Van Slyke's method of determination of acetone bodies applied to small volumes of blood and urine

Abstract

IN the method described below the proportions of the various reacting substances have been adjusted with the help of data given by Van Slyke [1917; Van Slyke and Fitz, 1917], and the strengths of solutions have been so arranged that the volumes are easily and accurately measured. The mercury-acetone precipitate is titrated, minor improvements being made in the technique, and a table is supplied to facilitate calculations. For a single estimation 0 5 cc. of blood or 1 cc. of urine is needed. It is possible therefore to make determinations on capillary blood obtained by skin puncture. The writer has made parallel determinations with Van Slyke's original technique and the micro-technique described below on diabetic blood and urine, on known aqueous solutions of pure f-hydroxybutyric acid and acetone, and on normal blood to which known amounts of fl-hydroxybutyric acid and acetone had been added. He finds that if the acetone body content is of the order of that found in severe ketosis (0.1 % reckoned as acetone), the microtechnique gives fully as accurate results as the original gravimetric technique of Van Slyke. In lesser grades of ketosis, the micro-technique is less accurate than the original technique, but it gives results of value in clinical work where only relatively gross variations in the content of acetone bodies are of significance. It gives an approximate measure of the acetone-body content of blood and urine even in health.