Production of Biogenic Volatile

Organic Compounds by Mangroves Steven Curtis

The goal was to determine and

measure Biogenic Volatile Organic

Compounds (BVOC’s) produced by

Mangroves.

Why?

Motivation/ Purpose Why we did what we did?

- RED MANGROVE

Mangroves are marine

shrubs and trees that grow

at the ocean-land interface

in tropical and subtropical

regions

Over 80 species

Mangroves cover nearly

two-thirds of tropical

coastline

Intricate room system

including anchor root, prop

roots, and pneumatophores

Mangroves What are they?

Mangroves

Red Mangroves

(Rhizophora mangle)

Black Mangroves

(Avicennia germinanas)

BVOC’s include organic atmosphere trace gases other than monoxide and carbon dioxide

BVOC’s are known to be produced by plants as metabolic byproducts

Extremely reactive within the atmosphere

Often react with hydroxyl radicals, ozone, and nitrate radicals

Can lead to production of surface ozone and atmospheric aerosols

List of prominent BVOC’s compounds

Isoprene

Monoterpenes

Alcohols

Carbonyls

Alkanes, Alkenes, esters , ethers, and acids

Biogenic Volatile Organic

Compounds

Formed by a process called biosynthesis

D: Biosynthesis – The building of a chemical compound in the physiological process of a living organism

Isoprene and monoterpene synthesis take place in plastids (within the plant cell)

Other BVOC synthesis occurs within the cytoplasm of the plant cell

Formation of BVOC’s By Plants

http://aubreymsims.com/plantcell.gif

Collect gaseous compounds on TENAX-TA Traps:

Approximately three inches

long

Filled with 100 mg of TENAX-TA

Glass wool held TENAX-TA in

place

Silicon stoppers were used at

each end of the trap to prevent

contamination Remove any compounds on the TENAX-TA prior to trapping

Plan of Action TENAX-TA

To purge TENAX-TA of impurities:

