“The highest form of human intelligence is the ability to
observe without judging”
judging”
Krishnamurti
“The intuitive mind is a sacred gift and the rational mind is
a faithful servant. We have created a society that honors
the servant and has forgotten the gift”
gift”
Albert Einstein
“The mind is everything,
what you think you become”
become”
Buddha
Chemical Elements - Essential for life
Carbon
Carbon forms three-dimensional molecules of large size and
complexity in organic (carbon-containing) compounds that
form large molecules (amino acids, sugars, enzymes, DNA),
and other chemicals vital to life on Earth.
Chemical Elements (the Periodic
Table) and those essential for life
Of the 103 elements in
the Periodic Table, only
24 are required by
organisms
Macronutrients:
Required in large
amount (“Big Six”
Six”: C,
N, P, S, O, H)
Micronutrients: small
or moderate amount
Required elt
Required for some life forms
Toxic elt
Chemical Elements - Essential for life
Nitrogen
Nitrogen (along with carbon) is the essential
element that allows formation of amino acids (
proteins) and DNA.
Proteins contain up to
16% N
Chemical Elements - Essential for life
Phosphorus
Phosphorus is the “energy element”
element” occurring in
compounds called ATP and ADP important for energy
transfer processes and DNA.
Chemical Elements - Essential for life
Carbon:Nitrogen:Phosphorus Ratios
Organisms actively concentrate certain elements
essential for life:
Algae concentrate Iron (Fe) 100,000
times vs. its concentration in the Ocean
• Most organisms keep a rather
constant chemical composition
Algae and plankton C:N:P
ratio of 106:16:1 (Redfield
Ratio)
Soil microbes maintain a
relatively constant proportion of
nutrients in their biomass (and
at higher levels than the OM
they decompose)
Chemical Elements - Essential for life
• Availability of some elements (particularly N & P) is often
limited and the supply of these elements may control the rate
(or type) of primary production in terrestrial ecosystems.
• External sources of nutrients are varied and depend of
nutrient
Annual circulation dominates most inputs of limiting
elements (N, P, K)
Molecular (bio)markers
Source/Process
Molecular Markers
Example
Complementary
Isotope Proxies
Vascular Plants
Lignins/Tannins
Waxes-Cellulose
!13C - (!15N - !14C)
Phytoplankton
Lipids-Aliphat.
Pigments
!13C - !15N
Microbes
Lipids-Aliphat.
Aminosugars
Diagenesis
(Soils-Sedts)
Amino acids
Aromatic Carbox. Ac.
!15N - !34S
Thermal
Maturation
Lipids-Aliphat.
Hopanes-PAHs
!13C - (!15N - !34S)
Combustion
PAH, anhydro-sugars
Carbox. Acids
!13C - !14C
(!15N - !34S)
!13C - !15N
Characterization of TOM
using Lignin as a biomarker
Macromolecule: Part of Lignocellulosic complexes
exclusive to vascular plants (“
(“nature's cement”
cement”)
Multifunctionality: Support, Defense, Impermeability
Lignin as a Biomarker
Why? Its presence in the aquatic systems ! TOM
How? Oxidative cleavage of 3-D polymer
into 4 types of monomers which retain structural information
Cinnamyls (C)
p-hydroxyls (P)
Lignin as a Biomarker
Vanillyls (V)
Syringyls (S)
Using the right endmembers!
30% Anthr.
70% Anthr.
Up to 15% of industrial effluents buried in
estuarine sediments – 100 103 T (1980-92)
What is Black Carbon (BC)?
From aquatic geochemistry to soil/atmospheric chemistry
BC Ring Trial: Comparative analysis of reference materials
BC and matrices containing pyrogenic material:
material: NIST SRMs !
Aerosols (UD), Water way sediment (WWS), Diesel particulate
matter (DPM) and bituminous coal (CB); Soils (CSRIO); Chars
(U. of Zurich); Soot (U of Denver);
Interferences:
Interferences: NOM
(IHSS); Shale (USGS);
Coals (Argonne)
H/C Ratio
1.3
1.0
0.8
0.6
0.3
0.0
Masiello (2004) Marine Chemistry.
Chemistry. Vol.
Vol. 92; Hammes et al. (2007) Global Biogechemistry.
Biogechemistry. Vol.
Vol. 21
Chemically heterogeneous, biologically refractory class of carbon compounds
produced during biomass burning and fossil fuel combustion
! Charcoal:
Charcoal: Remains of solid fuel phase (retain structural character)
! Soot:
Soot: Condensation of hydrocarbon radicals from gas phase into
submicron particles (usually nucleated - onion structure)
How extensive is an airshed?
a) Since we are dealing with ultra-fine particles ! we are bound to
see some wide geographical distribution
Why Study Black Carbon?
! Radiatively important aerosols (direct and indirect impacts)
! “Short-circuit
Short-circuit”” in the carbon cycle?
!Atmospheric chemistry and health impact
(PM2.5-10, PAHs,
PAHs, BC, VOCs)
VOCs)
! Prescribed fires and wildfires contribute 20%
of the PM2.5 emissions in the U.S.
Cooney, C. (2008) ES&T. Vol.
Vol. 42( 5).
Hadley et al. (2007) J. Geophys.
Geophys. Res.
Res. Vol.
Vol. 112.
North American emissions of BC: 41.5 G/Month
Input transport: 32 G/Month (75% originates from Asia!)
