The sample is transferred from the funnel and a magnetic stirrer added. The sample is stirred and flushed with nitrogen for 1 hour. Filter paper is conditioned by adding de-ionised water while using the vacuum pump. The sample is filtered and washed with de-ionized water until neutral pH. The filtrate is discarded. The sample is transferred from the funnel and stirred for 10 minutes.
Filter paper is conditioned by adding de-ionised water while using the vacuum pump.
The sample is placed on aluminium foil, labelled and placed in the oven at 110o for a few days.