43 PHYSIOLOGICAL CHEMISTRY 



Acetone, chemically considered, is a ketone, di-methyl ketone. When 

 pure it is a liquid which possesses a characteristic aromatic fruit-like 

 odor, boils at 56-5 7C. and is miscible with water, alcohol, or ether 

 in all proportions. Acetone is a physiological as well as a pathological 

 constituent of the urine and under normal conditions the daily output 

 (preformed acetone + acetoacetic acid) is about 3-15 mg. 



Pathologically, the elimination of acetone is often greatly increased 

 and at such times a condition of acetonuria is said to exist. Values 

 from 0.02-6 grams or higher have been obtained for preformed acetone 

 plus acetone derived from acetoacetic acid. This pathological ace- 

 tonuria may accompany diabetes mellitus, scarlet fever, typhoid 

 fever, pneumonia, nephritis, phosphorus poisoning, grave anemias, 

 fasting, and a deranged digestive function; it also frequently accom- 

 panies auto-intoxication and chloroform and ether anethesia. The 

 types of acetonuria most frequently met with are those noted in febrile 

 conditions and in advanced cases of diabetes mellitus. The blood in 

 diabetic comas has been found to contain as high as 45 mg. of total 

 acetone (acetone + acetoacetic acid) for 100 c.c. of blood serum. 



EXPERIMENTS 



1. Isolation from the Urine. In order to facilitate the detection of acetone in 

 the urine, the specimen under examination should be distilled and the tests as given 

 below applied to the resulting distillate. If it is not convenient to distil the urine, 

 the tests may be conducted upon the undistilled fluid. To obtain an acetone dis- 

 tillate proceed as follows: Place 100-250 c.c. of urine in a distillation flask or retort 

 and render it acid with acetic acid. Collect about one-third of the original volume 

 of fluid as a distillate, add 5 drops of 10 per cent hydrochloric acid and redistil about 

 one-half of this volume. With this final distillate conduct the tests as given below. 



2. Gunning's lodoform Test. To about 5 c.c. of the urine or distillate in 

 a test-tube add a few drops of Lugol's solution 1 or ordinary iodine solution (I in 

 KI) and a few drops of dilute NH 4 OH to form a black precipitate (nitrogen iodide). 

 Allow the tube to stand (the length of time depending upon the content of 

 acetone in the fluid under examination) and note the formation of a yellowish sedi- 

 ment consisting of iodoform. Examine the sediment under the microscope and 

 compare the form of the crystals with those shown in Fig. 8, page 42. 



If the crystals are not well formed recrystallize them from ether 

 and examine again. The crystals of iodoform should not be confounded 

 with those of calcium phosphate (Fig. 105, page 3 2 2) which may be formed 

 in this test, particularly if made upon the undistilled urine. This test 

 is preferable to Lieben's test (4) since no substance other than acetone 

 will produce iodoform when treated according to the directions for 



1 Lugol's solution may be prepared by dissolving 4 grams of iodine and 6 grams of potas- 

 sium iodide in 100 c.c. of distilled water. 



