Labconco Rapid Distillation Apparatus 65000 - Manual (Page 10)

INSTALLATION
6
(2)
Fill steam reservoir flask 2/3 full with ammonia free distilled water. Adjust flow control
valve to give approximately 7 ml/minute flow. Proper adjustment of valve will replace the
water lost from the distillation. If the flow control valve is to be used for low level
nitrogen determinations, it may be necessary to install a deionization cartridge (available
from your laboratory supply dealer) between the flow control valve and water source.
Usually a blank determination on reagents and water is sufficient for most low level
nitrogen determinations.
(3)
Check sample addition funnel stopcock. Mare sure it is CLOSED!
(4)
Close aspirator stopcock located between condenser and steam reservoir.
(5)
Turn on tap water source and fill condenser.
(6)
Place a small graduated cylinder on receiving holder at output of condenser to measure
distillation rate.
(7)
Turn heater control dial to “9.” Press On/Off switch to “On.”
(8)
The water in the steam reservoir will begin boiling in about 5-6 minutes. The heater
control setting should be turned down until a distilling rat of 5 ml/min. is obtained. The
flow control valve is adjusted to replace water lost during distillation.
(9)
Measure temperature of distillate and adjust cooling water input at tap water source to
maintain distillate temperature of 25°C or lower.
(10) For low level nitrogen determinations, allow steam distillation to continue until distillate is
nitrogen free. Removal of nitrogen entrained in steam reservoir water may require 30
minutes at initial start-up, or if the apparatus has been out of use for sufficient time to allow
nitrogen containing fumes to be reabsorbed in steam reservoir liquid. Add approximately
15 ml of ammonia free distilled water to the mixing chamber through the sample-addition
funnel. Close sample stopcock after test liquid drains through! Open the aspirator
stopcock and siphon off all liquid in the mixing chamber to check out aspirator operation.
Water flow to condenser can be adjusted to increase or decrease “siphon” rate. When
mixing chamber is cleared of the test liquid, close the aspirator stopcock.
(11) The unit is now ready for samples. Refer to the following appropriate method for the
determination of nitrogen content from predigested samples.