Hydrocarbon Composition of Gasoline 

Vapor Emissions from Enclosed Fuel Tanks

Draft
EPA-420-R-11-018

December 2011

Assessment and Standards Division

Office of Transportation and Air Quality

and

Human Exposure & Atmospheric Sciences Division

Office of Research and Development 

U.S. Environmental Protection Agency

Hydrocarbon Composition of Gasoline 

Vapor Emissions from Enclosed Fuel Tanks

Draft

NOTICE

This technical report does not necessarily represent final EPA decisions or 

positions. It is intended to present technical analysis of issues using data 

that are currently available. The purpose in the release of such reports is to 

facilitate the exchange of technical information and to inform the public of 

technical developments.
1

Introduction

The purpose of this report is for EPA OTAQ (Office of Transportation and Air Quality) to give a 

summary of EPA ORD (Office of Research and Development) work on the composition of 

hydrocarbon emissions from gasoline, specifically the head space components above gasoline in 

an enclosed fuel tank. These profiles were used in EPA’s proposed Tier 3 rule and antibacksliding study. The profiles were used to speciate hydrocarbon emissions from onroad 

vehicle and nonroad engine gasoline refueling, portable fuel container emissions, and vapor 

losses during storage and transport. 

Overview and Prior Work

Headspace vapors are those hydrocarbon compounds in gaseous form above a gasoline sample in 

an enclosed space such as a vehicle fuel tank or frequently a fuel storage tank used in the 

distribution for gasoline. Some of these vapors are emitted to the atmosphere in transport, 

storage, and utilization of gasoline. The numerous hydrocarbon compounds (about 120 

individual hydrocarbons) represent the more volatile and lower molecular weight components of 

the gasoline. 

For EPA’s RFS2 rule, EPA ORD measured headspace emissions for an E0 base gasoline and an 

E10 sample splash-blended from the E0 gasoline For EPA’s RFS2 rule, EPA ORD measured 

headspace emissions for an E0 base gasoline and an E10 sample splash-blended from the E0 

gasoline.1

However, the anti-backsliding and Tier3 analyses also required modeling an E15 blend, since in 

January, 2011, EPA granted partial waivers that allow the introduction into commerce of 

gasoline that contains greater than 10 volume percent (vol%) ethanol and up to 15 vol% ethanol 

(E15) for use in model year (MY) 2001 and newer light-duty motor vehicles, subject to certain 

conditions.2 On October 13, 2010, EPA granted the first partial waiver for E15 for use in 

MY2007 and newer light-duty motor vehicles (i.e., cars, light-duty trucks and medium-duty 

passenger vehicles). On January 21, 2011, EPA granted the second partial waiver for E15 for use 

in MY2001-2006 light-duty motor vehicles. These decisions were based on test results provided 

by the U.S. Department of Energy (DOE) and other test data and information regarding the 

potential effect of E15 on vehicle emissions.

In order to ensure consistency between headspace profiles for E0, E10 and E15 fuels, new 

profiles were developed using fuel samples from the EPAct test program.3

 

1 U. S. EPA. 2009. Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks. Office of 

Transportation and Air Quality, Ann Arbor, MI, and Office of Research and Development, RTP, NC. EPA-420-D10-011, January 2010.

 Properties of the six 

fuels tested are summarized in Table 1. Fuels 13 and 14 are E0 fuels, fuels 6 and 10 are E10, and 

2 Federal Register. 2011. Partial Grant of Clean Air Act Waiver Application Submitted by Growth Energy to 

Increase the Allowable Ethanol Content of Gasoline to 15 Percent; Decision of the Admininstrator. 76(17):4662-

4683.

3 Add reference: Phase 3 EPAct/V2?E-89 Test Program.
2

fuels 27 and 28 are E15. One fuel in each pair is low in aromatics (15-17 volume percent) and 

one is high in aromatics (about 34-35 percent). Olefin levels range from 6-9 percent, and 

volatilities are similar, with DVPEs of about 7 percent. 

Sample Preparation

The 6 gasoline samples tested for headspace and whole composition were received from 

Southwest Research Institute in amber-tinted quart bottles via FedEx shipment. To prepare for 

testing, these bottles were placed in large cooler containing ice. After a 20 – 30 min period 25 ml 

aliquots were withdrawn using Pasteur pipettes and put into 50 ml Erlenmeyer flasks then placed 

into a constant water-temperature bath maintained at 25oC. Similar 25 ml aliquots of each 

sample were placed into 20 x 150 mm Pyrex culture bottles, capped and stored in the ice bath. 

Triple distilled water (70 μl) was injected into recently cleaned and vacuum evacuated six liter 

SUMMA canisters to condition the canister surface. This small volume of water vaporizes to 

coat the internal surfaces of the canister with a monolayer of water vapot. This deactivates and 

conditions active surface sites, allowing the storage of the VOC vapors obtained from the 

gasoline and gasoline head space injections at 25 °C. Without this deactivation, significant losses 

of these compounds from benzene to the higher molecular weight hydrocarbons would be 

observed during the sample storage period. 

.After a 20 min equilibration time, 100 μL aliquots of the headspace vapors were taken from the 

Erlenmeyer flask and injected into the SUMMA canisters. The canisters were then filled with 

UHP helium to 40 psig. The prepared canisters were allowed to equilibrate for a 12 to 15 h 

period before performing both GC/FID and GC/MS analyses. Whole fuel samples were prepared 

by injecting 0.02 μL aliquots of the cooled liquid into the 6-L canisters, then filled with UHP 

helium to 40 psig. More details of these procedures are published elsewhere. Likewise more 

detail concerning the GC/FID and GC/MS methodology are published elsewhere.4

 

The results obtained for two each E0, E10, and E15 fuels sent to RTP for headspace analysis are 

provided in the attached tables. Results for both the headspace at 25 °C and whole fuel analyses 

of E0, E10 and E15 gasolines are included. About 140 compound peaks are presented from the 

more than 200 compound peaks observed representing approximately 98% of total VOC 

concentration. Compound name, VOC type (paraffin, olefin, aromatic, oxygenate, unknown), 

and RTINDEX5

 

4 Harley, R.A., S.A. McKeen, M.O. Rodgers, and W.A. Lonneman, Analysis of motor vehicle emissions during the 

Nashville/Middle Tennessee Ozone Study, J. Geophys. Res., 106, 3559-3567, 2001

 for each compound are provided in the first 3 columns to the left. 

5

 RTINDEX is a technique used to place the elution order and/or location of various VOCs on the GC column. The 

most common approach is to determine the retention time of a mixture of the C2-C15 normal paraffins (i.e., ethane 

through pentadecane) then place other VOCs by retention time where these compounds elute in reference to the 

normal paraffins. For example, the retention time of benzene on an EPA GC column with an RTINDEX value of 

651.21 is about half way between the centerary retention times of the C6 and C7 nornal alkanes – n-hexane being 

defined with an RTINDEX value of 600.00 and n-heptane with a defined RTINDEX value of 700.00. 
3

Table 1. Properties of EPAct fuels tested.

