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An analytical method has been developed for the assignment of recent and archaeological wood tar pitches to the species of trees used for their preparation. It Incorporates the prepurlflcatlon by Kugelrohr distillation and solid-phase extraction followed by gas chromatography/mass spectrometry analysis. Distribution patterns of volatile, thermostable triterpenoids and steroids characterizing the biological origin of the pitches are evaluated by principal component analysis (PCA) and discriminant component analysis (DCA) of the data. Quantities of 10-100 mg of archaeological material can thus be characterized. Fourteen archaeological samples have been identified as birch bark pitches by comparison with recent pitches of known origin. In addition 28 substances present In recent barks and recent pitches could be Identified showing that the method developed can also be applied to the chemotaxonomy of broad-leaved trees.
Hydroxylapatite is the stable orthophosphate of calcium in neutral and alkaline media. Its preparation in pure form is difficult, since with the customary precipitation reaction the monohydrogen phosphate ion always forms according to the reaction: 5Ca++ + 4P043-+ HzO % Ca5(OH)(P04)3 + HP04--Therefore, tetracalcium monohydrogen triphosphate ("octaphosphate"), Ca4H(P04) 3-2H20, which displays a structure similar to apatite, readily forms, solely or a t least partially, in the place of hydroxy1apatite.l Such precipitates change to the P-tricalcium phosphate upon calcination. I n the preparation of a uniformly crystalline product one must perform a tedious boiling-out process2 or the hydrothermal synthesis;3 either of these methods, however, accommodates only a small lot (ca. 70 mg., crystal size 0.3 mm.) or else the preparation has a small sodium content4 (0.5% from 2 g. of material and up to 2-mm. crystal size). In either case, considerable apparatus and expenditure of time are required.These difficulties can be overcome, for example, by carrying out the precipitation a t normal temperature in a medium of sufficiently high pH so that the Po43concentration is not exceeded by that of HP04-and, moreover, by
An Stelle der friiher vie1 benutaten Knochenasche werden heute u. a. synthetische Produkte, meiet Bog. Trioalciumphosphat, ale Adsorbentien in der Zuokerindustrie verwendet und solche Priiparate haben sich z. B. auch zur Chromatographie von Aminosiiurenl) und Carotinen:) sowie zur Entfluorierung von Trinkwassera) bewihrt. Die Erkenntnis nus Rbntgenuntereuchungen, daD diese Prfparate nus Hydroxylapatit Ca6(P0,)sOH4) bestehen, hat nichts damn gefndert, daU eie auch jetzt noch in den Arzneibiichern a l~ ,,Calcium phosphoricum tribasicum" gefiihrt werden und als solche im Handel sind. Die Analyse ergibt wechselnde Zusammensetmngen, die nut biischungen des Apatites mit eek. Phosphat oder auf Adsorption zurlickgefiihrt werden kbnnen. Hier eei behandelt ob und wie ein Priiparat mbglichet groUer aktiver Oberfliche, das analytisch und rbntgenographiech dem Hydroxylapatit entspricht, hergeetellt werden kann.Es ist bekannt, dell verdiinnte Lbsungen nus Alkalihydroxyd und Phesphorsiiure bei pH etwa 9 im wesentliohen HPO,*--1onen enthalten, bei p~ = 12 etwa gleich vie1 HPOf-und PO,,-, wiihrend ab = 14 im wesentlichen nur POf-vorliegt. Daher wird man die FiUlung eines reinen ,,Triphosphatee", oder gar basiecheren Salzes, weil auch schon CaHPO, schwer lbelioh ist, erst bei hohen pH-Werten erwarten kbnnen. Denn obwohl Hydroxylapatit we-IV. Mittellung ilber Trennung von Phosphaten durch Papierelektrophorese ( I l l . Mittlg. B. Sansoni u. R. Klement, diese Ztschr. 66, 598 [1954]; Berichtlgung: S. 602, linke Spalte, Zelle 3 und 7 1st die Trennung Di-flrimetaphoaphat zu strelchen.) Als Dlskussionsbemerkuna voraetragen auf der Taauna ..Problerne der Chemie kondensierterPho
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