Method: Injection of N_{2 to achieve anaerobic environment Procedure:}

1.	Put carefully one long needle in the vessel for injecting N2
2.	Put one short needle in the vessel for removing the containing oxygen
3.	Open the pressure valve of the Nitrogen gas container
4.	Turn round (anticlockwise) the nitrogen valve to open it until there is a flow of gas.
5.	 Sparge with N2 by connecting the N2 gas tube with the long needle. 
6.	After 3/ 5 min remove first the small needle and after 2 seconds the long needle.
7.	Turn off the nitrogen valve. 
8.	Turn off the pressure valve.