carbon preference index

SupportNortheast States for Coordinated Air Use

Management (NESCAUM)

New York State Energy & Research Development Authority (NYSERDA)

National Science Foundation, Atmospheric Chemistry

Speciation of Organics in PM2.5 for the

New York City Area

ContributorsMonica Mazurek, Min Li

Rutgers University

Steve McDow, NERL U.S. EPAJohn Graham, NESCAUMDirk Felton, NYDECTom McKenna, Charlie

Pietarinen, NJDEPAl Leston, Steve Bailey, CT DEP

Presented atMARAMA/NESCAUM Science MeetingOctober 18-20,2004, Atlantic City, NJ

There are about 65 million people in the United States that live with annual average PM 2.5 levels above 15 µg/m3.

Average PM2.5 concentrations from FRM monitors in the EPA AIRS database 7/98 through 7/00. NARSTO Assessment 2003

Eastern U.S. Fine MassRural Urban

NARSTO Assessment, 2003

Sources of fine carbonaceous particles

Mass ratios organic markers to ambient EC, OC

Toll Plaza 13, NJ Turnpike, Elizabeth, NJ

Speciation of Organics for Source Apportionment of PM-2.5 (SOAP) Project

ObjectivesAmbient concentrationsmolecular markers

Detection Limits & Contaminant Minimization

Tisch 2-Channel Sampler

Quartz fiber filter collection substrate

YEAR 1Sampling, transport, sample handling, and analytical procedures for ppb-level organics

PM-2.5 Collection

•

•

•

•SOAP network field programQueen’s College NY

SupersiteElizabeth, NJChester, NJWestport, CT

YEAR 2Completed full annual cycle May 2002-2003 using Speciation Trends Network Schedule

400 successful ambient filters

SOAP Fine Particle CompositesIdentical days, 6-10 filters per composite

Early summer ‘02 Eliz, Qns, ChsSummer ’02 Eliz, Qns, Wpt, ChsEarly fall, ’02 Eliz, Qns, Wpt, ChsFall, ’02 Eliz, Qns, Wpt, ChsFall, ’02 precision Eliz, Qns, Wpt, Chs(2)Early winter, ’02-’03 Eliz, Qns, Wpt, ChsWinter, ’03 Eliz, Qns, Wpt, ChsEarly spring, ’03 Eliz, Qns, Wpt, ChsSpring, ’03 Eliz, Qns, Wpt, ChsLate spring, ‘03 Eliz, Qns, Wpt, Chs

EC, OC Archive

LCMS Polar

25%

25%

50%

GCMS markers

SOAP Fine Particle Filters

Color range chart

Carbon Chemical Mass Balance

Accounts for various forms of organic carbon

Multiple analytical measurements

Monitor variations in fine aerosol composition from bulk C to molecular organic C

West Los Angeles (Rogge et al., 1993)

Seasonal Composites Extracted by Groups6-10 filters per compositeQA/QC

Analytical, trip and field blanks

Sensitivity and procedural tests, stds and test ambient

Filter Composite Extraction

Filter Composite Extraction & Derivatization

4 hrs Soxhlet extraction 250 ml (1:1) acetone:CH2Cl2

Extract concentration Kuderna-Danish appar. (5ml) N2 gas (1ml)

Extract Split (1:1) Neutral organics Acid+Neutral organics

Diazomethane synthesis Conversion Acid+Neutral to methyl esthers, methoxy ethers

Molecular Marker Analysis

GCMS ion trap analysis neutral and derivatized fractions

YEAR 3Molecular marker identification & quantitation

Data interpretation

PM-2.5 Complex Mixture Analysis

SOAP Molecular MarkersAlkanes

n-pentacosanen-hexacosanen-heptacosanen-octacosanen-nonacosanen-triacontanen-hentriacontanen-dotriacontaneanteiso-triacontaneiso-hentriacontaneanteiso-hentriacontaneiso-dotriacontaneanteiso-dotriacontaneiso-tritriacontanephytanepristane

PAHsbenzo[b]fluoranthenebenzo[k]fluoranthenebenzo[e]pyreneindeno[1,2,3-cd]pyreneindeno[1,2,3-cd]fluorantheneretenecoronene

