Biochemical notes : laboratory work. First and second parts.

  • Gies, William John, 1872-1956.
Date:
1906
Catalogue details

Licence: Public Domain Mark

Credit: Biochemical notes : laboratory work. First and second parts. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    ammonium carbonate to it until precipitation is complete. Warm the mixture but do not heat to boiling. Filter off the precipitate of calcium carbonate and use the filtrate for the detection of mag- nesium in process 28. Confirm the presence of calcium in the washed precipitated carbonate by dissolving the precipitate in a slight quantity of acetic acid. In this acid liquid, ammonium oxa- late causes precipitation of calcium oxalate (17)' Let the mixture stand if precipitation does not occur immediately. Equation (17): CaCCHjCOj)^ + (NHJ2C2O4 = CaCp, + 2NH,CH3C02 Calcium oxalate (white) 27. Sixth group. Magnesium, sodium, potassium (and am- monium) are present in practically all biological products. 28. Magnesium, Concentrate by evaporation the filtrate from the precipitated carbonate (26), and add moderate excesses of am- monium chlorid and ammonium hydroxid. Treat the solution with ammonium oxalate. Let the mixture stand several minutes. Filter off any calcium oxalate that may have been precipitated. * Add drop by drop to the filtrate a moderate excess of di-sodium hydrogen phosphate. Stir thoroughly. Let the mixture stand a few minutes. Equation : MgCl^ + Na^HPO, + NH,OH = NH.MgPO, + 2NaCl + H,0 Ammonio-mag- nesium phosphate (white) In each of the remaining tests for cations (29-30) use portions of the original solution, as follows : 29. Sodium and potassium. Flame tests.-\ Use platinum wire. Persistent yellow indicates sodium. A violet color, not obscured by blue glass, indicates potassium. 30. Ammonium. Add sodium hydroxid in excess. Boil. No- tice the character of any (a) odor that may be detected, also the reaction of the steam on (6) wet litmus paper, and the effect of the steam on (c) hydroohloric acid adherent to a glass rod. Equations : a. NH.Cl + NaOH = NH3 + H^O + NaCl Ammonia (gas) c. NH3 + HCl = NH.Cl Ammonium chlorid (white fumes) * Calcium is not completely precipitated by ammonium carbonate, t Special methods are required in unusual cases. Sodium and potassium are invariably present in biological products.