PROPERTY UNIT TEST METHOD

EPAct Phase 3 Fuel

6 10 13 14 27 28

Density, 60oF g/cm3 D4052 0.7342 0.7644 0.7540 0.7223 0.7434 0.7699

API Gravity, 

60oF

o

API D4052 61.1 53.4 56.0 64.2 58.6 52.1

Ethanol vol. % D5599 10.56 9.82 <0.10 <0.10 14.91 14.98

Total Content 

of Oxygenates 

Other Than 

Ethanol

vol. % D5599 <0.10 <0.10 <0.10 <0.10 <0.10 <0.10

Distillation 

IBP oF 

D86 (OptiDist or 

equivalent for E10, 

E15 and E20 fuels)

106.7 104.7 96.6 100.4 104.8 103.9

5% evap oF 130.4 130.0 127.0 126.5 135.3 136.3

10% evap oF 135.9 136.3 139.8 135.5 142.3 144.2

20% evap oF 142.6 144.3 158.7 147.3 152.0 154.0

30% evap oF 148.3 151.0 178.2 160.0 158.0 160.2

40% evap oF 153.4 161.6 199.9 175.1 163.8 165.8

50% evap oF 188.5 217.1 222.5 192.8 221.5 216.6

60% evap oF 228.2 261.5 245.2 212.0 265.1 240.2

70% evap oF 267.7 290.4 269.8 237.3 274.9 251.6

80% evap oF 310.1 317.5 303.5 280.1 311.3 268.4

90% evap oF 340.4 340.2 337.9 338.5 340.3 298.8

95% evap oF 352.7 354.3 354.4 354.5 351.9 327.3

FBP oF 369.2 372.4 377.5 377.5 372.2 363.2

DVPE (EPA 

equation) psi D5191 7.24 7.11 6.92 7.14 6.97 6.87

Aromatics vol. % D1319 15.0 34.0 34.1 16.9 14.9 34.5

Olefins vol. % D1319 8.8 6.1 6.3 8.5 7.4 7.0

Saturates vol. %

100 - D1319Aromatics 

- D1319Olefins - 

D5599Ethanol

65.6 50.1 59.6 74.6 62.9 43.5

Benzene vol. % D3606 0.68 0.52 0.51 0.52 0.56 0.59

S mg/kg D5453 23 25 23 24 26 24

RON - D2699 96.3 98.5 95.8 91.5 100.8 102.7

MON - D2700 86.6 87.2 85.8 84.6 89.2 89.4

(RON+MON)/2 - - 91.5 92.9 90.8 88.1 95.0 96.1

C mass % D5291 mod. 81.52 83.47 86.76 85.28 80.27 81.78

H mass % D5291 mod. 14.21 12.83 13.15 14.29 14.01 12.62

O mass % D5599 4.0 3.6 <0.1 <0.1 5.5 5.4

Net Heat of 

Combustion MJ/kg D4809 41.785 41.210 43.171 43.519 41.062 40.383

Water mass % E-1064 0.073 0.067 0.014 0.015 0.090 0.091

Lead g/l D3237 - <0.003 <0.001 <0.001 <0.003 <0.003

Copper Strip 

Corrosion - D130 1A 1A 1A 1A 1A 1A

Solvent Washed 

Gum Content mg/100ml D381 <0.5 <0.5 1.5 <0.5 0.5 <0.5

Oxidation 

Stability min. D525 >240 >240 >240 >240 >240 >240
The columns labeled HS and Whole provide the fraction that the observed peak concentration 

obtained as parts-per-billion carbon (ppbC) is to the sum of all observed peaks obtained as ppbC. 

At the bottom of the spreadsheet column is the ratio that the sum of listed peaks is of all the 

observed peaks. This value is typically 98 – 99%. Also included are tables with the percent sum 

of the various compound groups to the total VOC. The concentration of ethanol was corrected 

for the reduced FID response due to the presence of an oxygen atom. For ethanol, the carbon 

atom attached to the hydroxyl (OH) group has about 50% reduced response with the FID 

compared to the other carbon in the compound. Consequently the correction for the 2 carbons in 

ethanol is given as 2/1.5 or 1.33. 

Precision and Accuracy of Results 

In past analyses of whole gasoline and gasoline headspace samples at 25 °C, ORD has measured 

both precision and accuracy for these analyses. Repeat analysis for instrumental precision is

more commonly performed with repeatability of 5% or better. 

National Institute of Standards and Technology/Standard Reference Material 

(NIST/SRM) propane in air standard cylinder is used to determine accuracy. The assumption is 

made (as it is in EPA measurements of motor vehicle exhaust) that all hydrocarbons respond in 

the flame ionization detector (FID) with a uniform per carbon response. However, ethanol, as 

well as any other oxygenated hydrocarbons in gasoline, does not respond in this way. As 

discussed earlier, an adjustment was made for the presence of oxygen in the FID response. 

4
Table 2. Headspace (HS) and whole fuel composition of Fuel 13. Compound type: p = paraffin, 

o = olefin, a = aromatic, ox = oxygenate, u = unknown. 

