| Test sample |
Standard compound |
| A known quantity of sample solution is transferred in a separating funnel |
A standard lead solution is prepared equivalent to the amount of lead permitted in the sample under examination |
| Add 6ml of ammonium citrate |
Add 6ml of ammonium citrate |
| Add 2 ml of potassium cyanide and 2 ml of hydroxylamine hydrochloride |
Add 2 ml of potassium cyanide and 2 ml of hydroxylamine hydrochloride |
| Add 2 drops of phenol red |
Add 2 drops of phenol red |
| Make solution alkaline by adding ammonia solution. |
Make solution alkaline by adding ammonia solution. |
| Extract with 5 ml of dithizone until it becomes green |
Extract with 5 ml of dithizone until it becomes green |
| Combine dithizone extracts are shaken for 30 mins with 30 ml of nitric acid and the chloroform layer is discarded |
Combine dithizone extracts are shaken for 30 mins with 30 ml of nitric acid and the chloroform layer is discarded |
| To the acid solution add 5 ml of standard dithizone solution |
To the acid solution add 5 ml of standard dithizone solution |
| Add 4 ml of ammonium cyanide |
Add 4 ml of ammonium cyanide |
| Shake for 30 mins |
Shake for 30 mins |
| Observe the color |
Observe the color |