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Miscellaneous Procedures and Instructions
Exhaust System
It is your responsibility to provide an adequate exhaust system. Much of what is
introduced into the mass spectrometer will eventually be exhausted from the
mechanical pump, along with the small amounts of oil vapor that these pumps
characteristically emit. Therefore, the pump outlets should be connected to a
fume exhaust system. Consult local regulations for the proper method of
exhausting the fumes from your system.
Gas Requirements
Helium - GC Carrier Gas
Minimum 99.998% ultra-high purity, with less than 1.0 ppm each of water,
oxygen, and total hydrocarbons. One 257-ft3 tank with Matheson regulator
#3104-580, or equivalent tank and regulator.
NOTE: The presence of >1 ppm oxygen or water in the carrier gas supply may
significantly affect the performance of Saturn, and it damage such components
as the capillary column, filaments, and multiplier. Varian recommends that its
customers verify that their gas suppliers use controlled tanks; this will ensure that
purity standards are maintained. If you purchase pure gases in contaminated
tanks, you may end up with a contaminated system requiring costly and time
consuming repair.
Methane, Isobutane - CI Reagent Gases (with CI
option only)
99.99% purity. One gas cylinder with a two-stage pressure regulator, which has
a stainless steel diaphragm and maximum inlet pressure of 15 psi (1 bar).
Ammonia - CI Reagent Gas (with CI option only)
99.99%, anhydrous grade. One gas cylinder with a two-stage pressure regulator,
which has a stainless steel diaphragm and maximum inlet pressure of 15 psi
(1 bar).
Gas lines for helium, nitrogen, methane, and isobutane should be made of
copper or stainless steel. Gas lines for ammonia should be made of stainless
steel. All gas lines should be free of oil; they will have preferably been flame
dried. The gas lines should be fitted to within 2m of Saturn. Do not store gas
tanks or lecture bottles where they can damage cables or gas lines; always
secure them in accordance with standard safety practices. Gas supply lines
should terminate with 1/8-in., Swagelok
nuts and ferrules.
Cryogenics
Systems equipped with SPI/1079 injectors or column oven cryogenics require
one of the following:
•
Liquid CO
2
at 850-1000 psig
•
Liquid N
2
at 20-50 psig
