Should not be more intense than of a reference solution consisting of 2.5ml of reference 16 for colouring and 7.5ml of reference for turbidity.
Chlorides
Dissolve 2g of the preparation upon heating in a water bath in 5ml of nitric acid. Add 02ml of 01 n silver nitric solution. Filter the solution and add 1 drop of 0.1 n hydrochloric acid solution to the filtrate ; turbidity should should appear.
Phosphates
Wet 0.1g of preparation with 2~3 drops of silver nitric solution the preparation should not immediately colour in yellow.
Proteins
Dissolve 10g of the preparation in 100ml of dilute hydrochloric acid and lilter through a paper lilter. Wash the precipitate with cold water until a negative reaction for chlorine ions .then put in a glass together with a lilter .add 5ml of 40% sodium hydroxide solution stir and carefully pour solution in a test tube .there must not be bluish violet colouring.
