U.S. Department of the Interior

U.S. Geological Survey

Methods of Analysis by the U.S. Geological Survey 

National Water Quality Laboratory—Determination of 

Polycyclic Aromatic Hydrocarbon Compounds in Sediment 

by Gas Chromatography/Mass Spectrometry

Water-Resources Investigations Report 03–4318
Methods of Analysis by the U.S. Geological Survey 

National Water Quality Laboratory—Determination of 

Polycyclic Aromatic Hydrocarbon Compounds in Sediment 

by Gas Chromatography/Mass Spectrometry

By Mary C. Olson, Jana L. Iverson, Edward T. Furlong, and Michael P. Schroeder

U.S. Department of the Interior

U.S. Geological Survey

Water-Resources Investigations Report 03-4318
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2004

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

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Any use of trade, product, or firm names in this publication is for descriptive purposes only and 

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Although this report is in the public domain, permission must be secured from the individual copyright 

owners to reproduce any copyrighted materials contained within this report.
iii

Contents

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Analytical method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1. Scope and application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

2. Summary of method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3. Interferences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

4. Apparatus and equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

5. Reagents and consumable materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

6. Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

7. Sample preparation procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

8. Instrumental analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9. Calculation and reporting of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

10. Quality assurance and quality control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

11. Method performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Summary and conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

References cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Attachment 1: Determination of polycyclic aromatic hydrocarbons in sediment by

gas chromatography/mass spectrometry using selected-ion monitoring. . . . . . . . . . . . . . . . 33

Figures

1. Flowchart showing polycyclic aromatic hydrocarbons, organophosphate pesticides, 

and organochlorine pesticides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

2. Graphs showing quantitation and monitor ions in the homolog series for the isomeric

parent polycyclic aromatic hydrocarbons phenanthrene/anthracene in a sample . . . . . . . .18

Tables

1. Individual polycyclic aromatic hydrocarbon compounds determined using this method . . .3

2. Alkylated polycyclic aromatic hydrocarbon homolog groups determined

using this method and reported permanently as estimated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3. Suggested gel permeation chromatography processing sequence. . . . . . . . . . . . . . . . . . . . . . .12

4. Retention times, relative retention times, gas chromatography/mass 

spectrometry quantitation ions, confirmation ions, and percent relative abundance 

of confirmation ions for individual polycyclic aromatic hydrocarbons (PAHs) and 

alkylated PAH homolog groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

5. Gas chromatography/mass spectrometry analytical sequence 

suggested for use in this method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

6. Relative response factors used for the quantitation of alkylated

polycyclic aromatic hydrocarbon homolog series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

7. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for 

seven replicates using full-scan acquisition with compound concentrations of 4.8, 

12.0, and 24.0 micrograms per kilogram in three matrices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
iv

8. Polycyclic aromatic hydrocarbon matrix background concentrations in 

full-scan acquisition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

9. Recovery of semivolatile organic compounds from Evergreen Lake 

sediment samples spiked at 800 micrograms per kilogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

10. Recovery of semivolatile organic compounds from Evergreen Lake sediment 

samples spiked at 2,000 micrograms per kilogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

11. Recovery of semivolatile organic compounds from Mississippi River

sediment samples spiked at 400 micrograms per kilogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

12. Polycyclic aromatic hydrocarbon concentrations certified by the 

National Institute of Standards and Technology for Standard Reference 

Material 1941b and determined using this method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

13. Alkylated polycyclic aromatic hydrocarbon homolog group

 concentrations detected in Standard Reference Material 1941b not

 reported by the National Institute of Standards and Technology and 

determined using this method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

14. Polycyclic aromatic hydrocarbon concentrations certified by the 

National Institute of Standards and Technology for Standard Reference 

Material 1944 and determined using this method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

15. Alkylated polycyclic aromatic hydrocarbon homolog group 

concentrations detected in Standard Reference Material 1944 not

 reported by the National Institute of Standards and Technology and 

determined using this method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

16. Bias and precision data of polycyclic aromatic hydrocarbon spike 

recoveries for seven replicates using selected-ion monitoring acquisition 

with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in 

three matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

17. Polycyclic aromatic hydrocarbon matrix background concentrations in 

selected-ion monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

18. Polycyclic aromatic hydrocarbon method spike recoveries using selected-ion 

monitoring at a concentration of 24 micrograms per kilogram for year 2000. . . . . . . . . . . . . . .40

19. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute 

of Standards and Technology for Standard Reference Material 1941b and 

determined using selected-ion monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

20. Alkylated polycyclic aromatic hydrocarbon homolog groups detected in

 Standard Reference Material 1941b not reported by the National Institute 

of Standards and Technology and determined using selected-ion monitoring . . . . . . . . . . . .41

21. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute 

of Standards and Technology for Standard Reference Material 1944

 and determined using selected-ion monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

22. Alkylated polycyclic aromatic hydrocarbon homolog groups detected in 

Standard Reference Material 1944 not reported by the National Institute

 of Standards and Technology and determined using selected-ion monitoring. . . . . . . . . . . .43

23. Polycyclic aromatic hydrocarbon concentrations detected in Certified 

Reference Material 354 using selected-ion monitoring for year 2001. . . . . . . . . . . . . . . . . . . . . .43

24. Statistics for selected-ion monitoring and full-scan acquisition data 

fortified at 12.0 micrograms per kilogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
v

Conversion Factors

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8 x °C) + 32

ABBREVIATED WATER-QUALITY UNITS ABBREVIATIONS AND ACRONYMS

°C degree Celsius ACS American Chemical Society

°C/min degree Celsius per minute amu atomic mass unit

g/mole gram per mole ASMB Alberta Sweet Mix Blend

μg/kg microgram per kilogram (parts per billion) CAS Chemical Abstracts Service

mg/kg milligram per kilogram CRM Certified Reference Material

mg/L milligram per liter CCV continuing calibration verification solution

mL/min milliliter per minute DFTPP decafluorotriphenylphosphine

ng/μL nanogram per microliter dPAH perdeuterated polycyclic aromatic hydrocarbon

pg/μL picogram per microliter dPAHIS perdeuterated polycyclic aromatic hydrocarbon 

internal standard

Multiply By To obtain

Length

centimeter (cm) 3.94 x 10-1 inch

meter (m) 3.28 x 10-0 foot

micrometer (μm) 3.94 x 10-5 inch

millimeter (mm) 3.94 x 10-2 inch

nanometer (nm) 3.94 x 10-8 inch

Mass

gram (g) 3.53 x 10-2 ounce, avoirdupois

microgram (μg) 3.53 x 10-8 ounce, avoirdupois

nanogram (ng) 3.53 x 10-11 ounce, avoirdupois

picogram (pg) 3.53 x 10-14 ounce, avoirdupois

Volume

liter (L) 3.38 x 10-1 ounce, fluid 

microliter (μL) 3.38 x 10-5 ounce, fluid 

milliliter (mL) 3.38 x 10-2 ounce, fluid 

Pressure

kilopascal (kPa) 1.45 x 10-1 pounds per square inch
vi

ERL estimated reporting limit

eV electron volts

FEP fluorinated ethylene propylene

FS full-scan ion monitoring

GC gas chromatographic (or gas chromatograph)

GC/MS gas chromatography/mass spectrometry

GC/MS/MS gas chromatography/mass spectrometry/mass spectrometry

GPC gel permeation chromatography

HPLC high-performance liquid chromatography

ID internal diameter

IDL instrument detection limit

IS internal standard

K-D Kuderna-Danish

LRB laboratory reagent blank

LRS laboratory reagent spike

MDL method detection limit

MRL minimum reporting level

MS mass spectrometric (or mass spectrometer)

MSD mass selective detector 

MSDS Material Safety Data Sheets

m/z mass-to-charge ratio

NAWQA National Water-Quality Assessment Program

N-Evap nitrogen gas evaporator

NIST National Institute of Standards and Technology

no. number

NWIS National Water Information System

NWQL National Water Quality Laboratory

OC organochlorine

OP organophosphate

PAH polycyclic aromatic hydrocarbon

PCBs polychlorinated biphenyls

PTFE polytetrafluoroethylene 

QA/QC quality assurance/quality control

QC quality control

rpm revolutions per minute

RRF relative retention factor

RRT relative retention time
Methods of Analysis by the U.S. Geological Survey 

National Water Quality Laboratory—Determination of 

Polycyclic Aromatic Hydrocarbon Compounds in Sediment 

by Gas Chromatography/Mass Spectrometry

Abstract

A method for the determination of 28 polycyclic 

aromatic hydrocarbons (PAHs) and 25 alkylated PAH 

homolog groups in sediment samples is described. The 

compounds are extracted from sediment by solvent 

extraction, followed by partial isolation using 

high-performance gel permeation chromatography. The 

compounds are identified and quantitated using 

capillary-column gas chromatography/mass 

spectrometry. The report presents performance data for 

full-scan ion monitoring. Method detection limits in 

laboratory reagent matrix samples range from 1.3 to 5.1 

μg/kg for the 28 PAHs. The 25 groups of alkylated PAHs 

are homologs of five groups of isomeric parent PAHs. 

Because of the lack of authentic standards, these 

homologs are reported semiquantitatively using a 

response factor from a parent PAH or a specific alkylated 

PAH. Precision data for the alkylated PAH homologs are 

presented using two different standard reference materials 

produced by the National Institute of Standards and 

Technology: SRM 1941b and SRM 1944. The percent 

relative standard deviations for identified alkylated PAH 

homolog groups ranged from 1.55 to 6.98 for SRM 1941b 

and from 6.11 to 12.0 for SRM 1944. Homolog group 

concentrations reported under this method include the 

concentrations of individually identified compounds that 

are members of the group.

Organochlorine (OC) pesticides—including 

toxaphene, polychlorinated biphenyls (PCBs), and 

organophosphate (OP) pesticides—can be isolated 

simultaneously using this method.

In brief, sediment samples are centrifuged to remove 

excess water and extracted overnight with 

dichloromethane (95 percent) and methanol (5 percent). 

The extract is concentrated and then filtered through a 

0.2-micrometer polytetrafluoroethylene syringe filter. 

The PAH fraction is isolated by quantitatively injecting an 

aliquot of sample onto two polystyrene-divinylbenzene 

gel-permeation chromatographic columns connected in 

series. The compounds are eluted with dichloromethane, 

a PAH fraction is collected, and a portion of the 

coextracted interferences, including elemental sulfur, is 

separated and discarded. The extract is solvent 

exchanged, the volume is reduced, and internal standard is 

added. Sample analysis is completed using a gas 

chromatograph/mass spectrometer and full-scan 

acquisition.

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are 

hydrophobic compounds composed of two or more fused 

conjugated benzene rings. They are commonly associated 

with fossil fuels, combustion of fossil fuels, and other 

complex carbon sources. They are found in air, water, and 

sediment and many are considered to be toxic and 

carcinogenic (Nauss, 1995), thus indicating that 

long-term exposure pose a risk to aquatic and terrestrial 

organisms. 

The PAHs can be loosely divided into unsubstituted or 

parent PAHs and alkyl-substituted PAHs or alkylated 

PAHs. Alkylated PAHs are defined as PAHs with 

attached alkyl substituent(s). The alkylated PAHs are 

grouped by the number of carbon atoms present in the 

alkyl substituent(s). A particular homolog group includes 

all the isomers with the same number of carbon atoms in 

the substituents and the same parent PAH. Various 

combinations can occur depending on the alkyl 

substituent(s) involved. For example, the possible 

substitutions for a C3-PAH could include 

By Mary C. Olson, Jana L. Iverson, Edward T. Furlong, and Michael P. Schroeder
2 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

propyl-(n-propyl-, isopropyl), trimethyl- and ethylmethyl. 

An alkylated PAH homolog series is C1 through C5 

substituent(s) for the same parent PAH. For example, an 

alkylated PAH homolog series for naphthalene follows: 

C1-alkylated naphthalene, C2-alkylated naphthalene, 

C3-alkylated naphthalene, C4-alkylated naphthalene, and 

C5-alkylated naphthalene.

In the processes that result in the production of 

alkylated PAHs, not all isomers within a homolog group 

are produced in equal amounts. Isomers within a homolog 

group have common physical properties, such as the same 

molecular weight and fragmentation patterns in a mass 

spectrometer. The fragment ions produced for each 

isomer within the same homolog group typically are 

identical, although the abundance ratios can be different. 

This results in a complex chromatographic pattern of 

partially resolved components.

If the parent PAH also is an isomer of another PAH, 

their homolog groups are combined. For example, 

phenanthrene and anthracene are isomers of each other. 

Their C1-alkyl substituent homolog group includes the C1

substituent attached to phenanthrene and those attached to 

anthracene. This homolog group is called C1-alkylated 

phenanthrene/anthracene.

Analytical methods are needed to quantitate low 

concentrations of PAH compounds and homolog groups 

in sediment. The U.S. Geological Survey (USGS) 

National Water Quality Laboratory (NWQL) developed a 

new method to quantitate these compounds in sediment 

by gas chromatography/mass spectrometry (GC/MS) at 

low method detection limits with greater confidence 

compared to commonly used methods. Improved 

instrumentation allowed a selected-ion monitoring 

custom method to be updated to GC/MS in full-scan 

mode. See Attachment 1 for a discussion of the custom 

method and differences between full-scan and 

selected-ion monitoring. 

The purpose of this report is to describe method 

performance for the determination of 28 PAHs and the 

semiquantitation of 25 alkylated PAH homolog groups for 

five parent PAHs, four of which are groups of isomers. 

Bias and precision data for three matrices and three 

fortification levels are presented and define the low end of 

detection (10 μg/kg). These performance data are 

supplemented by bias and precision data from Furlong 

and others (1996), which are included in this report 

because the same methodology is used, identical parent 

PAHs are described, and sediment matrices are similar. 

Bias and precision data also are included in the 

attachment for selected-ion monitoring (SIM) acquisition 

for the three matrices and three fortification levels 

presented in this report. The method described in this 

report (O-5505-03) was originally designed using SIM 

methodology. With the advances of instrumentation 

providing full-scan acquisition rivaling SIM in detection 

limits and the need for better qualitative identification of 

the alkylated PAH homolog groups, full-scan acquisition 

is preferred. The additional SIM data are provided for 

historical and comparison purposes.

This method was approved by USGS in November 

2003 and implemented at the NWQL in January 2004. It 

uses elements outlined in the method by Furlong and 

others (1996), which was implemented at the National 

Water Quality Laboratory (NWQL) in January 1993 and 

supplements other USGS methods for determination of 

organic substances in bottom sediment described by 

Fishman (1993) and by Wershaw and others (1987).

This method was designed so that selected 

organochlorine (OC) pesticides, polychlorinated 

biphenyls (PCBs), and organophosphate pesticides (OP) 

can be determined from the same sediment sample 

extraction as the PAHs, although only the PAHs are 

described in this report. The OC method is described by 

Noriega and others (in press), and the OP method is 

described by Jha and others (2002). Use of a common 

extraction provides the advantage of reduced analytical 

cost, especially valuable when the amount of sample is 

small or difficult to collect.

This report provides a detailed description of all 

aspects of the method, from sample preparation through 

calculation and reporting of results. This method is 

applicable for samples of soil and bottom sediment. 

Matrices described in this report include a laboratory 

reagent matrix and bottom sediment from two separate 

sources. Recovery data and method detection limits 

(MDLs) for 28 PAHs are presented. Although no recovery 

data are presented for the 25 alkylated PAH homolog 

groups, precision data using standard reference material 

are provided.

The following parent PAHs are discussed: 

naphthalene, isomeric parents phenanthrene/anthracene, 

fluoranthene/pyrene, benzo[a]anthracene/chrysene, and 

benzopyrene/perylene. Increasing the number of fused 

rings in the parent PAH results in a greater number of sites 

for alkyl-substitution, increasing the number of possible 

isomers and the complexity of the observed homolog 

groups. For example, there are greater numbers of isomers 

within the C3-phenanthrene/anthracene (3 fused rings) 

group compared to the C3-alkylated naphthalene (2 fused 

rings) group. 

In the method described herein, 25 groups of alkylated 

PAH homologs can be qualitatively identified and 
Analytical Method 3

semiquantitated using the response factor and calibration 

curve from a selected compound within its homolog series 

or the appropriate parent PAH. These homolog groups are 

semiquantitated as the summed C1-, C2-, C3-, C4-, 

C5-alkylated homolog groups of the parent PAH(s). 

Reference mass spectra agreement and pattern 

recognition are used to qualitatively identify the alkylated 

PAH homolog groups.

Because a particular group is composed of more than 

one isomer, the responses of each isomer are added 

together for a total response. The concentration of the 

alkylated PAH homolog group is calculated using this 

total response and a relative response factor (RRF) from a 

related compound calibration curve. The RRF, although 

from a related compound, may or may not reflect each 

individual isomer's response. Wang and others (1994) 

found that by using the RRF produced from the parent 

naphthalene standard's calibration curve, an error of 30 to 

150 percent was introduced when quantitating alkylated 

naphthalene homolog groups. For this reason and because 

authentic standards are not available for every isomer, the 

concentration of a particular homolog group is reported as 

an estimate calculated from the sum of all its measured 

isomers. The alkylated PAH homolog groups are reported 

with an "E" qualifier, thus indicating an estimated value. 

The PAH compounds whose concentrations are defined 

are listed in table 1, and the alkylated PAH homolog 

groups whose concentrations are estimated are listed in 

table 2.

Analytical Method

Organic Compounds and Parameter Codes: Polycyclic 

aromatic hydrocarbons, sediment, high-performance gel 

permeation chromatography, capillary-column gas 

chromatography/mass spectrometry, O-5505-03 

(see table 1)

1. Scope and Application

This method is suitable for the determination of 

polycyclic aromatic hydrocarbons in soil and sediment 

samples containing at least 10 μg/kg of each PAH 

compound. This method is applicable to compounds that 

are (1) efficiently extracted from sediment by a 

dichloromethane/methanol azeotrope, (2) adequately 

separated from natural coextracted compounds by gel 

permeation chromatography (GPC), and (3) sufficiently 

volatile and thermally stable for determination by gas 

chromatography/mass spectrometry (GC/MS). The 

individual PAH compounds determined using this 

method, the National Water Information System 

parameter code, and Chemical Abstracts Service number 

for each compound are listed in table 1. The alkylated 

PAH homolog groups determined and their National 

Water Information System parameter codes are listed in 

table 2.

Table 1. Individual polycyclic aromatic hydrocarbon compounds 

determined using this method.

