Principles of Biochemistry (2+1)

Reagents

1. 0.1N Sodium thiosulphate solution

2. 0.025N Sodium thiosulphate solution

3. 15% potassium iodide

4.1% starch

5.  Hanus iodine reagent :Dissolve 13.6g of iodine in 825ml of glacial acetic acid (warm). Titrate 25ml of this solution against 0.1N sodium thiosulphate. Dissolve 13.6 g of iodine in 825 ml of glacial acetic acid (warm). Titrate 25ml of this solution against 0.1N sodium thiosulphate. Add about 3 ml of bromine to 200 ml of acetic acid. Titrate 25ml of this solution against 0.1N sodium thiosulphate. To 5ml of this solution add 10ml of 15% potassium iodide solution and titrate against 0.1N thiosulphate solution. Calculate the volume of bromine solution to double halogen content of the remaining 800ml of the iodine solution as follows:

X=B/C,

where X= ml of bromine solution required to double the halogen content,

B= 800x thiosulphate equivalent of 1ml iodine solution and 

C= thiosulphate equivalent of one ml of bromine solution. Mix well and keep in a glass stoppered bottle, preferably in the dark.