STUDIES ON THE CHEMICAL COMPOSITION OF BONE ASH
1931; Elsevier BV; Volume: 93; Issue: 2 Linguagem: Inglês
10.1016/s0021-9258(18)76453-3
ISSN1083-351X
Autores Tópico(s)Bone health and osteoporosis research
ResumoThe contribution which this paper attempts to make to this controversial subject deals with a study of the balance of basic and acid equivalents in the bone ash.It is based upon an analysis of the mineral composition of the vertebrae in a variety of animal forms from fishes to mammals. Analytical ResultsThe vertebrae, freed from soft tissue as nearly as possible, and defatted with boiling alcohol, were ashed by the process proposed by Gabriel (1) but with certain important modifications.The method consists in dissolving the entire organic matrix of bone by heating in a 3 per cent KOH solution in glycerol.We found it, however, essential to use a reagent previously freed from water by boiling and we carry out the ashing by heating the bone at about 250".The bone thus leached out with alkaline glycerol reagent retains its morphological form perfectly, only the organic matter being destroyed and leaving a compact white mass of bone salts.Our procedure of washing the ashed bone is also an important departure from Gabriel%.The leached bone is boiled briskly with distilled water once or twice, depending on how much of the reagent adheres to the surface; it is then extracted several times in boiling 95 per cent alcohol, to remove as nearly as possible all the glycerol reagent, and is dried to constant weight at 110".The bone in this condition can be easily reduced to a fine powder; indeed it crumbles when pressed between the fingers.The bone powder which may be snowy white or only slightly tinged, dissolves in hydrochloric acid without leaving any insoluble residue.The analyses were made on bone ash powders thus prepared.A weighed amount of powder dried to constant weight is dissolved in a measured quantity of standard HCl, calcium, magnesium, potassium, and phosphate being determined in aliquot portions of this solution by the usual procedures.Calcium was precipitated as ammonium oxalate, which was dissolved in sulfuric acid and titrated with 0.005 N KMn04.The phosphates were determined by the Fiske-Subbarow calorimetric method.However, all the phosphate determinations were subsequently repeated by two other procedures; gravimetrically, by precipitating the phosphate as strychnine phosphomolybdate and also, volumetrically, by Fiske's method.Except for one or two instances the results
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