The following chemistry laboratory practices shall
(a) Chemicals and reagents. Analytical
reagent grade (AR) chemicals or better grade shall be used for analyses.
Individual analytical methods in the approved references may specify additional
requirements for the reagents to be used.
(b) Laboratory safety. Where safety practices
are included in an approved method, they shall be strictly followed.
(a) Reagent water. The laboratory shall have
a source of reagent water having a resistivity value of at least 0.5 megohms
(less than 2.0 micromhos) at 25°C. Quality checks to meet these
specifications shall be made at planned intervals of at least once per
(b) Glassware preparation.
Glassware shall be washed in a warm detergent solution and thoroughly rinsed
first with tap water and then with reagent water. This cleaning procedure is
sufficient for general analytical needs, but the individual procedures shall be
referred to for precautions to be taken against contamination of
(a) Reagent water. Reagent
water for organic analysis shall be free of interferences for the analytes
being measured. Water shall be treated when necessary to eliminate
preparation. Glassware and sample bottles shall be washed in a detergent
solution and thoroughly rinsed first in tap water and then in reagent water.
Glassware shall have a final organic solvent rinse or shall be baked at
400°C for 30 minutes and then dried or cooled in an area free of organic
contamination. Glassware shall be covered with organic-free aluminum foil
during storage. Bottles and cap liners, used for collection of samples for
determination of volatile organic chemicals (VOCs) shall be dried at 105°C
for one hour, sealed, and stored in an area free of volatile