On the Presence of Aluminum in Blood.

Abstract

The question of the absorption of aluminum by the blood and its presence in other body tissues is one of considerable interest. A few figures have been reported for the dog, but they possess little value for the reason that the methods used were inadequate to estimate the very small amounts of aluminum found.

Several very delicate color reactions for aluminum have recently been described. After considerable effort we have been able to utilize one of these reactions, that with aurin described by Hammett and Sottery, 1 for the estimation of small amounts of aluminum in biological material containing iron. Since the amounts of iron left by the ordinary means of separation give a color very similar to that of aluminum, it must be removed more completely. The presence of iron has, however, been utilized to advantage in carrying down aluminum in the first precipitation. For this reason it is necessary to add iron when it is absent.

The method employed for blood is carried out briefly as follows: 5 cc. of blood are digested in a large Pyrex test tube over a micro burner with 2 cc. of sulfuric acid and 3 cc. of perchloric acid, until oxidation is complete. This requires less than 15 minutes.

The digestion mixture is diluted with a little distilled water and transferred quantitatively with washing to a smaller Pyrex test tube, the volume being made up to about 15 cc. One cc. of saturated ammonium acetate is now added and the solution made alkaline with conc. ammonium hydroxide. The tube is placed in a vigorously boiling water bath until the excess of ammonia is expelled. The precipitate, which at first has tendency to rise, will settle out on shaking.