The
capillary is loaded by pushing its open end into the solid sample (figure at left).Melting Point Determinations: Capillary Packing
The
capillary is loaded by pushing its open end into the solid sample (figure at left).
Use a clean watch glass to hold your sample. Repeatedly push the open end of the capillary into the solid sample until enough of the solid is stuck in the top of the capillary. Best results are obtained when you use a minimum of sample. After packing (the next step) the height of the sample in the column should be no greater than ~2 mm.
Pack the solid sample into the capillary by dropping it several times using the long glass tube.
Hold the long glass tube upright with its bottom resting on a lab counter or benchtop (left). Now, position the capillary at the top of the long tube (right). Be sure the closed end of the capillary is down. Drop the capillary (don't worry, it won't break). The capillary will bounce several times as it strikes the table top or floor. This action packs the sample into the capillary.
Carefully remove the capillary when it finishes bouncing and repeat the procedure several more times.
Example
of a properly packed column:
Note the size of the dark brown colored sample in the capillary. Samples no more than 2 mm in height work the best. Generally use only as much solid sample as is required to observe melting.