Trace concentration mixtures of nitric acid vapor are
particularly difficult to prepare and store due to the aggressive chemical
properties of nitric acid. Even with
conventional permeation or diffusion tubes, establishing the nitric acid
emission rate of the device can be problematic.
Reagent grade nitric acid is relatively stable but contains thirty
percent water and emission is the azeotrope. Pure nitric acid spontaneously
decomposes even at room temperature liberating large amounts nitrogen
dioxide. In either case, traceable
weight-loss certification is not possible.
KIN-TEK’s Trace
Source™ Permeation Tubes use a mixture of reagent grade nitric and sulfuric
acids as the analyte source. The sulphuric acid binds the water, reducing water
emission to negligible levels. Emission
of the sulfuric acid is extremely low compared to that of nitric acid, so the
emission is primarily nitric acid.
Formation of nitrogen oxides in the vapor is minimized by dynamically
blending the emission to form trace concentration mixtures that are then used
immediately.
Tubes are available for concentrations from low ppb to to
about 10 ppm in 1 l/min dilution flow.
For more information, please write or call: KIN-TEK Laboratories, Inc., 504 Laurel, La
Marque, TX 77568, Phone: (409) 938-3627, Fax: (409) 938-3710,
www.kin-tek.com,
email: sales@kin-tek.com
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