Other9 hopanes nonanallevoglucosangalactosanmannosancholesterol7H-benz[de]anthracen-7-onebenz[a]anthracene-7,12-dione

Acids21 n-alkanoic acids(with C10 to C30)10 aliphatic dicarboxylicacids(C3 to C10)1 aromatic polycarboxylicacid cis-9-n-octadecenoic acid

Authentic standards for 63 marker cmpdsmeasured in SOAP ambient composites

N-Alkane Carbon Number and Source Provenance

Distribution of hydrocarbons versus Carbon Number

Mazurek and Simoneit, 1984

Surface waxes from vegetation vs. gasoline, diesel fuels

Carbon Preference Index (CPI) and Source Provenance

Carbon Preference Index = ∑odd homologs∑even homologs

Carbon Preference Index = ∑even homologs∑odd homologs

N-Alkanes & N-Alkanones N-Fatty Acids & N-Alkanols

Carbon Preference Index (CPI) & Carbon Number Distribution

CPI > 3 Significant contribution of recent biological material

CPI ~ 1 Significant contribution degraded material and fossil fuel compounds

Homolog Range and Carbon Number Maximum

Source Range CMaxBacterial, microbial C15-C19 C16, C18

Petroleum hydrocarbons C12-C35 C23-C24

Plant waxes C22-C36 C27, C29

Mazurek and Simoneit, 1984

NYC Area Ambient Concentrations

n-Alkanes (C25-C32)

0

2

4

6

8

10

12

Qns 1 Qns 2 Elz 1 Elz 2 Chs 1 Chs 2 Wpt 1 Wpt 2

ng

/m3

Composite 1: Winter Dec02, Jan03, Feb03 (6 filters)

Composite 2: Spring Mar03, Apr03 (10 filters)

1.5

2.3

1.7

2.6 1.2

2.71.9 2.0

N-Alkanes (C25-C32)

Carbon Preference Index = ∑odd homologs∑even homologs

Alkanesn-pentacosanen-hexacosanen-heptacosanen-octacosanen-nonacosanen-triacontanen-hentriacontanen-dotriacontaneanteiso-triacontaneiso-hentriacontaneanteiso-hentriacontaneiso-dotriacontaneanteiso-dotriacontaneiso-tritriacontanephytanepristane

NYC Area Molecular Markers

n-Alkanoic acids (C10-C30) and diacids (C3-C9)

0

20

40

60

80

100

120

Qns 1 Qns 2 Elz 1 Elz 2 Chs 1 Chs 2 Wpt 1 Wpt 2

ng

/m3

N-Alkanoic Acids (C10-C30) and Diacids (C3-C9)

Composite 1: Winter Dec02, Jan03, Feb03 (6 filters)

Composite 2: Spring Mar03, Apr03 (10 filters)

Acids

21 n-alkanoic acids

(with C10 to C30) CPI noted above bar

10 aliphaticdicarboxylic acids(C3 to C10)1 aromatic polycarboxylic acid cis-9-n-octadecenoicacid

21.5

16.0

12.616.9

18.018.0

50.114.4

NYC Area Vehicle Emission Markers in Fine Particle Samples

Hopanes (C27-C32)

0

1

1

2

2

3

Qns 1 Qns 2 Elz 1 Elz 2 Chs 1 Chs 2 Wpt 1 Wpt 2

ng

/m3

Hopane detection limit > 0.01 ng/m3

Composite 1Winter --Dec 2002, Jan + Feb 2003 (6 filters)

Composite 2Spring --Mar + April 2003 (10 filters)

NYC Area PM-2.5 Organics (STN)SOAP

CompositeOC

µg/m3Organics µg/m3

EC µg/m3

Hopanes/ Organics

Ratio (10-3)

Hopanes/EC Ratio (10-3)

