can be distinguished only by experts, who depend upon the senses of smell and taste, a chemical method for differentiating them would be advantageous. The purpose of this paper is to point out certain differences in composition between Tahiti and Bourbon beans and to describe a method for detecting the addition of extract of Tahiti beans or extract of vanillons to the better and more costly grades of vanilla extract.
U
Aromatic Constituents of Tahiti Beans
I n his work on Tahiti vanilla beans, Wahlbaum3 found anisyl alcohol, anisaldehyde, and anisic acid among the aromatic constituents other than vanillin. Wahlbaum did not investigate the composit,ion of Bourbon beans, and this work was accordingly undertaken by the writer. Preliminary to the examination of Bourbon beans the work of Wahlbaum on Tahiti beans was repeated, using a slightly different procedure. Five kilograms of Tahiti beans were extracted by percolation with chloroform, which was then distilled to a volume of 800 cc. The chloroform solution was distilled with steam, the chloroform separated, and the aqueous distillate extracted with ether. The chloroform and ether extracts were combined and washed with 5 per cent sodium hydroxide solution. and then with saturated sodium bisulfite solution. The chloroform-ether solution was again distilled with steam and the 1 2
8
Received September 24, 1924. Officeof Secretary, U.S. Dept. Agr., Circ. 186. Schimmel's Semi-Annual Report, October, 1909, p. 142.
aqueous distillate extracted with ether. This chloroformether solution yielded on evaporation 3 grams of yellowish oil having a pleasant odor and pungent taste. A portion of the oil on oxidation with dilute acid permanganate solution yielded a colorless, tasteless acid, which on recrystallizing from hot water had a melting point of 182.8' C. (corrected), compared with 184.2' C. for anisic acid. A minute quantity of the oil mixed with 2 cc. concentrated sulfuric acid gave a red color, identical with that obtained with anisyl alcohol. The refractive index a t 24" C. was 1.5411, compared with 1.5438 for anisyl alcohol prepared in the laboratory. The oil did not solidify a t 0" C. This portion of the volatile oil of Tahiti vanilla appears to consist largely of anisyl alcohol with small amounts of other compounds, probably esters. The sodium bisulfite solution washings were treated with an excess of sulfuric acid, and carbon dioxide was passed to remove the liberated sulfur dioxide. The solution was then extracted with ether and the ether evaporated spontaneously. A small amount of liquid having a pleasant odor was obtained. On treating with phloroglucin and hydrochloric acid a faint orange color was obtained, indicating the absence of piperonal and the absence of more than traces of anisaldehyde. The quantity obtained was too small for identification. The nonvolatile residue from the original steam distillation was dissolved in ether and washed nrith the 5 per cent sodium hydroxide washings mentioned above. The alkaline solution was acidified with sulfuric acid and extracted with ether. The ether solution was washed repeatedly with saturated sodium bisulfite solution to remove vanillin and evaporated to dryness. Six grams of tasteless acid were obtained. This material was purified by crystallizing three times from hot water and three times from alcohol. Its melting point was 184.1O C. (corrected), and its neutralization equivalent 151.3. The constants for anisic acid are 184.2" C. and 152, respectively. On fusing with potassium hydroxide an acid melting a t 213.2' C. was obtained. Under similar conditions anisic acid yields p-oxybenzoic acid, melting a t 213" to 214" C. The acid is therefore anisic acid.