[NWIS, National Water Information System; CAS, Chemical Abstracts 

Service registry number]

Compound

NWIS 

parameter 

code

CAS number

Acenaphthene

Acenaphthylene

Anthracene

Benz[a]anthracene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[g,h,i]perylene

Benzo[a]pyrene

Benzo[e]pyrene

Chrysene

Dibenz[a,h]anthracene

1,2-Dimethylnaphthalene

1,6-Dimethylnaphthalene

2,6-Dimethylnaphthalene

2-Ethylnaphthalene

Fluoranthene

9H-Fluorene

Indeno[1,2,3-cd]pyrene

2-Methylanthracene

1-Methyl-9H-fluorene

1-Methylphenanthrene

1-Methylpyrene

4,5-Methylenephenanthrene

Naphthalene

Perylene

Phenanthrene

Pyrene

2,3,6-Trimethylnaphthalene

2-Fluorobiphenyl (method 

 surrogate)

Nitrobenzene-d5 (method 

 surrogate)

Terphenyl-d14 (method 

 surrogate)

62549

62550

62551

62552

62554

62557

62556

62553

62555

62558

62560

62538

62539

62544

62545

62561

62548

62562

62546

62540

62541

62542

62547

62563

62565

62566

62568

62543

62594

62595

62596

83-32-9

208-96-8

120-12-7

56-55-3

205-99-2

207-08-9

191-24-2

50-32-8

192-97-2

218-01-9

53-70-3

573-98-8

575-43-9

581-42-0

939-27-5

206-44-0

86-73-7

193-39-5

613-12-7

1730-37-6

832-69-9

2381-21-7

203-64-5

91-20-3

198-55-0

85-01-8

129-00-0

829-26-5

321-60-8

4165-60-0

1718-51-0
4 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

2. Summary of Method

A flowchart of the analytical method described in this 

report is shown in figure 1, and the method is summarized 

as follows. 

Wet-sediment samples are homogenized and 

centrifuged, if necessary, to remove water, and water 

content is determined. Each sample is mixed with 

anhydrous sodium sulfate and placed into a glass Soxhlet 

thimble. After adding the method surrogate compounds 

and 25 mL of methanol to remove water not bound by 

sodium sulfate, wait 30 minutes. Extract the sample with 

350 mL of dichloromethane plus the methanol in a 

Soxhlet apparatus for at least 12 hours, typically 

overnight. The extract is dried with sodium sulfate and 

reduced to 3 mL by Kuderna-Danish concentration and 

filtered with a polytetrafluoroethylene (PTFE) membrane. 

A method gel permeation chromatography (GPC) 

surrogate compound is added and the volume is increased 

to 4 mL. A 1,400-μL aliquot of the sample extract is 

injected quantitatively onto two polystyrenedivinylbenzene GPC columns, connected in series and 

eluted with dichloromethane. The PAH compounds are 

isolated from coextracted chemical interferences and 

collected in an 8.6-mL fraction. This GPC fraction is 

exchanged into ethyl acetate and reduced to 0.5 mL. A 

perdeuterated polycyclic aromatic hydrocarbon internal 

standard (dPAHIS) solution is added to each extract. The 

extract-containing vial then is sealed and held at <5°C 

until analysis for PAHs. Organophosphate pesticides (OP) 

also can be determined using this extract (Jha and others, 

2003). A second aliquot (1,100 μL) of the sample extract 

is injected onto the GPC if OCs are requested and taken 

through separate steps (Noriega and others, 2004).

The instrumental analysis consists of a gas 

chromatographic (GC) separation of the compounds 

followed by mass spectrometric (MS) identification and 

quantitation. The compounds are separated within the GC 

using a fused-silica capillary column with temperature 

programming to optimize compound separation. The 

compounds are identified by comparison to a library

of reference mass spectra. The internal standard method is 

used to quantitate the compounds using a multiple-point 

calibration curve.

3. Interferences

3.1 Organic compounds that are coextracted, 

collected in the GPC fraction, and have GC retention 

times and characteristic ions with masses identical to 

those of the selected PAHs of interest might interfere. In 

particular, hydrocarbons and hydrocarbon degradation 

products can cause substantial interferences. Diluting the 

sample extract before analysis can minimize the 

interferences. 

Analyses of laboratory reagent blanks provide 

information about the presence of contaminants and are 

used to determine if an interference exists. If interferences 

are identified, cleaning or replacement of parts may be 

required to remove the interference(s).

3.2 Contaminants might interfere when a sample 

containing low (micrograms per kilogram) concentrations 

of compounds is analyzed immediately after a sample 

containing high (milligrams per kilogram) concentrations 

of compounds. Syringes and splitless injection port liners 

need to be cleaned carefully or replaced as needed. The 

GPC system needs to be monitored continuously to ensure 

that it is not a source of sample cross-contamination.

Table 2. Alkylated polycyclic aromatic hydrocarbon homolog 

groups determined using this method and reported permanently as 

estimated.

[NWIS, National Water Information System]

Compound NWIS parameter 

code

C1-alkylated naphthalene

C2-alkylated naphthalene

C3-alkylated naphthalene

C4-alkylated naphthalene

C5-alkylated naphthalene

C1-alkylated phenanthrene/anthracene

C2-alkylated phenanthrene/anthracene

C3-alkylated phenanthrene/anthracene

C4-alkylated phenanthrene/anthracene

C5-alkylated phenanthrene/anthracene

C1-alkylated fluoranthene/pyrene

C2-alkylated fluoranthene/pyrene

C3-alkylated fluoranthene/pyrene

C4-alkylated fluoranthene/pyrene

C5-alkylated fluoranthene/pyrene

C1-alkylated benz[a]anthracene/chrysene

C2-alkylated benz[a]anthracene/chrysene

C3-alkylated benz[a]anthracene/chrysene

C4-alkylated benz[a]anthracene/chrysene

C5-alkylated benz[a]anthracene/chrysene

C1-alkylated benzopyrene/perylene

C2-alkylated benzopyrene/perylene

C3-alkylated benzopyrene/perylene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

62569

62574

62579

62584

62589

62570

62575

62580

62585

62590

62571

62576

62581

62586

62591

62572

62577

62582

62587

62592

62573

62578

62583

62588

62593
Analytical Method 5

Solvent exchange to ethyl acetate; reduce 

fraction to 0.5-mL final volume; add 

perdeuterated PAH internal standard; 

(Single extract for PAHs and OPs) 

↓

PAHs 

Gas chromatography/mass spectrometry in 

full-scan; identify and quantify or 

semiquantify selected compounds 

↓

OPs 

Capillary gas chromatography with flame 

photometric detection and dual column 

confirmation 

Solvent exchange to hexane; reduce 

fraction to 1.0 mL 

↓

Alumina/silica combined column 

adsorption chromatography with hexane 

and hexane:acetone; collect two fractions 

↓

Reduce fraction 1 to 0.5-mL final volume; 

↓

Reduce fraction 2 to 1.0 mL; 

Florisil column clean-up of fraction 2; 

↓

Reduce fraction 2 to 0.5-mL final volume; 

add retention time standards to fractions 

1 and 2 

↓

Capillary gas chromatography with 

electron-capture detection and dual column 

confirmation 

Homogenize wet sediment; centrifuge a portion 

to remove excess water; determine percent moisture (separate aliquot) 

Weigh centrifuged sediment into beaker: 

(25-gram equivalent dry weight) 

↓

Mix with anhydrous sodium sulfate to form 

loose mixture 

↓

Transfer to extraction thimble and add method surrogate 

compounds 

↓

Add 25 milliliters (mL) methanol; wait 30 minutes: 

extract sample for 12 hours in Soxhlet apparatus with 

350 mL dichloromethane; cool; 

dry extract with sodium sulfate 

↓

Reduce sample volume to 3.0 mL using Kuderna-Danish apparatus; filter extract; 

 add method gel permeation chromatography (GPC) surrogate (benzo[e]pyrene-d12) compound; 

 increase volume to 4.0 mL. 

↓

GPC using dichloromethane; collect time-window fraction for 

polycyclic aromatic hydrocarbons (PAHs) and organophosphate (OP) pesticides, 

1,400 microliters (μL) injected, 

and a second injection for organochlorine (OC) pesticides, 1,100 μL injected 

↓

Reduce each collected fraction using 

micro-Kuderna-Danish apparatus and nitrogen evaporation 

 

 PAHs and OPs OCs 

Figure 1. Flowchart for polycyclic aromatic hydrocarbons, organophosphate pesticides, and organochlorine pesticides.
6 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

4. Apparatus and Equipment

The equipment required, along with specific models 

and sources that were used to develop this method, are 

listed as follows.

4.1 Sample storage, dewatering, and percent 

moisture determination

4.1.1 Freezer—upright, capable of storing 100 

or more 1,000-mL wide-mouthed jars at –15°C for up to 

1 year.

4.1.2 Centrifuge—with four-place rotor, 

capable of 5,000 relative centrifugal force, International 

Equipment Co. Model EXD or equivalent.

4.1.3 Centrifuge bottles—250-mL Teflon 

(FEP) with sealing-cap assemblies and centrifuge bottle 

adapter.

4.1.4 Analytical balance—top loading, capable 

of weighing 250 g ±0.1g. 

4.1.5 Moisture determination balance—

capable of moisture determination on a 1.8- to 2.2-g 

aliquot of sediment sample to ±0.1 percent moisture, 

Sartorius Corp. Thermo Control Balance Model YTC 

O1L or equivalent.

4.1.6 Glass beakers—borosilicate, 400-mL 

volume.

4.2 Sediment extraction

4.2.1 Soxhlet apparatus—85-mL extractor 

capacity, with 45/50 standard taper top joint and 24/40 

standard taper bottom joint; fitted with a 500-mL roundor flat-bottom flask with a 24/40 standard taper joint and 

a water-cooled extractor condenser with 45/50 bottom 

joint.

4.2.2 Soxhlet extraction sample thimble—

borosilicate glass, 35 by 90 mm, Kontes, Inc. Model 

K-586500-0022EC or equivalent.

4.2.3 Soxhlet extraction combined steam 

bath/condenser unit—Organomation Associates, Inc. 

Model 13055 ROT-X-TRACT or equivalent.

4.2.4 Fixed volume micropipet—50- and 

100-μL sizes, Drummond micropipetor-microdispenser 

or equivalent.

4.3 Sediment extract concentration

4.3.1 Kuderna-Danish (K-D) evaporative 

concentrator—500-mL flask, three-ball Snyder column, 

and a custom-designed 10-mL centrifuge receiver tube 

(see 4.3.2), all with 19/22 standard taper joints.

4.3.2 Centrifuge receiver tube—10 mL, made 

using the top of a 10-mL K-D receiver tube, with 19/22 

standard female taper joint, fused to an 8-cm long by 

1.6-cm outer diameter centrifuge tube, volume graduated 

at 2, 3, and 5 mL; Allen Scientific Glassblowers, Inc. 

ASG-215-01 or equivalent.

4.3.3 Kuderna-Danish combined steam 

bath/condenser unit—Organomation Associates, Inc. 

Model 120 S-Evap or equivalent.

4.3.4 Nitrogen manifold sample 

concentrator—Organomation Associates, Inc. Model 124 

N-Evap or equivalent.

4.4 Sediment extract filtration

4.4.1 Syringe filter—Gelman Acrodisc, 25-mm 

syringe filter with 0.2-μm PTFE membrane or equivalent.

4.4.2 Syringe—5-mL gas-tight or ground-glass 

syringe equipped with Luer-LokTM fitting.

4.5 Gel permeation chromatography

4.5.1 Gel permeation chromatography 

system—an automated GPC system consisting of the 

following components from Waters Corporation or 

equivalent.

4.5.1.1 High-performance liquid 

chromatography (HPLC) pump—model 501.

4.5.1.2 Autosampler—model 717 with 

2.4-mL injection loop capacity with tray storage region 

maintained at 20°C.

4.5.1.3 Absorbance detector—model 

441 with excitation wavelength set at 254 nm. 

4.5.1.4 Data module and integrator— 

model 746.

4.5.1.5 Fraction collector—no model 

number, fitted with in-house-built tube holder capable of 

holding 36, 25-mL K-D receiver tubes.

4.5.1.6 HPLC in-line precolumn filter 

unit—model WATO84560 with replaceable 0.2-μm 

filters. 

4.5.1.7 Column heater—set at 27.0°C; 

Jones Chromatography Ltd. or equivalent.

4.5.1.8 Nitrogen pressurization 

system— consisting of a regulated grade 5 nitrogen 

source, PTFE tubing, a 23-gage needle, and associated 

metal fittings and ferrules for connecting the needle to the 

nitrogen source by the tubing.

4.5.1.9 Helium sparging system—used 

for deoxygenating the dichloromethane solvent prior to 

GPC.

4.5.1.10 HPLC pump priming syringe—

25 mL, Hamilton Gas-Tight 1,000 Series, Model 82520 or 

equivalent.

4.5.1.11 Balance—capable of weighing 

to 200 ± 0.001 g; Mettler-Toledo Model AT 200 or 

equivalent.

4.5.1.12 K-D receiver tube—calibrated 

25-mL volume, with 19/22 ground-glass stopper.
Analytical Method 7

4.5.1.13 HPLC syringe assembly for 

Waters 717 autosampler—2,500 μL, Waters 

Chromatography Model 077342.

4.6 GPC fraction concentration and solvent 

exchange

4.6.1 Water bath—Precision Scientific Co. 

Model 82 or equivalent, fitted with a rack capable of 

holding at least eighteen 25-mL receiver tubes.

4.6.2 Micro-Snyder column—three-ball.

4.7 Fraction concentration

4.7.1 Micropipet—50-μL volume; Hamilton 

Co. Model 80366 or equivalent; for addition of internal 

standard solution.

4.8 Gas chromatography/mass spectrometry 

analysis

4.8.1 Gas chromatograph/mass 

spectrometer—Agilent Technologies 5973B MSD 

coupled to an Agilent Technologies 6890 gas 

chromatograph and equipped with an autosampler, a 

split/splitless injector, and a computer controller 

(ChemStation instrument control and Target data review 

software) or equivalent. The GC system must be suitable 

for use with capillary column GC analysis. Full-scan and 

SIM mass-spectral data are acquired using this system.

4.8.2 Syringe—10-μL; Hamilton Co. Model 

80377 for GC autosampler or equivalent.

4.9 Instrument calibration and spike standards 

solution preparation

4.9.1 Analytical balance—capable of 

accurately weighing to 0.0001g.

4.9.2 Volumetric flasks—varied volumes from 

1 to 50 mL.

4.9.3 Micropipets—fixed- and variablevolume pipets from 25 to 250 μL.

4.9.4 Syringes—variable volumes from 10 to 

2,500 μL.

5. Reagents and Consumable Materials

The following reagents and consumable materials 

required for this method are grouped by the specific 

preparation or analysis step but are not repeated if used in 

more than one step of the method. Specific models and 

sources that were used to develop or implement this 

method also are listed, as appropriate. 

5.1 Sample storage, dewatering, and percent 

moisture determination

5.1.1 Sample containers—wide-mouth, 1,000 

mL, with PTFE-lined lids.

5.1.2 Weighing boats—disposable, aluminum, 

5.1-cm diameter.

5.1.3 Sodium sulfate—anhydrous, granular, 

reagent grade, bake at 450°C for 8 hours and store in a 

ground-glass stoppered flask in a desiccator until used.

5.2 Sediment extraction

5.2.1 Solvents—dichloromethane and 

methanol, pesticide grade, or higher purity.

5.2.2 Boiling chips—amphoteric alundum, 

Hengar granules from Hengar Co., Thorofare, New 

Jersey. Pre-extract with dichloromethane and bake at 

450°C for 8 hours.

5.2.3 Disposable glass capillaries—to fit the 

50- and 100-μL fixed-volume micropipets described in 

sections 4.2.4 and 4.9.3. Clean the glass capillaries by 

baking at 450°C for 8 hours.

5.2.4 Surrogate solution

5.2.4.1 PAH surrogate solution—

containing nitrobenzene-d5, 2-fluorobiphenyl, and 

terphenyl-d14 obtained as a mixed solution at 1,000 

μg/mL per component from Supelco, Inc. (Bellefonte, 

Pennsylvania). Dilute purchased intermediate 

concentration solutions to a final mixed solution 

concentration of 40 ng/μL in methanol. Other appropriate 

surrogate compounds and levels can be added or 

substituted after demonstrating acceptable method 

performance.

5.2.5 Individual spike solutions

5.2.5.1 PAH spike solution—contains the 

individual PAH compounds listed in table 1. Four 

solutions were obtained from Absolute Standards, Inc. 

(Hamden, Connecticut), each containing a subset of the 

semivolatile compounds. Individual compounds in each 

solution are at concentrations of 2,000 ng/μL. Dilute an 

aliquot of each solution into a single final spike solution. 

The final selected concentration of each component is 

150.0 ng/μL in ethyl acetate.

5.2.6 Standard reference materials (SRMs), 

certified reference material (CRM) or other 

quality-control (QC) reference materials—any 

SRM/CRM or other sediment or soil reference material 

available to test the method for recovery of some or all of 

the selected compounds may be an appropriate QC 

material. SRM 1941b and SRM 1944 were produced by 

the National Institute of Standards and Technology 

(NIST) and consist of natural sediment certified for 

specific compounds with additional uncertified values 

also reported. No single SRM currently (2003) available 

contains all of the compounds determined using this 

method. The CRM used in this report was obtained from 

Environmental Resource Associates (Arvada, Colorado) 

catalog no. PPS-45, lot no. 354. 
8 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

5.3 Sediment extract concentration

5.3.1 Nitrogen gas—for solvent evaporation, 

grade 5 or equivalent.

5.4 Sample extract filtration

5.4.1 Filter—0.2-μm pore size, 25-mm 

diameter disposable PTFE membrane syringe filter, 

Gelman Sciences AcrodiscTM CR or equivalent.

5.4.2 Pasteur pipet—14.6- and 22.9-cm-long 

disposable borosilicate pipets with rubber bulbs.

5.4.3 GPC vial, 4-mL—with open-top screw 

cap and PTFE-faced silicone rubber septum. Supelco, Inc. 

part numbers 2-3219M, 2-3261M, and 3-3185M or 

equivalent.

5.4.4 GPC-PAH surrogate solution—contains 

benzo[e]pyrene-d12 at a concentration of 100 ng/μL in 

dichloromethane. Make solution from a neat standard, 

Cambridge Isotope Laboratories or equivalent.

5.5 Gel permeation chromatography

5.5.1 Helium gas—grade 5 or equivalent.

5.5.2 Gel permeation chromatographic 

columns—two 30-cm-long by 7.5-mm inside diameter 

(ID) columns packed with 5-μm diameter styrenedivinylbenzene resin particles using 50-angstrom pore 

size; Polymer Laboratories, Ltd. PL GelTM or equivalent. 

Connect the columns in series with a low dead-volume 

union.

5.5.3 GPC-PAH fraction calibration 

solution—contains di-n-octylphthalate, 

benzo[g,h,i]perylene, and elemental sulfur, each at a 

maximum concentration of 250 pg/μL in 

dichloromethane. 

