The sample is placed in 2 litres of de-ionized water.12 mls of HCL and 30 g sodium chlorite are added. The mixture is stirred for a few minutes before it is placed on a hotplate for 10 minutes to warm and initiate the reaction. It is then removed and left for 1 day. The addition of 12 mls HCL and 30g sodium chlorite is repeated three more times. It is not necessary to place on hotplate.
Filter paper is conditioned by adding de-ionised water while using the vacuum pump.
The sample is filtered. It is not necessary to wash sample at this stage. The filtrate is discarded. The sample is transferred from the funnel and placed on a hotplate at 80o for 1 hour. Filter paper is conditioned by adding de-ionised water while using the vacuum pump.