Fuel # 13 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.029 0.025

Isobutane p 361.88 0.355 0.060

Butene-1 o 389.97 0.147 0.055

Isobutylene o 390.92 0.167 0.000

n-Butane p 400.00 9.555 1.906

t-Butene-2 o 411.64 0.729 0.155

2,2-Dimethylpropane* p 413.35 0.075 0.073

c-Butene-2 o 425.94 0.551 0.128

3-Methyl-1-Butene o 457.43 0.249 0.070

Ethanol ox 461.50 0.000 0.000

Isopentane p 474.54 21.286 8.590

Pentene-1 o 489.36 0.873 0.356

2-Methyl-1-Butene o 496.17 1.361 0.630

n-Pentane p 500.00 6.190 3.070

Isoprene o 504.19 0.024 0.011

trans-2-Pentene o 508.72 1.950 1.000

Unknown u 513.67 0.015 0.012

cis-2-Pentene o 516.35 1.045 0.547

2-Methyl-2-Butene o 521.04 2.276 1.255

2,2-Dimethylbutane p 535.47 0.336 0.213

Cyclopentene o 551.84 0.343 0.221

3-Methyl-1-pentene o 557.98 0.195 0.138

Cyclopentane p 562.82 0.500 0.340

2,3-Dimethylbutane p 565.46 1.917 1.450

2-Methylpentane p 570.09 4.769 3.764

3-Methylpentane p 583.52 3.376 2.807

2-Methyl-1-Pentene o 588.52 0.322 0.271

Hexene-1 o 589.36 0.186 0.147

n-Hexane p 600.00 5.275 4.786

trans-3-Hexene o 602.80 0.348 0.320

trans-2-Hexene o 604.98 0.488 0.451

2-Methyl-2-Pentene o 607.37 0.458 0.429

Unknown u 608.87 0.135 0.112

cis-3-Hexene o 610.49 0.281 0.262

4-Methylcyclopentene* o 612.17 0.069 0.062

cis-2-Hexene o 614.50 0.258 0.238

cis-3-Methyl-2-pentene* o 620.74 0.386 0.376

2,2-DiMethylpentane p 625.13 0.191 0.201

Methylcyclopentane p 627.20 2.443 2.342

2,4-Dimethylpentane p 631.38 0.992 1.051

2,2,3-TriMethylbutane p 637.00 0.103 0.105

2,4-DiMethyl-1-Pentene o 647.79 0.014 0.015

1-Methylcyclopentene o 651.00 0.309 0.331

Benzene a 651.21 0.784 0.842

3,3-DiMethylpentane p 657.00 0.093 0.120

Cyclohexane p 660.96 1.783 1.891

4-Me-1-Hexene o 665.23 0.003 0.017

2-Methylhexane p 668.68 0.788 0.952

2,3-Dimethylpentane p 670.80 0.557 0.666

1,1-DiMeCyclopentane p 674.11 0.066 0.082

3-Methylhexane p 677.22 0.599 0.746

5-Methyl-2-hexene* o 680.55 0.008 0.010

c-1,3-DiMeCyclopentane p 684.41 0.133 0.160

t-1,3,-DiMeCyclopentane p 687.12 0.149 0.188

5
6

2,2,4-TriMethylpentanep 690.72 4.010 5.261

3-Methyl-3-hexeneo 695.08 0.005 0.011

trans-3-Hepteneo 697.82 0.007 0.011

n-Heptanep 700.00 0.370 0.508

3-Me-cis-3-Hexeneo 701.44 0.032 0.000

2,4,4-TriMethyl-1-Penteneo 712.30 0.008 0.011

MethylCyclohexanep 724.30 0.671 0.947

2,5-DiMethylhexanep 733.56 0.452 0.758

2,4-DiMethylhexane + EthylCyclopentanep 735.91 0.613 1.021

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.018 0.031

ctc-1,2,3-TriMeCyclopentanep 751.44 0.007 0.013

2,3,4-TriMethylpentanep 753.56 1.203 2.127

Toluenea 758.58 10.681 18.840

2,3-DiMethylhexanep 762.98 0.243 0.632

2-Methyl-3-Ethylpentanep 765.00 0.000 0.000

2-Methylheptanep 767.55 0.049 0.123

4-Methylheptanep 769.28 0.015 0.038

3,4-DiMethylhexanep 772.50 0.048 0.101

3-Methylheptanep 775.34 0.047 0.122

ctc-1,2,4-TriMeCyclopentanep 781.70 0.037 0.082

t-1,4-DiMeCyclohexanep 783.92 0.017 0.034

2,2,5-Trimethylhexanep 785.98 0.418 0.909

1,1-DiMethylCyclohexanep 790.50 0.008 0.017

2,2,4-TriMethylhexanep 794.85 0.004 0.023

n-Octanep 800.00 0.051 0.153

cis-2-Octeneo 812.37 0.010 0.021

2,3,5-TriMethylhexanep 819.44 0.063 0.142

2,4-DiMethylheptanep 825.88 0.015 0.023

2,6-DiMethylheptanep 831.77 0.016 0.029

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.000 0.005

2,5-DiMeHeptane p 838.60 0.036 0.091

Ethylbenzene a 855.40 0.479 1.765

ctt-1,2,4-TriMeCyclohexanep 860.26 0.012 0.036

m-& p-Xylenea 863.65 1.654 6.945

3-Methyloctanep 873.73 0.004 0.017

ctc-1,2,4-TriMeCyclohexanep 881.42 0.037 0.113

o-Xylenea 887.56 0.319 1.582

Nonene-1o 889.31 0.000 0.000

Nonanep 900.00 0.007 0.024

trans-2-Noneneo 902.49 0.017 0.047

cis-2-Noneneo 912.37 0.006 0.008

Isopropylbenzenea 920.34 0.026 0.071

3,5-DiMethyloctanep 927.97 0.007 0.010

2,6-DiMethyloctanep 937.70 0.022 0.029

n-Propylbenzenea 950.95 0.041 0.313

m-Ethyltoluenea 957.45 0.163 1.364

p-Ethyltoluenea 960.02 0.106 0.702

1,3,5-TriMethylbenzenea 964.32 0.094 0.934

3-Methylnonanep 973.55 0.003 0.016

o-Ethyltoluenea 976.97 0.069 0.561

Unknownu 986.65 0.037 0.033

Unknownu 988.06 0.000 0.000

1,2,4-TriMethylbenzenea 991.48 0.250 2.578

n-Decanep 1000.00 0.036 0.117

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.013 0.065

sec-Butylbenzenea 1010.39 0.012 0.055

m-Cymenea 1018.22 0.013 0.066

1,2,3-TriMethylbenzenea 1022.13 0.117 0.619

Unknownu 1031.59 0.094 0.428

Indanen 1036.98 0.017 0.138

Unknownu 1040.81 0.040 0.164
7

Unknown u 1048.17 0.129 0.772

n-Butylbenzene + p-Diethylbenzene a 1054.69 0.000 0.271

1-Me-4-isoPropylbenzene a 1059.44 0.020 0.042

Unknown u 1062.68 0.009 0.109

1-Me-2-n-Propylbenzene a 1067.27 0.020 0.423

1,4-DiMe-2-Ethylbenzene a 1075.98 0.081 0.134

Unknown u 1078.46 0.017 0.175

1,2-DiMe-4-Ethylbenzene a 1084.27 0.021 0.289

Unknown u 1086.66 0.000 0.339

1,3-DiMe-2-Ethylbenzene a 1092.85 0.087 0.050

Unknown u 1094.62 0.017 0.038

n-Undecane p 1100.00 0.004 0.072

1,2-DiMe-3-Ethylbenzene a 1107.49 0.010 0.126

1,2,4,5-Tetra-Me-Benzene a 1119.01 0.016 0.220

Unknown u 1123.00 0.026 0.326

t-1-But-2-MeBenzene a 1139.52 0.056 0.027

Unknown u 1144.96 0.005 0.143

Methylindane n 1156.53 0.019 0.142

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.017 0.069

t-1-But-3,5-DiMeBenzene a 1174.77 0.000 0.030

Unknown u 1175.94 0.079 0.000

t-1-But-4-Ethylbenzene a 1183.89 0.000 0.023

Naphthalene n 1189.56 0.000 0.000

n-Dodecane p 1200.00 0.000 0.000

% Listed Peaks are of Total VOC 99.02 98.25
8

Table 3. Summary statistics for the hydrocarbon composition of Fuel 13. 

Summary Statistics for Fuel #13

HS Whole

%Ethanol 0.000 0.00

%Paraffins 70.10 48.96

%Olefins 13.12 7.57

%Aromatics 15.15 38.81

%Unknowns 0.60 2.64

%Fused Rings 0.04 0.28
9

Table 4. Headspace and whole fuel composition of Fuel 14. 

