VOLATILITY MEASUREMENTS OFF LABORATORY GENERATEDORGANIC AEROSOLS WITH VOLATILITY TANDEM

DIFFERENTIALLY MOBILITY ANALYZER.

VTDMA

K. Salo*, Å. M. Jonsson, P. U. Andersson and M. HallquistDepartment of Chemistry, Atmospheric Science ,Göteborg University, Sweden*kent.salo@chem.gu.se

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Temperature(°C)

No

rmal

ized

mo

dal

par

ticl

e d

iam

eter

(N

MD

p)

succinic

glutaric

adipic

pimelic

suberic

azelaic

sebacic

Outline

• Background

• Secondary Organic Aerosols

• Analyze methods

• Results

• Other work

• Summary

Background

• Coarse particles cause Lung an respiratory diseases.

• Fine particles cause increased cardiovascular mortality.

• Aerosols affect earths radiation budget.

• Alters cloud properties.

• Possible effect on formation of precipitation.

Health Climate

Background

Example of aerosol Constituents.

SecondaryOrganic Aerosols

Many different reactive

Volatile Organic

Compounds (VOC)

are emitted from

biogenic sources.

Ref from: Goldstein et al. 2007

Analyze methods

• Scanning mobility particle sizer (SMPS).

DMACPC

Analyze methods

CompressedDry

cleanair

Dilution volumeSilica diffusion

dryer

Aqueoussamplesolution

DMA 1TSI 3071

HEPAFilter

Pump

TSI 3071Aerosol

generator

Aqueoussample

Silica diffusiondryer

CharcoalFilter

RHmonitor

Oven3

Oven 4

Oven 1

Oven 2SMPS

TSI 3096

Scrubber

Scrubber

Scrubber

Scrubber

Analyze methods

Analyze methods

Analyze methods

Results

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T (C°)

VFR

Glutaric

Pimelic

Pinonic

Ammonium sulphate

Ammonium nitrate

Volume Fraction Remaining (VFR) of selectedOrganic and inorganic compounds.

ResultsMixtures of dicarboxylic acid/ammonium sulphate.

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temperature (°C)

Vol

ume

fract

ion

rem

aini

ng (V

FR)

suberic/ammoniumsulphate

suberic

ammonium sulphate

ResultsMixtures of dicarboxylic acid.

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Temperature (°C)

Vol

ume

frac

tion

rem

aini

ng (

VF

R)

suberic/pimelic

suberic

pimelic

SOA

Results

Assumptions:1. Spherical particles2. Surface free energy isotropic.3. Neglected latent heat effects.4. Partial pressure of evaporating species negligible.

J. Mönster et al. 2004.

Results

Assuming Clausius-Clapeyron relationship betweenvapor pressure and temperature. ΔHvap/sub can be inferredFrom linear least squares analysis.

J. Mönster et al. 2004.

Results

Bilde(296K)

y = -5114.3x + 14.158R2 = 0.9264

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-2.5

-2

-1.5

-1

-0.5

0

3.10E-03 3.15E-03 3.20E-03 3.25E-03 3.30E-03 3.35E-03 3.40E-03

1/T

log

P0

Glutaric acid

Results

Bilde(296K)

Chattopadhyay(298K)

y = -4327.8x + 10.114R2 = 0.9087

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-1

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2.90E-03 3.00E-03 3.10E-03 3.20E-03 3.30E-03 3.40E-03 3.50E-03

1/T

log

P0

Pimelic acid

ResultsPhysical properties of used dicarboxylic acid (results and litterature data)

1 Calculated from linear least square analysis assuming Clausius – Clapeyron relationship (log p0 = ΔHvap/2.303 +C) 2 Extrapolated to 296K 3 Calculated from experimental data using Lennard-Jones parameters and surface free energy values from reference [4]. 4 Estimated Lennard-Jones parameters and surface free energy.

