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4. Experiment Procedures
(1). Make one extraction thimble with filter paper (use the paper rod attached).
Measure 2-5g sample with the analytical balance (to the nearest 0.0001g)
and put the sample in the thimble. Put the thimble in the holder, which will be
attached to the instrument by magnet.
(2). Dry a constant weight extraction cup and measure its weight. Put 60ml
Petroleum ether or absolute ether in the cup and put it on the heating plate.
(3). Push down the lever to seal the extraction cup with the joint washer.
Move the gliding ball to put the thimble in the cup and make sure that the
sample is fully in the solvent.
(4). Turn on the power and open the condensate. Set up the temperature and
time.
(5). After a while, move the gliding ball to lift up the thimble and start the
extraction. When the extraction is completed, close the cock on the
condensate pipe and the solvent will be evaporated, condensed at the
condenser, and collected in the empty extraction chamber under the
condensate pipe. Then open the cock and start the rinsing process, during
which the condensed solvent washes final traces of fat from the sample. In
the end, close the cock and the solvent will be condensed and collected in
the extraction. Stop heating.
(6). Cool the heating plate and extraction cup. Pull up the lever and open the
cock. Get the solvent in the extraction chamber.
(7). Remove the extraction cup from the heating plate and put it in the drying
oven. Then put the cup in the desiccator to cool down. Measure the weight of
the cup and work out the percentage of the fat content.
(8). Turn off the power and condensate.