5.6 GPC fraction concentration and solvent 

exchange

5.6.1 Ethyl acetate—pesticide-residue grade, 

or higher purity.

5.7 Fraction concentration 

5.7.1 Vial—1.5- or 2-mL, amber glass, with 

plastic caps that have dual PTFE-faced silicone rubber 

septa.

5.7.2 Perdeuterated PAH internal standard 

(dPAHIS) solution—contains the following: 1,4 

dichlorobenzene-d4, naphthalene-d8, phenanthrene-d10, 

perylene-d12, acenaphthene-d10, and chrysene-d12, all at 

100 ng/μL in ethyl acetate. This standard solution was 

obtained from NSI Solutions, Inc. (Raleigh, North 

Carolina) and diluted in ethyl acetate.

5.8 Gas chromatography/mass spectrometry 

analysis

5.8.1 Capillary GC column—fused-silica, 

25-m long by 0.20-mm ID, internally coated with a 

5-percent diphenyl and 95-percent dimethyl polysiloxane 

stationary phase with a 0.33-μm film thickness; J&W 

Scientific Columns from Agilent Technologies Ultra 2TM 

or equivalent.

5.8.2 GC injection-port glass liner—use any 

instrument-specific splitless or direct injection-port liner 

that provides acceptable peak shape and detector 

response.

5.9 Instrument calibration and quality-control 

solution preparation

5.9.1 GC/MS PAH calibration solution

5.9.1.1 Prepare working solutions of the 

entire suite of individual PAH compounds listed in table 1 

at 0.1, 0.2, 0.5, 1.0, 2.5, 5.0, 8.0, 10.0, and 20.0 ng/μL per 

component in ethyl acetate using mixed stock solutions, 

including PAH surrogate solution (section 5.2.4.1) and 

GPC-PAH surrogate solution (section 5.4.4). Obtain stock 

solutions from Absolute Standards, Inc., Supelco, Inc. or 

equivalent. Aliquots of the dPAHIS solution (section 

5.7.2) are added to each of the calibration solutions to 

produce individual dPAHIS compound concentrations of 

10 ng/μL. 

5.9.2 Alkylated PAH homolog retention time 

source material—any crude-oil-containing sample can be 

used to test GC retention times for alkylated PAH 

homolog groups and create reference mass spectra. The 

original material used was a sediment sample from the 

Powell River near Knoxville, Tennessee. It was submitted 

to the NWQL for the National Water-Quality Assessment 

Program (Station 03532000; sampled on December 13, 

1995). Optionally, use Alberta Sweet Mix Blend 

(ASMB). ASMB crude is the standard oil used for 

dispersant-treating tests in the Emergencies Science 

Division of Environment Canada (Wang and others, 

1994). 

5.10 GC/MS quality control/quality assurance 

solutions—concentrations of selected PAHs in these 

solutions are measured at periodic intervals within the 

analytical sequence to monitor instrument performance.

5.10.1 Continuing calibration verification 

(CCV) solution—a CCV solution, having individual 

compound concentrations of 2.5 ng/μL, is analyzed after 

every 10 environmental and laboratory QC samples, 

verifying that the initial quantitation calibration is 

maintained.

5.10.2 Instrument detection limit (IDL) 

solution—an IDL solution, having individual compound 

concentrations of 0.2 ng/μL, is analyzed (1) at the 

beginning and (2) at the end of the analytical sequence. 

This analysis is used to verify instrument performance 

near the lowest concentrations of the calibration curve 

during the entire analytical sequence. 
Analytical Method 9

5.10.3 Mass spectrometer calibration—a 

solution of decafluorotriphenylphosphine (DFTPP) is 

analyzed before the first CCV analysis. This analysis 

verifies the initial mass spectrometer axis calibration and 

the relative abundance of ions formed over the mass range 

of the analysis. Prepare this solution from commercially 

available neat standards, Ultra Scientific or equivalent.

5.10.4 Third-party check (TPC) —a solution of 

all compounds or selected compounds to be analyzed. The 

TPC is analyzed after the initial calibration sequence to 

independently verify the instrument calibration. This 

solution is prepared from a source other than that used for 

preparing calibration standards. Currently (2003), a 

0.4-ng/μL standard (stock solution from Supelco, Inc.) is 

being used at the NWQL.

6. Safety Precautions

It is important to observe proper laboratory safety 

procedures. Several of the compounds and materials in 

this method are known or suspected human carcinogens. 

A well-vented fume hood needs to be used for all steps 

involving organic solvents and compounds. Eye 

protection and the appropriate type of gloves needs to be 

worn. It is important to read the Material Safety Data 

Sheets (MSDS) on each compound and solvent prior to 

using this method. Disposal of all organic solvents, 

sediment samples, standards and rinse wastes needs to be 

performed in accordance with NWQL hazardous waste 

disposal rules and regulations.

7. Sample Preparation Procedure

Samples are grouped into sets of 16, including QC 

samples. A typical sample set consists of 13 field samples, 

a set reagent blank, a set reagent spike, and a QC reference 

material sample. 

7.1 Sample dewatering and percent moisture 

determination

7.1.1 Retrieve samples from the freezer and 

allow to thaw overnight in refrigerator.

7.1.2 Thoroughly homogenize each sample 

with spatula or scoopula.

7.1.3 Remove about 20-g wet weight aliquot to 

an appropriate container for separate determination of 

total carbon and total inorganic carbon if requested 

(Wershaw and others, 1987). Total organic carbon is 

obtained by the difference.

7.1.4 If necessary, weigh about 150 g of 

homogenized sample into a tared 250-mL TeflonTM 

centrifuge bottle. Repeat with a second sample, 

identically weighing to ±0.1 g of the first sample for 

balanced centrifuge operation. Repeat for two more 

samples and centrifuge the two pairs of four individual 

samples for 20 minutes at 2,000 rpm. Carefully decant the 

clear supernatant water; remove the supernatant using a 

Pasteur pipet if the sediment pellet is too soft for 

decantation. If the supernatant is not clear, repeat 

centrifugation before decanting. 

7.1.5 Thoroughly rehomogenize the sediment 

sample in the centrifuge bottle. Remove a 1.8- to 2.2-g 

aliquot of sediment and determine the moisture content of 

the centrifuged sediment to ±0.1 percent using the 

moisture determination balance (4.1.5).

7.1.6 Based on determinations in section 7.1.5, 

calculate the weight of wet, centrifuged sediment needed 

to produce a 25-g equivalent dry-weight sample (sample 

weight required for extraction equals 25-g/fraction dry 

weight). From this result, calculate the total weight of 

water, in grams, present in this sample of wet, centrifuged 

sediment. Then determine the amount of anhydrous 

sodium sulfate required to adequately absorb the weight 

of water present in the sample, as follows: the amount of 

sodium sulfate required is equivalent to about four times 

the weight of water. If the sum of the weights of wet, 

centrifuged sediment and anhydrous sodium sulfate is less 

than 160 g, combine these two weights in a tared 400-mL 

beaker. If the combined calculated weights are greater 

than 160 g, reduce the specified dry weight required by 20 

percent to 20-g equivalent dry weight. Recalculate the 

required weights of wet sediment and anhydrous sodium 

sulfate and determine if the sum of these two weights is 

less than 160 g. If it is, combine these new recalculated 

weights in a tared 400-mL beaker. If not, repeat the 

equivalent dry-weight reduction and recalculation 

procedure until the combined calculated weight is less 

than 160 g. Record the combined weight to ±0.1 g. Mix 

thoroughly, and, if necessary, add additional anhydrous 

sodium sulfate to ensure that the mixture is dry and loose, 

always remaining less than a net combined weight of 160 

g of wet, centrifuged sediment and anhydrous sodium 

sulfate. Method detection limits and laboratory reporting 

levels are determined on a 25-g dry-weight basis. If 

smaller quantities of sediment are used in the method, 

laboratory reporting levels are adjusted proportionately.

7.2 Sediment extraction

7.2.1 Add the sediment-sodium sulfate mixture 

to a Soxhlet extraction thimble with spatula. Repeat for all 

samples.

7.2.2 Prepare the following QC samples as 

required, depending on types of analyses to be performed.
10 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

7.2.2.1 Laboratory reagent blank (set 

blank)—Weigh and place 125 g of sodium sulfate into an 

extraction thimble. 

7.2.2.2 Set laboratory reagent spike 

(PAH spike)—Weigh and place 125 g sodium sulfate into 

an extraction thimble, place thimble into Soxhlet, and 

spike sodium sulfate with 100 μL of individual PAH spike 

solution (5.2.5.1) using a 100-μL fixed-volume 

micropipet. 

7.2.2.3 A quality-control reference 

material sample—Place 1 to 25 g of appropriate dry 

SRM/CRM (see 5.2.6) into an extraction thimble; the 

amount extracted will depend on SRM/CRM availability, 

compound concentrations relative to the reporting level, 

and cost. Mix in 100 g of sodium sulfate to simulate step 

7.1.6. (SRM/CRMs usually do not contain appreciable 

water.) The previously described QC samples (sections 

5.2.5 and 5.2.6) are extracted and processed through the 

remainder of the method exactly as for the field samples.

7.2.3 Place each extraction thimble into a 

Soxhlet apparatus connected to a 500-mL flask containing 

350 mL dichloromethane and 5 to 10 boiling chips.

7.2.4 Using a micropipet, add 100 μL of PAH 

surrogate solution (5.2.4.1) on top of each sample 

contained in a thimble.

7.2.5 Carefully add 25 mL methanol to the top 

of the sample and allow 30 minutes for it to percolate 

through sample and the thimble frit. This step helps to 

remove any residual moisture not bound by the sodium 

sulfate.

Note 1. Do not use more than 25 mL of methanol 

during this step. The amount of methanol added must not 

exceed 7 percent of the total volume of dichloromethane 

plus methanol used during the extraction. 

7.2.6 Attach the Soxhlet apparatus to the 

condenser and extract the sample at 70°C for at least 12 

hours. Carefully monitor Soxhlet extraction to ensure that 

the siphoning mechanism works correctly and the fresh 

solvent cycles through each sample at least once each 

hour.

7.2.7 Following extraction, add about 50 g of 

sodium sulfate to the flask and swirl to remove residual 

water. Add additional sodium sulfate as needed to ensure 

water removal. Excessive amounts of water might require 

separation using a 1-L separatory funnel. Seal with a 

ground-glass stopper and store sodium sulfate-containing 

extract in a refrigerator for at least 4 hours.

7.3 Sediment extract concentration

7.3.1 Decant the extract (but not the sodium 

sulfate) from the flask to a K-D concentrator (4.3.1) fitted 

with a 10-mL centrifuge receiver tube (4.3.2) containing 

boiling chips. Rinse the flask three times using 5- to 

10-mL aliquots of dichloromethane and transfer these 

rinses to the K-D concentrator. 

7.3.2 Concentrate the extract to about 3 mL at 

70°C.

Note 2. The methanol used in the extraction step 

needs to be removed during this K-D concentration step, 

otherwise it will interfere with the GPC cleanup (7.5). 

Methanol is completely removed only by the formation of 

an azeotrope having a 92.7 percent dichloromethane and 

7.3 percent methanol composition that boils at 37.8°C (at 

101.3 kPa). Therefore, the amount of methanol must not 

exceed 7 percent of the total extract volume of 

dichloromethane plus methanol in the Soxhlet extract 

(7.2.6); otherwise, the desired azeotrope composition will 

not occur during the K-D concentration.

7.3.3 Store extract in a refrigerator or freezer 

until step 7.4.

7.4 Sediment extract filtration

7.4.1 Tare a labeled, 4-mL GPC vial with cap 

and septum attached (5.4.3) to ±0.0001 g.

7.4.2 Attach a 0.2-μm PTFE filter (4.4.1) to a 

5-mL Luer-Lok syringe (4.4.2). Remove syringe plunger 

and place a tared GPC vial under filter-tip outlet.

7.4.3 Transfer the extract to the syringe barrel 

using a Pasteur pipet. 

7.4.4 Carefully insert the plunger into the 

syringe and pass the extract through the filter into the GPC 

vial. After expelling sample, push air through the filter to 

remove residual extract from the filter.

7.4.5 Rinse the centrifuge receiver tube with 

500 μL dichloromethane, washing down the tube walls 

using the Pasteur pipet. Transfer the rinse to the syringe 

barrel using the Pasteur pipet. Filter this rinse into the 

GPC vial as in 7.4.4.

7.4.6 Repeat step 7.4.5.

7.4.7 Add 50 μL of the GPC-PAH surrogate 

solution (5.4.4) to the extract in the GPC vial if 

determining PAHs by GC/MS.

7.4.8 Bring extract volume up to 4 mL with 

dichloromethane and cap GPC vial. Store extract in a 

refrigerator or freezer at <5°C until step 7.5.

7.5 Gel permeation chromatography

Complete details of GPC operation are beyond the 

scope of this report. Instead, the following procedure 

outlines the steps necessary for GPC instrument fraction 

calibration and subsequent cleanup of sample extracts. 

Consult the appropriate instrument manuals for additional 

details regarding general GPC system operation.

7.5.1 The GPC data system needs to be turned 

on continuously. Other system components, including the 
Analytical Method 11

pump, autosampler, detector, fraction collector, and 

column heater, need to be turned on at least 2 hours in 

advance of fraction calibration. 

7.5.2 Degas the dichloromethane mobile phase 

with helium for 15 to 30 minutes prior to use.

7.5.3 Pump degassed dichloromethane through 

the GPC columns at the mobile phase flow rate of 

1 mL/min for at least 2 hours prior to fraction calibration 

(7.5.8).

Note 3. Slowly ramp up the flow rate from 0.1 to 1 

mL/min for 1 minute to minimize pressure shock to the 

GPC columns.

7.5.4 Bring the GPC vial containing the sample 

to room temperature. 

7.5.5 Prior to vial pressurization (7.5.6), weigh 

the extract in the tared GPC vial with cap and septum 

(7.4.8) to ±0.001 g and record weight. 

7.5.6 For all samples, the GPC vial headspace 

is pressurized with nitrogen gas, just prior to beginning a 

GPC fractionation sequence. Pierce the vial septum with 

the pressurization needle, and pressurize with 207 kPa 

nitrogen for about 1 minute. Make sure the end of the 

needle is not placed into the liquid. Rinse the needle with 

clean dichloromethane after pressurizing each vial. 

7.5.7 Verify GPC system cleanliness and 

baseline stability by injecting a 1,400-μL aliquot of fresh 

pesticide-grade dichloromethane (system blank) and 

monitoring detector response at low attenuation (usually 

at attenuation 8, depending upon the collector). Fractions 

typically are not collected for GPC system blank analyses. 

7.5.8 GPC fraction calibration—PAH elution 

times might vary between analyses of sample sets because 

of GPC column aging, the presence of residual methanol 

from sample extraction, and other factors. Therefore, 

prior to beginning automated analysis, the fraction 

collection beginning and ending times are established for 

the PAHs to allow final configuration of the fraction 

collector. 

7.5.8.1 Establish PAH fraction 

collection times by injecting 1,400 μL of the GPC–PAH 

fraction calibration solution (5.5.3) and monitoring the 

elution times of the peaks at attenuation 8 for 30 minutes. 

Repeat injections of the GPC–PAH fraction calibration 

solution to ensure chromatographic reproducibility. The 

retention times should be within ±12 seconds of each 

other. Fractions are not collected for the GPC–PAH 

fraction calibration test analyses.

7.5.8.2 The beginning time is determined 

by processing the chromatogram resulting from the 

injection of the GPC–PAH fraction calibration solution at 

attenuation 8 and graphically determining when the 

baseline begins to rise, thus indicating the first peak. Set 

the "beginning time" on the fraction collector at the time 

just before the detector baseline begins to rise for the first 

peak (di-n-octylphthalate). Set the "end time" on the 

fraction collector for the GPC–PAH fraction at the valley 

between the benzo[g,h,i]perylene and sulfur peaks, the 

second and third peaks. 

7.5.8.3 Fraction cutoffs originally are 

determined by injecting a solvent blank spiked with the 

suite of analytes into the GPC system. Fractions are 

collected in 2-minute intervals for the 30-minute analysis. 

The 15 extracts are concentrated and analyzed on the 

GC/MS. This exercise identifies the first peak 

(di-n-octylphthalate) and the last well-chromatographed 

peak (benzo[g,h,i]perylene) to elute and their retention 

times. The remaining compounds elute between these 

two. This step is taken at the initial setup of a GPC system 

for this analysis. GPC fraction calibration subsequently is 

validated with the PAH fraction calibration solution. This 

step must be repeated if new types of GPC columns or 

instruments are used.

Note 4. The GPC window used for the PAHs 

complements the organophosphate pesticides (Jha and 

others, 2003), and one extract can be used for both 

analyses. Different GPC fraction collection window start 

and end times are used when an aliquot of the sample 

extract is processed by GPC for OC pesticides and PCBs 

described in Noriega and others (2004).

7.5.9 Perform a GPC automated separation. 

Inject 1,400 μL of the sample extract and collect the 

GPC–PAH fraction in a 25-mL K-D receiver tube. 

Process each sample for 30 minutes. A suggested 

processing sequence, using the sample types contained in 

a normal sample set at the NWQL (one set blank, set PAH 

spike, quality-control reference material, and 13 field 

samples), is listed in table 3. Repeated 1,400-μL 

injections of the GPC–PAH fraction test solution along 

with system blanks help to ensure continued calibration 

and system cleanliness. The PAH elution times are 

reproducible from sequence to sequence.

7.5.10 Reweigh the GPC sample vial with 

original cap and septum to ±0.001 g as soon as possible 

after injection of the sample and record weight.

 
12 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

7.5.11 Cap K-D receiver tube containing the 

GPC–PAH fraction with a ground-glass stopper and store 

in a refrigerator until the concentration step (7.6).

7.5.12 Replace the septum on the GPC sample 

vial and store the remaining extract at <5°C.

7.6 GPC–PAH fraction concentration and solvent 

exchange

7.6.1 Add 4 mL of ethyl acetate and two to 

three small boiling chips to the extract and attach a 

three-ball micro-Snyder column to the top of the K-D 

receiver tube.

7.6.2 Slowly introduce the K-D receiver tube to 

a water bath (4.6.1) maintained at 70°C ± 2° and reduce 

the solvent volume to about 4 mL or until solvent 

evaporation dramatically decreases. Remove the tube 

from the bath and cool.

7.6.3 Raise bath temperature to 85°C±2°. Add 

two to three fresh boiling chips and 1 mL ethyl acetate to 

the K-D receiver tube, vortex, and replace into water bath 

for no longer than 20 minutes. Do not reduce solvent 

volume to less than 1 mL.

7.6.4 Remove tube from water bath and reduce 

the extract to 0.5 mL by using a gentle stream of nitrogen 

(4.3.4).