Aromatic Constituents of Bourbon Beans
Fur the work on Bourbon beans, prime 20-cni. lieuriiuii Iwans were used. Fifl,y-nine kilograms of the finely chopped material were extracted hy ma,ceration and percolation with chloroform during a period of one month. The chlorofi,rm extract was treated in much the same manner as the extract obtained from the Tahiti beans. Thrce grams of light yellow volatile oil were obtained. Tlx reSrai,tire index a t 24' C . vas 1.4850; specific gravity at C., 1.079; taste,slightly pungent; odor, agrceirblc sit(! rstrcmely uersistent; and it was insoluble in boiling watrr or in 40 per ~ e n alcohol t hut soluble in alcohol. On chilling to - 20° C a few small crystals formed, hut the bulk remainrri liqiiic!. .4eids, phenols, and aldehydes had been previously riwioI:id. Appropriate qualitatiT-e tests indicated the prrsenre of ahwhois and enters. A port,ion of the oil was sapiinihed with aqneous pot:assiitni liydmaide solution. From tbe saponification products :I smd1 amount of ciniirimio arid was isolated. This was identified tiv its melting point,, 131 c.,b.v the formation of b e n d drhyde on treating with cold dilute permanganate solotiim, mil by its soluhility. The hiiiling point of tltr mixed alrohols separaied after sapotiifieatioil was 190" C. by the capillriry totie method. S o anisyl alcohol or anisic acid was present, eitber befirre or after the saponification, Ciriiiamir acid mat formd i u small amorint in the alkalinr washing.; wt~ercitnisic Rcid I i u d hrm Sonnrl i n the Tahiti beans. A n i a ~ Alcuhol l i n Vanilla ExtractsTealfor Age of
d r : i r t s were of statrdard stretigt.1, (IO gralirs of beaus per 100 vr.1 and r:oiitained 40 per cent aleohol and 12 grains of sogm per 100 ce. The results are given in the table. Forty per cent alcohol extracts of shavings from oak arid fir harrels gave negative tests. By comparison with known mixtures under identical conditions thc test can be made roughly qiiantitative. Summary
'l'lir whitilc! uil of Tahiti vanilla beans consists cliieHy miisyl iilrohol a,%Wnhlharirn has pointed out. The tieails m i t n i n about O.O(i per rent of volatile oil. Anisic :acid is :also present in these beans. The vidat.ile oil of Bourbon vmiliir kieaia does not coiitaiii i m i s y l alcohol brit consists of a small amount of cinnanrie :wid esters and an unidentified alcohol haviirg a pleasatit persistent odor. Cinnamic acid is present in minute quantities in Bourbon heans. The percentage of volatile oil is Jbiiiit me-tenth of the amount present in Tahiti beans. ;knisyl alcohol is also present in vanillons. .i method for detecting anisyl alcohol in vanilla extracts is dc?scriheil. By this test the presence of 5 to 10 per ceut of Tahiti extract or extract of vanillotis in t,he more costly llourbon or Mexican extract cat1 be dct.ected. Mexican, South American. and J n r a ranilla extracts, iis wcll as 13oiirh01i extracts, *vi: negatiI:r tevts for a i k y l akottol by tliia metho& iif
A New Laboratory Mill'
extract
KIND0s BEAN Mericso Mexican Mexican MeXica*-
South American Java Bourbon tComoieri Bourbon (Reunion) Bourbon Reunion) Bourbon hkxt%ion>
Tonka Surinam
T o o k Angosturn Tahiti Tahiti Tahiti Tahiti Tahiti (contained 105%BIYE-
Months 23 18 6 4 I 1 27 I8
10
1
5 5
27 24 14
6 I
Detection of Anisyl Alcohol i n Vanilla Extract
It. was clearly shown that Tahiti berrns contain anisyl d c i i l i d and Bourbon beans do not,. This suggested a posribk method for distinguishing betweeti the extracts of the two kinds of beans, sincc the color react.iirn produrrd on itrisiitg a minute quantity of anisyl alcohol Tvith 2 to 3 cc. of i:onceiitrated sulfuric acid is VPI ' semitiye. The following test was foimd to give satisfaet,o rrsults when :ipi)Iiril to differeitt vanilla extracts: 1
Measure 50 cc. of the extract into an vvapoiating dish anti evaporate spontaneously before a iarr to 8 volume pf about 15 C E . Transfer to a separatory funnel r\&h water, dilutmg to 50 cc. Extract once with 50 cc. of ether. Wash the ether extract thrce times with 15-cc. portions of 2 per mnt sotlimn hydroxide .solution and once with 15 cc. of water. Evaporate the ether cxtract before a fan,and as soon as the ethpr is driven offdissolve the residue in 0.5 ec. of alcohol. Add two to three drops of the alcohol solution to 2 to 3 cc. of concentrated sulfuric acid in a test tnbe and mix. In the case o i Tahiti vanilla extract a deep, prrmanent red color develops immediately.
This method was applied to a number of different extracts i u the lalioratorr from hmtrs of knovn oripin. These
iii:iilr
By S . W. Wiley \\:~LxY
& C o i i r ~ ~Iuu .r , . B I I . T I M O ~ L Sin .
W I L recently there has not beeu any mill on the mnrkct bith so wide a range of adaptation as the laborat,ory inill hiarewith illustrated. Four knives on a revolving ahaft work with a shearing action against six knives which are set in the frame of the mill. Since the screen is dovetailed into this frame, none of the material comes out of the grinding chamber itntil it is fine enough to pass through the mesh. The door tieing hinged, the mill is quickly and easily i.lraned. With-
