Determination of Gas/Particle Partitioning of
Glyoxal and Other Bifunctional Species using the Annular Denuder-Filter Sampling Technique
Simon Ip, Hilda Huang, Jian Zhen Yu
Hong Kong University of Science and Technology
May, 2010
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OUTLINEOUTLINEOUTLINEOUTLINE• IntroductionIntroductionIntroductionIntroduction
– Sources and abundance of glyoxal
– Secondary organic aerosols from glyoxal
– Literature of Gas/Particle measurements of glyoxal
• ExperimentalExperimentalExperimentalExperimental
– Sulfite-coated method
– H2O2 vs. Barium Chloride
– Recovery and Collection Efficiency
• ResultsResultsResultsResults
– G/P measurements of glyoxal in Hong Kong
– Gas/particle partition coefficients from field study
– Estimated Effective Henry’s law constant of glyoxal from field study
• ConclusionsConclusionsConclusionsConclusions
Introduction
4444
Sources of glyoxal
IsopreneTerpenes
BenzeneTolueneXyleneEthylene
VOC precursorsVOC precursorsVOC precursorsVOC precursors
O
O
glyoxal
18 mm Hg@ 20°C
5555
INCREASE inINCREASE inINCREASE inINCREASE inparticle volume
Kroll et al., JGR, 2005
500 ppb 2,4-hexadienal at t = 50 min
200 ppb glyoxal at t = 53 min
No change inparticle volume
�No growth is observed for most carbonyls studied, even at high conc. (500 ppb to 5 ppm)�At RH = 12%, no growth was observed at conc. as high as ~1 ppm of glyoxal�Increase in particle volume was observed only when RH was higher than 40%
Why glyoxal is special?
Liquid Water ContentLiquid Water ContentLiquid Water ContentLiquid Water Contentis Important!
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Large Gap between modeled and measured SOA formation
Current model parameterizations based on G/P thermodynamic partitioning of semi-volatile species of VOC oxidation underestimateOC aerosol concentrations as a function of photochemical age.
Volkamer et al., GRL, 2006
Knowledge Gap: SOA Model vs. Measurement
7777
Available Literature for gas/particle glyoxal
1591342G , ng m-3
2265231P, ng m-3
58%80%46%P/(P+G)
TSPPM2.5PM4Particle type
10 – 40 min5.5 hr3.5 hrSampling
Duration
16.7 L/min16.7 L/min10 L/minFlow rate
Denuder
coating
method
PFBHA
Ortiz et al.,
2006
XAD-4
+
PFBHA
Ortiz et al.,
2009
XAD-7
+
BHA
Matsunaga et al.,
2004
Experimental Methods
9999
Annular Denuder-Filter Setup
XADXADXADXAD----4444XADXADXADXAD----7777
Types of sorbentsTypes of sorbentsTypes of sorbentsTypes of sorbents
1.1.1.1. XADXADXADXAD----4444
2.2.2.2. XADXADXADXAD----4 + PFBHA4 + PFBHA4 + PFBHA4 + PFBHA
3.3.3.3. XADXADXADXAD----7 + OBE7 + OBE7 + OBE7 + OBE
4.4.4.4. PFBHA onlyPFBHA onlyPFBHA onlyPFBHA only
Quartz FilterQuartz FilterQuartz FilterQuartz Filter
Air Flow
Denuder coated with sorbent
KI-coatedDenuder
Cyclone
10101010
The Use of Sulfite Coating
Carbonyls + S(IV) � Carbonyls S(IV) adduct
Volatile Non-volatile
AdvantagesAdvantagesAdvantagesAdvantages
Unlimited sulfite can be used for coating
The reaction between sulfite and aldehydes is generally fast
