The Qualitative Tests for Acetone Bodies ; Their Significance and Value

The qualitative tests most commonly used for acetone bodies in the urine are the sodium nitroprusside test and the ferric chloride test. These are usually regarded as selective tests for acetone and diacetic acids, respectively. In fact, few text-books on methods of analysis mention the sodium nitroprusside test as a test for diacetic acid, while some workers-Harding and Ruttan (1) and Hunter (2)Lregard it as probably selective for diacetic acid alone. Occasionally, in case reports these qualitative tests have been allotted an unwarranted quantitative significance. Both tests are known to be interfered with or rendered positive by other substances. For these reasons and because there is contradictory evidence in the literature on the subject, we took the opportunity afforded in a metabolic study of a series of cases of diabetes to make both qualitative and quantitative analyses on the same samples of many specimens of urine. In addition we have carried out certain experiments devised to throw light upon the selectivity, sensitivity, and quantitative significance of these tests, in some instances repeating the work of others.