Measurement of ambient nitrous acid and a reliable calibration source for gaseous nitrous acid

• Published in: Environmental science & technology Vol. 25; no. 2; pp. 255 - 260
• Main Authors: Vecera, Zbynek, Dasgupta, Purnendu K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-02-1991
• Subjects: 400102 - Chemical & Spectral Procedures; 540120 - Environment, Atmospheric- Chemicals Monitoring & Transport- (1990-); Analysis methods; Applied sciences; ATMOSPHERIC CHEMISTRY; Atmospheric pollution; CHEMISTRY; CHROMATOGRAPHY; DATA; ENVIRONMENTAL SCIENCES; Exact sciences and technology; EXPERIMENTAL DATA; HYDROGEN COMPOUNDS; INFORMATION; INORGANIC ACIDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ION EXCHANGE CHROMATOGRAPHY; MEASURING METHODS; NITROUS ACID; NUMERICAL DATA; Pollution; SENSITIVITY; SEPARATION PROCESSES; SPECTRAL RESPONSE; Scrubber; Ambient air concentration; Automation; Ion chromatography; Check; Instrumentation; Air pollution; Calibration; Ultraviolet spectrometry; Nitrous acid
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es00014a006

A diffusion scrubber based automated instrument measures HONO utilizing ion chromatography and UV detection with time resolutions of 7-15 min and a detection limit of ca. 20 pptv. The thermodynamic equilibrium of NH{sub 3}(g) and HONO(g) over NH{sub 4}NO{sub 2}(s) can be described by ln (p{sub HONO}, atm) = {minus}8,018 {plus minus} 84/T + 16.81 {plus minus} 0.30 and provides a convenient and reliable source for HONO(g) free from major contamination with NO{sub x}. Ambient measurement data for Lubbock, TX, are presented. Persistent daytime concentrations of HONO in the 100-500 pptv range, weekday morning peak concentrations up to 1 ppbv following peak traffic hours, and typical nighttime peak concentrations between 1 and 2 ppbv are observed.