J u n e , 1915
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
Table I1 should be compared with t h e analyses reported b y m i n t o n a n d Berry.‘ T h e influence of sugar or glycerine in t h e menstruum on t h e a m o u n t of acidity a n d ash extracted was hardly appreciable. Decreasing t h e strength of t h e alcohol increased t h e amount of ash a n d diminished t h e acidity. S U M S IA R Y
I-The following ranges in acidity a n d in ash values were found in 7 7 U . S. P. extracts made i n t h e laboratory from different varieties, grades a n d lengths of vanilla beans: TOTAL ACIDITY:
30 to 52 cc. N/10 alkali per 100 cc. ACIDITYOTHER THAN VANILLIN: 14 t o 42 cc. “10 alkali per 100 cc. TOTAL ASH: 0.220 to 0.432 gram per 100 cc. SOLUBLE ASH: 0.179 t o 0.357 gram per 100 cc. OF TOTAL ASH: 30 to 54 CC; N/10 acid per 100 CC. ALKALINITY ALKALINITY OF SOLUBLE ASH: 22 to 40 cc. hr/10 acid per 100 cc.
11-Practically t h e same values were obtained with a n d without t h e use of sugar or glycerine in t h e menstruum. 111-Diminishing t h e strength of alcohol in t h e mens t r u u m tended t o increase t h e ash values a n d diminish t h e acidity. IV-The possibility of developing a method of determining vanillin based on t h e acidity is suggested. BUREAU OF CHEMISTRY, WASHIBGTON, D. C.
A MODIFICATION O F WICHMANN’S M E T H O D F O R THE DETECTION OF SMALL AMOUNTS O F COUMARIN, PARTICULARLY I N FACTITIOUS VANELA* EXTRACTS By J. R. DEAN Received April 9, 1915
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T h e essential part of t h e Wichmann method for t h e detection of coumarin in vanilla extracts is t h e conversion of t h e coumarin, in t h e residue obtained b y evaporating t h e distillate from a vanilla extract t o dryness, into salicylic acid b y fusion with potassium hydroxide a n d testing for salicylic acid with ferric chloride. Saccharin a n d salicylic acid interfere completely with this test. T h e following modification of TVichmann’s method has been found t o be as useful as t h e original, is much less troublesome a n d is not interfered with by either salicylic acid or saccharin. Render a de-alcoholized portion of t h e extract alkaline with j cc. of ammonia (use of t h e residue after a n alcohol determination is recommended) a n d extract with I 5 cc. of ether.3 Iranillin, salicylic acid and saccharin are insoluble in ether in t h e presence of ammonia while coumarin is readily dissolved. Transfer t h e ether t o a nickel or porcelain crucible a n d evaporate on t h e steam b“ath or hot plate. Add five drops of a j o per cent solution of potassium hydroxide a n d , after carefully drying, fuse a t t h e lowest possible temperature, care being t a k e n t o avoid any blackening. Dissolve t h e mass i n a few cc. of water, render acid with dilute sulfuric acid a n d transfer t o a test tube. Add j cc. of Lac. C i l . Method for the Detection of Small Amounts of Coumarin. Particularly in Factitious Vanilla Extracts,” by H. J. Wichmann. Circular 96, U. S. Dept. of Agr., Bureau of Chemistry. Hess and Prescott, J. A . C. S., 28 (1899), 256. 1
’ “A
519
chloroform t o dissolve o u t t h e salicylic acid produced i n t h e fusion a n d shake t h e t u b e vigorously. Xllow t h e chloroform t o separate a n d remove i t with a small pipette extended t o t h e b o t t o m of t h e tube. Transfer t h e chloroform t o a second test tube, filtering through a small plug of cotton. Add I or z cc. of water, containing a drop or t w o of ferric chloride solution, t o t h e chloroform a n d shake a s before. T h e presence of coumarin is indicated b y t h e formation of t h e purple color of ferric salicylate. TABLEOF R ~ S U L T S SAMPLES Extract of vanilla plus A’othing 25 mg. salicylic acid 25 mg. saccharin 1 mg. coumarin 2 . 5 mg. coumarin 5 mg. coumarin 5 mg. coumarin 25 mg. salicylic acid 25 mg. saccharin 25 mg. coumarin
No. of samples Results 4 Negative 4 Negative 4 h’egative 4 Positive 4 Positive 4 Positive
1\
Depth of purple color
Light purple Strong purple Deep purple
4
Positive
Deep purple
4
Positive
Very deep purple
I t does not seem possible t o employ t h e above reaction i n a n accurate quantitative method for coumarin t h a t would be a n y shorter or better t h a n t h e extraction method now employed. By experience, however, one can learn t o form a very good idea of t h e a m o u n t of coumarin present b y t h e depth of color obtained. Attention is called t o t h e f a c t t h a t coumarin would interfere with Durand’sl test for saccharin as both coumarin a n d saccharin yield salicylic acid when fused with either potassium or sodium hydroxide. It is possible t o eliminate t h e saccharin, as stated above, b u t as coumarin is of such a n inert nature chemically, i t s removal is far less easy-an extraction b y means of a n immiscible solvent in t h e presence of a n alkali being t h e method generally used. Coumarin a n d saccharin are very likely t o be f o u n d together in food products, especially in soft drinks of a cheap nature where coumarin has been used in place of, or with, vanilla or vanillin. I n using Durand’s test for saccharin i t would be necessary t o remove t h e coumarin b y rendering t h e substance alkaline a n d extracting as above. After t h e complete removal of t h e coumarin, t h e sample under e x a m h a t i o n could be rendered acid a n d tested for saccharin as in Durand’s method. 520 CHURCH STREET,ANH ARBOR,MICHIGAN
STUDIES I N SYNTHETIC DRUG ANALYSIS 111-ESTIMATION O F CAFFEINE AND ANTIPYRIN I N
ADWXTURE By
a‘.0. EMERYA N D
S. PALKIN Received March 20, 1915
T h e first recorded a t t e m p t s looking t o t h e quantitative separation of these t w o drugs were apparently made by J . J . Hofman,2 who, taking advantage of t h e tendency of antipyrin t o yield with mercury salts difficultly soluble products, subjected t h e caffeineantipyrin mixture t o t h e action of mercuric nitrate, thereby precipitating t h e antipyrin as t h e molecular compound CllHl2N20.Hg(N03)2. After separating t h e precipitate b y filtration, t h e caffeine was isolated from a n aliquot of t h e filtrate by extraction with chloroform a n d estimated as pure caffeine. The weight of t h e 1
Halsey Durand, THISJOURNAL, 6 (1913), 987.
2
Pharm. Weekblad, No. 49 (1894).
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