Some results with a new technique in vitamine measurement

Abstract

By means of a technique described in detail in the March, 1920 number of the PROCEEDINGS certain results have been attained that seem to indicate the specifity of the test for the “B” vitamine. These results are briefly as follows:

(a) Application of the test to three specimens of Funk's antineuritic vitamine prepared in 1912 and‘13 showed that the two 1913 preparations were active, though one was markedly more so than the other, and that the 1912 preparation was inactive. These specimens were supplied by Dr. Funk and represent the products of greatest purity as obtained by his fractional precipitation method. The only known impurity present was nicotinic acid and pure synthetic nicotinic acid failed to respond to the test.

(b) Lloyd's reagent was shown by Seidell and Williams to remove the B vitamine and by Harden and Silva to have little if any action upon the C vitamine. This point was tested with the new method and orange juice obtained by sterile puncture was shown to be deprived of its powers of responding to the test by shaking with the Lloyd reagent. This showed that the reagent removes the cause of the test reaction. Through the kindness of Mr. La Mer working in Professor Sherman's laboratory orange juice shaken with the Lloyd reagent and then filtered, was used in the treatment of a guinea pig suffering from scurvy. The filtrate was curative in fifteen days. It was also used as a protective agent in the diet of a pig started on a scurvy-producing diet. The symptoms had not appeared in twenty days. From these two experiments we can conclude that the test is not affected by the C vitamine and that the cause of the response is removed by Lloyd's reagent.