PHENAOETIN. 41 



but the presence of acctanilid CMUM^ a precipitate of p-hmmacctanilid 

 which melts at from 166 to 168 C. This test is recognized in the 

 British and German pharmacopeia^. 



SAPONIFICATION TEST (P. N. I:\IK..\\ \M> P. SCHTARBANO\V). 



This test is based on the fact that . acetanilid decomposes more readily 

 with a fixed alkaline solution than phenacetin. It is applied as follows: 



In a test tube of suitable size, provided with a perforated rubber 

 stopple carrying a bent tube about 20 cm long, place 1 gram of 

 acetanilid or phenacetin or a mixture of the two and 8 cc of a 25 per 

 cent solution of potassium hydroxid and submit the mixture to distil- 

 lation. Receive the distillate in a second test tube containing about 

 5 cc of a good bleaching-powder solution. With acetanilid alone a 

 violet blue or purplish coloration develops, due to the anilin distilled; 

 with phenacetin a brick-red opalescent solution forms by the inter- 

 action of the phenetidin and calcium h} T perchlorite; with a mixture 

 of phenacetin and acetanilid the first few drops of the distillate give 

 the violet-blue coloration, while the latter portion of the distillate, 

 received in a separate test tube, gives a brick-red turbidity and some 

 coloration. With a considerable quantity of phenacetin the color 

 becomes intense!} 7 red and the turbidity increases. In order to clearly 

 differentiate between these two colorations it is necessary to collect 

 the first few drops of the distillate for the acetanilid test and the latter 

 portion for the phenacetin test. If this precaution is not carefully 

 observed the phenetidin color reaction will obscure the anilin test, and 

 the results are valueless. If acetanilid is not present the first few 

 drops of the distillate will not produce any coloration with the calcium 

 l^perchlorite solution. 



G. M. Beringer* has studied this method very thoroughly and sug- 

 gests several changes which he thinks materially improve it. By 

 replacing the chlorinated-lime solution with a chlorinated-soda solu- 

 tion the end color reactions obtained become much more character- 

 istic. With this reagent, acetanilid gives a decidedl} 7 purple tint not 

 in the least obscured by a cloudy brownish-red, as is the case with the 

 chlorinated-lime solution. With phenacetin the sodium -hyperchlorite 

 solution changes to a " bright orange" (brick-red) and remains clear. 

 The chlorinated-soda solution is considered to be a far more delicate 

 and satisfactory reagent. Beringer says that he did not have any 

 difficulty in detecting 3 per cent of acetanilid in phenacetin. 



Another modification of this test suggested by the same writer is to 

 heat together for one minute 0.1 gram of the substance and 3 cc of a 

 sodium-ltydroxid solution, cool thoroughly, add 5 cc of a chlorinated- 

 soda solution, shake well, and set aside for a few minutes. If phenac- 

 etin only is present the upper layer is never of a deeper tint than 



aOesterr. Chem. Ztg., 1900, 3: 125. &Drug Circular, 1903, 47: 184. 