7.6.5 Transfer the fraction to a 1.8-mL amber 

autosampler vial using a Pasteur pipet. Add 50 μL of the 

PAH internal standard (dPAHIS, 5.7.2) solution, cap the 

vial, and mix. Store in a freezer at <5°C until analysis by 

GC/MS.

8. Instrumental Analysis

Samples are analyzed by GC/MS using full-scan 

monitoring. A capillary column GC system is equipped 

with an autosampler and a split/splitless injection port 

operated in the splitless mode, and is directly connected to 

a quadrupole mass spectrometer. A computer system is 

used to allow complete control of the autosampler, GC 

and MS operations, and to acquire, process, and store 

signals from the GC/MS. Complete details of GC/MS 

operation are beyond the scope of this report. Instead, the 

suggested GC/MS operating conditions and sample 

sequence used in this method are outlined in the following 

procedure. Users should consult the appropriate 

instrument manuals for additional details regarding 

general GC/MS system operation. Note that the GC/MS 

operating conditions are provided for guidance only. 

Different GC/MS systems will require different operating 

conditions to achieve acceptable instrument performance. 

Use those operating conditions that result in acceptable 

instrument performance for the available GC/MS system.

8.1 Instrumental conditions and setup

8.1.1 Suggested GC-operating conditions for 

PAHs. Begin with the oven temperature at 65°C (hold for 

3 minutes), then ramp at 6°C/min to 320°C, and hold for 

20 minutes to allow for sufficient column bake-out; 

injection port temperature, 285°C with electronic pressure 

control set for constant flow of helium gas of 0.7 mL/min, 

1 μL, splitless injection.

8.1.2 Determine compound retention times. 

Following GC/MS setup, establish compound retention 

times with calibration standards. Peak identifications, 

retention times, mass-to-charge ratios and abundances 

relative to the quantitation ion for PAHs, using the 

GC/MS operating conditions described in section 8.1.1 

with a J&W Scientific Ultra 2TM Column from Agilent 

Technologies, are listed in table 4. The relative ion 

abundances are not provided for the alkylated PAH 

homolog groups because the ratios are different among 

isomers. The determination of retention times for the 

alkylated PAH homolog groups is described in 8.1.3. 

CAUTION: Because of differences in GC columns, 

even from the same manufacturer, and operational 

characteristics between instruments, the elution profiles 

will vary. Therefore, it is critical to verify 

instrument-specific compound retention times. Use 

Table 3. Suggested gel permeation chromatography processing 

sequence.

[PAH, polyclcylic aromatic hydrocarbon compound; GPC, gel permeation 

chromatography]

Analytical 

sequence Sample type

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

System blank

Set blank

Set PAH spike (or set spike options)

Quality-control reference material sample

Sample 1

Sample 2

Sample 3

Sample 4

Sample 5

Sample 6

Sample 7

GPC–PAH fraction test solution

System blank

Sample 8

Sample 9

Sample 10

Sample 11

Sample 12

Sample 13

GPC–PAH fraction test solution

System blank

 
Analytical Method 13

Table 4. Retention times, relative retention times, gas chromatography/mass spectrometry quantitation ions, confirmation ions, and 

percent relative abundance of confirmation ions for individual polycyclic aromatic hydrocarbons (PAHs) and alkylated PAH homolog groups.

[Compounds are reported in chromatographic elution order; min, minute; compounds followed by RR are method internal standards and are followed by a 

designation (RR-1, RR-2,...), which indicates their order as a retention reference; min, minutes; m/z, mass-to-charge ratio]

Compound

Retention

time

(min)

Relative

retention

time

Retention

reference

compound

Quantitation

ion 

(m/z)

Confirmation

ions (m/z)

Percent relative 

to quantitation 

ion abundance

1,4-Dichlorobenzene-d4 (RR-1)

Nitrobenzene-d5

Naphthalene-d8 (RR-2)

Naphthalene

C1-alkylated naphthalene 

2-Fluorobiphenyl

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

C2-alkylated naphthalene 

1,6-Dimethylnaphthalene

Acenapthylene

1,2-Dimethylnaphthalene

Acenaphthene-d10 (RR-3)

Acenaphthene

2,3,6-Trimethylnaphthalene

C3-alkylated naphthalene 

9H-Fluorene

1-Methyl-9H-fluorene

C4-alkylated naphthalene 

Phenanthrene-d10 (RR-4)

Phenanthrene

Anthracene

C5-alkylated naphthalene 

2-Methylanthracene

4,5-Methylenephenanthrene

C1-alkylated phenanthrene/anthracene 

1-Methylphenanthrene

C2-alkylated phenanthrene/anthracene 

Fluoranthene

Pyrene

C3-alkylated phenanthrene/anthracene 

Terphenyl-d14

C4-alkylated phenanthrene/anthracene 

C1-alkylated fluoranthene/pyrene

1-Methylpyrene

C2-alkylated fluoranthene/pyrene

Benz[a]anthracene

Chrysene-d12 (RR-5)

Chrysene

C3-alkylated fluoranthene/pyrene

6.8

8.6

11.0

11.1

14.0

15.3

15.9

16.1

16.1

16.5

16.6

17.2

17.7

17.8

19.1

19.5

19.8

22.0

23.0

23.3

23.4

23.6

23.9

25.6

25.7

25.8

25.9

28.0

28.1

28.8

29.6

29.9

31.0

31.0

31.1

32.0

33.4

33.6

33.7

34.6

1.000

1.265

1.000

1.009

1.272

1.391

1.445

1.464

1.464

1.500

.937

1.564

1.000

1.006

1.079

1.102

1.186

1.243

1.300

1.000

1.004

1.013

1.026

1.100

1.103

1.107

1.112

1.202

1.206

1.236

1.270

1.238

1.330

1.330

1.335

1.373

.994

1.000

1.003

1.030

1

1

2

2

2

2

2

2

2

2

3

2

3

3

3

3

3

3

3

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

5

5

5

5

152

128

136

128

141

172

141

141

141

141

152

151

162

153

170

170

166

180

184

188

178

178

198

192

190

192

192

206

202

202

220

244

234

216

216

230

228

240

228

244

150, 115

 82, 98

none

129, 102

142, 127

171, 85

156, 115

156, 115

156, 115

156, 115

151, 76

156, 115

164, 80

154, 152

155, 153

155, 153

165, 82

165, 89

169, 141

189, 94

176, 89

176, 89

183

191, 96

189, 94

191, 95

191, 94

191

101, 203

101, 203

205

122, 245

219

215, 108

215, 108

215

229, 226

120, 241

229, 114

229

150, 60

280, 40

none

10, 10

variable

 30, 10

 45, 25

140, 25

variable

125, 25

 20, 30

 70, 25

100, 40

 95, 50

100, 25

variable

 95, 15

130, 30

variable

 15, 20

20, 15

20, 15

variable

45, 10

90, 10

 variable

55, 5

 variable

20, 15

20, 15

 variable

25, 20

 variable

 variable

70, 20

 variable

20, 25

25, 20

20, 20

 variable
14 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

single-component standards to verify retention times and 

mass spectra of closely eluting or coeluting compounds. 

Verify retention times following any GC maintenance 

procedures applied to the capillary columns to improve 

chromatography.

8.1.3 Determine retention times for alkylated 

PAH homolog groups. Because authentic standards are 

not available for many of the substituted PAHs, retention 

times for these groups are determined by using an 

alkylated PAH homolog source material (5.9.2). The 

reference sample is analyzed at about 20 ng/mL. 

Extracted ion chromatograms are created using the 

quantitation and confirmation ions for each alkylated 

PAH homolog group. The retention times are determined 

for the first and last isomers for the alkylated PAH 

homolog group. Quantitation is explained in section 9.4.

8.1.4 Prior to each analytical sequence, assess 

GC/MS performance by examining peak shape, efficiency 

of separation for closely eluting compound pairs, and 

response-factor variation determined for the compounds. 

Assess these findings prior to the analysis of 

environmental samples, relative to the performance 

obtained with a new capillary column, by using freshly 

prepared CCV (5.10.1) solutions. CCVs are the primary 

indicator of changes in instrument performance during an 

analytical sequence and bracket every 10 samples. 

8.2 GC/MS tuning and calibration

8.2.1 Tune GC/MS prior to analysis or after 

any instrument maintenance using automated or other 

tuning procedures as prescribed by the system 

manufacturer. Prior to any analysis, verify the GC/MS 

tune and mass axis calibration by injecting a solution of 

decafluorotriphenylphosphine (DFTPP). The relative 

mass fragment abundance and mass assignments need to 

be within the range of values specified by the U.S. 

Environmental Protection Agency (1997, p. 265–267).

Table 4. Retention times, relative retention times, gas chromatography/mass spectrometry quantitation ions, confirmation ions, and 

percent relative abundance of confirmation ions for individual polycyclic aromatic hydrocarbons (PAHs) and alkylated PAH 

homolog groups.—Continued

[Compounds are reported in chromatographic elution order; min, minute; compounds followed by RR are method internal standards and are followed by a 

designation (RR-1, RR-2,...), which indicates their order as a retention reference; min, minutes; m/z, mass-to-charge ratio]

Compound

Retention

time

(min)

Relative

retention

time

Retention

reference

compound

Quantitation

ion 

(m/z)

Confirmation

ions (m/z)

Percent relative to 

quantitation ion 

abundance

C1-alkylated benzo[a]anthracene/chrysene 

C5-alkylated phenanthrene/anthracene 

C4-alkylated fluoranthene/pyrene

C2-alkylated benzo[a]anthracene/chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene-d12

Benzo[e]pyrene

Benzo[a]pyrene

Perylene-d12 (RR-6)

Perylene

C1-alkylated benzopyrene/perylene

C5-alkylated fluoranthene/pyrene

C3-alkylated benzo[a]anthracene/chrysene

C2-alkylated benzopyrene/perylene

Indeno[1,2,3-cd]pyrene

C4-alkylated benzo[a]anthracene/chrysene 

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

C3-alkylated benzopyrene/perylene

C5-alkylated benzo[a]anthracene/chrysene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

35.8

36.4

36.9

37.3

37.5

37.6

38.3

38.4

38.6

38.8

38.9

39.8

39.8

41.1

42.0

42.0

42.1

42.2

42.7

43.2

44.8

45.0

45.4

1.065

1.083

.951

1.110

.966

.969

.987

.990

.995

1.000

1.003

1.026

1.026

1.059

1.082

1.082

1.085

1.088

1.101

1.113

1.155

1.160

1.170

5

5

6

5

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

242

248

258

256

252

252

264

252

252

264

252

266

272

270

280

276

284

278

276

294

298

308

322

241, 227

233

243

241

253, 126

253, 126

260, 132

250, 126

250, 126

260, 132

250, 126

251

257

255

265

138, 137

269

139, 279

138, 274

279

283

293

307

variable

variable

variable

variable

20, 25

20, 25

25, 25

30, 20

25, 20

25, 30

25, 25

variable

variable

variable

variable

30, 20

variable

30, 25

40, 20

variable

variable

variable

variable

variable

 
Analytical Method 15

8.2.2 Analyze appropriate calibration solutions 

(5.9.1.1) and determine a best-fit calibration curve using 

the curve-fitting routines provided by the instrument 

manufacturer. Carefully inspect the curves to ensure a 

correlation coefficient (r2

) of 0.995 or greater and verify 

that the lowest calibration standard level meets QC 

criteria. Check the calibration using the third-party check 

solution (5.10.4), which should result in ±25 percent of 

expected concentrations. If these QC criteria cannot be 

met, the source of the problem needs to be identified and 

resolved before a new calibration curve is analyzed and 

assessed. Instrument maintenance might be necessary or 

new calibration standards or a TPC solution prepared. 

After calibration results are determined to be acceptable, 

assemble samples, set QC samples, mass spectrometer 

verification solutions, continuing calibration verification 

solutions, and instrument detection limit solutions into an 

analytical sequence, and analyze them under conditions 

identical to those used for the calibration. A typical 

analytical sequence is listed in table 5. Use an automated 

sample injection system to inject 1 μL of the appropriate 

sample extract or standard solution into the GC/MS. Data 

acquisition conditions for full scan range from 45 to 450 

atomic mass units (amu), scanned at a rate of 2.4 scans per 

second (5–10 scans per peak), with the filament operated 

at 70 electron volts (eV). Store all data electronically for 

subsequent qualitative identification, quantitation, and 

archiving. 

8.3 Qualitative identification

8.3.1 Criteria and single-component 

identification. Two criteria are evaluated when 

establishing a positive compound identification: expected 

relative retention time and comparative fit of the mass 

spectrum. The relative retention time (RRT) is the 

retention time of the compound normalized to the 

retention time of an internal standard. The internal 

standard used is one of several perdeuterated polycyclic 

aromatic hydrocarbons (dPAHIS) added to the sample 

just prior to analysis. The particular dPAHIS used 

depends on where in the chromatogram the compound of 

interest elutes. The formula for determining RRT is

where

Tc = the retention time (referenced to the start of 

the analysis) of the compound of interest, in 

minutes; and

Tis = the retention time of the internal standard used 

for that compound, in minutes.

Determine the RRT for each compound by 

analyzing standard solutions of PAHs and internal 

standards under identical instrumental conditions as used 

for samples. Compare RRTs; the match between samples 

and standards needs to agree within 1 percent. RRTs for 

PAHs determined in this method are listed in table 4. The 

second component for qualitative identification is 

comparison of library and sample mass spectra. Library 

mass spectra are derived from authentic compound 

standards, collected under identical GC/MS conditions as 

the sample spectra. The GC/MS operator visually 

compares library spectra provided by computer routines. 

In addition, ratios of the integrated abundances of one 

quantitation ion to two confirmation ions are compared 

between standards and samples. Peak area ratios of the 

ions need to agree within ±30 percent between standards 

and samples.

8.3.2 Qualitative identification of the alkylalted 

PAH homolog groups. Using the approach of Wang and 

others (1994, 2000) and the extracted ion chromatograms 

as a reference, critically examine peaks within a retention 

time window for spectral confirmation and typical 

alkylated PAH homolog group patterns. Because of the 

RRT

Tc

Tis

= ------

Table 5. Gas chromatography/mass spectrometry analytical 

sequence suggested for use in this method.

[PAH, polycyclic aromatic hydrocarbon]

Analytical 

sequence Sample type

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

Decafluorotriphenylphosphine mass spectrometer

calibration solution

Instrument blank (injection of pure solvent)

Instrument detection level (IDL) solution

Continuing calibration verification (CCV) solution

Set blank

Set PAH spike

Set quality-control reference material sample

Sample 1

Sample 2

Sample 3

Sample 4

Sample 5

Sample 6

Sample 7

CCV

Sample 8

Sample 9

Sample 10

Sample 11

Sample 12

Sample 13

CCV

IDL

(1)
16 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

variability in ion ratios between isomers for the 

mulitcomponent groups, there are no rigid criteria. Sum 

and quantitate the responses for all verified peaks within 

the retention time window. Note that a characteristic 

group of peaks defined from the standard analysis is 

summed to yield a single estimated concentration and it 

includes the concentrations of the individually identified 

compounds that are members of the group. For example, 

concentrations of 1,2-dimethylnaphthalene, 

1,6-dimethylnaphthalene, 2,6-dimethylnaphthalene and 

2-ethylnaphthalene are included in the reported 

concentration for C2-alkylated naphthalene. In field 

samples not all isomers may be present. Figures 2A 

through 2F show the complexity of patterns for specified 

homolog groups.

Figures 2A through 2F show typical patterns for 

the homolog groups for phenanthrene/anthracene. Figure 

2A shows a mass fragmentogram corresponding to the 

quantitation and monitor ions for the isomeric parent 

PAHs phenanthrene, 23.46 minutes, and anthracene, 

23.65 minutes. Figure 2B shows the mass fragmentogram 

for the five integrated C1-alkylated phenanthrene/

anthracene isomers. Figures 2C and 2D show the complex 

chromatographic pattern of partially resolved components 

for the C2- and C3-alkylated phenanthrene/

anthracenes. The peak areas are summed when there is 

mass spectral agreement for each peak and a reference 

mass spectrum. The reference spectra are produced from 

the alklyated PAH homolog retention time source 

material (5.9.2). Figures 2E and 2F show the retention 

time windows for the C4- and C5-alkylated 

phenanthrene/anthracenes. Although there are peaks in 

the expected retention time window, no peaks were 

integrated because of the lack of agreement with the 

reference mass spectra.

9. Calculation and Reporting of Results

The calculation of a final concentration requires 

multiple equations. A comprehensive discussion of the 

math is found in Furlong and others (1996).

9.1 Calculate the dry weight of sediment extracted, 

in grams (Ws):

where

Ww = wet weight of sediment, in grams (7.1.6); 

 and

fd = dry-weight fraction of sediment (7.1.5).

9.2 Calculate the GPC fraction (FGPC)

where

FGPC = fraction of the total extract processed 

through the GPC; 

where

W1 = weight of sample before GPC (7.5.5) minus

weight of sample after aliquot is collected 

for GPC, in grams (7.5.10); and 

W2 = weight of sample before GPC (7.5.5) minus 

tared GPC vial weight, in grams (7.4.1).

9.3 Determination of single-component 

compound concentrations 

The concentration of a compound is calculated after 

a compound has met qualitative criteria for retention time 

and mass spectral agreement (see section 8.3.1). 

Concentration (μg/kg) = 

where

CFr = on-column concentration determined by 

calibration curve-fitting routines, in nanograms per microliter;

Vf = final volume of extract, in microliters 

(7.6.5);

Ws = dry weight of sediment extracted, in grams 

(9.1); and

FGPC = fraction processed through the GPC (9.2).

Calibration curve-fitting routines are based on the 

relative response factor (RRF) and are used to obtain a 

calibration curve for each compound. They are provided 

by the instrument manufacturer and summarized in 

Furlong and others (1996). If the calculated concentration 

of a compound in a sample exceeds the highest 

concentration point of the calibration curve, dilute the 

extract to bring the compound response within the range 

of the calibration curve. If curve-fitting routines 

(quadratic curves and power curves) are used for 

calibration, verify that the sample compound response is 

not outside the working range of the calibration curve.

9.4 Calculation of multicomponent 

concentrations

 9.4.1 Calculation of alkylated PAH homolog 

groups. Each alkylated PAH homolog group is composed 

Ws Ww f = × d

FGPC W1 W2 = ( ⁄ )

CFr Vf × [ (Ws ⁄ × )] FGPC

(3)

(4)

(2)
Analytical Method 17

of many discernable isomers, many without authentic 

reference standards. Begin by manually integrating the 

isomer peak areas based on the appropriate quantitation 

ion (table 4) present in their expected retention time 

window range (8.1.3). Using the calibration curves for the 

compounds selected to represent each homolog group 

listed in table 6, calculate the concentration of each alkylated PAH homolog group listed in table 4. Reported concentrations are considered semiquantitative and reported 

as estimated ("E" coded). If interferences are determined 

to be present within the integrated isomeric peaks, then 

manually integrate that portion of the ion chromatogram 

corresponding to the interference and subtract its peak 

area from the sum of the peak areas.