Carbonyl S(IV) adducts are non-volatile and therefore the effective
sampling time is longer
DisadvantagesDisadvantagesDisadvantagesDisadvantages
Not applicable for every carbonyl species
The reaction between sulfite and ketone is generally much slower
than aldehyde S(IV)-adduct formation
Removed by precipitation
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Extraction Procedures for Sulfite-Coated Denuder
• The denuder were extracted with DI water x 3
• BaCl2 is added into the sample extract
• The mixture is then centrifuged at RT for 30min
• Acidified PFBHA is added
• The extract was extracted x 3 with DCM
• Purged to near dryness under N2
• Reconstitution with Hexane and DCM
• Then 100 µl of BSTFA is added
• Baked at 60 °C for an hour
• GC-MS analysis
12121212
Sulfite coated vs. XAD coated denuder
0.0004
PFBHA
0.24
SulfiteLoading derivatizing reagent, mole
Tedious Simple Coating and extraction Procedure
DeterioratedCleanIntegrity of GC mass spectrum
5.5 hours12 hoursSampling time
Collection efficiencya ~ 60%~85%
XAD coatedThis study
a Average collection efficiencies for glyoxal, methylglyoxal, glycoaldehyde, glyoxylic
acid and pyruvic acid
13131313
Gas Chromatogram
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
16 17 18 19 20 21 22
Time (min)
Re
lati
ve
Ab
un
dan
ce
Methylglyoxal
Glycoaldehyde
Hydroxyacetone
Glyoxylic acid
Pyruvic acidGlyoxal
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
16 17 18 19 20 21 22
Time (min)
Re
lati
ve A
bu
nd
an
ce
Glycoaldehyde
Hydroxyacetone
Glyoxylic acid Pyruvic acid
Glyoxal
Methylglyoxal
Figure 2. Total ion chromatogram (Top) and m/z = 181 ion chromatogram (bottom) of daytime denuder sample on 15th January, 2010.
14141414
Sampling at Air Pollution Monitoring Site
• Important gas-phase species (CO,
NOx, O3, SO2, etc.) and PM10 - EPD
• PM2.5
• OC, EC
• Ionic species (SO42-, NO3
-, Cl-,
oxalate, Na+, NH4+, K+, Ca2+, Mg2+,
and other dicarboxylic acid)
• Gas- and particle-phase carbonyl
species
Sampling at Tsuen Wan
Results and Discussion
16161616
0.500.440.021.030.540.490.280.94Methylglyoxal (MW: 72.06)
0.750.650.261.560.530.560.101.10Glyoxal (MW: 58.04)
4.183.711.187.441.811.320.425.40Pyruvic acid (MW: 88.06)
0.810.450.094.451.261.660.721.90Glyoxylic acid (MW: 74.04)
3.802.361.1410.191.701.630.403.70Glycoaldehyde (MW: 60.05)
MeanMedianMin.Max.MeanMedianMin.Max.
Winter
Gas phase
(µg m-3)
Summer
Gas phase
(µg m-3)
23.111.18.997.13.84.61.66.1Methylglyoxal (MW: 72.06)
24.818.17.167.812.810.63.995.3Glyoxal (MW: 58.04)
562.4337.443.61851.9286.9286.958.3581.8Pyruvic acid (MW: 88.06)
190.2208.512.1295.927.826.89.040.8Glyoxylic acid (MW: 74.04)
172.448.91.2554.816.618.2LOD39.8Glycoaldehyde (MW: 60.05)
MeanMedianMin.Max.MeanMedianMin.Max.
Winter
Particle phase
(ng m-3)
Summer
Particle phase
(ng m-3)
Maximum, minimum, average, and median of individual bifunctional carbonyl concentrations in the gas phase.
Maximum, minimum, average, and median of individual bifunctional carbonyl concentrations in the particle phase.
