The Determination of Inorganic and Organic Phosphorus in Meats

In 1906 Emmett and Grindleyl concluded from their investigations, that the Hart and Andrews2 method for the determination of inorganic and organic phosphorus in feeding stuffs, could not be used directly for determining these different forms of phosphorus in aqueous extracts of flesh, on account of the large quantity of soluble proteins present. They concluded, however, that if the soluble proteins were removed by coagulation, then the neutral ammonium molybdate method proposed by Hart and Andrews could be used for the separation and estimation of inorganic and organic phosphorus. Investigations in this laboratory since that time have clearly tended to confirm the accuracy of the method proposed and have also confirmed the conclusion of Emmett and Grindley that a considerable proportion of the soluble phosphorus of beef flesh, i.e., from 50 to 90 per cent, occurs in the form of inorganic phosphorus. In the meantime Forbes and associates3 have made extensive and thorough investigations of the methods for the quantitative determination of inorganic and organic phosphorus in vegetable and animal substances. Their work clearly demonstrated the accuracy of the Emmett and Grindley method for the determin-