Labconco RapidStill II 65200 - Manual (Page 20)

NORMAL OPERATION
16
Standard Procedure
(1) Turn on the cooling water, allowing it to flow through the condenser. The flow rate
will be regulated to 1 gallon per minute (3.8 liters per minute).
(2)
Depress the ‘Boiler Water’ switch. Looking through the Boiler viewing slot, fill the
boiler approximately 2/3 full, or to the top line of the flask. If the boiler fills too
slowly, slightly increase the flow rate of the cooling water supply. If the Optional
Water Inlet Kit is installed and the boiler fills too slowly, increase the pressure or flow
rate of the purified water supply. When the proper water level is obtained, release the
switch.
(3) Turn the ‘Boiler Heater’ switch to the ‘ON’ position. After approximately 10 minutes,
or when the water in the boiler is at a steady boil, the unit is ready for operation.
(4) Place the digestion tube with a digested sample in the RapidStill II, giving the tube a
slight twist to assure a complete seal.
(5) Place a receiver flask under the Distillate Outlet Tube. Make sure that the outlet tube is
fully submerged.
(6) Add NaOH solution to the digestions tube by depressing the ‘NaOH Addition’ switch.
For each 5 ml of concentrated sulfuric acid used in the digestion process, add
approximately 15 ml of 50% NaOH solution to make the distillation solution strongly
alkaline. Use the graduated decal on the front panel of the RapidStill II as an
approximate gauge of the volume in the digestion tube.
(7) Turn the distillation Time switch to the desired time setting. Be sure to allow enough
time for the distillation solution to reach boiling.
(8) When the distillation is completed, the unit will return to a standby position, with the
boiler heater still in operation.
(9) Remove the digestion tube, using appropriate heat and chemically resistant gloves.
(10) If there are to be additional distillations and the boiler water level is low, turn the
‘Boiler Heater’ switch off and depress the ‘Boiler Water’ switch on. Allow the boiler
to refill with water, release the ‘Boiler Water’ switch and turn the ‘Boiler Heater’
switch on. When the water in the boiler resumes boiling, the RapidStill II is ready for
another distillation.
(11) Titrate the distillate in the receiving flask. If the temperature of the solution exceeds
120°F (50°C), check the flow rate of the condenser cooling water.