# C Name

(IUPAC) Melting

Point ( °C) ΔHvap 1

(kJ/mol) p°(296 K)2

(10-6Pa)

4 Succinic Acid

(Butanedioic Acid) 185-190

103 ± 2 [This work] 138 ± 11 [4]

70 [This work]3 46[4]

5 Glutaric Acid

(Pentadioic Acid) 95-99

95 ± 2 [This work] 91 ± 7[4] 102 [10]

67 ± 7 [9]

758 [This work] 910[4]

6 Adipic Acid

(Hexanedioic Acid) 151-153

95 ± 2 [This work]

154 ± 6 [4] 140±21[9] 118 [10]

115 [This work] 14 [4]

7 Pimelic Acid

(Heptanedioic Acid) 105-106

150 ± 2 [This work]

147 ± 11 [4] 178±27[9]

31[This work] 99 [4] 76 [9]

8 Suberic Acid

(Octandioic Acid) 143-144

100 ±2 [This work]

184 ± 12 [4] 148±22[9]

27 [This work] 1.2[4] 2.4 [9]

9 Azelaic Acid

(Nonanedioic Acid) 100-103

129 ± 2 [This work]

153 ± 24[4] 5.1 [This work]

6.0 [4]

10 Sebacic acid

(Decanedioic acid) 131-134 72 ± 2 [This work] 17 [This work]4

10 Pinonic acid 77 76-77 [This work] 30 [This work] 70 [10]

Results

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temperature (°C)

No

rmal

ized

mo

dal

par

ticl

e d

iam

eter

(NM

Dp

)

4,5 s

2,3 s

1,1 s

0,7 s

Heat transfer resistance problem?

Results

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-1

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0.0027 0.0028 0.0029 0.003 0.0031 0.0032 0.0033 0.0034

1/T (1/K)

log

(p

0/P

a)

4.5 s

2.3 s

1.1 s

0.7 s

P0 independent of residence time.

Results

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Temperature (°C)

Nor

mal

ized

mod

al p

artic

le d

iam

eter

(N

MD

p)

0,2 µg.

0,5µg.

2 µg.

No saturation, independent of mass load

ResultsPinonic acid

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Temperature/C

NM

Dp

test9

test10

test12

test14

OOH

O

ResultsPinonic acid (recryst.)

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Temperature/C

NM

Dp

test20

test21

test17

OOH

O

Other work

G-FROSTG-FROST Göteborg- FlowReactor for Oxidation Studiesat low TemperaturesTemperature range: 243-325KRH: GORE-TEX®Terpene: Diffusion vialOH-scavenger: wash bottle

O2/ N2 UV OzoneGenerator

RH-Meter

Dew Point Meter SMPS

SystemExhaust

Exhaust

LaminarFlow-tube

SlidingInjector

Organic Delivering

System

Temperature Controlled Housing

Humidifying System (Goretex))

Ozone Meter

PurifiedAir

N2

Other worklimonene, 2-but, ozone

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T(C)

VF

R

10%"

50%

80%

Other work

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2008-06-2416:48

2008-06-2419:12

2008-06-2421:36

2008-06-2500:00

2008-06-2502:24

2008-06-2504:48

2008-06-2507:12

2008-06-2509:36

2008-06-2512:00

Limone, 2-butanol, ozone at 10 % RH. SOA conc. From 4 – 20 μg/m3

Summary• The VTDMA is proved to be an efficient and

useful tool to analyze the volatility properties and vapour pressures of different aerosol particles.

• The volatility (evaporation rates), heat of vaporization (ΔHvap) and vapour pressures obtained in this work is generally in line with earlier published results obtained from VTDMA experiments and other methods.

• Knowledge obtained from experiments with pure substances and simple mixtures makes it possible to evaluate more complex systems.

Summary

• Water effect on SOA formation from monoterpenes. Possible effect on volatility.

• Clear masseffect on SOA volatility properties. Positive, Negative?

The End