How extensive is an airshed?
b) Since we are dealing with particles ! we are bound to have
some geographical heterogeneity
BC inputs to urban systems:
The legacy of geography
Are some urban systems are “underserved”
underserved” by their geography?
Los Angeles
Mexico City
Malm et al. (2004) J. Geophys.
Geophys. Res.
Res. Vol.
Vol. 109.
Molecular markers of biomass combustion
What about more “open”
open” urban airsheds?
airsheds?
Levoglucosan:
Levoglucosan: Pyrogenic derivative of cellulose combustion
Houston
New York
Central American Smoke Event (May 1998)
Fraser, M.P. and Laksmanan K.
(2000). Env.
Env. Sci.
Sci. & Technol.
Technol. Vol.
Vol. 34.
Elias et al. (2001) Geochim.
Geochim. Cosmochim.
Cosmochim. Acta.
Acta. Vol.
Vol. 65(2)
Fraser, M.P. and Laksmanan K. (2000).
Using Levoglucosan as a Molecular Marker
for the Long-Range Transport of Biomass
Combustion Aerosols.. ES&T. Vol.
Vol. 34.
Intercomparison
Washington D.C. Urban Dust
(n = 11)
Wetlands as “memory” of environmental change
(n = 2)
Piermont Tidal Wetland
The influence of biomass
combustion on paleoproxies
(charcoal fluxes)
! Important component in the
carbon cycle?
Carbon stocks (up to 10% of
terrestrial SOC storage!) in
<0.5% of the surface
! Memory of coastal systems
Pederson, Peteet,
Peteet, Guiderson,
Guiderson, and Kurdyla (2004). Environment during the Last Millenium in the
Lower Hudson Valley, NY - Medieval Warming, Little Ice Age, and European Impact. Quat. Res.
Res.
Pederson, et al. (2004). Quaternary Research.
Research.
Piermont Tidal Wetland
Levoglucosan “Yields”: Thermal dependence
2500.0
Cordgrass char
Levoglucosan (ug/goc)
2000.0
Loblolly Pine char
Honey Mesquite char
1500.0
1000.0
500.0
0.0
0
100
200
300
400
500
600
700
800
900
Combustion temperature (degree C)
Kuo,
Kuo, Herbert, Louchouarn. (2008b-in review) Org.
Org. Geochem.
Geochem.
Internal Standards in GLC
Molecular markers of biomass combustion
Levoglucosan:
Levoglucosan: Pyrogenic derivative of cellulose combustion
•
•
•
•
Kuo et al. (2008b-submitted) Org.
Org. Geochem.
Geochem.
An internal standard (IS
(IS)) is a substance which is similar
in the chemical behavior (chemical structure - polarity)
and analytical response to a certain target analyte.
A defined volume of the IS solution is added to both the
sample and calibration solutions such that they both
contain an identical concentration.
When the sample and the calibration solutions are
analyzed, the peaks for both the IS and the target
analyte are integrated.
The area of the analyte peak is divided by the area of
the internal standard peak to produce a peak area ratio
(PAR) value.
Internal Standard Quantification
Internal Standards in GLC
•
•
This method corrects for run-to-run-variation in
extraction efficiency and chromatographic response.
The use of an IS eliminates all injection volume related
sources of error and leads to an improvement of method
precision and is a powerful tool to monitor the sample
preparation.
•
The IS must not overlap with the sample peak and may
elute near before or after the peak of interest.
•
To convert the peak areas to mass of analyte, the peak
areas must be calibrated.
•
IS
IS
The two main strategies are based on repeated onepoints standard calibration and multiple-points
calibration curves.
The relative response factor (RRF) is:
RRFStd =
Amt x
Areax
x
Std
AreaIS
Amt IS
Std
!
Internal Standard Quantification
Internal Standard Quantification
The relative response factor (RRF) is:
IS
RRFSpl = RRFStd
IS
Amt x
Areax
x
Spl
AreaIS
Amt IS
=
Spl
!
The relative response factor (RRF) is:
RRFStd
Amt x
=
Areax
AreaIS
x
Amt IS
Std
Amt x Spl = Areax Spl x
!
Std
!
Amt x
Areax
Amt IS
AreaIS
x
Std
AreaIS
Amt IS
xRRFStd
Spl
Std
Methods
Molecular markers of biomass combustion
Internal Standard Quantification
Levoglucosan:
Levoglucosan: Pyrogenic derivative of cellulose combustion
Solvent extraction ! sonication (DCM:MeOH - 3x10 min)
Analysis: GC/MS (phenols - organic acids - sugars)
The relative response factor (RRF) is:
RRFStd =
Amt x
Areax
x
Std
AreaIS
Amt IS
Std
!
Internal Standard Quantification
Multiple-points IS Quantification
Keeping the [IS]std constant:
!
RRFStd =
Amt x
Amt IS
÷
Std
Areax
AreaIS
Std
Multiple-points IS Quantification
Multiple-points IS Quantification
Keeping the [IS]std constant:
RRFStd =
Amt x
Amt IS
÷
Std
Areax
AreaIS
Keeping the [IS]std constant:
Std
!
!
Multiple-points IS Quantification
Keeping the [IS]std constant:
!
RRFStd =
Amt x
Amt IS
÷
Std
Areax
AreaIS
Std
RRFStd =
Amt x
Amt IS
÷
Std
Areax
AreaIS
Std