ACETONE - DIABETES To 100 c.c. of urine are added five drops of hydrochloric acid, and the mixture is then distilled. A few cubic centimetres of the distillate are now treated with three drops of caustic potash and a few drops of compound solution of iodine. If acetone is present a light yellow precipitate of iodoform, having the characteristic odor of this sub stance, is thrown down.
In a quantitative analysis we have to determine not only the amount of already existent acetone but also of that formed by the splitting up of diacetic acid. One drop of glacial acetic acid is added to 100 c.c. of urine and distilled, the receiver and tube being kept very cool, until three-quarters of the entire amount has passed over. This distillate is treated with five drops of dilute (25 per cent.) sul phuric acid, and after a few crystals of urea are added is again dis tilled, the receiver and tube being cooled as before. To the second
distillate caustic potash is first added and then compound solution of iodine in excess. A precipitate of iodoform is thrown down which is collected, at the end of six hours, on a weighed filter and washed with distilled water. After the filter and precipitate have been al lowed to dry in the air they are placed in an exsiccator with sulphuric acid, and weighed at the end of one and one-half to two hours. One gram of iodoform represents 0.147 gm. acetone. By reason of the volatility of iodoform the loss of a small amount (one or two per cent.) cannot be avoided. This small error may be ignored, but there is another source of error that is of more importance; for when the patient has been taking large doses of alcohol a certain amount will always pass off in the urine and will give the same reaction as acetone in the distillate.