Gas/Liquid Separator - Agilent Technologies VGA 77 User Manual

The working life of the cell will depend on the type of analytical
programs carried out. At some stage, the glass will start to turn white
indicating the onset of devitrification. Initially, devitrification will
not degrade the analytical performance, but eventually the devitrified
area will extend over most of the cell at which point it may be
necessary to discard the cell.
If devitrification is excessive, the cell will eventually crack
spontaneously or fail through thermal shock.
Whether the cell becomes devitrified or not, and even with
meticulous cleaning, the inside surface may deteriorate to the extent
that the analytical signal will be suppressed. You should regularly
monitor the performance of the cell using absorbance measurements
obtained from standard solutions. Discard the cell as soon as the
results of this monitoring become unacceptable.
When a significant number of samples are being analyzed, the use of a Drierite
NOTE
trap inserted between the absorption cell and the output of the gas/liquid
separator will protect the absorption cell and extend its lifetime. (Refer to 'Use of
Drierite Trap to Extend the Lifetime of Vapor Generation Absorption Cell', 1986,
October, No. 65 on www.agilent.com.)
Under some circumstances, the center section of the cell may
gradually soften in the flame and sag. If uncorrected, this may
become so severe that alignment of the cell within the optical path is
impossible. When sagging is first noticed, it can be corrected by
simply turning the cell over so that it will return to its normal shape
the next time it is heated.

Gas/Liquid Separator

As with the cell, the gas/liquid separator must be cleaned
immediately if contamination is suspected during conditioning, or
whenever the system has been left unused for some time. Do not
allow hydrochloric acid solutions to remain in the separator.
Agilent Vapor Generation Accessory VGA 77 and VGA 77P User's Guide
Maintenance and Spare Parts
73