Gas/Particle Distribution in Hong Kong
17171717
Literature vs. Findings
12hr
5 L min-1
2.8%
530
12.8
Sulfite
+
Glycerol
This Study
Summer
10 – 40 min
16.7 L min-1
58%
159
226
XAD-4
+
PFBHA
Ortiz et al.,
2009
7501342[Glyoxal]gas, ng m-3
24.85231[Glyoxal]particle, ng m-3
3.4%80%46%P/(P+G), %
12hr5.5 hr3.5 hrSampling
Duration
5 L min-116.7 L min-110 L min-1Flow rate
Denuder
coating
method
PFBHA
Ortiz et al.,
2006
Sulfite
+
Glycerol
This Study
Winter
XAD-7
+
BHA
Matsunaga et al.,
2004
18181818
Partition coefficient, Kp
(0.68±1.16)x10-2(1.23±0.39)x10-7(1.27±0.89)x10-2(1.43±0.32)x10-7Pyruvic Acid
(1.82±2.19)x10-2(4.98±1.59)x10-7(1.63±1.33)x10-3(5.83±1.42)x10-7Glyoxylic Acid
(2.30±3.47)x10-3(4.56±1.45)x10-8(6.48 ±5.74)x10-2(5.33±1.30)x10-8Glycoaldehyde
(2.98±5.04)x10-3(7.79±2.48)x10-10(4.62±2.82)x10-4(9.11±2.23)x10-10Methylglyoxal
(1.18±1.12)x10-3(3.37±1.07)x10-10(1.43±1.33)x10-3(3.95±0.96)x10-10Glyoxal
Winter
Kp,i
(n=20)
(experimental)
Winter
Kp,i
(n=20)
(theoretical)
Summer
Kp,i
(n=17)
(experimental)
Summer
Kp,i
(n=17)
(theoretical)
Compounds
FSPC
CerimentalK
ig
ip
ip
,
,
, )(exp = (Odum et al., 1996)
iLiom
om
ippMW
RTfltheoreticaK
,
6,10
760)(
°=
ζ(Pankow, 1994a; Pankow, 1994b)
19191919
Experimental Heff of glyoxal
3.1 x 105c(0.85 ± 1.21)x 109(1.61 ± 1.30)x 109Pyruvic Acid
1.1 x 104a(1.81 ± 1.72)x 109(1.78± 1.30)x 108Glyoxylic Acid
4.1 x 104b(2.06 ± 2.89)x 108(8.50 ± 7.90)x 107Glycoaldehyde
3.7 x 103b(3.90 ± 8.86)x 108(1.66 ± 1.42)x 108Methylglyoxal
4.2 x 105a(1.40 ± 0.85)x 109(1.21 ± 1.36)x 109Glyoxal
Effective KH in Pure Water,
M atm-1
Winter
Effective KH in Wet Aerosols,
M atm-1
Summer
Effective KH in Wet Aerosols,
M atm-1
Compounds
a [Ip et al., 2009]b [Betterton and Hoffmann, 1998]c [Khan et al., 1995]
)()1( LWCRTF
FPK H
−=
)( ,,
,
igip
ip
CC
CF
+=
where Cg,i and Cp,i are the concentrations of one species in gas phase and particle phase, respectively (µg m-3), R is the ideal gas constant (8.314472 m3 Pa K-1 mol-1), P is the atmospheric pressure (Pa), T is the temperature (K) and LWC is aerosol liquid water content (µg m-3) calculated by AIM III. Experimental temperatures were used for calculations.
(Seinfeld and Pandis, 1998)
20202020
Summary• CE prove that sulfite-coated denuder is capable of performing 12
hours
• Recovery studies prove that S(IV) precipitation by BaCl would not
cause artifact
• Large gap between experimental Kp and theoretical KP suggested
that g/p partition theory cannot fully explain the partition pathways
of glyoxal
• Estimated Heff from field study (1.12 x 109M atm-1) are in agreement
to Heff measured in acidic solution (>109M atm-1, Ip et al., 2009).
• More studies are needed to investigate the effect of ionic strength,
acidity and other major aerosol components on Heff of methylglyoxal,
glyoxylic acid, pyruvic acid and glycoaldehyde, etc.
21212121
Acknowledgement
• Prof. Jianzhen YU
• Hilda Huang
• Dr. Eric Wan and Dr. Steven Ho
• ENVF Staffs
– Mr. To, Mr. Tsui, Ah Pong, Waiman, Ah Man
• Group Mates
– Elber Sit, Emily Au, Yu Huan, Li yun chun, Hu Di, Tony So, Wu
Cheng, Huang xiao feng, Yuan zibing, Eric Xue, Lin Peng
Thank you!
Q & A