Perchloric Acid - Agilent Technologies AA Series User Manual

When operating a flame system, always operate your spectrometer
with the flame shield closed, and the sample compartment front
panel in place. Keep your hands out of the sample compartment
while a flame is burning.
When operating a flame system make sure the chimney is in place
with the cutaway skirt (if present) to the back. Before you touch the
instrument chimney, turn the flame off and allow the chimney to
cool.
When you change burners, remember that the burner may be very
hot. Always use protective gloves when removing a burner from the
instrument.

Perchloric Acid

Aspiration of perchloric acid and perchlorates into a nitrous oxide-
acetylene flame can create an explosion hazard which can result in
death or serious injury, including temporary or permanent
impairment of hearing.
Do not use perchloric acid unless it is absolutely essential for sample
preparation. If perchloric acid must be used, it may be possible to
reduce the risk of explosion by taking the following measures:





Agilent 240/280 Series AA User's Guide
Use an air-acetylene flame instead of a nitrous oxide-acetylene
flame.
Reduce the concentration of perchloric acid and metal in all
analytical solutions to the lowest practicable level. The
concentration of perchloric acid should be reduced in the
digestion stage and further reduced by extending the fuming
stage.
Aspirate all solutions for the shortest practicable period.
Aspirate distilled water between samples. Minimize the
aspiration of air.
Use separate spray chamber/liquid trap and drain assemblies for
perchloric acid analyses and organic solvent analyses to prevent
perchloric acid from mixing with organic solvent residues.
Safety Practices and Hazards
23