Porphyrins in calcareous structures with special reference to bones from porphyric cattle and swine.

Bones from porphyric animals are treated first with 40% sodium hydroxide and subsequently with concentrated hydrochloric acid which dissolves the chalky residue from the alkaline digestion under violent foaming. The porphyrins are precipitated from the acid solution at pH ca. 3 together with calcium salts and subsequently washed and dissolved in about 50% acetic acid. The solution is then diluted with an approximately equal volume of water and the pH adjusted to ca. 3, after which the porphyrins are adsorbed on to a talc filter. After \vashing, the porphyrins are eluted with sulphuric acid-methanol and subsequently extracted with chloroform as their esters. Thin layer Chromatographie analysis of the ester crystals and mother liquors showed the presence of both uroand coproporphyrin and a series of intermediary porphyrins in bones from porphyric cattle and pigs.