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Appendix I: List of instruments, measurable compounds (examples)
1) LIF-NO2 analyzer and its applications:
Fast, continuous, sensitive observation of ambient NO2
Observation of ambient NOx = NO+NO2 (NO is converted to NO2)
Observation of ambient PO(Ox) = O3+NO2 (O3 is converted to NO2)
Total organic nitrates (ANs, PANs) detection by conversion to NO2
Total particulate organic nitrates (ANs(p), PANs(p)) detection
2) Others:
Chemiluminescence detecter CLD for NO (CLD-NO)
Chemiluminescence detecter CLD for O3 (CLD-O3)
VOC measurement as total ozone reactivity (as an application of CLD-O3)
Commercial-based O3 analyzer based on UV absorption (UV-O3)
Commercial-based laser particle counter (LPC)
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Appendix II: Parts of abstracts of our recent research papers (selected)
Note:
If you want to know 'what is the LIF-NO2 analyzer in this laboratory ?',
please refer to the paper No. 11, which is listed at the bottom of this
page !! .
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No. 43 Measuring biogenic volatile organic compounds (BVOCs) from vegetation
in terms of ozone reactivity, AAQR, in press:
A new system that uses the total reactivity with ozone (RO3) was developed
for measuring biogenic volatile organic compounds (BVOCs) emitted from
vegetation into the atmosphere. The decrease in ozone caused by the reaction
with VOCs was monitored at the ppbv level by dual chemiluminescence detectors
(CLDs) based on the NO-O3 reaction. ... (snip) ... Consequently, the detection
limit for RO3 in a 57-s reaction was determined to be 1.4 x 10-4 s-1 (S/N
= 3), which corresponded to 27 ppbv of limonene. It was confirmed that
the RO3 analyzer was capable of measuring BVOC levels. Finally, a practical
trial was conducted in which BVOCs emitted from a real needle-leaf tree
were monitored. BVOC emissions from the tree were detected and a significant
increase in RO3 was observed when the tree was irradiated with light.
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No. 42 Measurement of atmospheric potential ozon based on the laser-induced fluorescence technique, J. Jpn. Soc. Atmos. Environ. (2013) [in Japanese]:
To evaluate atmospheric potential oxidant (Ox) in a second time scale,
we propose a modification of a fast-response NO2 analyzer based on the
laser-induced fluorescence (LIF) technique. In this study, we tested the
combination of the conversion of O3 to NO2 by adding NO to the sample air
and the following quantification of NO2. Direct measurement of 'potential
ozone (PO)', which was defined as the sum of O3 and NO2, was examined.
... (snip)... To explore the applicability of the analyzer to atmospheric
observation, a preliminary observation test was conducted in a suburb of
Tokyo. Consequently, O3 concentrations observed by this analyzer agreed
excellently with those by a commercial-based UV-O3 analyzer. The reasonability
of the PO analyzer was experimentally confirmed. From the acquired relationship
among 1-s data of NO, NO2, and O3, NO2 fraction was estimated as 12 % of
emitted NOx.
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No. 40 Kinetics of the Reactions of Ozone with 2,5-Dimethylfuran and its
Atmospheric Implication, Chem.Lett. (2011):
To determine the reaction rate coefficient of volatile organic compounds
with ozone, the reduction of ozone through a flow-tube reactor was measured
by a chemiluminescent detector. The validity of the method was confirmed
by examination on isoprene. Consequently, the reaction rate coefficient
of 2,5-dimethylfuran, DMF, with ozone was determined as (4.2 +- 0.9) x
10-16 cm3 molecule-1 s-1 for the first time. It was suggested that ozonolysis
can be important for the fate of DMF in the atmosphere.
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No. 22 Examination on photostationary state of NOx in the urban atmosphere
in Japan, Atmos. Environ. (2006):
To investigate the photostationary state (PSS) of nitrogen oxides (NOx),
fast and precise measurements of related compounds were simultaneously
carried out in the urban atmosphere. A PSS parameter f including the observed
peroxy radical (ROx) was examined. Consequently, f was not significantly
different from unity in many cases. Observed NOx, O3, JNO2 and ROx could
reasonably elucidate the PSS of NOx. Meanwhile, in some cases with large
ROx/O3, f was significantly less than unity. It was suggested that the
reaction rate coefficients of ROx with NO could be critical for the PSS
in the urban atmosphere. It was confirmed that the LIF instrument is promising
to observationally approach the PSS of NOx.
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No. 11 Improved analyzer for nitrogen dioxide by laser-induced fluorescence
technique, Atmos. Environ. (2003):
A compact, fast-response instrument for measuring atmospheric NO2 by single-wavelength
excitation laser-induced fluorescence (LIF) technique was improved. A single-pass
alignment of a more powerful, pulsed laser was utilized to realize the
pptv (=10^-12 by volume) of the limit of detection (LOD). As a result,
the LOD reached 1.8 pptv for 1-min averaging (S/N=1). To determine the
instrumental zero accurately, interference by particles was cancelled out
utilizing an NO2 scrubber tube coated with a mixture of titanium dioxide
(TiO2) and hydroxyapatite. Consequently, it was confirmed that the combination
of the improved single-wavelength LIF instrument with the scrubber was
reasonable for measuring atmospheric NO2.
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