Detection of Nitrooxypolyols in Secondary Organic Aerosol |Formed from the Photooxidation of Conjugated dienes under High-NOx ConditionsKei Sato, Atmospheric Environment, 42 (2008) 6851–6861

6-m3,Teflon-coated, stainless steel laboratory smog chamber

2 ppmv of Isoprene

NO concentrations were ranged from 0.2, 0.5 and 1 ppmv

Particles collected on filters and solvent extracted

Filters cut in small pieces and sonicated in 3ml of methanol for 40 min

Analysis was by HPLC MS (Shimadzu LC–MS QP-8000a )

negative-ion mode ESI probe at 3.5 kV.

What if NO is very low; the primary reaction is with HO2 Jenkin et al, 1997 Atmos. Envir.,

Pitts and Pitts , 186

RO2. + HO2. ROOH + O2

ROOH carbonyl +H2O +O2

and

ROOH alcohol + O3 (dark O3)

does the R group matter???rate constants range: 5.2x10-12 R is CH3

7.7x10-12 R is C2H5

1.5x10-11 larger

What are the reactions of RO2

(self reactions)?

RO2. + RO2. 2RO.+O2

ROH+RCHO + O2

ROOR+ O2 (SMALL)

generally the larger the R group the slower the reaction

Atkinson recommends 2.5x10-13, 5x10-15 and 2x10-17 for primary, secondary and tertiary RO2(s)

Is there data on the branching of 2RO vs. ROH+RCHO??

RO2. + RO2. 2RO.+O2

ROH+RCHO + O2

ROOR+ O2 (SMALL)

See Jenkin, et. al,1997, and Pitts and Pitts, Table 6.6, p 187

2RO. ROH+RCHOCH3OO. 0.35 0.65CH3H7OO. 0.55 0.45

High NOx

RO2 + NO RO + NO2

RO2 + NO RONO2

Low NOx

RO2 + HO2 ROOH + O2

RO2 + ROCH2O2 ROH + O2 ROCHO

RO R=O +HO2

Low NOx

Formation of secondary organic particle phase compounds from isoprene gas-phase oxidation products: An aerosolchamber and field study: Alaf Bo¨ge, Yunkun Miao, Antje Plewka, Hartmut Herrmann, Atmos. Environ. Inpress, 2008)

An overall yield of just 0.01–0.09% was estimated for methyl tetrol formation

How much methyl tetrols forms?

What did Alaf Boge and Hartmut Herrmann do?

9 m3 chamber

Added isoprene + H2O2

Dimethyl tetrol + H2O2

Isoprene epoxide + H2O2

How do we write particle phase reactions for isoprene?

Low NOx

Isoprene + OH IsoRO2

IsoRO2 + ?

High NOx

How much organic nitrate formation should we assume??

Isoprene in the presence of NOx produces nitric acid, 2-methylglyceric acid, 2-methyltetrols and nitrooxypolyols as the major products in SOA samples.

The concentrations of the nitrooxypolyol products decreased three days after the extraction, whereas the concentrations of nitric acid and 2-methyltetrols increased.

These results suggest that the nitrooxypolyols produced by the diene oxidation in the presence of NOx contribute toward the SOA formation and that they can be decomposed into polyols and nitric acid in the aqueous solution.

It was concluded that the direct formation of 2-methyltetrol by gas-phase diene oxidation is suppressed in the presence of NOx.

October 15, 2008 Run Log Purpose: Isoprene + O3 vs isoprene + NOx with VMU particle instrument to look at differences in particle phase and look for tetrols.. Injected Isoprene (117l) into South or 1 ppmC (Sato article had ~2ppmV)  Chamber conditions: vented from 18:00 to 22:37 pm gate valves. At 22:37 chamber gate valves were closed; exhaust blower off; compressor on, clean air generator on.

10 20 30 40

Minutes

-1

0

1

2

3

4

5

6

mVoltset

hyle

ne (4.

