Salt (NaCl) Reagents

•         Silver nitrate solution (5per cent)

•         Nitric acid solution (1:2)

•         Ammonium hydroxide solution (1:1)

•         Standard sodium chloride solution (0, 0.1, 0.2 and 0.3 per cent)

Procedure

Weigh 1 g of feed sample and add 100 ml of distilled water. Stir and filter through Whatman filter paper no. 4. Take 1 ml of above feed solution and 8 ml of nitric acid solution in a test tube. Stir and add 1 ml of silver nitrate solution. Similarly add 1 ml standard solution (0, 0.1,

0.2 and 0.3 per cent) in different test tube and add 1 ml of silver nitrate solution. Compare the test sample with the standard sample. The test should be read within 5 minutes.

Positive results

Presence of salt will produce a white turbidity.