Fuel # 14 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.006 0.02

Isobutane p 361.88 0.139 0.05

Butene-1 o 389.97 0.090 0.00

Isobutylene o 390.92 0.111 0.03

n-Butane p 400.00 1.329 0.39

t-Butene-2 o 411.64 0.386 0.15

2,2-Dimethylpropane* p 413.35 0.127 0.09

c-Butene-2 o 425.94 0.439 0.12

3-Methyl-1-Butene o 457.43 0.242 0.07

Ethanol ox 461.50 0.000 0.00

Isopentane p 474.54 27.892 10.72

Pentene-1 o 489.36 0.987 0.35

2-Methyl-1-Butene o 496.17 1.513 0.62

n-Pentane p 500.00 6.924 3.03

Isoprene o 504.19 0.027 0.01

trans-2-Pentene o 508.72 2.296 1.00

Unknown u 513.67 0.020 0.01

cis-2-Pentene o 516.35 1.247 0.54

2-Methyl-2-Butene o 521.04 2.739 1.28

2,2-Dimethylbutane p 535.47 1.142 0.65

Cyclopentene o 551.84 0.442 0.22

3-Methyl-1-pentene o 557.98 0.246 0.15

Cyclopentane p 562.82 2.766 1.65

2,3-Dimethylbutane p 565.46 1.313 0.93

2-Methylpentane p 570.09 5.353 4.11

3-Methylpentane p 583.52 4.147 3.51

2-Methyl-1-Pentene o 588.52 0.375 0.30

Hexene-1 o 589.36 0.200 0.15

n-Hexane p 600.00 6.840 6.87

trans-3-Hexene o 602.80 0.354 0.36

trans-2-Hexene o 604.98 0.503 0.49

2-Methyl-2-Pentene o 607.37 0.462 0.46

Unknown u 608.87 0.154 0.13

cis-3-Hexene o 610.49 0.281 0.28

4-Methylcyclopentene* o 612.17 0.073 0.06

cis-2-Hexene o 614.50 0.268 0.25

cis-3-Methyl-2-pentene* o 620.74 0.379 0.41

2,2-DiMethylpentane p 625.13 0.181 0.22

Methylcyclopentane p 627.20 2.741 3.00

2,4-Dimethylpentane p 631.38 0.490 0.67

2,2,3-TriMethylbutane p 637.00 0.055 0.08

2,4-DiMethyl-1-Pentene o 647.79 0.012 0.02

1-Methylcyclopentene o 651.00 0.290 0.39

Benzene a 651.21 0.760 0.86

3,3-DiMethylpentane p 657.00 0.077 0.12

Cyclohexane p 660.96 2.520 3.46

4-Me-1-Hexene o 665.23 0.023 0.00

2-Methylhexane p 668.68 0.581 1.04

2,3-Dimethylpentane p 670.80 0.639 1.13

1,1-DiMeCyclopentane p 674.11 0.049 0.07

3-Methylhexane p 677.22 0.466 0.86

5-Methyl-2-hexene* o 680.55 0.007 0.01

c-1,3-DiMeCyclopentane p 684.41 0.093 0.17

t-1,3,-DiMeCyclopentane p 687.12 0.109 0.21

2,2,4-TriMethylpentane p 690.72 7.510 15.87

3-Methyl-3-hexene o 695.08 0.004 0.01

trans-3-Heptene o 697.82 0.006 0.01

n-Heptane p 700.00 0.275 0.65

3-Me-cis-3-Hexene o 701.44 0.024 0.00

2,4,4-TriMethyl-1-Pentene o 712.30 0.190 0.41

MethylCyclohexane p 724.30 0.423 0.95

2,5-DiMethylhexane p 733.56 0.328 0.84
10

2,4-DiMethylhexane + EthylCyclopentanep 735.91 0.411 1.06

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.012 0.03

ctc-1,2,3-TriMeCyclopentanep 751.44 0.005 0.01

2,3,4-TriMethylpentanep 753.56 0.529 1.43

Toluenea 758.58 3.049 7.86

2,3-DiMethylhexanep 762.98 0.119 0.35

2-Methyl-3-Ethylpentanep 765.00 0.008 0.00

2-Methylheptanep 767.55 0.041 0.10

4-Methylheptanep 769.28 0.015 0.03

3,4-DiMethylhexanep 772.50 0.020 0.05

3-Methylheptanep 775.34 0.038 0.10

ctc-1,2,4-TriMeCyclopentanep 781.70 0.029 0.08

t-1,4-DiMeCyclohexanep 783.92 0.012 0.04

2,2,5-Trimethylhexanep 785.98 0.108 0.33

1,1-DiMethylCyclohexanep 790.50 0.007 0.02

2,2,4-TriMethylhexanep 794.85 0.004 0.02

n-Octanep 800.00 0.044 0.16

cis-2-Octeneo 812.37 0.004 0.01

2,3,5-TriMethylhexanep 819.44 0.016 0.06

2,4-DiMethylheptanep 825.88 0.005 0.02

2,6-DiMethylheptanep 831.77 0.006 0.02

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.003 0.01

2,5-DiMeHeptane p 838.60 0.021 0.05

Ethylbenzene a 855.40 0.359 1.15

ctt-1,2,4-TriMeCyclohexanep 860.26 0.007 0.02

m-& p-Xylenea 863.65 1.229 4.01

3-Methyloctanep 873.73 0.005 0.02

ctc-1,2,4-TriMeCyclohexanep 881.42 0.010 0.04

o-Xylenea 887.56 0.270 0.88

Nonene-1o 889.31 0.000 0.00

Nonanep 900.00 0.009 0.03

trans-2-Noneneo 902.49 0.008 0.03

cis-2-Noneneo 912.37 0.002 0.00

Isopropylbenzenea 920.34 0.024 0.09

3,5-DiMethyloctanep 927.97 0.006 0.02

2,6-DiMethyloctanep 937.70 0.026 0.08

n-Propylbenzenea 950.95 0.063 0.20

m-Ethyltoluenea 957.45 0.241 0.75

p-Ethyltoluenea 960.02 0.133 0.37

1,3,5-TriMethylbenzenea 964.32 0.147 0.45

3-Methylnonanep 973.55 0.004 0.01

o-Ethyltoluenea 976.97 0.110 0.35

Unknownu 986.65 0.024 0.07

Unknownu 988.06 0.000 0.00

1,2,4-TriMethylbenzenea 991.48 0.409 1.33

n-Decanep 1000.00 0.061 0.19

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.021 0.07

sec-Butylbenzenea 1010.39 0.015 0.05

m-Cymenea 1018.22 0.020 0.06

1,2,3-TriMethylbenzenea 1022.13 0.156 0.41

Unknownu 1031.59 0.196 0.57

Indanen 1036.98 0.022 0.07

Unknownu 1040.81 0.075 0.22

Unknownu 1048.17 0.284 0.87

n-Butylbenzene + p-Diethylbenzenea 1054.69 0.000 0.18

1-Me-4-isoPropylbenzenea 1059.44 0.067 0.05

Unknownu 1062.68 0.022 0.13

1-Me-2-n-Propylbenzenea 1067.27 0.048 0.49

1,4-DiMe-2-Ethylbenzenea 1075.98 0.168 0.10

Unknownu 1078.46 0.033 0.15

1,2-DiMe-4-Ethylbenzenea 1084.27 0.047 0.19

Unknownu 1086.66 0.064 0.32

1,3-DiMe-2-Ethylbenzenea 1092.85 0.123 0.03

Unknownu 1094.62 0.023 0.04

n-Undecanep 1100.00 0.019 0.07

1,2-DiMe-3-Ethylbenzenea 1107.49 0.031 0.06

1,2,4,5-Tetra-Me-Benzenea 1119.01 0.023 0.14

Unknownu 1123.00 0.042 0.20
11

t-1-But-2-MeBenzene a 1139.52 0.060 0.02

Unknown u 1144.96 0.005 0.09

Methylindane n 1156.53 0.027 0.08

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.025 0.05

t-1-But-3,5-DiMeBenzene a 1174.77 0.011 0.09

Unknown u 1175.94 0.005 0.00

t-1-But-4-Ethylbenzene a 1183.89 0.000 0.05

Naphthalene n 1189.56 0.000 0.00

n-Dodecane p 1200.00 0.000 0.00

% Listed Peaks are of Total VOC 98.95 97.27
12

Table 5. Summary statistics for the hydrocarbon composition of Fuel 14. 

Summary Statistics for Fuel #14

HS Whole

Ethanol 0.000 0.000

%Paraffins 76.11 65.81

%Olefins 14.23 8.17

%Aromatics 7.61 20.35

%Unknowns 0.95 2.79

%Fused Rings 0.05 0.15
13

Table 6. Headspace and whole fuel composition of Fuel 6. 

