IX] SACCHARINE PRODUCTS 129 



turn the filter paper and contents to the platinum dish, ignite carefully, and weigh. 

 Calculate the percentages of water-soluble and water-insoluble ash. 



1 8 ALKALINITY OF THE SOLUBLE ASH.-TENTATIVE, 



Cool the filtrate from 1 7 and titrate with N/10 hydrochloric acid, using methyl 

 orange as an indicator. 



Express the alkalinity in terms of the number of cc. of N/10 acid per 1 gram of 

 the sample. 



19 ALKALINITY OF THE INSOLUBLE ASH.-TENTATIVE. 



Add an excess of N/10 hydrochloric acid (usually 10-15 cc.) to the ignited insolu- 

 ble ash in the platinum dish, under 1 7, heat to boiling over an asbestos plate, cool, 

 and titrate the excess of hydrochloric acid with N/10 sodium hydroxid, using methyl 

 orange as an indicator. 



Express the alkalinity in terms of the number of cc. of N/10 acid per 1 gram of 

 the sample. 



20 MINERAL ADULTERANTS IN THE ASH.-TENTATIVE. 



Mix 100 grams of molasses, sirup, honey, or the confectionery solution prepared 

 as directed under 1 (b) and evaporate to a sirupy consistency, with about 35 grams 

 of concentrated sulphuric acid in a large porcelain evaporating dish. Pass an 

 electric current through it while stirring by placing one platinum electrode in the 

 bottom of the dish near one side and attaching the other to the lower end of the 

 glass rod with which the contents are stirred. Begin with a current of about 1 

 ampere and graduallj'- increase to 4 (modified from method of Budde and Schou* 

 for determining nitrogen electrolytically). In 10-15 minutes the mass is reduced 

 to a fine dry char, which may be readily burnt to a white ash in the original dish 

 over a free flame or in a muffle. 



This method^ is preferred to the ordinary method of heating with sulphuric acid, 

 especially in the case of molasses, because, if properly manipulated, it comes quietly 

 into the form of a very finely divided char or powder, especially adapted for subse- 

 quent quick ignition. 



If an electric current is not available, treat in a large porcelain dish 100 grams of 

 the saccharine solution, evaporated to a sirupy consistency, with suflBcient concen- 

 trated sulphuric acid to thoroughly carbonize the mass and ignite in the usual 

 manner. 



The following adulterants may be present: salts of tin, used in molasses to bleach; 

 mineral pigments, such as chromate of lead in yellow confectionery; oxid of iron, 

 sometimes used to simulate the color of chocolate; and copper. These elements 

 may be detected by the usual qualitative tests. 



21 NITROGEN.— TENTATIVE. 



Determine nitrogen in 5 grams of the material as directed under I, 18, 21 or 23, 

 using a larger quantity of the sulphuric acid if necessary for complete digestion. 



SUCROSE. 



22 Method I.— Tentative. 



(Substances in which the volume of the combined insoluble matter and precipitate 

 from clarifying agents is less than 1 cc. from 26 grams.) 



Determine sucrose by polarization before and after inversion, as directed under 

 VIII. 14. 



