tube (also known as “cold finger”) with crushed ice. Start heating the assembly (~200 o
C)
and observe how the caffeine sublimes and collects on the cold finger. When no more
deposition of product is observed, remove the flask from the sand bath. Carefully take out
the cold finger and scrape off the product onto a weighing paper. Some of the product
will be collected on the sides of the filter flask. Scrape it off the flask and collect it. If the
two fractions that you collected are looking different than don’t combine them and
analyze each one separately. Weigh the product obtained and measure it’s melting point.
Calculate the percentage of caffeine that was isolated from the crude and the percentage
of caffeine in dry tea leaves. Submit the product to your TA with the lab report.