Fuel # 6 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.009 0.02

Isobutane p 361.88 0.126 0.06

Butene-1 o 389.97 0.076 0.00

Isobutylene o 390.92 0.085 0.03

n-Butane p 400.00 4.886 1.34

t-Butene-2 o 411.64 0.371 0.10

2,2-Dimethylpropane* p 413.35 0.026 0.17

c-Butene-2 o 425.94 0.376 0.09

3-Methyl-1-Butene o 457.43 0.247 0.07

Ethanol ox 461.50 6.487 8.76

Isopentane p 474.54 11.796 4.37

Pentene-1 o 489.36 1.071 0.37

2-Methyl-1-Butene o 496.17 1.602 0.63

n-Pentane p 500.00 2.463 1.02

Isoprene o 504.19 0.032 0.01

trans-2-Pentene o 508.72 2.477 1.03

Unknown u 513.67 0.018 0.01

cis-2-Pentene o 516.35 1.347 0.57

2-Methyl-2-Butene o 521.04 2.910 1.30

2,2-Dimethylbutane p 535.47 0.250 0.12

Cyclopentene o 551.84 0.507 0.25

3-Methyl-1-pentene o 557.98 0.260 0.15

Cyclopentane p 562.82 0.345 0.17

2,3-Dimethylbutane p 565.46 2.701 1.81

2-Methylpentane p 570.09 10.877 7.81

3-Methylpentane p 583.52 7.087 5.65

2-Methyl-1-Pentene o 588.52 0.268 0.24

Hexene-1 o 589.36 2.287 1.91

n-Hexane p 600.00 5.932 5.27

trans-3-Hexene o 602.80 0.367 0.35

trans-2-Hexene o 604.98 0.523 0.48

2-Methyl-2-Pentene o 607.37 0.471 0.44

Unknown u 608.87 0.159 0.13

cis-3-Hexene o 610.49 0.293 0.28

4-Methylcyclopentene* o 612.17 0.078 0.07

cis-2-Hexene o 614.50 0.281 0.26

cis-3-Methyl-2-pentene* o 620.74 0.387 0.40

2,2-DiMethylpentane p 625.13 0.162 0.18

Methylcyclopentane p 627.20 2.043 1.89

2,4-Dimethylpentane p 631.38 0.763 1.03

2,2,3-TriMethylbutane p 637.00 0.074 0.09

2,4-DiMethyl-1-Pentene o 647.79 0.013 0.02

1-Methylcyclopentene o 651.00 0.316 0.39

Benzene a 651.21 0.949 1.15

3,3-DiMethylpentane p 657.00 0.073 0.09

Cyclohexane p 660.96 1.597 1.32

4-Me-1-Hexene o 665.23 0.016 0.00

2-Methylhexane p 668.68 0.655 0.93

2,3-Dimethylpentane p 670.80 0.611 0.70

1,1-DiMeCyclopentane p 674.11 0.032 0.03

3-Methylhexane p 677.22 0.519 0.70

5-Methyl-2-hexene* o 680.55 0.010 0.02

c-1,3-DiMeCyclopentane p 684.41 0.095 0.12

t-1,3,-DiMeCyclopentane p 687.12 0.117 0.16

2,2,4-TriMethylpentane p 690.72 7.197 6.82

3-Methyl-3-hexene o 695.08 0.007 0.01

trans-3-Heptene o 697.82 0.013 0.03

n-Heptane p 700.00 0.279 0.28

3-Me-cis-3-Hexene o 701.44 0.045 0.11

2,4,4-TriMethyl-1-Pentene o 712.30 0.145 0.02

MethylCyclohexane p 724.30 0.356 0.12

2,5-DiMethylhexane p 733.56 0.441 0.82
14

2,4-DiMethylhexane + EthylCyclopentanep 735.91 0.582 1.19

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.011 0.01

ctc-1,2,3-TriMeCyclopentanep 751.44 0.004 0.00

2,3,4-TriMethylpentanep 753.56 0.973 2.92

Toluenea 758.58 4.071 9.04

2,3-DiMethylhexanep 762.98 0.235 0.82

2-Methyl-3-Ethylpentanep 765.00 0.012 0.00

2-Methylheptanep 767.55 0.045 0.05

4-Methylheptanep 769.28 0.016 0.02

3,4-DiMethylhexanep 772.50 0.040 0.14

3-Methylheptanep 775.34 0.043 0.06

ctc-1,2,4-TriMeCyclopentanep 781.70 0.027 0.01

t-1,4-DiMeCyclohexanep 783.92 0.011 0.00

2,2,5-Trimethylhexanep 785.98 0.279 1.19

1,1-DiMethylCyclohexanep 790.50 0.007 0.00

2,2,4-TriMethylhexanep 794.85 0.008 0.02

n-Octanep 800.00 0.049 0.03

cis-2-Octeneo 812.37 0.007 0.03

2,3,5-TriMethylhexanep 819.44 0.038 0.19

2,4-DiMethylheptanep 825.88 0.008 0.04

2,6-DiMethylheptanep 831.77 0.008 0.03

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.001 0.00

2,5-DiMeHeptane p 838.60 0.026 0.08

Ethylbenzene a 855.40 0.415 0.98

ctt-1,2,4-TriMeCyclohexanep 860.26 0.015 0.04

m-& p-Xylenea 863.65 1.430 3.53

3-Methyloctanep 873.73 0.005 0.01

ctc-1,2,4-TriMeCyclohexanep 881.42 0.034 0.15

o-Xylenea 887.56 0.327 0.75

Nonene-1o 889.31 0.000 0.10

Nonanep 900.00 0.008 0.01

trans-2-Noneneo 902.49 0.020 0.09

cis-2-Noneneo 912.37 0.003 0.01

Isopropylbenzenea 920.34 0.051 0.16

3,5-DiMethyloctanep 927.97 0.015 0.06

2,6-DiMethyloctanep 937.70 0.062 0.24

n-Propylbenzenea 950.95 0.084 0.23

m-Ethyltoluenea 957.45 0.324 0.86

p-Ethyltoluenea 960.02 0.174 0.41

1,3,5-TriMethylbenzenea 964.32 0.187 0.47

3-Methylnonanep 973.55 0.004 0.01

o-Ethyltoluenea 976.97 0.165 0.46

Unknownu 986.65 0.049 0.16

Unknownu 988.06 0.000 0.00

1,2,4-TriMethylbenzenea 991.48 0.529 1.27

n-Decanep 1000.00 0.115 0.40

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.035 0.11

sec-Butylbenzenea 1010.39 0.023 0.06

m-Cymenea 1018.22 0.029 0.08

1,2,3-TriMethylbenzenea 1022.13 0.219 0.45

Unknownu 1031.59 0.288 0.89

Indanen 1036.98 0.022 0.03

Unknownu 1040.81 0.100 0.30

Unknownu 1048.17 0.368 1.10

n-Butylbenzene + p-Diethylbenzenea 1054.69 0.000 0.15

1-Me-4-isoPropylbenzenea 1059.44 0.039 0.06

Unknownu 1062.68 0.018 0.16

1-Me-2-n-Propylbenzenea 1067.27 0.054 0.57

1,4-DiMe-2-Ethylbenzenea 1075.98 0.212 0.08

Unknownu 1078.46 0.033 0.11

1,2-DiMe-4-Ethylbenzenea 1084.27 0.046 0.13

Unknownu 1086.66 0.051 0.34

1,3-DiMe-2-Ethylbenzenea 1092.85 0.135 0.04

Unknownu 1094.62 0.018 0.05

n-Undecanep 1100.00 0.015 0.08

1,2-DiMe-3-Ethylbenzenea 1107.49 0.022 0.05

1,2,4,5-Tetra-Me-Benzenea 1119.01 0.016 0.12

Unknownu 1123.00 0.033 0.18
15

t-1-But-2-MeBenzene a 1139.52 0.047 0.02

Unknown u 1144.96 0.004 0.06

Methylindane n 1156.53 0.018 0.06

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.019 0.04

t-1-But-3,5-DiMeBenzene a 1174.77 0.009 0.06

Unknown u 1175.94 0.001 0.00

t-1-But-4-Ethylbenzene a 1183.89 0.000 0.03

Naphthalene n 1189.56 0.000 0.00

n-Dodecane p 1200.00 0.000 0.00

% Listed Peaks are of Total VOC 98.40 94.49
16

Table 7. Summary statistics for the hydrocarbon composition of Fuel 6. 

Summary Statistics for Fuel # 6

HS Whole

%Ethanol 6.49 8.76

%Paraffins 64.21 50.90

%Olefins 16.91 9.87

%Aromatics 9.61 21.36

%Unknowns 1.14 3.51

%Fused Rings 0.04 0.09
17

Table 8. Headspace and whole fuel composition of Fuel No 10. 