9.5 Reporting units—Report compound 

concentrations for field samples in micrograms per 

kilogram (μg/kg) dry sediment. Report surrogate data for 

each sample type as percent recovered. Report data for the 

set spike and quality-control reference material samples 

as percent recovered. Compounds quantified in the set 

blank sample are reported in micrograms per kilogram. 

Report compound concentrations for field samples to two 

significant figures. 

9.6 Reporting levels—Method detection limits 

(MDLs) using the procedures outlined by the U.S. 

Environmental Protection Agency (1997) have been 

calculated for this method and are discussed further in 

section 11. The MDL for each compound is used to 

calculate the minimum reporting levels. Minimum 

reporting levels have been established at two to five times 

the calculated MDL. Report qualitatively identified 

compound concentrations (those PAHs that are identified 

from relative retention time and MS spectral fit) that are 

less than the minimum reporting level as estimated ("E" 

coded) concentrations. Compounds that are not detected 

are reported as being less than the minimum reporting 

level. Report qualitatively identified alkylated PAH 

homolog groups as estimated ("E" coded) concentrations.

10. Quality Assurance and Quality Control

This sediment method adheres to the qualityassurance and quality-control (QA/QC) guidance 

document (Mark R. Burkhardt and Thomas J. Maloney, 

U.S. Geological Survey, written commun., 1998) 

prepared at the NWQL for organic chemistry. It provides 

a workable procedure for ensuring quality data. Possible 

scenarios and corrective actions are detailed for each QC 

sample type in this document. Laboratory reagent blanks 

and spikes, surrogate standards, and CCVs are used by the 

analyst to control data quality. Quality-control reference 

material samples and instrumental checks provide 

external verification of method performance. They are 

considered quality-assurance samples.

The laboratory reagent blank (LRB) (see 7.2.2.1) is 

an analyte- and matrix-free (Na2SO4) sample with 

minimal analyte interferences. The LRB monitors the 

entire sample preparation and analytical procedure for 

possible laboratory contamination. The blank is 

considered acceptable when a compound is undetected or 

detected at less than the MRL. Analyte concentrations in 

the LRB are reported and are not subtracted from the 

amount detected in an environmental sample. If the 

concentration of an analyte in the LRB is greater than the 

MRL, the sample set's data might need to be qualified. If 

there are interferences that would prevent the analysis of 

a compound, the source of contamination is determined 

and eliminated before continuing (Mark R. Burkhardt and 

Thomas J. Maloney, U.S. Geological Survey, written 

commun., 1998). 

The set laboratory reagent spike (LRS) (see 7.2.2.2) is 

a matrix-free (Na2SO4) sample fortified with known 

concentrations of all individual PAH compounds. It is 

used to monitor method performance recoveries for the 

set without the effects of sample matrix. The LRS results 

are compiled for long-term recovery performance used in 

creating control limits and charts. A series of at least 30 

LRS are analyzed and used in the statistical process 

analysis to create QC criteria updated annually. If the 

recovery of a compound is not within the criteria, the 

compound is judged out of control. Before continuing, the 

source of the problem is identified and resolved. The data 

for the compounds that fail can be reported as estimated 

("E" coded) or at raised reporting levels.

Table 6. Relative response factors used for the quantitation of 

alkylated polycyclic aromatic hydrocarbon homolog series.

[C1-C5, alkylated polycyclic aromatic hydrocarbon homolog series consisting 

of C1, C2, C3, C4, C5 groups; RRF, relative response factor]

Homolog series Compound whose RRF is 

used for calculations

C1-C5 Alkylated naphthalene

C1-C5 Alkylated phenanthrene/

 anthracene

C1-C5 Alkylated fluoranthene/pyrene

C1-C5 Alkylated benz[a]anthracene/

 chrysene

C1-C5 Alkylated benzopyrene/

 perylene isomers

2,6-Dimethylnaphthalene

2-Methylanthracene

1-Methylpyrene

Benz[a]anthracene

Benzo[a]pyrene
Monitor Ion 176 Quantitation Ion 178 Monitor Ion 191 Quantitation Ion 192 Monitor I

191 Quantitation 

206

ION ABUNDANCE, IN MICROGRAMS PER KILOGRAM

23.1 23.3 23.5 23.7 25.0 25.4 25.8 26.2 26.6 27.0 27.0 27.5 28.0 28.5 

2.82.42.0

1.61.2

0.80.4

0

5.54.53.52.5

1.5

0.55.04.03.02.0

1.0

0

2.8

2.42.0

1.61.2

0.80.4

0

1.61.2

0.80.4

1.41.0

0.60.2

0

1.2

0.80.4

1.0

0.60.2

064275310

TIME, IN MINUTES

A BC

C2 Phenanthrene/Anthracene

C1-alkylated phenanthrene/anthracene -alkylated phenanthrene/an
EXPLANATION

TIME—Retention time, in minutesQuantitation Ion —Response used for calculationMonitor Ion—Used for identification of compound

Shaded areas are the integrated responsesMMused for quantitation and confirmationION ABUNDANCE—Mass spectral response

Figures 2A through 2F. Quantitation and monitor ions in the homolog series for the isomeric ppolycyclic aromatic hydrocarbons phenanthrene/anthracene in a sample.

TIME, IN MINUTES

Monitor Ion

205

Quantitation Ion

220

Monitor Ion

219

Quantitation Ion

234

Monitor Ion

233

Quantitation Io

248

ION ABUNDANCE, IN MICROGRAMS PER KILOGRAM 4.0 3.2 2.4

1.6

4.43.62.82.0

2.82.3

1.81.3

0.80.32.52.0

1.51.0

0.5

0

2.42.0

1.61.2

0.80.42.2

1.81.41.0

0.60.2

0

4.03.22.4

1.6

0

3.62.82.0

1.2

2.82.42.0

1.61.2

0.82.62.2

1.81.41.0

0.60.4

28.5 29.5 30.5 30.0 29.0 30.0 31.0 31.5 30.5 31.0 31.5 32.0 35.0 35.5 36.0 

1.61.2

0.80.4

1.41.0

0.60.2

0

D EF
20 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Surrogate standards (5.2.4.1) are compounds similar 

in physical and chemical properties to the compounds in 

the method but not expected to be present in the 

environment. They are added to each environmental and 

QC sample and used to monitor preparatory steps, matrix 

effects, and overall method performance. Their recoveries 

are not used to correct concentrations of the compounds in 

samples. At least 30 LRBs are used to create QC criteria 

and are updated annually for each surrogate. The QC 

criteria are used to evaluate surrogate recoveries in 

samples. Specific corrective actions are employed if 

surrogate(s) recoveries fall outside the QC criteria 

(Mark R. Burkhardt and Thomas J. Maloney, U.S. 

Geological Survey, written commun., 1998).

CCVs (5.10.1) monitor the instrument's stability in 

comparison to the calibration curve. They bracket the 

environmental samples in the analytical sequence. 

Control limits are established at ±25 percent of the 

expected concentration for each analyte. If a CCV fails the 

QC criteria, reanalysis of the affected samples might be 

required. 

Instrumental checks include performance evaluation 

samples. These are instrument detection limit solutions 

(5.10.2), third-party check solutions (5.10.4), internal 

standards (5.7.2) added to the sample extracts, and a 

solution of DFTPP (5.10.3). The instrument detection 

limit (IDL) solution (5.10.2) is an aliquot of a low 

concentration calibration solution (0.2 ng/μL) 

representing compound concentrations near, but greater 

than, their respective method detection limit. They 

bracket the samples in the analytical sequence, and the 

control limits are established at ±25 percent of the 

expected concentration for each analyte. If an IDL fails 

the QC criteria, reanalysis of the affected samples might 

be required. The third-party check solution is made 

independently from the other standard solutions. 

Typically it contains all the analytes in the method or at 

least 1 from every class at a concentration near the 

midpoint of the calibration curve. It is analyzed after a 

calibration curve and is expected to fall within ±25 

percent of the expected value. Internal standards are 

added for quantitation as well as retention time reference 

to improve qualitative identification. Their responses are 

used to assess the quality of the instrumental analysis. 

DFTPP is analyzed at the beginning of each analytical 

sequence. It assesses mass spectrometer performance, 

such as sensitivity and resolution. The relative mass 

fragment abundance and mass assignments are expected 

to be within the range of values specified by the U.S. 

Environmental Protection Agency (1997, p. 265–267).

Quality-control standard reference materials or 

SRM/CRM (5.2.6) are received from an independent third 

party to provide objective assessment of methods. Their 

matrix is a mixture of sediment designed to represent 

environmental samples. These reference materials 

typically are certified for a small number of the 

compounds of interest. These samples are carried through 

the entire process to monitor performance of sample 

preparation and the analytical procedure in the presence of 

a matrix similar to the matrices of the environmental 

samples. One QC reference material sample is prepared 

and analyzed with each analytical set. Although the 

analysis is not controlled on these samples, they provide 

information about the method long-term recovery 

performance. 

11. Method Performance

Polycyclic Aromatic Hydrocarbon Recoveries in Spiked 

Reagent-Sodium Sulfate and Sediment

Method performance was determined for 28 PAHs in 

three matrices at three fortification levels (4.8, 12.0, and 

24.0 μg/kg). Samples were analyzed using full-scan 

conditions with an Agilent Technologies 5973 mass 

selective detector (MSD) GC/MS system. Supplemental 

data are provided by Furlong and others (1996) using two 

matrices at three fortification levels (400, 800, and 2,000 

μg/kg). The range of fortification concentrations 

compares with ranges of concentrations in environmental 

samples.

 Matrices chosen to test method performance were: 

reagent-sodium sulfate (matrix-free); bottom sediment 

collected from Evergreen Lake, Evergreen, Colorado; and 

bottom sediment collected near Clear Creek, Colorado. 

The Evergreen Lake sediment was dredged as part of 

routine dam maintenance, and the sediment was collected 

from a mound that had been dredged several weeks prior 

to collection. The sediment sample is coarse with a 

substantial sand component. The second sediment type 

was a sample collected near Clear Creek near Central 

City, Colorado. This sediment had been size-separated 

and consisted of particles less than 63 μm in diameter. The 

sediment was light brown, and was received as a dry 

sample from the donor, whereas the Evergreen Lake 

sample was collected by NWQL personnel. 

11.1 Bias and precision

The performance of this method for the extraction, 

isolation, and determination of the PAHs was evaluated 

by adding aliquots of standard solutions to seven 25-g 

dry-weight subsamples of each matrix and processing the 

fortified samples through the entire method. Three 25-g 
Analytical Method 21

dry-weight unfortified samples from each matrix were 

processed to determine the background concentrations of 

any ambient compounds. The separate sets of seven 

subsamples from each matrix were fortified with 4.8, 

12.0, and 24.0 μg/kg of each PAH. Final recoveries were 

adjusted by subtracting the mean background 

concentrations measured in the three unfortified samples. 

Laboratory reagent spikes and laboratory reagent blanks 

were processed with each set. 

Bias (percent mean recovery) and precision (percent 

relative standard deviation) for all matrices are listed in 

table 7. Background concentrations of the three matrices 

are listed in table 8. At the 4.8-μg/kg spiking level in 

sodium sulfate, the recoveries ranged from 4.6 to 97.0 

percent and the percent relative standard deviations 

(percent RSD) ranged from 5.5 to 170.9. The percent 

recoveries were low (4.6–43.5 percent) for the lighter 

compounds with molecular weights of 166 g/mole or less. 

The lighter compounds are more volatile and more 

inclined to loss during the preparatory steps. At the higher 

spike level of 12.0 μg/kg in sodium sulfate, the percent 

recoveries ranged from 51.7 to 93.5 percent with RSDs 

from 3.7 to 16.9 percent. At the spike level of 24.0 μg/kg 

in sodium sulfate the percent recoveries ranged from 50.4 

to 94.5 percent with RSDs from 4.8 to 17.1 percent. The 

recoveries in the sodium sulfate matrix are lower than the 

recoveries in the other sediment matrices and likely are 

caused by the retention of the analytes throughout the 

procedure by presence of the matrix.

At the 4.8-μg/kg spiking level in the Evergreen Lake 

sediment the recoveries ranged from 58.6 to 106.8 percent 

and the percent relative standard deviations (percent 

RSD) ranged from 3.5 to 123.3. The recoveries in the 

Evergreen Lake sediment at the 12.0-μg/kg spiking level 

ranged from 36.5 to 93.9 percent with RSDs from 13.6 to 

92.0 percent. At the 24.0-μg/kg spiking level, recoveries 

ranged from 49.1 to 138.4 percent with RSDs from 6.1 to 

79.1 percent. The RSDs for Evergreen Lake sediment 

were expectedly high for the 12.0- and 24.0-μg/kg spike 

levels for phenanthrene, fluoranthene, pyrene, 

benz[a]anthracene, chrysene, benzo[b]fluoranthene, 

benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, 

perylene, and indeno[1,2,3-cd]pyrene. This high 

variability probably is caused by the high background 

contributions varying among spike samples indicated by 

the large standard deviations for these compounds in the 

matrix background samples. 

At the 4.8-μg/kg spiking level in the Clear Creek 

sediment, the recoveries ranged from 23.5 to 107.6 

percent and the RSDs ranged from 5.6 to 168.5 percent. 

The recoveries in the Clear Creek sediment at the 

12.0-μg/kg spiking level ranged from 40.6 to 102.5 

percent with RSDs from 3.8 to 38.8 percent. At the 

24.0-μg/kg spiking level, recoveries ranged from 47.3 to 

99.2 percent with RSDs from 3.2 to 24.2 percent. The 

RSDs for the Clear Creek sediment improved as the 

concentration increased, thereby minimizing the effects of 

variation in background concentrations.

The method surrogates were added to each sample at 

20 μg/kg and are listed at the end of table 7. The average 

percent recovery for the three fortification levels was 

highest in sodium sulfate at 78.1 percent. The average 

percent recovery was 67.6 percent in Evergreen Lake 

sediment and 73.7 percent in Clear Creek sediment. Even 

though sediment matrices provide retention of 

compounds, they often add to the variability among 

measured results because of background matrix effects. 

The highest RSDs are seen in nitrobenzene-d5, which 

range from 11.9 to 32.6 percent likely because of higher 

volatility at the lower molecular weight (128 g/mole). 

11.2 Bias and precision from Furlong and others 

(1996)

Furlong and others (1996) calculated bias and 

precision data for two sediment matrices. The sediment 

samples were taken from Evergreen Lake and the 

Mississippi River. High spike-performance data are listed 

in tables 9, 10, and 11 and were acquired using the same 

methodology as the present report.

The analyte list in Furlong and others (1996) is larger 

than the list in the present report. To make it easier to read, 

the analytes of interest were extracted from the original 

tables. Note that two analytes are missing from Furlong's 

list that are included in the present report's list: 

benzo[e]pyrene and perylene. Because they are isomers of 

benzo[a]pyrene, which is included in both lists, their 

performance data are comparable. 

11.2.1 Evergreen Lake sediment—The 

Evergreen Lake sediment from Furlong and others (1996) 

is the same as the matrix used in section 11.1.1 of the 

present report. Two subsets of seven samples of each 

analyte were spiked at 800 and 2,000 μg/kg. Calculated 

mean recoveries, standard deviation of mean recovery, 

and relative standard deviation, in percent, are listed in 

tables 9 and 10. Final recoveries were adjusted by 

subtracting the mean concentrations of detected 

background compounds measured in the three unfortified 

samples.

The recoveries in the Evergreen Lake sediment 

at the 800-μg/kg spiking level ranged from 50.3 to 117.3 

percent with RSDs from 1.6 to 46.2 percent; at the 

2,000-μg/kg spiking level, recoveries ranged from 49.7 to 

69.5 percent, with RSDs from 4.0 to 26.8 percent. 
22 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 7. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using full-scan acquisition 

with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices.

[Percent recovery corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results (reagent 

spikes). μg/kg, micrograms per kilogram; RSD, relative standard deviation; ND, not detected; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment

Clear Creek 

sediment MDL

 (μg/kg) Percent

recovery 1

Percent

RSD

Percent 

recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenapthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.6

77.0

70.7

15.2

77.9

69.8

10.4

78.1

70.2

10.7

78.0

65.1

17.6

75.8

71.8

20.5

76.4

70.1

30.1

76.1

73.0

39.3

74.9

66.4

43.5

74.8

69.8

52.1

76.9

77.3

60.1

82.0

79.2

57.4

73.3

68.3

170.9

13.7

6.1

48.7

9.2

6.2

100.4

10.4

6.8

73.7

5.2

6.5

68.5

9.6

9.7

50.8

8.9

4.8

20.7

8.3

9.0

12.8

3.7

4.8

14.5

11.9

8.6

28.4

6.9

8.3

9.3

9.6

5.3

16.1

10.2

9.2

60.7

36.5

49.1

67.3

59.7

62.0

73.5

57.6

67.3

77.7

58.9

70.0

86.0

55.8

63.1

69.6

66.1

71.6

77.4

63.5

71.4

80.4

70.4

78.5

87.5

74.6

80.3

106.8

81.0

86.6

81.2

79.7

94.1

76.2

72.1

80.1

9.9

23.3

16.6

13.7

16.7

28.3

10.4

19.2

11.7

10.7

14.6

15.1

8.4

16.7

9.1

5.4

14.4

11.9

11.8

14.5

11.5

9.0

16.2

10.3

3.6

16.3

8.6

7.1

13.6

6.1

84.9

37.1

29.3

16.0

19.9

10.6

23.5

40.6

47.3

76.4

71.0

68.2

81.9

79.2

75.6

76.7

77.4

72.0

43.4

63.1

67.5

78.1

71.7

69.9

91.0

68.8

68.3

84.4

83.1

77.4

97.6

80.5

79.5

103.8

92.1

89.6

60.1

100.6

93.9

86.5

76.7

81.7

117.1

24.6

10.1

11.9

4.7

11.0

13.6

8.7

8.6

15.8

7.3

7.7

17.9

12.7

6.5

8.9

11.7

9.6

25.6

9.5

5.0

10.5

4.8

7.7

18.1

7.4

3.8

5.6

3.8

6.9

168.5

14.6

15.4

33.9

10.0

5.6

4.0

3.1

3.1

1.5

2.7

2.6

2.4

5.1

3.4

2.0

3.0

2.8
Analytical Method 23

Table 7. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using full-scan acquisition 

with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices.—Continued

[Percent recovery corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results (reagent 

spikes). μg/kg, micrograms per kilogram; RSD, relative standard deviation; ND, not detected; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment

