160 HEALTHY URINE. 



Recognition : 



1. Turbid urine clears on adding HNO 3 and heating = 



phosphates. 



2. Two drops acetic acid and drops of uranium acetate 



pp = P 2 O 5 reaction. 



3. Urine + half volume HNO 3 and not less than 2 volumes 



of molybdate of ammonia = yellow pp = P 2 O 5 reaction. 



4. Pp on adding NH 3 (or caustic alkali) = phosphates (earthy). 



16 Volumetric estimation of P 2 O 5 in Urine. 



(a) Standard solution uranium nitrate 35*5 g in 1 litre of 

 distilled water. l cc = -005 g P 2 O 5 . 



(6) Acid solution of sodium acetate. To 100 g sodium acetate 

 add 100 CC acetic acid 33 p - c - and make up to 1 litre 

 with water. To liberate all the P 2 O 5 and to combine 

 with the small quantity of free HNO.. evolved which would 

 dissolve part of the pp (Neubauer). 



(c) Solution of potassium ferrocyanide as indicator. It yields 

 a brown colour with the uranium acetate. 



Process : 



1. To 50 cc of the urine add 5 CC of (b) and maintain at 100 C. 



2. In a burette place (a) and run it into the urine slowly, 



and test a drop of the urine from time to time with 

 a drop of the indicator on a white plate. 



3. Read off the number of cubic centimetres of the SS which 



used and calculate the amount of P 2 O 5 as follows : 



PA in 24 



CC of SS used x 0-005 x CC of Urine in 24 hours * 

 = hours in 



50 



grammes. 