Fuel # 10 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.008 0.01

Isobutane p 361.88 0.076 0.02

Butene-1 o 389.97 0.055 0.00

Isobutylene o 390.92 0.058 0.04

n-Butane p 400.00 4.024 1.32

t-Butene-2 o 411.64 0.269 0.10

2,2-Dimethylpropane* p 413.35 0.047 0.07

c-Butene-2 o 425.94 0.266 0.09

3-Methyl-1-Butene o 457.43 0.170 0.07

Ethanol ox 461.50 6.406 7.74

Isopentane p 474.54 8.787 4.06

Pentene-1 o 489.36 0.762 0.36

2-Methyl-1-Butene o 496.17 1.140 0.58

n-Pentane p 500.00 3.817 1.94

Isoprene o 504.19 0.022 0.01

trans-2-Pentene o 508.72 1.823 0.95

Unknown u 513.67 0.016 0.01

cis-2-Pentene o 516.35 0.991 0.52

2-Methyl-2-Butene o 521.04 2.197 1.18

2,2-Dimethylbutane p 535.47 0.618 0.35

Cyclopentene o 551.84 0.396 0.24

3-Methyl-1-pentene o 557.98 0.229 0.13

Cyclopentane p 562.82 0.601 0.37

2,3-Dimethylbutane p 565.46 2.063 1.32

2-Methylpentane p 570.09 11.190 7.62

3-Methylpentane p 583.52 6.106 4.35

2-Methyl-1-Pentene o 588.52 0.364 0.27

Hexene-1 o 589.36 0.290 0.16

n-Hexane p 600.00 6.388 5.22

trans-3-Hexene o 602.80 0.384 0.31

trans-2-Hexene o 604.98 0.549 0.45

2-Methyl-2-Pentene o 607.37 0.498 0.41

Unknown u 608.87 0.159 0.12

cis-3-Hexene o 610.49 0.306 0.25

4-Methylcyclopentene* o 612.17 0.082 0.05

cis-2-Hexene o 614.50 0.297 0.24

cis-3-Methyl-2-pentene* o 620.74 0.414 0.38

2,2-DiMethylpentane p 625.13 0.209 0.22

Methylcyclopentane p 627.20 2.235 2.04

2,4-Dimethylpentane p 631.38 0.449 0.41

2,2,3-TriMethylbutane p 637.00 0.062 0.06

2,4-DiMethyl-1-Pentene o 647.79 0.014 0.02

1-Methylcyclopentene o 651.00 0.367 0.38

Benzene a 651.21 0.793 0.95

3,3-DiMethylpentane p 657.00 0.081 0.10

Cyclohexane p 660.96 1.548 1.66

4-Me-1-Hexene o 665.23 0.018 0.03

2-Methylhexane p 668.68 0.712 0.93

2,3-Dimethylpentane p 670.80 0.316 0.24

1,1-DiMeCyclopentane p 674.11 0.037 0.05

3-Methylhexane p 677.22 0.547 0.72

5-Methyl-2-hexene* o 680.55 0.012 0.02

c-1,3-DiMeCyclopentane p 684.41 0.110 0.15

t-1,3,-DiMeCyclopentane p 687.12 0.135 0.19

2,2,4-TriMethylpentane p 690.72 3.599 0.20

3-Methyl-3-hexene o 695.08 0.009 0.02
18

trans-3-Hepteneo 697.82 0.018 0.03

n-Heptanep 700.00 0.300 0.39

3-Me-cis-3-Hexeneo 701.44 0.061 0.12

2,4,4-TriMethyl-1-Penteneo 712.30 0.107 0.02

MethylCyclohexanep 724.30 0.363 0.39

2,5-DiMethylhexanep 733.56 0.368 0.16

2,4-DiMethylhexane + EthylCyclopentanep 735.91 0.489 0.27

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.014 0.02

ctc-1,2,3-TriMeCyclopentanep 751.44 0.006 0.01

2,3,4-TriMethylpentanep 753.56 0.913 0.98

Toluenea 758.58 6.355 15.10

2,3-DiMethylhexanep 762.98 0.248 0.35

2-Methyl-3-Ethylpentanep 765.00 0.000 0.00

2-Methylheptanep 767.55 0.064 0.07

4-Methylheptanep 769.28 0.022 0.03

3,4-DiMethylhexanep 772.50 0.043 0.06

3-Methylheptanep 775.34 0.062 0.06

ctc-1,2,4-TriMeCyclopentanep 781.70 0.039 0.03

t-1,4-DiMeCyclohexanep 783.92 0.017 0.01

2,2,5-Trimethylhexanep 785.98 0.309 0.60

1,1-DiMethylCyclohexanep 790.50 0.007 0.01

2,2,4-TriMethylhexanep 794.85 0.010 0.02

n-Octanep 800.00 0.078 0.07

cis-2-Octeneo 812.37 0.009 0.02

2,3,5-TriMethylhexanep 819.44 0.049 0.11

2,4-DiMethylheptanep 825.88 0.011 0.03

2,6-DiMethylheptanep 831.77 0.014 0.02

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.003 0.00

2,5-DiMeHeptane p 838.60 0.044 0.06

Ethylbenzene a 855.40 0.958 2.36

ctt-1,2,4-TriMeCyclohexanep 860.26 0.020 0.04

m-& p-Xylenea 863.65 3.423 8.48

3-Methyloctanep 873.73 0.011 0.01

ctc-1,2,4-TriMeCyclohexanep 881.42 0.043 0.11

o-Xylenea 887.56 0.731 1.54

Nonene-1o 889.31 0.000 0.00

Nonanep 900.00 0.019 0.01

trans-2-Noneneo 902.49 0.025 0.05

cis-2-Noneneo 912.37 0.000 0.00

Isopropylbenzenea 920.34 0.067 0.11

3,5-DiMethyloctanep 927.97 0.017 0.04

2,6-DiMethyloctanep 937.70 0.080 0.15

n-Propylbenzenea 950.95 0.191 0.41

m-Ethyltoluenea 957.45 0.751 1.66

p-Ethyltoluenea 960.02 0.367 0.88

1,3,5-TriMethylbenzenea 964.32 0.464 0.99

3-Methylnonanep 973.55 0.009 0.02

o-Ethyltoluenea 976.97 0.348 0.70

Unknownu 986.65 0.066 0.13

Unknownu 988.06 0.000 0.00

1,2,4-TriMethylbenzenea 991.48 1.308 2.70

n-Decanep 1000.00 0.187 0.27

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.064 0.10

sec-Butylbenzenea 1010.39 0.043 0.07

m-Cymenea 1018.22 0.061 0.09

1,2,3-TriMethylbenzenea 1022.13 0.387 0.74

Unknownu 1031.59 0.590 0.65

Indanen 1036.98 0.064 0.14

Unknownu 1040.81 0.218 0.23

Unknownu 1048.17 0.840 1.01

n-Butylbenzene + p-Diethylbenzenea 1054.69 0.000 0.26
19

1-Me-4-isoPropylbenzene a 1059.44 0.214 0.05

Unknown u 1062.68 0.053 0.12

1-Me-2-n-Propylbenzene a 1067.27 0.142 0.52

1,4-DiMe-2-Ethylbenzene a 1075.98 0.500 0.14

Unknown u 1078.46 0.109 0.17

1,2-DiMe-4-Ethylbenzene a 1084.27 0.151 0.29

Unknown u 1086.66 0.212 0.31

1,3-DiMe-2-Ethylbenzene a 1092.85 0.319 0.07

Unknown u 1094.62 0.045 0.04

n-Undecane p 1100.00 0.056 0.07

1,2-DiMe-3-Ethylbenzene a 1107.49 0.095 0.12

1,2,4,5-Tetra-Me-Benzene a 1119.01 0.149 0.21

Unknown u 1123.00 0.148 0.29

t-1-But-2-MeBenzene a 1139.52 0.210 0.03

Unknown u 1144.96 0.022 0.15

Methylindane n 1156.53 0.094 0.13

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.089 0.08

t-1-But-3,5-DiMeBenzene a 1174.77 0.057 0.05

Unknown u 1175.94 0.000 0.00

t-1-But-4-Ethylbenzene a 1183.89 0.024 0.02

Naphthalene n 1189.56 0.020 0.00

n-Dodecane p 1200.00 0.000 0.00

% Listed Peaks are of TotalVOC 97.21 95.52
20

Table 9. Summary statistics for the hydrocarbon composition of Fuel 10. 

Summary Statistics for Fuel # 10

HS Whole

%Ethanol 6.41 7.74

%Paraffins 57.68 38.07

%Olefins 12.20 7.51

%Aromatics 18.26 38.71

%Unknowns 2.48 3.22

%Fused Rings 0.18 0.26
21

Table 10. Headspace and whole fuel composition of Fuel No 27. 