326)

4.67

9pr

opan

e (5

.000

)pr

opyl

ene

(5.3

48)

n-bu

tane

(10

.960

)1-

bute

ne (11

.042

)

buta

ne (12

.352

)

2-bu

tene

(13

.315

)

isop

enta

ne (16

.500

)

pent

ane

(17.

368)

met

hylp

enta

ne (20

.891

)

dim

ethy

lpen

tane

(23

.563

)

benz

ene

(25.

850)

cycl

ohex

ane,

trim

epen

tane

(25

.921

)

tolu

ene

(28.

920)

o-xy

lene

(33

.290

)

m-p

xyl

ene

(33.

930)

a-pi

nene

(34

.700

)

tri-m

e be

nz (36

.940

)

b-pi

nene

(37

.547

)

d-lim

onen

e (3

9.12

3) File:Channel:

Last recalc:

c:\saturnws\data\1019.runMiddle = FID ResultsNA

X:Y:

10.1106 Minutes0.944 mVolts

c:\saturnws\data\1019.run

T%:7WI:4 WI:2 GR+

T%:10GR-

WI:4

Chamber Background

10 20 30 40

Minutes

0.0

2.5

5.0

7.5

10.0

12.5

mVolts

ethy

lene

(4.

326)

4.61

14.

660

4.79

2pr

opan

e (5

.000

)pr

opyl

ene

(5.3

48)

n-bu

tane

(10

.960

)1-

bute

ne (11

.042

)

buta

ne (12

.352

)

2-bu

tene

(13

.315

)

14.6

55

isop

enta

ne (16

.500

)

pent

ane

(17.

762)

17.8

76

met

hylp

enta

ne (21

.199

)

dim

ethy

lpen

tane

(23

.563

)

24.3

10

benz

ene

(25.

850)

cycl

ohex

ane,

trim

epen

tane

(25

.921

)

tolu

ene

(28.

920)

o-xy

lene

(33

.318

) m-p

xyl

ene

(33.

930)

a-pi

nene

(34

.634

)34

.805

35.6

07

tri-m

e be

nz (36

.940

)

b-pi

nene

(37

.853

)

d-lim

onen

e (3

9.12

3)

43.6

5543

.717

44.6

60

45.9

21

47.3

47

47.9

10c:\saturnws\data\4016.run File:Channel:

Last recalc:

c:\saturnws\data\4016.runMiddle = FID ResultsNA

X:Y:

8.2134 Minutes-2.09 mVolts

0.0

2.5

5.0

7.5

mVolts

ethy

lene

(4.

326)

4.67

7pr

opan

e (5

.000

)pr

opyl

ene

(5.4

41)

n-bu

tane

(10

.960

)1-

bute

ne (11

.042

)

buta

ne (12

.352

)

2-bu

tene

(13

.315

)

isop

enta

ne (16

.385

)

pent

ane

(17.

806)

18.6

18

met

hylp

enta

ne (21

.232

)

dim

ethy

lpen

tane

(23

.563

)

24.3

10

benz

ene

(25.

850)

cycl

ohex

ane,

trim

epen

tane

(25

.921

)

tolu

ene

(28.

920)

o-xy

lene

(33

.290

)

m-p

xyl

ene

(33.

930)

a-pi

nene

(34

.700

)

35.5

85

tri-m

e be

nz (36

.940

)

b-pi

nene

(37

.547

)

d-lim

onen

e (3

8.84

9)

48.2

96c:\saturnws\data\6012.run File:Channel:

Last recalc:

c:\saturnws\data\6012.runMiddle = FID ResultsNA

X:Y:

11.2452 Minutes-0.213 mVolts

WI:4T%:7VB+GR+

HM+T%:10

HM-VB-GR -

WI:2 WI:4

WI:4T%:7WI:8 WI:4 GR+

HM+T%:10

HM-GR -

08 Oct 16 Old NOx

0.00.05

0.10.15

0.20.25

0.30.35

7 12 17

pp

m

O3

NO

NO2