ACETONE BODIES 63 



compound. Glucose and certain other interfering substances 

 are removed by precipitation with copper sulphate and calcium 

 hydroxide. Preservatives other than toluene or copper sulphate 

 should not be used. 



Procedure. Removal of Glucose and other Interfering Sub- 

 stances from Urine. 



Place 25 c.c. of urine in a 250 c.c. measuring flask. Add 100 c.c. 

 of water, 50 c.c. of copper sulphate solution and mix. Then add 

 50 c.c. of 10 per cent calcium hydroxide suspension, shake, and 

 test with litmus. If not alkaline, add more calcium hydroxide. 

 Dilute to the mark and let stand at least one-half hour for glucose 

 to precipitate. Filter through a dry folded filter. This pro- 

 cedure will remove up to 8 per cent of glucose. Urine containing 

 more should be diluted enough to bring the glucose down to 8 

 per cent. The copper treatment is depended upon to remove 

 interfering substances other than glucose, and should therefore 

 never be omitted, even when glucose is absent. The filtrate 

 may be tested for glucose by boiling a little in a test-tube. A 

 precipitate of yellow cuprous oxide will be obtained if the removal 

 has not been complete. A slight precipitate of white calcium 

 salts always forms, but does not interfere with the detection of 

 the yellow cuprous oxide. 



Determination of Total Acetone Bodies (Acetone, Acetoacetic 

 Acid, and /3-hydroxybutyric Acid.) Place in a 500 c.c. Erlen- 

 meyer flask 25 c.c. of urine filtrate. Add 100 c.c. of water, 10 c.c. 

 of 50 per cent sulphuric acid, and 35 c.c. of the 10 per cent mer- 

 curic sulphate. Or in place of adding the water and reagents 

 separately, add 145 c.c. of the " combined reagents." Connect 

 the flask with a reflux condenser having a straight condensing 

 tube of 8 or 10 mm. diameter and heat to boiling. After boiling 

 has begun, add 5 c.c. of the 5 per cent dichromate through the 

 condenser tube. Continue boiling gently 1^ hours. The 

 yellow precipitate which forms consists of the mercury sulphate- 

 chromate compound of the preformed acetone, and the acetone 

 which has been formed by decomposition of acetoacetic acid and 

 by oxidation of the /3-hydroxybutyric acid. It is collected in 

 a Gooch or " medium density " alundum crucible, washed with 

 200 c.c. of cold water, and dried for an hour at 110. The 

 crucible is allowed to cool in room air (a desiccator is unnecessary 

 and undesirable) and weighed. Several precipitates may be 



