Outlines of the clinical chemistry of urine
(This historic book may have numerous typos and missing te...)
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 Excerpt: ... The Estimation of Ammonia in urine is generally performed by the method of Schlosing and Neubauer, which consists in placing a measured quantity of urine, to which milk of lime has been added, under an air-tight bell-glass, together with an open vessel containing a measured quantity of titrated acid. In from twenty-four to thirty-six hours all the ammonia has passed out of the urine into the acid, which is then titrated with standard alkali to find the amount of ammonia absorbed. Sutton ("Volumetric Analysis," p. 326) finds, however, that this method is liable to defects, and recommends the following:--"100 c.c. urine are exactly neutralized with decinormal () soda or potash, as for the estimation of free acid; it is then put into a flask capable of holding five or six times the quantity, 10 c.c. of normal alkali added, and the whole brought to boiling, taking care that the bladders of froth which at first form do not boil over. After a few minutes these subside, and the boiling proceeds quietly. When all ammoniacal fumes are dissipated, the lamp is removed, and the flask allowed to cool slightly; the contents then emptied into a tall beaker, and normal nitric acid delivered in from the burette with constant stirring, until a fine glass rod or small feather dipped in the mixture and brought in contact with violet litmus paper produces neither a blue nor a red spot. The number of cubic centimeters of normal acid are deducted from the 10 c.c. of alkali, and the rest calculated as ammonia. 1 c.c. of alkali = 0-017 gram of ammonia. Example: 100 c.c. of urine were taken, and required 7 c.c. of alkali to saturate its free acid; 10 c.c. of normal alkali were then added, and the mixture boiled until a piece of moistened red litmus paper was not turn...
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