Quality control methods for

Benzylpenicillin sodium R. C
16
H
17
N
2
NaO
4
S. Quality conforms to the 
monograph in The international pharmacopoeia. Vol. 2, p. 51. 
Bile salts R. 
Description. A concentrate of beef bile, the principal constituent of which is 
sodium desoxycholate, determined as cholic acid. 
Solubility. Soluble in water and in ethanol (∼750g/l) TS.
Acidity. pH of a 0.02 g/ml solution 5.8-6.2. 
A suitable commercially available reagent. 
Brilliant black BN R. C.I. 28440; C
28
H
17
N
5
Na
4
O
14
S
4
. 
Description. A bluish violet or greyish black powder or fine crystals. 
Solubility. Freely soluble in water, practically insoluble in ethanol (∼750g/l) TS, 
acetone R, chloroform R and ether R. 
A suitable commercially available reagent. 
Brilliant green R. Malachite green G; basic green 1; C.I. 42040; C
27
H
34
N
2
O
4
S. 
Description. Small, glistening golden crystals. 
Solubility. Soluble in water and ethanol (∼750 g/l) TS. A suitable commercially 
available reagent. 
Bromine R. Br
2
 
A suitable commercially available reagent. 
Bromine AsTS. 
Procedure. Dissolve 30g of potassium bromide R in 40 ml of water, add 30g of 
bromine R and dilute with sufficient water to produce 100 ml. The solution 
complies with the following test: Evaporate 10 ml nearly to dryness on a water-
bath, add 50 ml of water, 10ml of hydrochloric acid (∼250g/l) AsTS, and 
sufficient stannous chloride AsTS to reduce the remaining bromine, and apply 
the general test for arsenic. The colour of the stain produced is not more intense 
than that produced from a 1-ml standard stain, showing that the amount of 
arsenic does not exceed 1 µg/ml.