The Quantitative Estimation of Extractive and Protein Phosphorus.’

The different combinations of phosphorus to be found in a given tissue may be divided into three main groups: I. Protein phosphorus or phosphorus in combination with protein, including nucleoprotein and phospho-proteins or nucleoalbumins, insoluble in water especially after treatment with alcohol; 2. Lecithin and kephalin phosphorus or phosphorus in combination with fat and a nitrogen complex, soluble in alcohol and ether, but insoluble in acid chloroform water; 3. Extra&e phosphorus, including inorganic phosphates and the simpler combinations of phosphoric acid, such as glycerophosphoric acid, phytin or diethoxy-diphosphoric acid, and a number of related compounds as yet little investigated, all of which are soluble in water and partly soluble in dilute alcohol. In a previous papeP a method for the estimation of lecithin and kephalin phosphorus was described. In the following pages are given methods for the determination of extractive and nuclein phosphorus, which can be carried on at the same time and with the same material as the lecithin estimation.