Elz, summer 6.55 9.17 1.65 0.14 0.80

Elz, fall 4.22-4.55 5.91-6.37 1.59-1.72 0.18-0.19 0.62-0.77

Elz, winter 6.86-7.28 9.60-10.20 1.69-1.77 0.24-0.37 1.38-2.09

Elz, spring 5.37-6.01 7.52-8.41 1.39-1.94 0.14-0.39 0.77-1.74

Qns, fall 2.16 3.02 0.60 0.30 1.54

Qns, winter 2.04-4.28 2.86-6.00 0.46-1.16 0.29-0.32 1.64-1.79

Qns, spring 3.20-3.46 4.48-4.84 0.82-0.89 0.15-0.32 0.83-1.90

Wpt, winter 3.77-4.27 5.27-5.98 0.74-0.21 0.03-0.22 0.20-1.11

Wpt, spring 3.01-3.20 4.21-4.48 0.70-0.80 0.08-0.14 0.44-0.85

Chs, spring 2.54-3.30 3.56-4.62 0.41-0.47 0.03-0.04 0.29

Estimating Source ContributionTotal C (EC+OC) : Organic Matter (1.4 X OC) :

Elutable Organic Matter : Molecular Tracer

Mass emission ratios

hopane concentration ng/m3

OC concentration µg/ m3

= ratio of source emission rates

Rogge et al., 1993 vehicle exhaust = 2.7X10-3

Relative Source Contribution to Modeled OC Compounds Ambient Concentrations

Schauer et al., 1996Diesel vehicles = 60% Gasoline Vehicles = 30%Paved road dust = 10%

Comparison to Los Angeles AreaTotal C (EC+OC) : Organic Matter (1.4 X OC) :

Elutable Organic Matter : Molecular Tracer

Site Organics µg/m3

RatioHopanesng/m3 to Organics µg/m3

(10^-3)

Organics from Diesel+ Gasoline

Vehicles µg/m3

(% Fine Particle Mass)

Organics from All Vehicle (road dust, tire debris

µg/m3

(% Fine Particle Mass)

Pasadena 8.14 0.46-0.89 2.44 (24%) 3.13 (38%)

Downtown LA 8.72 0.43-0.83 4.28 (42%) 4.97 (54%)

West LA 7.00 0.53-1.04 2.08 (24%) 2.68 (37%)

Rubidoux 6.24 0.60-1.17 1.51 (14%) 2.40 (27%)

Metropolitan Los Angeles 1982, Chemical Mass Balance –Schauer et al., 1996

Comparison to Los Angeles Area 1982Site Organics

µg/m3Ratio Hopanes

ng/m3 to Organics µg/m3

(10^-3)

Organics from Diesel+ Gasoline Vehicles µg/m3

(% Fine Particle Mass)

Organics from All Vehicle (road dust, tire debris µg/m3

(% Fine Particle Mass)

Pasadena 8.14 0.46-0.89 2.44 (24%) 3.13 (38%)

Downtown LA 8.72 0.43-0.83 4.28 (42%) 4.97 (54%)

West LA 7.00 0.53-1.04 2.08 (24%) 2.68 (37%)

Rubidoux 6.24 0.60-1.17 1.51 (14%) 2.40 (27%)

Elizabeth, NJ 5.91-10.20 0.14-0.39 42% est. max.42% est. max. 54% est. max.54% est. max.

Queens, NY 2.16-4.28 0.15-0.29 42% est. max.42% est. max. 54% est. max.54% est. max.

Westport, CT 4.21-5.98 0.03-0.22 24% est. max.24% est. max. 38% est. max.38% est. max.

Chester, NJ 3.56-4.62 0.03-0.04 14% est. max.14% est. max. 27% est. max.27% est. max.

Preliminary Findingsn-Alkanes: winter> spring CPI spring,summer > winter

increased input of biogenic sources

n-Alkanoic acids & diacids: ambient concentrations similar each site, composite

diacids not only photochemical sources

CPI>3 for n-alkanoic acids suggest biogenic origin

Hopanes: winter maxima Elz>Qns>>Wpt>Chs

estimate maximum organics from all motor vehicle sources 27% to 54%

DISCLAIMER:Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Air Quality Trends

Control of gas phase pollutants (NOX, SOX, O3) and PM has improved urban atmospheres

Thank you

End of Presentation