The magnesium of bone mineral

Abstract

1. Fractionation experiments have been described in which powdered bone materials were extracted with dilute acids using three different techniques. Ethylene diamine tetracetic acid (EDTA) was also used in one series of experiments.2. The results suggested that the magnesium of bone is present in two main forms, one relatively soluble and the other relatively insoluble in dilute acids.3. It appeared that a large proportion (at least 70%) of the total bone magnesium was located on the surfaces of the bone crystals either as Mg2+ or MgOH+ ions adsorbed at the primary cation adsorbing centres (the surface phosphate ions of the apatite crystals) or as Mg2+ ions replacing surface Ca2+ ions of the crystal lattice.4. Evidence that magnesium carbonate does not occur in significant amounts in bone salt was obtained.5. These results were discussed in relation to the hypomagnesaemia of lactating cows.6. The carbon dioxide of bone also appeared to be present in two main forms, one relatively soluble and the other relatively insoluble in dilute acids.