Fuel # 27 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.004 0.04

Isobutane p 361.88 0.098 0.05

Butene-1 o 389.97 0.063 0.04

Isobutylene o 390.92 0.067 0.00

n-Butane p 400.00 4.764 1.68

t-Butene-2 o 411.64 0.319 0.11

2,2-Dimethylpropane* p 413.35 0.029 0.27

c-Butene-2 o 425.94 0.302 0.11

3-Methyl-1-Butene o 457.43 0.185 0.09

Ethanol ox 461.50 26.516 12.35

Isopentane p 474.54 9.620 5.05

Pentene-1 o 489.36 0.813 0.41

2-Methyl-1-Butene o 496.17 1.230 0.66

n-Pentane p 500.00 1.834 1.05

Isoprene o 504.19 0.025 0.03

trans-2-Pentene o 508.72 1.930 1.09

Unknown u 513.67 0.017 0.01

cis-2-Pentene o 516.35 1.057 0.59

2-Methyl-2-Butene o 521.04 2.328 1.34

2,2-Dimethylbutane p 535.47 0.058 0.04

Cyclopentene o 551.84 0.435 0.26

3-Methyl-1-pentene o 557.98 0.241 0.15

Cyclopentane p 562.82 0.193 0.13

2,3-Dimethylbutane p 565.46 2.334 1.64

2-Methylpentane p 570.09 3.356 2.27

3-Methylpentane p 583.52 1.985 1.45

2-Methyl-1-Pentene o 588.52 0.419 0.29

Hexene-1 o 589.36 0.250 0.20

n-Hexane p 600.00 1.639 1.26

trans-3-Hexene o 602.80 0.429 0.34

trans-2-Hexene o 604.98 0.627 0.50

2-Methyl-2-Pentene o 607.37 0.565 0.46

Unknown u 608.87 0.190 0.14

cis-3-Hexene o 610.49 0.344 0.29

4-Methylcyclopentene* o 612.17 0.092 0.07

cis-2-Hexene o 614.50 0.342 0.28

cis-3-Methyl-2-pentene* o 620.74 0.492 0.41

2,2-DiMethylpentane p 625.13 0.043 0.03

Methylcyclopentane p 627.20 1.317 1.10

2,4-Dimethylpentane p 631.38 1.276 1.25

2,2,3-TriMethylbutane p 637.00 0.093 0.09

2,4-DiMethyl-1-Pentene o 647.79 0.018 0.02

1-Methylcyclopentene o 651.00 0.439 0.42

Benzene a 651.21 1.148 1.04

3,3-DiMethylpentane p 657.00 0.003 0.05

Cyclohexane p 660.96 0.385 0.33

4-Me-1-Hexene o 665.23 0.027 0.03

2-Methylhexane p 668.68 0.552 0.63

2,3-Dimethylpentane p 670.80 0.678 0.81

1,1-DiMeCyclopentane p 674.11 0.011 0.01

3-Methylhexane p 677.22 0.435 0.50

5-Methyl-2-hexene* o 680.55 0.015 0.01

c-1,3-DiMeCyclopentane p 684.41 0.096 0.11

t-1,3,-DiMeCyclopentane p 687.12 0.122 0.14

2,2,4-TriMethylpentane p 690.72 6.601 9.26

3-Methyl-3-hexene o 695.08 0.016 0.02

trans-3-Heptene o 697.82 0.025 0.03

n-Heptane p 700.00 0.154 0.18

3-Me-cis-3-Hexene o 701.44 0.086 0.12

2,4,4-TriMethyl-1-Pentene o 712.30 0.033 0.03

MethylCyclohexane p 724.30 0.095 0.08

2,5-DiMethylhexane p 733.56 0.756 1.42
22

2,4-DiMethylhexane + EthylCyclopentanep 735.91 1.042 1.96

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.006 0.01

ctc-1,2,3-TriMeCyclopentanep 751.44 0.000 0.00

2,3,4-TriMethylpentanep 753.56 2.505 5.37

Toluenea 758.58 6.719 12.69

2,3-DiMethylhexanep 762.98 0.570 1.34

2-Methyl-3-Ethylpentanep 765.00 0.017 0.06

2-Methylheptanep 767.55 0.038 0.07

4-Methylheptanep 769.28 0.013 0.02

3,4-DiMethylhexanep 772.50 0.104 0.25

3-Methylheptanep 775.34 0.043 0.08

ctc-1,2,4-TriMeCyclopentanep 781.70 0.013 0.01

t-1,4-DiMeCyclohexanep 783.92 0.004 0.00

2,2,5-Trimethylhexanep 785.98 0.849 2.41

1,1-DiMethylCyclohexanep 790.50 0.003 0.00

2,2,4-TriMethylhexanep 794.85 0.010 0.03

n-Octanep 800.00 0.037 0.03

cis-2-Octeneo 812.37 0.021 0.07

2,3,5-TriMethylhexanep 819.44 0.112 0.38

2,4-DiMethylheptanep 825.88 0.015 0.05

2,6-DiMethylheptanep 831.77 0.019 0.07

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.000 0.00

2,5-DiMeHeptane p 838.60 0.050 0.17

Ethylbenzene a 855.40 0.452 0.99

ctt-1,2,4-TriMeCyclohexanep 860.26 0.027 0.08

m-& p-Xylenea 863.65 1.509 3.52

3-Methyloctanep 873.73 0.010 0.03

ctc-1,2,4-TriMeCyclohexanep 881.42 0.087 0.36

o-Xylenea 887.56 0.288 0.73

Nonene-1o 889.31 0.058 0.24

Nonanep 900.00 0.027 0.10

trans-2-Noneneo 902.49 0.041 0.16

cis-2-Noneneo 912.37 0.000 0.01

Isopropylbenzenea 920.34 0.062 0.23

3,5-DiMethyloctanep 927.97 0.026 0.09

2,6-DiMethyloctanep 937.70 0.084 0.30

n-Propylbenzenea 950.95 0.074 0.21

m-Ethyltoluenea 957.45 0.279 0.77

p-Ethyltoluenea 960.02 0.173 0.38

1,3,5-TriMethylbenzenea 964.32 0.176 0.50

3-Methylnonanep 973.55 0.015 0.05

o-Ethyltoluenea 976.97 0.154 0.44

Unknownu 986.65 0.058 0.15

Unknownu 988.06 0.000 0.00

1,2,4-TriMethylbenzenea 991.48 0.441 1.16

n-Decanep 1000.00 0.000 0.48

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.038 0.10

sec-Butylbenzenea 1010.39 0.023 0.06

m-Cymenea 1018.22 0.033 0.09

1,2,3-TriMethylbenzenea 1022.13 0.000 0.26

Unknownu 1031.59 0.297 0.77

Indanen 1036.98 0.024 0.06

Unknownu 1040.81 0.105 0.26

Unknownu 1048.17 0.388 0.88

n-Butylbenzene + p-Diethylbenzenea 1054.69 0.000 0.06

1-Me-4-isoPropylbenzenea 1059.44 0.057 0.04

Unknownu 1062.68 0.031 0.13

1-Me-2-n-Propylbenzenea 1067.27 0.056 0.45

1,4-DiMe-2-Ethylbenzenea 1075.98 0.195 0.05

Unknownu 1078.46 0.028 0.06

1,2-DiMe-4-Ethylbenzenea 1084.27 0.034 0.08

Unknownu 1086.66 0.036 0.22

1,3-DiMe-2-Ethylbenzenea 1092.85 0.145 0.02

Unknownu 1094.62 0.025 0.03

n-Undecanep 1100.00 0.013 0.05

1,2-DiMe-3-Ethylbenzenea 1107.49 0.026 0.02

1,2,4,5-Tetra-Me-Benzenea 1119.01 0.016 0.06

Unknownu 1123.00 0.033 0.10
23

t-1-But-2-MeBenzene a 1139.52 0.047 0.01

Unknown u 1144.96 0.004 0.03

Methylindane n 1156.53 0.022 0.04

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.019 0.03

t-1-But-3,5-DiMeBenzene a 1174.77 0.010 0.01

Unknown u 1175.94 0.009 0.00

t-1-But-4-Ethylbenzene a 1183.89 0.000 0.01

Naphthalene n 1189.56 0.004 0.00

n-Dodecane p 1200.00 0.000 0.00

% Listed Peaks are of TotalVOC 97.56 92.90
24

Table 11. Summary statistics for the hydrocarbon composition of Fuel 27. 

Summary Statistics for Fuel# 27

HS Whole

% Ethanol 26.52 12.35

%Paraffins 44.27 44.76

%Olefins 13.33 8.87

%Aromatics 12.17 24.02

%Unknowns 1.22 2.79

%Fused Rings 0.05 0.10
25

Table 12. Headspace and whole fuel composition of Fuel 28. 

