XX] 



FLAVORING EXTRACTS 



267 



45 Quantitative Method. — Tentative. 



(In the absence of chlorids.) 

 Measure 25 cc. of the extract into a small flask and add 5 cc. of freshly precipi- 

 tated magnesium hydroxid (chlorin-free). Titrate with N/10 silver nitrate solu- 

 tion, using potassium chromate as an indicator; 1 cc. of N/10 silver nitrate is 

 equivalent to 0.00268 gram of hydrocyanic acid. 



NITROBENZOL. 



46 Qualitative Test. — Tentative. 



Boil a few cc. of the extract with some zinc dust and acetic acid and filter. Add 

 to the filtrate a drop of chloroform, make strongly alkaline with sodium hydroxid 

 solution and heat. The presence of nitrobenzol in the original extract is indicated 

 by the development of the characteristic odor of phenylisonitrile. 



CASSIA, CINNAMON AND CLOVE EXTRACTS. 



47 ALCOHOL.-TENTATIVE. 

 Determine as directed under 41 . 



48 



Hortvet and West Method^.— Tentatii 



Transfer 10 cc. of the extract to a separatory funnel, add 30 cc. of water, acidify 

 with 1 cc. of hydrochloric acid (1 to 1) and extract 3 times with ether, using not 

 less than 100 cc. altogether. Wash the combined ether solutions twice with water 

 and, in the case of cinnamon extract, dry by shaking with a small amount of granu- 

 lated calcium chlorid. Transfer to a tared, wide-mouthed weighing bottle and evap- 

 orate the ether as rapidly as possible on a boiling water bath, rotating the liquid 

 upon the sides of the bottle in order to rid the residual oil of traces of ether. Weigh 

 the residue and divide the weight by the specific gravity of the oil in order to ob- 

 tain the per cent of oil by volume. In the case of clove oil, allow the weighing bottle 

 to remain in the balance case until the usual film of moisture has evaporated. The 

 time of weighing, however, should not be delayed over 3 minutes. 



Determine the refractive index of the residual oils at 20°C. 



Dissolve a drop of the oil in several drops of alcohol and add a drop of ferric 

 chlorid solution. The following tabulation gives the specific gravity, refractive 

 index at 20°C. and color reaction with ferric chlorid solution: 



GINGER EXTRACT. 



49 ALCOHOL.-TENTATIVE. 

 Determine as directed under XVII, 4. 



50 SOLIDS.-TENTATIVE. 



Evaporate 10 cc. of the extract nearly to dryness on a water bath, dry for 2 hours 

 in a water oven and weigh. 



