43 8 PHYSIOLOGICAL CHEMISTRY 



the distillate to secure most accurate results. 1 Sobel 2 has suggested a 

 quantitative method for acetone based on Lieben's test. 



5. Reynolds-Gunning Test. This test depends upon the solubility of mercuric 

 oxide in acetone and is performed as follows: To 5 c.c. of the urine or distillate add 

 a few drops of mercuric chloride, render the solution alkaline with potassium hy- 

 droxide and add an equal volume of 95 per cent alcohol. Shake thoroughly in 

 order to bring the major portion of the mercuric oxide into solution and filter. 

 Render the clear nitrate faintly acid with hydrochloric acid and stratify some am- 

 monium sulphide (NBU^S upon this acid solution. At the zone of contact a 

 blackish-gray ring of precipitated mercuric sulphide, HgS, will form. Aldehyde 

 also responds to this test. Aldehyde, however, has never been detected in the urine 

 and could be present in this instance only if the acidified urine was distilled too far. 



6. Rothera's Reaction. 3 To 5-10 c.c. of urine or distillate in a test-tube add a 

 little solid ammonium sulphate, 2-3 drops of a freshly prepared 5 per cent solution 

 of sodium nitroprusside and 1-2 c.c. of concentrated ammonium hydroxide. The 

 development of a permanganate color indicates the presence of acetone. 



Hunter 4 claims that this reaction serves to detect acetoacetic acid rather than 

 acetone. Others claim it detects both acetone and acetoacetic acid. 



8. Salicylaldehyde Reaction (Frommer). Render 10 c.c. of urine strongly 

 alkaline with potassium hydroxide, add 10-12 drops of a 10 per cent solution of 

 Salicylaldehyde in absolute alcohol and warm the mixture to about 70. If 

 acetone be present the fluid becomes yellow, then red, reddish-purple and dark 

 red hi turn. The color of the urine is practically unchanged if no acetone is 

 present. 



This color is due to the formation of dihydroxydibenzoylacetone 

 through the interaction of Salicylaldehyde and acetone. 



CH 3 



1 



ACETOACETIC ACID, C = 



I 



CH 2 -COOH. 



Acetoacetic or diacetic acid occurs in traces in normal urine. 

 The sum of the acetone and the acetoacetic acid excreted in normal 

 urine per day ranges from 3 to 15 mg. and ordinarily three-quarters 

 of this is acetoacetic acid. Under certain pathological conditions 

 it occurs in larger quantities and is rarely found except associated 

 with acetone. It is formed from /3-hydroxybutyric acid, another of 

 the acetone bodies, and upon decomposition yields acetone and car- 

 bon dioxide. Acetoaceturia occurs ordinarily under the same condi- 

 tions as the pathological acetonuria, i.e., in fevers, diabetes, etc. (pp. 

 435 an d 534)- If very little acetoacetic acid is formed it may be 

 transformed into acetone, whereas if a larger quantity is produced both 



1 Rosenbloom: Jour. Am. Med. Ass'n, 59, 445, 1912. 

 2 Sobel: Schweiz. Apoth. Ztg., 52, 62, 1914. 

 'Rotliera: Jour. Physiol., 37, 491, 1908. 

 4 Hunter: Quart. Jour. Exp. Physiol., 8, 13, 1914. 