Used Ionicon HR-PTR-TOF-MS 8000 Series to

monitor compounds on the trap

Flowed purified air through the trap while

heating it to 260 C° at 50 sccm

After approximately twenty minutes or the trap

appeared clean, a background was taken

Repeated for ever trap

After every run a back flush was performed and

recorded to ensure system was clean

Purging TENAX-TA PTR-TOF-MS

1) Zeolite

2) Charcoal Trap

3) Cooled ethanol to

catch water vapor in air

4) Tenax-TA Trap

5) Two-way valve to

change flow pathway

6) PTR-TOF-MS

PTR-TOF-MS Setup

Supplies for Bimini

Traps

Zeolite

Three four foot pieces of

¼”Teflon tubing

Push/pull pump

Teflon bag

Battery

Flow Meter

Preparing for Field Research South Bimini Island, Bahamas

http://img507.imageshack.us/i/biminiobscuredzv4.jpg/

N25.69767°

W79.28020°

RED MANGROVES

N25.69915°

W079.29666°

BLACK MANGROVES

Field Sights

Enclose a branch

with Teflon bag

using draw string

Flow filtered clean air

into bag for twenty

minutes

Let bag stand for

one hour

Collection of BVOC’s Procedure

Evacuate the enclosure at 70 mL/min pulling

air across the TENAX-TA to trap BVOC’s for a

total of 50 minutes

Collection of BVOC’s Procedure

Recorded: Time of collection

Temperature

Dew Point

Relative Humidity

Wind Speed

Heat Index

UV Index

Ozone Concentrations

Number of leaves

Data Collection

PROCEDURE

Utilized the PTR-TOF-MS

to view and discover

compounds given off by

mangroves

Used same procedure as

blanking traps

Noted 35 peaks of

unknown compounds that

had been absorbed onto

TENAX-TA

BLACK MANGROVE

Analysis of Trap

Mass

Molecular

Weight Compound Chemical

Formula

36.0172 Carbon Timer C3

40.0222 Propyne C3H4

42.0172 Propene C3H6

44.2922 Propane C3H8

54.0422 1,3-Butadiene C4H6

58.0419 Acetone C3H6O

60.0172 Propanol C2H4O2

62.0182 DMS C2H6S

68.0622 Isoprene C5H8

72.0522 Butanone (MEK) C4H8O

Molecular

Weight Compound Chemical

Formula

74.0122 Butanol C3H6O2

76.0222 Benzyne C6H4

90.0322 Dihydroxyacetone C3H6O3

92.0622 Toluene C7H8

108.0922 1,5-Cyclooctadiene C8H12

136.1242 Pinene C10H16

206.0922 Dicyclohexylcarbodiimide C13H22N2

208.0422 1,1'-but-1-ene-2,4-diyldibenzene C16H16

222.0622 2,5,8,11,14-pentaoxapentadecane C10H22O5

Identified Peaks

Isoprene emissions Toluene Emissions

Individual Peak Analysis

68.8 68.9 69.0 69.1 69.2 69.3 69.4

-50

0

50

100

150

200

CP

S

Masses

93.00 93.01 93.02 93.03 93.04 93.05 93.06 93.07 93.08 93.09

0

20000

40000

CP

S

Masses

Calculating Emission Rates

ppb ppb ppb ppb ppb

Mass 37(PEAK0) Mass 39(PEAK1) Mass 41(PEAK2) Mass 43(PEAK3) Mass 45(PEAK4) …

8.82E+02 8.18E+01 1.55E+02 1.31E+02 2.28E+02 …

9.06E+02 8.09E+01 1.46E+02 1.38E+02 3.05E+02 …

9.21E+02 9.06E+01 1.71E+02 1.43E+02 3.23E+02 …

8.76E+02 8.12E+01 1.60E+02 1.30E+02 2.54E+02 …

9.12E+02 8.60E+01 1.60E+02 1.25E+02 2.28E+02 …

9.83E+02 8.91E+01 1.63E+02 1.44E+02 1.94E+02 …

8.86E+02 7.89E+01 1.56E+02 1.34E+02 1.84E+02 …

9.21E+02 8.44E+01 1.52E+02 1.39E+02 2.53E+02 …

9.70E+02 8.62E+01 1.69E+02 1.37E+02 2.72E+02 …

…

…

…

…

…

…

Nair =

~ 4.48829E+16

Nair x PPB for each spectra

Apply to all spectra and masses

Sum number of molecules for

each mass

Divide by 3500

Divide by number of molecules

~ 2.41406E+19

After previous

Multiply by (6/5 hrs)

Multiply by volume of bag (.307

m^3)

Subtract out background

Divide by leaf weight

Calculating Emission Rates

Data – Averaged Emissions

17.64373677

6.698651843

5.1948277

4.3641007

3.8799548

3.6425219

2.7997192

2.041036703

1.28009963

1.206472858

1.168312393

1.10920363

1.038586311

1.015983633

0.665670403

0.523188271

0.512970269

0.250505575

0.034208013

0 2 4 6 8 10 12 14 16 18 20

Toluene

Benzyne

Dihydroxyacetone

Butanone (MEK)

Butanol

Dicyclohexylcarbodiimide

Acetone

2,5,8,11,14-pentaoxapentadecane

Propene

Carbon Timer

Propyne

Propane

Propanol

1,1'-but-1-ene-2,4-diyldibenzene

1,3-Butadiene

Isoprene

1,5-Cyclooctadiene

Pinene

DMS

BVOC Emission Rates (µg g(LDW)-1h-1)

Data – Red/Black Mangrove Comparisons

17.64373677

6.698651843

5.1948277

4.3641007

3.8799548

3.6425219

2.7997192

2.041036703

1.28009963

1.206472858

1.168312393

1.10920363

1.038586311

1.015983633

0.665670403

0.523188271

0.512970269

0.250505575

0.034208013

0 2 4 6 8 10 12 14 16 18 20

Toluene

Benzyne

Dihydroxyacetone

Butanone (MEK)

Butanol

Dicyclohexylcarbodiimide

Acetone

2,5,8,11,14-pentaoxapentadecane

Propene

Carbon Timer

Propyne

Propane

Propanol

1,1'-but-1-ene-2,4-diyldibenzene

1,3-Butadiene

Isoprene

1,5-Cyclooctadiene

Pinene

DMS

BVOC Emission Rates (µg g(LDW)-1h-1)

Literature Comparisons

Source Isoprene

(µg g(LDW)-1 h-1)

Monoterpenes

(µg g(LDW)-1 h-1)

Red Mangroves 0.02 0.41

Black Mangroves 0.25 0.33

Birch 0 .19

Sun Flower <0.1 .7

Red Oak 14.8 1.8

Ginkgo <1 3.0

Blue Spruce 12 1.0

Quaking Aspen 50.2 0.0

Apple Tree <1 <0.2

Atmospheric Interactions

Isoprene Reacts with hydroxyl radical (OH-) to form surface

ozone

Increased amounts of tropospheric ozone have been shown to increase methane lifetime in atmosphere

Toluene Primarily reacts with hydroxyl radical (OH-) and has a

13 hour half-life in the atmosphere

Dimethyl Sulfide (DMS) Primarily with the hydroxyl radical (OH-) and the NO3

radical, forming SO3

Where does it go?

Summary

BVOC are produced by Red and Black Mangroves at measureable amounts Used HR-PTR-TOF-MS to demonstrate full capability of instrument. Shown to accurately and precisely compute concentrations of BVOC’s emitted by Mangroves Black Mangroves tend to significantly produce more BVOC’s than Red Mangroves in the conditions of which we measured

Future Research

More research is needed to better understand BVOC emissions by Mangroves and their overall impact on the atmospheric chemistry budget BVOC Emissions as they relate to:

Temperature

Time of day

Plant Stress

Apply emissions to larger scale

Acknowledgements

• Tracey Evans • Dr. Josie Aller • Dr. Daniel Knopf • Eileen Goldsmith • The entire SoMAS Department •Shark Lab • NSF