Clear Creek 

sediment MDL

 (μg/kg) Percent

recovery 1

Percent

RSD

Percent 

recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene

Benzo[a]pyrene

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

62.2

72.3

73.3

67.9

79.4

78.9

76.2

80.4

79.5

87.5

86.9

85.8

79.8

88.3

86.6

92.6

86.3

86.8

87.2

89.9

94.5

83.6

93.5

91.2

97.0

75.5

80.8

91.4

90.5

93.0

80.1

75.1

72.1

72.9

77.9

73.0

22.1

6.1

6.1

10.5

9.0

8.2

8.5

6.8

6.9

14.8

4.0

7.3

8.2

8.3

9.1

7.1

11.4

6.2

9.4

6.4

9.6

6.0

4.8

6.9

7.6

5.7

11.9

5.5

9.4

10.3

5.8

6.4

7.1

11.5

6.3

4.9

93.3

69.7

80.8

95.6

79.4

90.8

77.7

80.8

91.1

88.3

83.9

129.5

79.2

89.3

124.2

101.8

92.4

102.0

81.3

86.9

125.6

63.0

84.9

130.3

80.3

92.6

138.4

70.9

80.3

118.3

78.5

93.9

101.6

78.7

84.7

131.3

6.2

17.7

7.5

3.5

15.7

10.1

11.8

16.5

7.0

123.3

59.9

53.8

96.3

52.4

63.9

5.3

14.4

7.9

45.3

26.5

52.6

73.8

29.2

61.2

44.5

30.1

76.0

38.8

26.2

61.5

21.1

24.7

55.4

49.8

28.1

79.1

80.9

93.2

88.5

85.8

102.5

92.9

79.5

83.7

85.8

87.5

99.4

98.9

80.9

101.2

97.2

91.7

101.3

98.5

95.8

82.0

88.5

74.7

86.0

88.9

64.1

63.7

82.5

58.3

101.1

99.2

74.0

84.0

69.1

63.8

73.0

80.8

12.5

5.5

7.8

23.1

6.6

4.3

11.0

8.1

4.3

157.8

38.8

22.6

148.4

38.0

19.9

9.3

4.5

3.2

100.1

19.8

12.7

121.2

22.3

13.2

118.6

27.6

15.3

139.7

15.0

16.4

83.1

10.8

13.4

126.7

31.4

16.8

1.7

2.7

2.1

1.3

2.8

3.7

2.2

1.7

1.6

3.2

2.4

1.8
24 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

When comparing the percent recoveries 

for the Evergreen Lake sediment for 12.0, 24.0, 800, and 

2,000 μg/kg, there are similar recoveries but higher 

variability at the lower spike levels demonstrated by the 

higher percent RSDs. This result is caused by the 

background contributions having a greater effect in 

variability at the lower concentrations than at the higher 

concentrations. For example, a background concentration 

of 11.3 μg/kg for fluoranthene in the Evergreen Lake 

sediment with a standard deviation of 2.9 μg/kg creates 

more variability at the 12-μg/kg spiking level than at the 

800-μg/kg spiking level. The compound with the lowest 

percent recovery is naphthalene at 36.5, 49.1, 50.3 and 

53.7 percent recovered for the four spiking levels. This 

finding most likely iscaused by its lower molecular 

weight and higher volatility. Overall, the similarities 

among the four levels indicate the method is consistent 

over time. 

 11.2.2 Mississippi River sediment—

The matrix was a bottom sediment sample collected from 

the lower Mississippi River in 1986 and was received dry 

and size separated of particles less than 63 μm in diameter 

from the donor. A set of seven subsamples was spiked at 

400 μg/kg; calculated mean recoveries, standard 

deviation of mean recovery, and relative standard 

deviation, all in percent, are listed in table 11.

The recoveries in the Mississippi River 

sediment samples ranged from 27.2 to 104.1 percent with 

RSDs from 9.0 to 18.6 percent.

Table 7. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using full-scan acquisition 

with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices.—Continued

[Percent recovery corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results (reagent 

spikes). μg/kg, micrograms per kilogram; RSD, relative standard deviation; ND, not detected; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment Clear Creek sediment

MDL

 (μg/kg) Percent

recovery 1

Percent

RSD

Percent 

recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

Perylene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

Method Surrogates

(Add to all samples at 20 μg/kg)

Nitrobenzene-d5

2-Fluorobiphenyl

Terphenyl-d14

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

67.6

78.0

75.6

81.3

88.8

83.4

75.0

88.2

92.0

80.1

51.7

50.4

67.6

86.8

70.9

70.3

71.1

67.1

87.1

90.4

90.8

12.8

11.0

10.8

12.9

11.4

7.0

12.2

7.6

8.2

9.4

16.9

17.1

11.9

10.7

12.4

9.3

5.8

3.3

6.2

6.4

5.8

72.1

87.5

104.9

89.1

90.3

125.1

70.7

93.7

103.3

58.6

75.3

93.8

61.3

53.3

51.6

62.7

58.4

56.7

85.6

89.2

90.4

17.5

92.0

49.3

39.8

25.7

67.8

11.4

17.4

15.6

41.6

32.6

62.1

12.2

20.9

15.8

8.0

15.7

13.1

6.5

12.9

8.7

81.6

75.7

83.8

67.2

69.9

73.0

107.6

101.2

84.1

33.7

63.6

52.1

67.8

63.3

52.5

69.8

60.0

62.9

92.0

97.0

98.4

38.3

12.0

7.6

105.9

24.4

19.7

21.3

5.7

5.5

127.4

26.4

24.2

12.6

26.4

32.6

12.4

4.2

14.3

3.2

6.6

7.0

3.1

3.8

2.5

3.3

1

Percent recovery corrected for background.
Analytical Method 25

11.3 Method detection limits

The NWQL uses the long-term method detection 

level procedure (Childress and others, 1999) to determine 

compound-reporting conventions for water analytical 

methods. Because of the varied nature of sediment 

samples, the long-term method detection level procedure 

has not been implemented for sediment analyses. 

Method detection limits (MDLs) were established 

using procedures outlined by the U.S. Environmental 

Protection Agency (1997). For this method, the MDL was 

determined by analyzing a set of seven replicate reagent 

(sodium sulfate) spike samples fortified at 12.0 μg/kg for 

PAHs. For the set of seven samples, the sample standard 

deviation was computed and the MDL calculated from the 

following formula:

MDL = S x t(n–1, 1–α = 0.99) (5)

where

S = standard deviation of replicate analyses, in 

micrograms per kilogram;

t(n–1, 1–α = 0.99) = Student's t-value for the 99-percent

confidence level with n-1 degrees of 

freedom; and

n = number of replicate analyses.

The MDLs were calculated at the 12.0-μg/kg 

concentration because of the better recoveries and greater 

precision than at the 4.8-μg/kg spiking concentration. 

The MDLs range from 1.3 μg/kg for fluoranthene to 5.1 

μg/kg for 2,3,6-trimethylnaphthalene, a lighter compound 

more inclined to volatile losses. The spiking 

concentration at 12.0 μg/kg was two to five times the 

anticipated MDL. The calculated MDL for each 

compound is listed in table 7.

Table 8. Polycyclic aromatic hydrocarbon matrix background concentrations in full-scan acquisition.

[μg/kg, micrograms per kilogram. Concentrations are expressed as an equivalent dry weight of 25 grams; n=3]

Compound

Mean concentration (μg/kg) Standard deviation (μg/kg)

Sodium 

sulfate

Evergreen

Lake

Clear

Creek

Sodium

sulfate

Evergreen

Lake

Clear

Creek

Naphthalene 

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene

Benzo[a]pyrene

Perylene

Indeno[1,2,3-cd]pyrene

Dibenzo[a,h]anthracene

Benzo[g,h,i]perylene

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0.3

0

0

0

0

0

0

0

0

0

5.8

2.1

.4

.4

1.8

11.3

9.2

0

4.9

8.1

4.6

4.1

3.6

6.5

7.0

3.4

1.2

2.9

5.3

0

.5

.9

3.5

0

0

0

0

.5

16.1

3.1

1.6

1.5

2.3

23.1

21.0

1.4

9.4

15.0

11.6

10.1

8.1

12.8

2.5

9.7

.7

7.6

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0.6

0

0

0

0

0

0

0

0

0

1.9

.2

.6

.6

.3

2.9

2.4

.0

.8

1.5

1.2

1.0

.9

1.2

.2

3.0

2.1

.9

4.0

0

.8

1.6

1.2

0

0

0

0

.9

10.6

.6

.2

.2

.8

6.8

6.0

.3

2.5

2.6

1.4

1.9

1.3

1.4

.8

1.7

1.2

.9
26 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Minimum reporting levels (MRLs) are assigned to 

compounds based on a combination of MDL data 

developed during method validation, observed matrix 

interference, and the effect of the varied matrices on 

instrument performance. Results are not censored at the 

MRL for this method because compounds are determined 

by mass spectrometry, and, therefore, the method is 

considered to be information rich (Childress and others, 

1999). The MRL for the PAH compounds is 10 μg/kg.

The method reporting levels for the alkylated PAH 

homolog groups are based on the method reporting levels 

of the compounds selected to represent each group (table 

6) because of the lack of authentic standards. The MRL is 

10 μg/kg. They will be permanently reported as estimated 

("E" coded). The concentrations of these groups are 

considered estimates because although the qualitative 

criteria were met for their detection, their concentrations 

are based on calibration using compounds that are 

different from those being determined. 

Table 9. Recovery of semivolatile organic compounds from Evergreen Lake sediment samples spiked at 800 micrograms per kilogram.

[μg/kg, micrograms per kilogram; n, number of determinations used to calculate means and standard deviations; < ERL, less than estimated reporting limit. 

Method compounds spiked at an equivalent sediment concentration of 800 μg/kg. Method surrogates spiked at a concentration of 160 μg/kg.]

Compound

(in elution order)

Mean 

amount 

recovered 

(μg/kg)

Standard 

deviation of 

amount 

recovered 

(μg/kg)

Mean 

recovery 

(percent)

Standard 

deviation of 

mean 

recovery 

(percent)

Relative 

stantard 

deviation 

(percent)

n

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[a]pyrene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

Nitrobenzene-d5 (method surrogate)

2-Fluorobiphenyl (method surrogate)

Terphenyl-d14 (method surrogate)

403

544

576

567

639

620

648

670

770

740

824

731

938

883

833

862

770

775

813

779

649

811

633

546

747

875

123

85

125

186

128

121

140

122

116

105

83

87

45

45

38

41

41

38

21

21

24

13

21

27

59

22

44

59

69

68

29

10

50.3

68.0

72.0

70.9

79.9

77.5

81.0

83.7

96.2

92.5

103.0

91.4

117.3

110.3

104.1

107.7

96.3

96.8

101.6

97.4

81.1

101.3

79.2

68.3

93.3

109.4

77.1

53.1

77.9

23.3

16.0

15.2

17.5

15.3

14.4

13.1

10.4

10.9

5.6

5.6

4.7

5.1

5.1

4.8

2.7

2.6

3.0

1.6

2.6

3.3

7.4

2.8

5.5

7.4

8.6

42.6

17.9

6.1

46.2

23.5

21.1

24.7

19.2

18.6

16.2

12.4

11.3

6.1

5.5

5.1

4.4

4.6

4.6

2.5

2.7

3.1

1.6

2.7

4.1

7.3

3.5

8.1

7.9

7.9

55.3

33.8

7.8

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7
Analytical Method 27

11.4 Performance data using standard reference 

materials

The SRMs analyzed routinely are 1941b and 1944. 

They are produced by the National Institute of Standards 

and Technology (NIST) and areused to evaluate analytical 

methods. They consist of natural sediment and have been 

certified for specific PAHs as well as other contaminates. 

Many alkylated PAH homolog groups are present but are 

not certified. The certified PAHs and uncertified alkylated 

PAH homolog groups present and their concentrations are 

appropriate for this method.

11.4.1 Standard Reference Material 

1941b—The NIST SRM 1941b is a marine sediment 

collected at the mouth of Baltimore Harbor in Maryland. 

A set of seven samples was prepared and analyzed using 

the present report's method. Table 12 lists the 

performance data for the PAHs certified through NIST. 

These recoveries ranged from 68.2 to 178 percent and 

RSDs from 0.77 to 9.25 percent. The high recoveries and 

the low RSDs suggest the method is performing well. 

Benzo[k]fluoranthene recovery was 178 percent and 

dibenz[a,h]anthracene recovery was 156 percent. SRM 

1941b was certified using slightly different preparation 

protocols, different extraction solvents, and isolation 

procedures than were used in this method. 

Table 10. Recovery of semivolatile organic compounds from Evergreen Lake sediment samples spiked at 2,000 micrograms per kilogram.

[μg/kg, micrograms per kilogram; n, number of determinations used to calculate means and standard deviations; < ERL, less than estimated reporting limit. 

Method compounds spiked at an equivalent sediment concentration of 2,000 μg/kg. Method surrogates spiked at a concentration of 160 μg/kg.]

Compound

(in elution order)

Mean 

amount 

recovered 

(μg/kg)

Standard 

deviation of 

amount 

recovered 

(μg/kg)

Mean 

recovery 

(percent)

Standard 

deviation of 

mean 

recovery 

(percent)

Relative 

standard 

deviation 

(percent)

n

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[a]pyrene

Indeno[1,2,3-cd]pyrene

Dibenz(a,h)anthracene

Benzo[g,h,i]perylene

Nitrobenzene-d5 (method surrogate)

2-Fluorobiphenyl (method surrogate)

Terphenyl-d14 (method surrogate)

1,074

1,091

1,069

1,159

1,151

1,105

1,310

1,250

1,354

1,295

1,391

1,390

1,252

1,343

1,301

1,339

1,198

1,301

1,254

1,261

1,062

1,031

1,083

1,076

994

1,311

64

79

85

52

50

53

53

46

52

85

73

71

80

79

80

70

85

57

66

50

64

99

71

86

87

105

84

217

352

8

4

8

53.7

54.5

53.4

57.9

57.6

55.2

65.5

62.5

67.7

64.7

69.5

69.5

62.6

67.2

65.0

67.0

59.9

65.0

62.7

63.0

53.1

51.5

54.1

53.8

49.7

65.5

39.9

49.4

53.3

2.6

2.5

2.7

2.6

2.3

2.6

4.3

3.7

3.6

4.0

3.9

4.0

3.5

4.2

2.8

3.3

2.5

3.2

5.0

3.6

4.3

4.4

5.2

4.2

10.9

17.6

4.7

2.8

4.9

4.8

4.6

5.0

4.6

4.0

4.7

6.5

5.9

5.3

6.2

5.7

5.7

5.6

6.3

4.4

4.9

4.2

4.9

7.9

5.7

8.1

8.5

9.7

7.8

21.9

26.8

11.8

5.6

9.3

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7
28 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 13 lists mean concentrations of alkylated 

PAH homolog groups present, but which are not reported, 

in the SRM certification documents supplied with SRM 

1941b. Many of the alkylated PAH homolog groups were 

not present, which is common in environmental samples. 

The RSDs are all less than 7 percent, thus showing good 

agreement between measurements. 

11.4.2 Standard Reference Material 

1944—The NIST SRM 1944 is a mixture of marine 

sediment. A set of seven samples was prepared and 

analyzed using the present report's method. Table 14 lists 

performance data for the PAHs certified through NIST. 

These recoveries ranged from 49.3 to 127 percent and 

RSDs from 5.53 to 10.5 percent. The high recoveries and 

the low RSDs suggest the method is performing well. 

Table 15 lists mean concentrations of alkylated 

PAH homolog groups present, but which are not reported 

in the SRM certification documents supplied with SRM 

1944. The RSDs are all less than 12 percent, thus showing 

good agreement between measurements. Not all of the 

alkylated PAH homolog groups were present.

Table 11. Recovery of semivolatile organic compounds from Mississippi River sediment samples spiked at 400 micrograms per kilogram.

[μg/kg, micrograms per kilogram; n, number of determinations used to calculate mean standard deviations; < ERL, less than estimated reporting limit. Method 

compounds spiked at an equivalent sediment concentration of 400 μg/kg. Method surrogates spiked at a concentration of 160 μg/kg.]

Compound

(in elution order)

Mean 

amount 

recovered 

(μg/kg)

Standard 

deviation of 

amount 

recovered 

(μg/kg)

Mean 

recovery 

(percent)

Standard 

deviation of 

mean 

recovery 

(percent)

Relative 

standard 

deviation 

(percent)

n

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[a]pyrene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene 

Nitrobenzene-d5 (method surrogate)

2-Fluorobiphenyl (method surrogate)

Terphenyl-d14 (method surrogate)

221

109

128

110

306

131

316

122

325

118

311

302

 90

123

131

335

290

114

302

323

300

294

297

314

373

416

 88.4

141

125

39

16

16

17

30

14

32

12

39

16

37

36

10

12

24

43

36

10

33

42

42

39

38

36

50

55

16.2

11

15

55.3

27.2

32.0

27.5

76.5

32.9

78.9

30.4

81.2

29.4

77.7

75.4

22.5

30.9

32.8

83.8

72.5

28.4

75.5

80.8

75.1

73.6

74.3

78.6

93.4

104.1

55.3

88.4

78.0

9.8

3.9

4.0

4.3

7.6

3.4

8.0

3.0

9.7

4.1

9.2

8.9

2.6

3.0

6.1

10.7

9.0

2.6

8.2

10.4

10.5

9.7

9.6

9.1

12.5

13.7

10.1

6.7

9.4

17.7

14.5

12.5

15.6

10.0

10.3

10.2

9.9

11.9

14.0

11.9

11.8

11.6

9.8

18.6

12.8

12.4

9.0

10.9

12.9

14.0

13.1

12.9

11.5

13.4

13.2

18.3

7.6

12.1

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

6

7

7
Analytical Method 29

Table 12. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute of Standards and Technology for Standard 

Reference Material 1941b and determined using this method.

[μg/kg, micrograms per kilogram; number of analyses=7]

Compound Expected concentration 

(μg/kg)

Measured mean 

concentration (μg/kg)

Recovery 

percent)

Relative standard 

deviation (percent)

Anthracene

Benz[a]anthracene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[g,h,i]perylene

Benzo[a]pyrene

Benzo[e]pyrene

Chrysene

Dibenz[a,h]anthracene

Fluoranthene

9H-Fluorene

Indeno[1,2,3-cd]pyrene

1-Methylphenanthrene

Naphthalene

Perylene

Phenanthrene

Pyrene

184

335

453

225

307

358

325

291

53.0

651

85.0

341

73.2

848

397

406

581

196

384

476

402

209

355

303

363

82.6

613

92.0

407

81.3

621

347

340

508

107

115

105

178

68.2

99.2

93.3

125

156

94.1

108

119

111

73.3

87.4

83.7

87.5

2.29

3.53

6.98

3.50

3.46

4.63

3.16

2.87

5.72

1.78

4.00

9.25

4.23

2.82

2.26

0.77

1.39

Table 13. Alkylated polycyclic aromatic hydrocarbon homolog group concentrations detected in Standard Reference Material 1941b not 

reported by the National Institute of Standards and Technology and determined using this method.

