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

2222

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!

6666

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