PMID- 32639152
OWN - NLM
STAT- MEDLINE
DCOM- 20201127
LR  - 20201127
IS  - 1520-5851 (Electronic)
IS  - 0013-936X (Linking)
VI  - 54
IP  - 16
DP  - 2020 Aug 18
TI  - Quantification of Non-refractory Aerosol Nitrate in Ambient Air by Thermal 
      Dissociation Cavity Ring-Down Spectroscopy.
PG  - 9854-9861
LID - 10.1021/acs.est.0c01156 [doi]
AB  - A thermal dissociation cavity ring-down spectrometer (TD-CRDS) for real-time 
      quantification of non-refractory aerosol nitrate in ambient air is described. The 
      instrument uses four parallel detection channels and heated quartz inlets to 
      convert particulate organic nitrate (pON) (at 350  degrees C) and ammonium nitrate 
      (NH(4)NO(3)) aerosol (at 540  degrees C) to nitrogen dioxide (NO(2)), whose mixing ratio 
      is monitored via its absorption at 405 nm. Concentrations of aerosol nitrate are 
      determined by difference relative to a parallel TD-CRDS channel in which aerosol 
      is removed by in-line filtering. The method was validated by sampling gas streams 
      containing laboratory-generated NH(4)NO(3) aerosol in parallel to a scanning 
      mobility particle sizer (SMPS). Scatter plots of TD-CRDS and SMPS data correlated 
      (r(2) > 0.9) with slopes near unity, confirming quantitative TD-CRDS response to 
      NH(4)NO(3) aerosol. In contrast, no response was observed when sampling 
      (NH(4))(2)SO(4) aerosol. Instrument limits of detection (LOD; 2sigma, 10 s) were 120 
      parts per trillion by volume (10(-12), pptv) for NO(2) and 148 pptv for ammonium 
      nitrate. Partial and unsustained conversion of refractory sodium nitrate 
      (NaNO(3)) was observed at the inlet temperature used for complete dissociation of 
      HNO(3) and NH(4)NO(3), suggesting that this channel may not constitute a robust 
      measurement of total odd nitrogen (NO(y)) in environments where NaNO(3) particles 
      may be present (e.g., the polluted marine boundary layer). A potential 
      application of the TD-CRDS is the calibration of particle counters, for which 
      convenient methods are not currently available. Sample ambient air measurements 
      of pON and total aerosol nitrate in Calgary are presented.
FAU - Garner, Natasha M
AU  - Garner NM
AD  - Department of Chemistry, University of Calgary, 2500 University Drive NW, 
      Calgary, Alberta T2N 1N4, Canada.
FAU - Matchett, Laura C
AU  - Matchett LC
AD  - Department of Chemistry, University of Calgary, 2500 University Drive NW, 
      Calgary, Alberta T2N 1N4, Canada.
FAU - Osthoff, Hans D
AU  - Osthoff HD
AUID- ORCID: 0000-0001-7155-6493
AD  - Department of Chemistry, University of Calgary, 2500 University Drive NW, 
      Calgary, Alberta T2N 1N4, Canada.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200803
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Aerosols)
RN  - 0 (Nitrogen Oxides)
RN  - N762921K75 (Nitrogen)
RN  - S7G510RUBH (Nitrogen Dioxide)
SB  - IM
MH  - Aerosols
MH  - Nitrogen
MH  - *Nitrogen Dioxide/analysis
MH  - *Nitrogen Oxides
MH  - Spectrum Analysis
EDAT- 2020/07/09 06:00
MHDA- 2020/11/28 06:00
CRDT- 2020/07/09 06:00
PHST- 2020/07/09 06:00 [pubmed]
PHST- 2020/11/28 06:00 [medline]
PHST- 2020/07/09 06:00 [entrez]
AID - 10.1021/acs.est.0c01156 [doi]
PST - ppublish
SO  - Environ Sci Technol. 2020 Aug 18;54(16):9854-9861. doi: 10.1021/acs.est.0c01156. 
      Epub 2020 Aug 3.