[μg/kg, micrograms per kilogram; NR, not reported; –, no data; number of analyses=7]

Compound Measured mean 

concentration (μg/kg)

Standard deviation 

(μg/kg)

Relative standard 

deviation (percent)

C1-alkylated naphthalene

C2-alkylated naphthalene

C3-alkylated naphthalene

C4-alkylated naphthalene

C5-alkylated naphthalene

C1-alkylated phenanthrene/anthracene

C2-alkylated phenanthrene/anthracene

C3-alkylated phenanthrene/anthracene

C4-alkylated phenanthrene/anthracene

C5-alkylated phenanthrene/anthracene

C1-alkylated fluoranthene/pyrene

C2-alkylated fluoranthene/pyrene

C3-alkylated fluoranthene/pyrene

C4-alkylated fluoranthene/pyrene

C5-alkylated fluoranthene/pyrene

C1-alkylated benzo[a]anthracene/chrysene

C2-alkylated benzo[a]anthracene/chrysene

C3-alkylated benzo[a]anthracene/chrysene

C4-alkylated benzo[a]anthracene/chrysene

C5-alkylated benzo[a]anthracene/chrysene

C1-alkylated benzopyrene/perylene

C2-alkylated benzopyrene/perylene

C3-alkylated benzopyrene/perylene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

448

478

690

NR

NR

456

413

300

NR

NR

576

427

NR

NR

NR

389

NR

NR

NR

NR

409

NR

NR

NR

NR

18.3

25.0

27.2

–

–

7.06

8.15

14.6

–

–

13.4

24.2

–

–

–

27.2

–

–

–

–

27.6

–

–

–

–

4.09

5.22

3.95

–

–

1.55

1.97

4.85

–

–

2.33

5.68

–

–

–

6.98

–

–

–

–

6.75

–

–

–

–
30 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 14. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute of Standards and Technology for 

Standard Reference Material 1944 and determined using this method.

[μg/kg, micrograms per kilogram; number of analyses=7]

Compound

Expected 

concentration 

(μg/kg)

Measured mean 

concentration 

(μg/kg)

Recovery 

(percent)

Relative standard 

deviation (percent)

Anthracene

Benz[a]anthracene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[g,h,i]perylene

Benzo[a]pyrene

Benzo[e]pyrene

Chrysene

Dibenz[a,h]anthracene

Fluoranthene

Indeno[1,2,3-cd]pyrene

Naphthalene

Perylene

Phenanthrene

Pyrene

1,770

4,720

3,870

2,300

2,840

4,300

3,280

4,860

424

8,920

2,780

1,650

1,170

5,270

9,700

1,440

3,870

3,160

2,920

1,680

3,170

2,480

4,470

347

6,670

2,820

820

740

3,970

6,580

81.3

81.9

81.7

127

59.2

73.6

75.6

92.1

81.8

74.8

102

49.3

63.3

75.3

67.8

7.79

6.78

8.63

7.30

7.05

7.61

6.67

7.22

7.38

6.07

6.77

10.5

7.13

6.36

5.53

Table 15. Alkylated polycyclic aromatic hydrocarbon homolog group concentrations detected in Standard Reference 

Material 1944 not reported by the National Institute of Standards and Technology and determined using this method.

[μg/kg, micrograms per kilogram; NR, not reported; -, no data; number of analyses=7]

Compound

Measured mean 

concentration 

(μg/kg)

Standard 

deviation (μg/kg)

Relative standard 

deviation 

(percent)

C1-alkylated naphthalene

C2-alkylated naphthalene

C3-alkylated naphthalene

C4-alkylated naphthalene

C5-alkylated naphthalene

C1-alkylated phenanthrene/anthracene

C2-alkylated phenanthrene/anthracene

C3-alkylated phenanthrene/anthracene

C4-alkylated phenanthrene/anthracene

C5-alkylated phenanthrene/anthracene

C1-alkylated fluoranthene/pyrene

C2-alkylated fluoranthene/pyrene

C3-alkylated fluoranthene/pyrene

C4-alkylated fluoranthene/pyrene

C5-alkylated fluoranthene/pyrene

C1-alkylated benzo[a]anthracene/chrysene

C2-alkylated benzo[a]anthracene/chrysene

C3-alkylated benzo[a]anthracene/chrysene

C4-alkylated benzo[a]anthracene/chrysene

C5-alkylated benzo[a]anthracene/chrysene

C1-alkylated benzopyrene/perylene

C2-alkylated benzopyrene/perylene

C3-alkylated benzopyrene/perylene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

1,090

2,630

6,180

NR

NR

5,630

6,110

3,330

NR

NR

7,930

5,430

NR

NR

NR

4,570

1,980

NR

NR

NR

4,860

NR

NR

NR

NR

131

242

480

–

–

660

373

263

–

–

548

562

–

–

–

354

157

–

–

–

473

–

–

–

–

12.0

9.19

7.78

–

–

11.7

6.11

7.90

–

–

6.91

10.4

–

–

–

7.74

7.96

–

–

–

9.73

–

–

–

–
Summary and Conclusions 31

Summary and Conclusions

This report presents a method for the determination 

of 28 polycyclic aromatic hydrocarbon (PAH) 

compounds and 25 groups of alkylated PAH homologs in 

sediment using gas chromatography/mass spectrometry. 

Method improvements include low (10 μg/kg) detection 

limits and full-scan flexibility. The alkylated PAH 

homolog groups are reported as estimated in the absence 

of authentic standards. This method has the ability to 

determine PAH compounds, organochlorine pesticides, 

polychlorinated biphenyls, and organophosphate 

pesticides from the same sample extraction. 

Extensive information is given for the preparation of 

the sediment samples and the analytical design for the 

detection of these compounds. The preparation includes a 

Soxhlet extraction, compound isolation using 

gel-permeation chromatography, and concentration 

through solvent reduction. Gas chromatography/mass 

spectrometry is used for the analytical detection and 

quantitation. Quantitation ions and monitor ions are 

provided and their use is illustrated with fragmentograms. 

 Performance data were presented for three matrices 

for the 28 PAH compounds at three spiking levels. The 

matrices were reagent sodium sulfate and two bed 

sediments. The spiking levels (4.8, 12.0, and 24.0 μg/kg) 

were designed to locate and refine the method detection 

limit for each PAH. The 4.8-μg/kg spiking level proved 

too low, with recoveries for many of the volatile 

compounds less than 40 percent and with high relative 

standard deviations greater than 50 percent. A 10-μg/kg 

minimum reporting level was calculated using the data 

from the 12-μg/kg spiking level in the reagent sodium 

sulfate because recoveries were greater than 50 percent 

and relative standard deviations were less than 20 percent. 

The recoveries and percent relative standard deviations 

for the 24-μg/kg spiking level were similar to the 

12-μg/kg spiking level for the three matrices. Higher 

spike levels and environmental data concentrations were 

provided by Furlong and others (1996) using a method 

similar to the method described in this report. Using two 

sediment matrices and the same preparatory procedure, 

they spiked compounds at three levels: 400, 800 and 2,000 

μg/kg. The recoveries were similar to the 24-μg/kg 

spiking level (greater than 50 percent), but the percent 

relative standard deviations were higher, less than 46.2 

percent for the 800-μg/kg spiking level and less than 26.8 

percent for the 2,000-μg/kg spiking level. 

Standard reference materials provided additional data 

showing good method precision for the certified 

compounds and the uncertified alkylated PAH homolog 

groups. The two standard reference materials were NIST 

1941b and 1944. The recoveries for the certified 

compounds in standard reference material 1941b ranged 

from 68.2 to 178 percent with percent relative standard 

deviations less than 10.0. The percent relative 

standard deviations for the detected alkylated PAH 

homolog groups were less than 7 percent. The recoveries 

for the certified compounds in standard reference materials 1944 ranged from 49.3 to 127 percent with percent relative standard deviations less than 10.5. The percent 

relative standard deviations for the detected alkylated 

PAH homolog groups were less than 12.0 percent.

The method described proves a preparatory procedure and 

analytical design to detect and quantitate 28 PAH compounds and 25 groups of alkylated PAH homologs in sediment samples.

References Cited

Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, 

T. J., 1999, New reporting procedures based on long-term 

method detection levels and some considerations for interpretations of water-quality data provided by the U.S. 

Geological Survey National Water Quality Laboratory: U.S. 

Geological Survey Open-File Report 99-193, 19 p.

Fishman, M.J., ed., 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of inorganic and organic constituents in water and 

fluvial sediments: U.S. Geological Survey Open-File Report 

93-125, 217 p.

Furlong, E.T., Vaught, D.G., Merten, L.M., Foreman, W.T., 

and Gates, P.M., 1996, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of semivolatile organic compounds in bottom sediment by solvent extraction, gel permeation chromatographic 

fractionation, and capillary-column gas chromatography/mass spectrometry: U.S. Geological Survey Open-File 

Report 95-719, 67 p.

Jha, V.K., and Wydoski, D.S., 2003, Methods of analysis by the 

U.S. Geological Survey National Water Quality Laboratory—Determination of organophosphate pesticides in 

bottom sediment by gas chromatography with flame photometric detection: U.S. Geological Survey Water-Resources 

Investigations Report 02-4222, 30 p.

Miller, J.C., and Miller, J.N., 1993, Statistics for analytical 

chemistry (3d ed.): New York, Ellis Horwood Limited. 

Nauss, K.M., 1995, Critical issues in assessing the carcinogenicity of diesel exhaust—A synthesis of current knowledge, 

in Diesel exhaust: A critical analysis of emissions, exposure, 

and health effects: Cambridge, Mass., Health Effects 

Institute, p. 11–61.
32 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Noriega, M.C., Wydoski, D.S., and Foreman, W.T., 2004, 

Methods of analysis by the U.S. Geological Survey National 

Water Quality Laboratory—Determination of organochlorine pesticides and polychlorinated biphenyls in bottom and 

suspended sediment by gas chromatography with electron-capture detection: U.S. Geological Survey 

Water-Resources Investigations Report 03-4293, 46 p.

U.S. Environmental Protection Agency, 1997, Guidelines 

establishing test procedures for the analysis of pollutants 

(App. B, Part 136, Definition and procedures for the 

determination of the method detection limit): U.S. Code of 

Federal Regulations, Title 40, p. 265–267.

Wang, Zhendi, Fingas, Merv, and Li, Ken, 1994, Fractionation 

of a light crude oil and identification and quantitation of aliphatic, aromatic, and biomarker compounds by GC–FID and 

GC–MS, Parts I and II: Journal of Chromatographic Science, 

v. 32, p. 361–382.

Wang, Zhendi, Fingas, Merv, and Sigouin, Lise, 2000, Characterization and source identification of an unknown spilled oil 

using fingerprinting techniques by GC–MS and GC–FID: 

LCGC, v. 18, no. 10, p. 1058–1067.

Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, L.E., 

eds., 1987, Methods for the determination of organic 

substances in water and fluvial sediments: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 

5, chap. A3, p. 79 and 80.
Attachment 1

Determination of Polycyclic Aromatic Hydrocarbons in 

Sediment by Gas Chromatography/Mass Spectrometry 

Using Selected-Ion Monitoring
34 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Introduction

The method described in this report was originally 

implemented at the NWQL in 1996 as a custom method. 

This attachment provides an overview of the custom 

method and differences between it and the method 

presented in the body of this report. It provides 

performance data for the parent PAH compounds and the 

alkylated PAH homolog groups using the custom method. 

An initial demonstration of capability provided that this 

method was suitable for the determination of PAH 

compounds in soil and sediment samples containing at 

least 5 μg/kg.

The custom method is similar to the method presented 

in the body of the report. The introduction and summary 

of the custom method is the same as that described in 

sections 1 and 2. Because this was a custom method, it did 

not have a method number. It was given the custom 

schedule code of 8022. The interferences are the same as 

in section 3, and the apparatus and equipment used is the 

same as in section 4. Section 5 describes reagents and 

consumable materials also used in the custom method. 

This custom method used the same safety precautions 

described in section 6, the same preparatory plan 

presented in section 7, and the same method of analysis 

discussed in section 8, except it used selected-ion 

monitoring for the acquisition of data on the mass 

spectrometer. It used the same method of reporting 

(section 9) and the same quality-assurance and 

quality-control practices described in section 10. 

The custom method differed in two aspects from the 

method described in this report: it used selected-ion 

monitoring (SIM) in data acquisition, and three additional 

analytes were included in the analysis. First, it used SIM 

acquisition instead of full-scan (FS) data acquisition. In 

1996, SIM was necessary for minimum reporting levels of 

5 μg/kg. With the improvement of instrumentation, FS 

acquisition now rivals SIM for sensitivity with added 

benefits. In FS acquisition the acquired spectra are more 

complete, thereby providing greater confidence when 

comparing sample spectra with reference spectra. This 

result is especially important for the analysis of alkylated 

PAH homolog groups. Because authentic standards are 

not available for many of them, a more complete mass 

spectra provides greater confidence in detection. Full scan 

also allows for future analysis of unknowns not initially 

requested. 

The second difference is the original SIM analyte list 

included phenol, p-cresol, and coronene. These three 

compounds were eliminated from the FS performance 

data (table 7) because of unacceptable method 

performance and recoveries of less than 50 percent. They 

are included, however, in the SIM performance data for 

historical purposes.

Because the 5 μg/kg reporting level in the SIM 

method is lower than the FS's reporting level (10 μg/kg), 

the working solutions for GC/MS PAH calibration 

standards (5.9.1.1) were prepared at lower concentrations. 

They were prepared for the entire suite of individual PAH 

compounds listed in table 1 at 0.01, 0.02, 0.05, 0.1, 0.2, 

0.5, and 1.0 ng/μL per component in ethyl acetate using 

mixed stock solutions, including PAH surrogate solution 

(section 5.2.4.1) and GPC–PAH surrogate solution 

(section 5.4.4). Aliquots of the dPAHIS solution (section 

5.7.2) were added to each of the calibration solutions to 

produce individual dPAHIS compound concentrations of 

1 ng/μL.

It was necessary to create SIM windows for the 

acquisition method on the GC/MS by using the peak 

identifications, retention times, mass-to-charge ratios, and 

abundances relative to the quantitation ion for PAHs 

listed in table 4. The relative ion abundances were not 

included for the alkylated PAH homolog groups because 

the ratios are different among isomers. Because authentic 

standards were not available for many of the individual 

components in the alkylated PAH homolog groups, 

retention times for these groups were determined using an 

alkylated PAH homolog retention time source material 

(5.9.2). 

OPTIONALLY: An Alberta Sweet Mix Blend, a 

light crude reference oil, can be used (Wang and others, 

1994). The reference sample was analyzed in FS mode at 

about 5 ng/mL. Extracted ion chromatograms were 

created using the quantitation and confirmation ions for 

each alkylated PAH homolog group. The retention times 

were determined for the first and last isomers. The 

quantitation and confirmation ions were entered into the 

SIM windows in the acquisition method that encompassed 

that time period. Some ions were included in more than 

one SIM window. SIM windows were constructed, and 

retention times were updated in the method using this 

procedure. The reference sample was analyzed again 

using the newly created SIM conditions to verify SIM 

windows.

This attachment provides method performance 

information for SIM acquisition of the original analyte 

list. The performance information includes bias and 

precision data, calculated MDLs, historical reagent spike 

data, standard reference material data, and certified 

reference material data. The last table (table 24) compares 

SIM and FS acquisition using the statistical F-test. 
Attachment 1 35

Performance Data

Method performance was determined for polycyclic 

aromatic hydrocarbons using SIM acquisition. The 

Agilent Technologies 5973 mass selective detector 

(MSD) GC/MS system was used. The bias and precision 

data include calculations for percent recovered and 

relative standard deviation (RSD) for three spike levels in 

the three different matrices (table 16). Matrices chosen to 

test method performance were reagent-sodium sulfate 

(matrix-free), bottom sediment collected from Evergreen 

Lake, Evergreen, Colorado, and bottom sediment 

collected near Clear Creek, Colorado. The matrices are 

described in section 11 in the main body of the report.

The performance of this method for the extraction, 

isolation, and analysis of the PAHs was evaluated by 

adding aliquots of standard solutions to seven subsamples 

of each matrix and processing the fortified samples 

through the entire method. Three unfortified samples 

from each matrix were processed to determine the 

background concentrations of any ambient compounds. 

The three separate sets of seven subsamples from each 

matrix were fortified with 4.8, 12.0, and 24.0 μg/kg of 

each PAH. Final recoveries were adjusted by subtracting 

the mean concentrations of detected background 

compounds measured in the three unfortified samples. 

Laboratory reagent spikes and laboratory reagent blanks 

were processed with each set. The alkylated PAH 

homolog groups were not quantitatively evaluated 

because of the lack of available standards. Bias and 

precision data for PAH spike recoveries are listed in table 

16. Background concentrations are listed in table 17.

The recoveries in the sodium sulfate in the 4.8-μg/kg 

spiking level ranged from 12.8 to 83.9 percent and relative 

standard deviations (RSD) from 1.8 to 74.8 percent. 

Compounds with molecular weights of 166 g/mole and 

less had recoveries ranging from 12.8 to 39.0 percent. The 

lighter compounds are more volatile and more inclined to 

loss during the preparatory steps, thus explaining the 

lower recoveries. At the higher spike level of 12.0 μg/kg 

in sodium sulfate, the recoveries ranged from 8.3 to 93.1 

percent with RSDs from 3.8 to 23.7 percent. At the spike 

level of 24.0 μg/kg in sodium sulfate, the recoveries 

ranged from 9.0 to 100.5 percent with RSDs from 6.3 to 

29.5 percent. 

The recoveries in the Evergreen Lake sediment in the 

4.8-μg/kg spiking level ranged from 14.4 to 91.8 percent 

and RSDs from 4.0 to 124.8 percent. The recoveries at the 

12.0-μg/kg spiking level ranged from 16.7 to 87.6 percent 

with RSDs from 12.1 to 115.4 percent. The recoveries for 

the 24.0-μg/kg spiking level ranged from 11.1 to 97.0 

percent with RSDs from 4.7 to 39.2 percent. The RSDs for 

Evergreen Lake sediment were expectedly high for the 

12.0-μg/kg spiking level for phenanthrene, fluoranthene, 

pyrene, benz[a]anthracene, chrysene, 

benzo[b]fluoranthene, benzo[k]fluoranthene, 

benzo[e]pyrene, benzo[a]pyrene, perylene, 

indeno[1,2,3-cd]pyrene, and benzo[g,h,i]perylene. This 

high variability is probably caused by the high 

background concentration in some spike samples. These 

statistics include phenol, p-cresol, and coronene because 

they were included in the analyte list when this was a 

custom method.

