The determination of hydrogen chloride in ambient air with diffusion/denuder tubes

✍ Scribed by N.A. Dimmock; G.B. Marshall

• Book ID: 104100322
• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 714 KB
• Volume: 202
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)85901-2

✦ Synopsis

A manual method for the determination of hydrogen chloride in air, based on diffusion/denuder tube separation from particulate chloride aerosol is described. When air is drawn through a tube coated with a selective absorbent (sodium fluoride), separation is achieved because gaseous hydrogen chloride diffuses much more rapidly to the tube walls than particulate chloride aerosol, which passes through virtually unabsorbed. After the sampling'period (the length of which depends on the concentration of gaseous hydrogen chloride expected), the sorbed hydrogen chloride is washed from the tube and measured with a highly sensitive chloride ion-selective electrode with a mercury (I) chloride membrane. The method is examined theoretically and experimentally. The experimentally derived absorption efficiencies of the diffusion/denuder tubes were > 90% and the standard deviation of the method was 0.023 B mm3 for hydrogen chloride concentrations of 0.16-0.55 M rne3. Interference from particulate chloride salts was negligible; this was confirmed by tests with artificially generated aerosol particles from an aerosol generator. The diffusion/denuder tubes have high capacity; levels as high as 330 M mm3 hydrogen chloride can be sampled for 60 min without affecting performance. A detection limit of (50/t) pg me3 can be achieved, where t is the sampling time (min); e.g., 1 cog me3 hydrogen chloride can be detected with a sampling period of 50 min.