Automated measurements of ammonia and nitric acid in indoor and outdoor air

被引：26

作者：

Fischer, ML ^{[1
]}

Littlejohn, D ^{[1
]}

Lunden, MM ^{[1
]}

Brown, NJ ^{[1
]}

机构：

[1] Ernest Orlando Lawrence Berkeley Lab, Dept Atmospher Sci, Environm Energy Technol Div, Berkeley, CA 94720 USA

来源：

ENVIRONMENTAL SCIENCE & TECHNOLOGY | 2003年 / 37卷 / 10期

关键词：

D O I：

10.1021/es026133x

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Simultaneous temporally resolved indoor and outdoor measurements of ammonia and nitric acid are valuable for determining the gas-particle equilibrium conditions governing concentrations of ammonium nitrate aerosol. We report the results of simultaneous automated indoor and outdoor measurements of ammonia and nitric acid concentrations made at an unoccupied, single-story residence in Clovis, CA during three periods from October 2000 to January 2001. The measurements were conducted as part of a controlled study to explore mechanisms governing indoor concentrations of fine aerosols of outdoor origin. The gas-phase measurements were performed using diffusion denuders and ion chromatography with 30 min temporal resolution and detection limits below 1 ppb. The conditions of the field experiment span a wide range of outdoor climate as well as natural and forced indoor conditions. During all periods ammonia concentrations were generally slightly higher indoors than out, with both outdoor and indoor concentrations varying in a range from approximately 5 to 30 ppb. Nitric acid was only detected in outdoor air in October 2000, at concentrations up to 3 ppb. During the October period, the product of outdoor nitric acid and ammonia concentrations sometimes deviated from that expected for equilibrium between gas and ammonium nitrate particulate phases and the degree and direction of disequilibrium were correlated with trends in air temperature. The consistently low indoor concentrations of nitric acid were not consistent with equilibrium between gas and particle phases and suggest that a combination of low penetration into the building and a high loss rate for nitric acid reduce indoor concentrations significantly below those outdoors.

引用

页码：2114 / 2119

页数：6

共 33 条

[31] MEASUREMENT OF ATMOSPHERIC NITRIC AND NITROUS ACIDS WITH A WET EFFLUENT DIFFUSION DENUDER AND LOW-PRESSURE ION CHROMATOGRAPHY POSTCOLUMN REACTION DETECTION [J].