SACCHARINE PRODUCTS. 45 



4. DETERMINATION OF ASH. 



Weigh out from 5 to 10 grams of molasses, honey, or sirup, or weigh 5 grams of the 

 pulverizable confectionery, or measure 50 cc of the 20 per cent solution 2 (c) (1) 

 (6) into a tared platinum dish; evaporate to dryness on the water bath and burn 

 slowly and cautiously over a low flame. After frothing has ceased, increase the flame 

 and ignite to a white ash at a low, red heat. 



In igniting saccharine products, frothing .may be largely held in check by direct- 

 ing the flame at first down upon the mass from above instead of from under the 

 dish, as ordinarily, until the material is well charred. 



5. EXAMINATION FOR MINERAL ADULTERANTS. 



(a) REDUCING TO ASH. 



Comparatively large quantities of saccharine products may be readily and quickly 

 reduced to an ash for mineral examination without the troublesome frothing that 

 ordinarily ensues in igniting at once with a free flame by proceeding as follows:* 



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

 (2 (c) (1) (&)) evaporated to sirupy consistency, with about 35 grams of concentrated 

 sulphuric acid in a large porcelain evaporating dish. An electric current is then 

 passed 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 gradu- 

 ally increase to 4. h In from ten to fifteen minutes the mass is reduced to a fine, dry 

 char, which may then be readily burnt to a white ash in the original dish over a 

 free flame or in a muffle. 



If an electric current is unavailable, treat in a large porcelain evaporating dish 100 

 grams of the saccharine solution to be ashed, which should be evaporated to sirupy 

 consistency if not already such, with sufficient concentrated sulphuric acid to thor- 

 oughly carbonize the mass, after which ignite in the usual manner. 



Among the suspected adulterants to be looked for in the ash are salts of tin, used 

 in molasses to bleach or lighten the color, and mineral pigments such as chromate 

 of lead in yellow confectionery, and oxide of iron, the latter being commonly used 

 as an intensifier of or substitute for the natural color of chocolate. 



(b) DETERMINATION OF TIN IN MOLASSES AND OTHER SACCHARINE PRODUCTS. 4 



Fu.se the ash from a weighed portion of the sample with sodium hydroxid in a 

 silver crucible, dissolve in water and acidulate with hydrochloric acid; 6 filter and 

 precipitate the tin from this solution with hydrogen sulphid; wash the precipitate 

 on a filter and dissolve it in an excess of ammonium sulphid. Filter this solution into 

 a tared platinum dish and deposit the tin directly in the dish by electrolysis, using 

 a current of 0.05 ampere. This current may be readily reduced from an ordinary 

 110- volt street circuit by means of a series of lamps, or a rheostat may readily be 

 improvised for this purpose, consisting of a long, vertical glass tube, sealed at the 

 bottom, containing a column of dilute acid through which the current passes, the 



Leach. 32.1 An. Rept. Mass, State Board of Health. (1900.) p. 663. Reprint, p. 37. 



This method is preferred to the ordinary method of heating with sulphuric: acid, especially in ease 

 of molasses, because, if properly manipulated, it so quietly comes into the form of a very finely divided 

 char or powder, especially adapted for subsequent quick ignition. 



' Modified from method of Budde & Schou for determining nitrogen electrolytically. Ztschr.anal. 

 Chem., Is'.i'i, :&S. :;(.-,. 



Leach. :;ist An. Kept. Mass. State Board of Health, 1899, p. 625; Hilger & Laband, Ztschr. fvir Unter- 

 snehniiK der Nahr.- u. (Jennss., 1X99, 2, 795. 



This method is npplieahle also to condensed milk, eanncd goods, etc. 



See Methods for the .\miiination of canned vegetables, p. 52. 



