Safety Practices and Hazards
24 Agilent 240/280 Series AA User’s Guide
NOTE
When solvent extractions of perchloric solutions are performed, some of the acid
may dissolve in the organic solvent that is subsequently aspirated. Also, if the
organic solution is aspirated while floating on the surface of the acid, do not
allow the capillary tube to drop below the organic layer and suck up aqueous
perchloric acid.
When using perchloric acid, wear approved ear protectors and
approved safety glasses and ensure that all instrument safety covers
are in position.
Flashbacks
Analysis over many years has shown that in most cases, flashbacks
are associated with one or more of the following points. If you
experience a flashback, check this list to see if any of the points are
relevant, and take steps to remedy the situation.
1 Keep the burner clean. Deposits must not be allowed to build up
in or on the burner slot because they can partially block it (thus
causing the pressure to build up in the spray chamber and breach
the seal provided by the liquid trap), or glowing particles can fall
down through the slot into the spray chamber and ignite the
combustible gas mixture inside.
The use of a hard object to brush off glowing carbon particles
during flame operation is not recommended because of the
increased risk of knocking one of the particles down the slot.
When using an organic solvent, a reduced uptake rate should be
used to restrict the amount of liquid fuel that is fed to the flame.
2 The width of the burner slot must not exceed the maximum
design specification [Mark VIA: 0.47 mm (0.0185 in.) for N
2
O;
Mark 7 0.46 mm (0.0181 in.) for N
2
O; or 0.54 mm (0.021 in.) for
air]. Even a small increase in width can greatly increase the
possibility of a flashback occurring.
The burner slot must be regularly cleaned according to the
instructions included in the Maintenance chapter of this manual.
To Next Page
Loading...
