Fast time response measurements of HNO₃ in air with a chemical ionization mass spectrometer

Abstract

Abstract. A chemical ionization mass spectrometer has been developed for fast time response measurements of HNO3 in ambient air. The apparatus was characterized in an informal intercomparison campaign at Green Mountain Mesa in Boulder, Colorado. Nitric acid was measured over a wide range of meteorological conditions. Detection limits of less than ! 5 pptv for a 1 s integration period were routinely obtained. The apparatus was sufficiently sensitive to measure ambient levels of HNO3 for all conditions except for periods of fog or heavy precipitation when HNO3 mixing ratios were less than 10 pptv.

Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): application to biomass burning emissions

“…Heating the ion flow tube and ionizer slightly (80 • C) is suggested as a means to reduce surface adsorbed material. The addition of NH 3 to CIMS systems to reduce backgrounds in HNO 3 measurements, has been described by Huey et al (1998) and Neuman et al (2002), and was suggested as a solution to the high background of nitrate and perhaps other acid anions, since NH 3 appears to react with surface-adsorbed nitric acid to prevent it from desorbing into the gas phase. However, preliminary work by one of our co-authors (J.…”

Atmospheric measurements of gas-phase HNO<sub>3</sub> and SO<sub>2</sub> using chemical ionization mass spectrometry during the MINATROC field campaign 2000 on Monte Cimone

“…For scrubbing HNO 3 from ambient air we used a nylon filter, which has long been used as a medium to collect HNO 3 in filter measurements or as HNO 3 scrubber (Goldan et al, 1983;Huey et al, 1998) and has also shown in this study to effectively remove HNO 3 from the sample flow. For background measurements the sample air was branched off into an extra tubing with two vacuum-proof filter holders, the first containing a Teflon prefilter to remove particulate matter from the sampled air (Zefluor, pore size 1 µm, diameter 90 mm, Pall Gelman Corp.) and the second one containing a nylon filter (Nylasorb TM membrane disc filter, pore size 1 µm, diameter 90 mm, Pall Gelman Corp.).…”

Measurements of HNO<sub>3</sub> and N<sub>2</sub>O<sub>5</sub> using ion drift-chemical ionization mass spectrometry during the MILAGRO/MCMA-2006 campaign

“…Several analytical techniques have been developed to measure gaseous HNO 3 in the troposphere, including nylon filter (Anlauf et al, 1988), mist chamber (Talbot et al, 1990), denuder technique (Perrino et al, 1990;Simon et al, 1995), luminol method (Hering et al, 1988), tunable diode laser spectroscopy (Horii et al, 2006), and chemical ionization mass spectrometry (CIMS) (Huey et al, 1998). Among the different approaches, the CIMS technique has the advantages of high sensitivity and fast time-response (Huey, 2007).…”