Fuel # 28 Headspace@25C and Whole Fuel Composition

Compound Type RTINDEX HS Whole

Propane p 300.00 0.009 0.02

Isobutane p 361.88 0.099 0.04

Butene-1 o 389.97 0.065 0.00

Isobutylene o 390.92 0.092 0.03

n-Butane p 400.00 6.827 1.98

t-Butene-2 o 411.64 0.319 0.11

2,2-Dimethylpropane* p 413.35 0.024 0.04

c-Butene-2 o 425.94 0.340 0.11

3-Methyl-1-Butene o 457.43 0.202 0.07

Ethanol ox 461.50 27.854 11.10

Isopentane p 474.54 8.310 3.58

Pentene-1 o 489.36 0.868 0.38

2-Methyl-1-Butene o 496.17 1.305 0.61

n-Pentane p 500.00 1.951 0.95

Isoprene o 504.19 0.029 0.01

trans-2-Pentene o 508.72 2.025 1.00

Unknown u 513.67 0.015 0.01

cis-2-Pentene o 516.35 1.107 0.55

2-Methyl-2-Butene o 521.04 2.425 1.24

2,2-Dimethylbutane p 535.47 0.060 0.03

Cyclopentene o 551.84 0.439 0.24

3-Methyl-1-pentene o 557.98 0.247 0.14

Cyclopentane p 562.82 0.198 0.12

2,3-Dimethylbutane p 565.46 1.336 0.83

2-Methylpentane p 570.09 3.393 2.20

3-Methylpentane p 583.52 2.261 1.54

2-Methyl-1-Pentene o 588.52 0.401 0.27

Hexene-1 o 589.36 0.248 0.18

n-Hexane p 600.00 2.724 2.03

trans-3-Hexene o 602.80 0.416 0.31

trans-2-Hexene o 604.98 0.607 0.45

2-Methyl-2-Pentene o 607.37 0.551 0.41

Unknown u 608.87 0.179 0.12

cis-3-Hexene o 610.49 0.334 0.25

4-Methylcyclopentene* o 612.17 0.090 0.06

cis-2-Hexene o 614.50 0.331 0.25

cis-3-Methyl-2-pentene* o 620.74 0.472 0.38

2,2-DiMethylpentane p 625.13 0.082 0.07

Methylcyclopentane p 627.20 1.480 1.18

2,4-Dimethylpentane p 631.38 0.706 0.62

2,2,3-TriMethylbutane p 637.00 0.057 0.05

2,4-DiMethyl-1-Pentene o 647.79 0.017 0.02

1-Methylcyclopentene o 651.00 0.433 0.37

Benzene a 651.21 1.021 0.95

3,3-DiMethylpentane p 657.00 0.061 0.05

Cyclohexane p 660.96 0.595 0.55

4-Me-1-Hexene o 665.23 0.031 0.03

2-Methylhexane p 668.68 0.541 0.60

2,3-Dimethylpentane p 670.80 0.367 0.38

1,1-DiMeCyclopentane p 674.11 0.012 0.01

3-Methylhexane p 677.22 0.412 0.47

5-Methyl-2-hexene* o 680.55 0.014 0.02

c-1,3-DiMeCyclopentane p 684.41 0.090 0.10

t-1,3,-DiMeCyclopentane p 687.12 0.112 0.14

2,2,4-TriMethylpentane p 690.72 2.981 3.53

3-Methyl-3-hexene o 695.08 0.012 0.02
26

trans-3-Hepteneo 697.82 0.023 0.03

n-Heptanep 700.00 0.133 0.18

3-Me-cis-3-Hexeneo 701.44 0.080 0.11

2,4,4-TriMethyl-1-Penteneo 712.30 0.019 0.02

MethylCyclohexanep 724.30 0.056 0.07

2,5-DiMethylhexanep 733.56 0.562 0.96

2,4-DiMethylhexane + EthylCyclopentanep 735.91 0.806 1.38

3,3-DiMethylhexane + 1,2,4-TriMeCyclopentanep 743.87 0.004 0.01

ctc-1,2,3-TriMeCyclopentanep 751.44 0.000 0.00

2,3,4-TriMethylpentanep 753.56 2.393 4.73

Toluenea 758.58 10.859 23.35

2,3-DiMethylhexanep 762.98 0.581 1.26

2-Methyl-3-Ethylpentanep 765.00 0.024 0.05

2-Methylheptanep 767.55 0.038 0.08

4-Methylheptanep 769.28 0.016 0.03

3,4-DiMethylhexanep 772.50 0.116 0.25

3-Methylheptanep 775.34 0.041 0.07

ctc-1,2,4-TriMeCyclopentanep 781.70 0.006 0.01

t-1,4-DiMeCyclohexanep 783.92 0.002 0.00

2,2,5-Trimethylhexanep 785.98 0.963 2.59

1,1-DiMethylCyclohexanep 790.50 0.000 0.00

2,2,4-TriMethylhexanep 794.85 0.012 0.03

n-Octanep 800.00 0.018 0.03

cis-2-Octeneo 812.37 0.024 0.08

2,3,5-TriMethylhexanep 819.44 0.127 0.42

2,4-DiMethylheptanep 825.88 0.017 0.06

2,6-DiMethylheptanep 831.77 0.024 0.07

1c2-DiMethylcyclohexane n-Propylcyclopentanep 834.70 0.000 0.00

2,5-DiMeHeptane p 838.60 0.047 0.18

Ethylbenzene a 855.40 0.750 2.88

ctt-1,2,4-TriMeCyclohexanep 860.26 0.028 0.11

m-& p-Xylenea 863.65 2.515 10.26

3-Methyloctanep 873.73 0.005 0.01

ctc-1,2,4-TriMeCyclohexanep 881.42 0.088 0.43

o-Xylenea 887.56 0.401 1.69

Nonene-1o 889.31 0.061 0.27

Nonanep 900.00 0.008 0.01

trans-2-Noneneo 902.49 0.031 0.15

cis-2-Noneneo 912.37 0.001 0.01

Isopropylbenzenea 920.34 0.019 0.08

3,5-DiMethyloctanep 927.97 0.005 0.01

2,6-DiMethyloctanep 937.70 0.016 0.02

n-Propylbenzenea 950.95 0.047 0.19

m-Ethyltoluenea 957.45 0.168 0.76

p-Ethyltoluenea 960.02 0.093 0.46

1,3,5-TriMethylbenzenea 964.32 0.090 0.43

3-Methylnonanep 973.55 0.002 0.01

o-Ethyltoluenea 976.97 0.064 0.28

Unknownu 986.65 0.011 0.05

Unknownu 988.06 0.000 0.00

1,2,4-TriMethylbenzenea 991.48 0.235 1.23

n-Decanep 1000.00 0.022 0.00

Isobutylbenzene + 1-Me-2-Propylcyclohexanea 1008.16 0.007 0.02

sec-Butylbenzenea 1010.39 0.007 0.02

m-Cymenea 1018.22 0.008 0.03

1,2,3-TriMethylbenzenea 1022.13 0.000 0.37

Unknownu 1031.59 0.048 0.12

Indanen 1036.98 0.012 0.07

Unknownu 1040.81 0.019 0.05

Unknownu 1048.17 0.074 0.26

n-Butylbenzene + p-Diethylbenzenea 1054.69 0.000 0.13
27

1-Me-4-isoPropylbenzene a 1059.44 0.018 0.04

Unknown u 1062.68 0.006 0.04

1-Me-2-n-Propylbenzene a 1067.27 0.010 0.14

1,4-DiMe-2-Ethylbenzene a 1075.98 0.038 0.06

Unknown u 1078.46 0.007 0.08

1,2-DiMe-4-Ethylbenzene a 1084.27 0.008 0.29

Unknown u 1086.66 0.011 0.08

1,3-DiMe-2-Ethylbenzene a 1092.85 0.020 0.00

Unknown u 1094.62 0.003 0.01

n-Undecane p 1100.00 0.002 0.03

1,2-DiMe-3-Ethylbenzene a 1107.49 0.004 0.04

1,2,4,5-Tetra-Me-Benzene a 1119.01 0.006 0.09

Unknown u 1123.00 0.006 0.14

t-1-But-2-MeBenzene a 1139.52 0.019 0.01

Unknown u 1144.96 0.000 0.05

Methylindane n 1156.53 0.004 0.05

n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 1158.21 0.005 0.04

t-1-But-3,5-DiMeBenzene a 1174.77 0.000 0.00

Unknown u 1175.94 0.000 0.00

t-1-But-4-Ethylbenzene a 1183.89 0.010 0.00

Naphthalene n 1189.56 0.000 0.00

n-Dodecane p 1200.00 0.000 0.00

% Listed Peaks are of TotalVOC 99.18 98.46
28

Table 13. Summary statistics for the hydrocarbon composition of Fuel 28. 

Summary Statistics for Fuel# 28

HS Whole

%Ethanol 27.85 11.10

%Paraffins 40.85 34.20

%Olefins 13.66 8.18

%Aromatics 16.42 43.86

%Unknowns 0.38 1.01

%Fused Rings 0.02 0.12