93 
Ret cc. “of Os iodine Ronition: ane 2 cc. of hydrochloric acid is heated up to 50° C. 
for 6 to 7 minutes. After cooling, the titration is carried out in the usual way; 
_ 1 molecule of the compound requires only 2 atoms of iodine, as this only oxidizes 
‘Z the sulphurous acid but does not act on the double bond of the cinnamaldehyde mole- 
cule. The content of cinnamaldehyde is then calculated from the difference between - 
: the consumption of bromine and iodine, as 1000 cc. (N-bromine solution — JN-iodine 
solution) correspond to half a molecule = “24 gram of cinnamaldehyde. The pure 
| cinnamaldehyde bisulphite compound must use up exactly twice as much bromine as 
iodine. If more iodine be consumed, a corresponding quantity of benzaldehyde bisulphite 
compound and sodium sulphite is present. The presence of a little benzaldehyde does 
3 not influence the shade of colour and may, therefore, be neglected. 
4 . In order to estimate the cinnamaldehyde in cinnamon, one proceeds as follows: 
1 gram of finely powdered cinnamon and 40 cc. of 95 per cent. alcohol are placed 
into a flask of 400 cc. capacity, which is connected with a condenser and a measuring 
flask of 100 cc. The mixture is kept slightly boiling for 10 minutes, after which 
time the alcohol is distilled off until only 5 to 10 cc. remain, when 100 cc. of water, 
previously boiled and therefore free from oxygen, are added. The distillation is then 
carried on fairly quickly, until the distillate, together with the alcohol that passed 
-_ ever in the beginning, comes up to nearly 100 cc. One then adds the difference, so 
: as to obtain fully 100 cc., and pours 5 cc. of the distillate, together with 2 cc. of the . 
solution of isobutyl alcohol and 3 cc. of alcohol of 38 per cent., into a measuring 
flask of 100 cc. Holding said flask a little inclined, one carefully adds 20 cc. of con- 
centrated sulphuric acid, shakes the mixture and then allows it to rest for °/4 of an 
3 hour. 5 cc. of the type solution are treated in the same way. The colorations are 
. then compared in the colorimeter (Duboscq’s being the best). It is permissible to | 
_ dilute with dilute sulphuric acid (2 vols. of concentrated sulphuric acid and 1 vol. of 
water) to the extent required. The intensity of coloration found is multiplied by 2, 
‘ and the corresponding percentage of cinnamaldehyde may then be read from tables 
~ that accompany the publication. 5 
The percentages of cinnamaldehyde in the materials tested were: 1.31 to 1.84 percent. | 
in Ceylon cinnamon, 1.01 to 1.05 per cent. in cinnamon chips, 1.23 to 2.77 per cent. in 
cassia bark and 3.77 per cent. in flores cassie. 
The same author’) likewise describes a colorimetric method of estimating vanillin 
in vanilla, founded, as in the case of cinnamaldehyde, on the coloration resulting when 
vanillin is brought together with concentrated sulphuric acid and isobutyl alcohol. 
When sampling, due regard must be given to the fact that the vanillin is not quite 
evenly distributed in the vanilla bean. According to von Fellenberg, a good average 
is obtained by taking either the middle ee or two pieces equally far apart from the 
- centre piece. 
a The following description of the method is given: The vanilla bean is weighed and 
| an average sample selected as indicated (about 1 gram). Its weight must be determined 
quite exactly. This sample is cut in transversal sections of 1 to 2 mm. thickness, 
’ but which ought still to hang together in one spot, quantitatively placed into a small 
flask and extracted 4 times under a reflux condenser with altogether 90 cc. of water, 
by boiling each time for 3 to 5 minutes and pouring the slightly cooled extract into 
a measuring flask of 100 cc. From and after the second extraction, one expresses 
5 
ae es a. rv 
1) Mitt. Lebensmittelunters. u. Hyg. 6 (1915), 267. 