The recoveries in the Clear Creek sediment in the 

4.8-μg/kg spiking level ranged from 11.0 to 98.6 percent 

with RSDs from 8.3 to 176.8 percent. The recoveries at 

the 12.0-μg/kg spiking level ranged from 21.8 to 107.4 

percent with RSDs from 5.4 to 164.0 percent. Recoveries 

at the 24.0-μg/kg spiking level ranged from 22.7 to 110.3 

percent with RSDs from 4.5 to 38.0 percent. The RSDs for 

the Clear Creek sediment improved as the concentration 

increased, thus minimizing the effects of background 

concentrations. The highest RSDs are associated with the 

compounds with the highest background concentrations. 

An example is fluoranthene. It has a matrix background 

concentration of 24.0 μg/kg with a relative standard 

deviation of 7.1 percent.

Method Detection Limits 

The NWQL uses the long-term method detection 

level procedure (Childress and others, 1999) to determine 

compound-reporting conventions for water analytical 

methods. Owing to the varied nature of sediment samples, 

the long-term method detection level procedure has not 

been implemented for sediment analyses. 

Method detection limits (MDLs) were established by 

using procedures outlined by the U.S. Environmental 

Protection Agency (1997). For this method, the MDL was 

determined by analyzing a set of seven replicate reagent 

(sodium sulfate) spike samples fortified at 12.0 μg/kg for 

PAHs. For the set of seven samples, the sample standard 

deviation was computed and the MDL calculated from the 

following formula:

MDL = S x t(n–1, 1–α = 0.99) (6)

where

S = standard deviation of replicate analyses, in 

micrograms per kilogram;

t(n–1, 1–α = 0.99) = Student's t-value for the 99-percent

confidence level with n-1 degrees of 

freedom; and

n = number of replicate analyses.
36 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 16. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using selected-ion 

monitoring acquisition with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices. Percent recovery 

corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results (reagent 

spikes).

[μg/kg, micrograms per kilogram; RSD, relative standard deviation; NR, not reported; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment

Clear Creek 

sediment MDL

(μg/kg) Percent 

recovery1 RSD Percent 

recovery1

Percent 

RSD

Percent 

Recovery1

Percent 

RSD

Phenol

p-Cresol

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenapthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

30.4

24.4

36.5

21.7

33.3

32.4

12.8

79.0

73.6

17.9

76.4

72.0

20.0

75.0

70.7

23.3

75.0

71.5

20.0

73.8

68.6

24.8

75.8

72.0

19.9

77.4

72.4

42.3

72.9

69.1

39.0

74.6

69.5

58.0

75.2

70.8

74.8

12.3

16.5

14.7

20.7

29.5

18.7

4.7

6.4

21.5

4.7

6.7

21.8

4.4

7.2

20.4

3.8

7.3

23.2

4.7

6.9

22.4

4.7

6.9

32.0

5.1

6.4

14.4

4.3

7.9

15.0

4.9

7.1

8.1

5.3

7.4

38.9

NR

18.1

61.7

50.6

63.1

45.7

39.7

51.8

60.7

55.6

65.9

64.5

52.4

63.1

65.6

54.9

63.8

69.0

50.7

60.3

65.3

58.9

68.8

63.8

59.4

67.8

75.9

68.8

79.0

72.2

66.0

76.3

76.6

78.8

86.7

8.2

NR

38.6

18.0

24.1

17.4

11.4

22.6

14.8

7.1

17.4

10.9

6.3

21.0

11.5

9.1

15.2

10.6

5.1

14.6

11.5

6.2

14.5

10.2

6.3

13.9

11.6

5.2

14.6

8.0

7.0

14.7

9.8

5.2

12.1

5.8

41.0

20.2

20.9

70.8

61.1

73.0

24.7

40.0

49.0

69.7

68.6

71.4

68.8

63.9

69.5

45.8

64.3

73.0

61.1

60.6

67.7

72.4

67.7

72.7

77.7

61.1

66.9

77.4

78.5

83.1

75.9

67.0

76.1

24.3

86.1

89.0

18.1

85.5

21.8

14.7

19.2

8.4

77.6

31.8

14.3

8.3

10.7

6.4

9.0

11.6

5.2

26.2

10.6

5.4

14.5

17.4

6.4

12.0

7.1

5.1

34.8

9.3

5.7

8.6

7.5

4.5

18.8

7.0

5.1

34.7

5.4

5.2

1.1

2.6

1.4

1.4

1.3

1.1

1.3

1.4

1.5

1.2

1.4

1.5
Attachment 1 37

Table 16. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using selected-ion 

monitoring acquisition with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices. Percent recovery 

corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results (reagent 

spikes).—Continued

[μg/kg, micrograms per kilogram; RSD, relative standard deviation; NR, not reported; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment Clear Creek sediment

MDL

(μg/kg) Percent 

recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

64.3

80.7

76.9

58.9

71.1

69.2

58.3

69.5

67.5

69.9

77.0

75.4

72.3

78.7

77.6

78.6

82.9

83.6

78.6

83.1

82.9

79.5

82.1

81.2

82.1

87.5

87.3

83.9

91.1

91.3

81.3

88.3

88.0

79.8

93.1

93.7

8.7

6.3

6.3

11.3

7.2

6.6

12.4

5.8

7.5

6.2

4.9

6.9

5.9

5.2

7.0

5.7

7.6

6.6

5.7

5.4

6.8

4.1

5.2

7.8

5.0

4.7

7.7

5.9

5.2

6.9

3.3

5.5

9.5

4.5

6.2

6.8

82.8

75.3

90.6

78.6

65.4

76.1

82.0

64.4

73.5

80.3

75.0

84.1

78.4

72.2

82.8

87.5

71.4

94.9

85.7

77.1

97.0

91.8

71.1

85.0

90.1

80.4

91.6

43.7

72.9

88.1

75.4

87.6

96.7

62.6

83.1

90.7

81.3

33.9

30.2

14.4

17.1

10.6

4.6

15.9

6.2

9.9

15.5

6.7

4.0

17.6

5.7

124.8

65.7

31.8

102.2

54.5

27.9

4.5

18.1

5.5

43.7

27.8

13.7

93.4

37.8

13.7

40.1

27.7

12.6

46.4

27.6

13.1

53.8

19.4

55.2

84.4

68.8

78.6

87.8

85.5

89.2

88.9

80.6

84.9

74.7

75.2

84.6

90.3

21.8

58.5

81.9

30.9

62.5

95.5

83.8

92.2

98.6

68.0

83.8

73.6

36.7

63.5

69.0

69.0

80.3

58.1

63.0

76.3

176.8

79.3

27.7

39.5

9.8

7.0

9.2

6.2

4.5

18.4

6.3

5.2

12.9

6.4

4.6

163.4

164.0

38.0

148.7

113.2

31.4

9.6

6.7

4.9

107.4

29.4

13.4

119.1

47.0

20.3

106.5

26.4

14.4

120.1

20.3

16.9

1.9

1.9

1.5

1.4

1.5

2.4

1.7

1.6

1.6

1.8

1.8

2.2
38 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 16. Bias and precision data of polycyclic aromatic hydrocarbon spike recoveries for seven replicates using selected-ion 

monitoring acquisition with compound concentrations of 4.8, 12.0, and 24.0 micrograms per kilogram in three matrices. Percent recovery 

corrected for ambient environmental concentration. Method detection limits calculated using the data for sodium sulfate results

(reagent spikes).—Continued

[μg/kg, micrograms per kilogram; RSD, relative standard deviation; NR, not reported; MDL, method detection limit]

Compound

Amount 

spiked 

(μg/kg)

Sodium sulfate Evergreen Lake 

sediment

Clear Creek 

sediment MDL 

(μg/kg) Percent 

recovery1

Percent 

RSD

Percent 

Recovery1

Percent 

RSD

Percent 

recovery1

Percent 

RSD

Benzo[e]pyrene

Benzo[a]pyrene

Perylene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

Coronene

Method Surrogates 

(Add to all samaples at 20 μg/kg)

Nitrobenzene-d5

2-Fluorobiphenyl

Terphenyl-d14

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

4.8

12.0

24.0

77.2

81.3

80.4

68.8

90.8

100.5

69.5

76.4

75.9

77.1

90.8

89.2

65.5

92.0

92.0

72.6

53.5

54.3

36.8

8.3

9.0

63.9

69.7

73.1

68.6

73.3

68.8

91.1

84.7

83.5

1.8

6.0

7.5

8.2

5.4

7.6

7.7

6.4

8.2

5.8

8.8

7.8

5.5

6.9

7.3

3.9

12.4

18.5

3.9

23.7

20.9

7.3

8.4

8.8

4.6

5.1

6.2

4.3

2.5

6.4

73.8

75.7

83.7

78.9

86.3

91.4

74.1

71.5

88.4

76.8

74.0

78.0

72.6

74.0

78.4

47.9

55.6

55.9

14.4

16.7

11.1

56.6

57.8

61.5

60.6

58.9

58.7

91.7

90.0

92.4

29.4

23.6

9.5

49.0

27.8

14.2

14.3

115.4

39.2

43.1

27.9

10.0

9.6

17.0

4.7

44.4

36.0

12.4

25.2

42.3

13.1

7.2

7.4

21.1

6.4

8.9

13.6

6.4

11.3

9.3

71.5

73.3

69.5

75.5

76.3

84.0

76.4

73.6

76.4

70.5

92.3

105.6

78.8

107.4

110.3

34.1

63.3

63.0

11.0

38.3

22.7

69.2

44.6

47.8

69.6

60.4

64.6

98.8

101.4

106.7

73.0

15.6

12.6

123.5

25.0

16.5

32.3

8.9

8.3

99.6

20.3

13.8

26.1

9.2

4.8

113.2

26.8

23.7

44.5

31.4

20.2

13.2

24.8

20.9

6.6

9.5

14.8

2.9

4.4

7.8

2.4

1.9

1.8

3.0

2.4

2.5

0.7

1

Percent recovery corrected for background.
Attachment 1 39

The MDLs were calculated at the 12.0-μg/kg spiking 

level because of the improved recoveries and greater 

precision than at the 4.8-μg/kg spiking level. The spiking 

concentration at 12.0 μg/kg was two to five times the 

anticipated MDL. The MDLs range from 1.1 μg/kg for 

1,6-dimethylnaphthalene to 3.0 μg/kg for 

indeno[1,2,3-cd]pyrene. The calculated MDL for each 

compound is listed in table 16. 

Minimum reporting levels (MRLs) originally were 

assigned to compounds on the basis of demonstration of 

capability data developed during method validation, 

observed matrix interference, and the effect of the varied 

matrices on instrument performance. Results were not 

censored at the MRL for this method because compounds 

are determined by mass spectrometry; therefore, the 

method is considered to be "information rich" (Childress 

and others, 1999). The MRL for all compounds 

determined by SIM was 5 μg/kg.)

Long-Term Laboratory Reagent Spike Results

This method initially was designed for custom work 

at the National Water Quality Laboratory beginning in 

1996, and method spikes were extracted in reagent 

sodium sulfate and fortified at 24.0 μg/kg. The mean, 

standard deviation, and percent relative standard 

deviation are listed in table 18 for the year 2000. Mean 

recoveries range from 22.18 to 94.86 percent with RSDs 

from 10.80 to 61.31 percent. Excellent performance was 

demonstrated for PAHs with molecular weights between 

Table 17. Polycyclic aromatic hydrocarbon matrix background concentrations in selected-ion monitoring.

[μg/kg, micrograms per kilogram. Concentrations are expressed as an equivalent dry weight of 25 grams; number of analyses=3]

Compound

Mean amount (μg/kg) Standard deviation (μg/kg)

Sodium 

sulfate

Evergreen 

Lake

Clear 

Creek

Sodium 

sulfate

Evergreen 

Lake

Clear 

Creek

Phenol

p-Cresol

Naphthalene 

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene

Benzo[a]pyrene

Perylene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

Coronene

0.8

.3

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2.7

2.2

1.0

.5

.9

.9

1.6

.6

.5

.5

.6

1.6

5.6

2.1

1.3

1.3

2.1

11.7

9.9

1.1

5.6

8.1

5.1

4.2

3.5

6.0

6.9

4.4

4.3

2.7

0.1

3.5

3.4

5.5

.8

1.4

2.8

3.5

.8

.5

1.0

.7

4.3

15.9

3.3

1.7

1.7

2.8

24.0

22.4

2.0

10.4

14.1

11.2

9.7

7.8

12.3

3.2

10.6

1.9

7.0

1.0

0.3

.5

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0.4

.3

.2

0

.1

.2

.1

0

.1

.4

.1

.1

1.8

.2

.1

.3

.2

3.1

2.6

.1

1.0

1.4

1.1

1.0

.8

1.4

.3

1.1

5.9

.8

.1

0.6

.6

3.9

.2

.4

1.0

2.1

.3

.1

.2

.1

5.3

11.0

.4

.2

.3

.8

7.1

6.4

.3

2.9

2.8

2.0

1.9

1.2

2.3

.7

1.6

.3

.9

.1
40 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

178 and 252 g/mole. Recoveries were greater than 70 

percent with RSDs less than 20 percent. 

 The spike recoveries in the sodium-sulfate matrix 

fortified at 24 μg/kg completed in 2002 (see table 16) and 

the spike recoveries in 2000 listed in table 18 are 

comparable and indicate that the method's performance is 

consistent over time. The differences are seen in the 

RSDs. The RSDs are two to three times lower in 2002, 

thereby suggesting improved method precision. This 

could be accounted for by greater efficiency in sample 

preparation and analysis along with improved 

instrumentation.

 The exceptions are phenol, benzo[g,h,i]perylene, and 

coronene. They had higher recoveries in the year 2000. 

These compounds are problematic, often displaying 

erratic performance at the GPC step during the sample 

preparation (section 7.5). The data in table 18 were 

compiled throughout 2000, thus minimizing variation 

over time, whereas the 24-μg/kg spike data in 2002 were 

compiled from a single GPC sequence.

Quality-Control Reference Material Data

Performance data are included for three 

quality-control reference material samples: SRM 1941b, 

SRM 1944, and CRM 354. The SRMs are produced by the 

National Institute of Standards and Technology (NIST) 

and are used to evaluate analytical methods. They consist 

of natural sediment and have been certified for specific 

PAHs as well as other contaminates. Many alkylated PAH 

homolog groups are present in the samples but are not 

certified. The certified PAHs and uncertified alkylated 

PAH homolog groups present and their concentrations are 

appropriate for this method. CRM 354 is a reference 

material certified through Environmental Resources 

Associates in Denver, Colorado. It has been certified for 

specific PAHs. No alkylated PAH homolog group data are 

included. 

The NIST SRM 1941b is a marine sediment. Seven 

samples were prepared and analyzed using SIM. Table 19 

lists the performance data for the PAHs certified through 

NIST. These recoveries ranged from 53.8 to 246 percent 

with RSDs from 0.92 to 5.76 percent. The high recoveries 

and the low RSDs suggest the method is performing well. 

No method performance acceptance criteria were 

provided in the SRM certification documents supplied 

with SRM 1941b. 

Table 20 lists mean concentrations, standard 

deviations, and relative standard deviations for the 

alkylated PAH homolog groups present, but which are not 

reported in the SRM certification documents. Many of 

the groups were not present, which is often the case for 

environmental samples. The RSDs are all less than 16 

percent thus showing good agreement between 

measurements except for C4-alkylated napthalene with a 

RSD of 48.0 percent. 

SRM 1944—The NIST SRM 1944 is a mixture 

marine sediment. Seven samples were prepared and 

analyzed using SIM. Table 21 lists performance data for 

the PAHs certified through NIST. These recoveries 

ranged from 47.2 to 145 percent with RSDs from 5.79 to 

26.2 percent. The high recoveries and the low RSDs 

suggest the method is performing well. 

Table 18. Polycyclic aromatic hydrocarbon method spike 

recoveries using selected-ion monitoring at a concentration 

of 24 micrograms per kilogram for the year 2000.

[μg/kg, micrograms per kilogram; n, number; percent relative standard 

deviation (mean/standard deviation) x 100]

Compound

Method spike recoveries (n=18)

Mean 

percent 

recovery

Standard 

deviation

Percent 

relative 

standard 

deviation

Phenol

p-Cresol

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthene

1,2-Dimethylnaphthalene

Acenaphthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene

Benzo[a]pyrene

Perylene

Indeno[1,2,3-cd]Pyrene

Dibenz[a,h]Anthracene

Benzo[g,h,i]Perylene

Coronene

49.33

34.68

73.79

71.98

70.84

71.46

67.15

71.55

72.42

72.28

73.37

76.08

78.34

71.62

71.60

81.20

81.41

89.47

89.15

90.00

88.71

89.23

94.56

94.86

87.35

79.42

71.60

89.36

93.66

67.48

22.18

17.11

21.26

14.18

13.72

14.54

14.62

12.67

14.16

13.65

15.44

13.82

13.63

13.15

12.25

12.76

11.43

12.23

11.13

11.32

9.72

12.21

13.79

14.88

18.11

14.73

13.87

12.08

14.96

16.46

11.24

7.59

34.69

61.31

19.22

19.07

20.53

20.45

18.87

19.80

18.85

21.36

18.83

17.91

16.78

17.10

17.82

14.08

15.03

12.44

12.70

10.80

13.77

15.45

15.73

19.09

16.87

17.46

16.87

16.74

17.58

16.66

34.23
Attachment 1 41

Table 19. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute of Standards and Technology for Standard 

Reference Material 1941b and determined using selected-ion monitoring.

[μg/kg, micrograms per kilogram; number of analyses=7]

Compound Expected concentration 

(μg/kg)

Measured mean 

concentration (μg/kg)

Recovery 

(percent)

Relative standard 

deviation (percent)

Anthracene

Benz[a]anthracene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[g,h,i]perylene

Benzo[a]pyrene

Benzo[e]pyrene

Chrysene

Dibenz[a,h]anthracene

Fluoranthene

9H-Fluorene

Indeno[1,2,3-cd]pyrene

1-Methylphenanthrene

Naphthalene

Perylene

Phenanthrene

Pyrene

184

335

453

225

307

358

325

291

53.0

651

85.0

341

73.2

848

397

406

581

241

371

459

411

165

398

268

351

131

658

105

349

125

622

354

359

545

131

111

101

183

53.8

78.5

82.6

120

246

101

124

102

171

73.9

89.2

88.5

93.8

2.05

2.79

4.50

5.76

3.10

4.67

2.84

2.34

4.51

1.77

2.96

4.14

2.29

3.17

3.27

.92

1.91

Table 20. Alkylated polycyclic aromatic hydrocarbon homolog groups detected in Standard Reference Material 1941b 

not reported by the National Institute of Standards and Technology and determined using selective-ion monitoring.

[μg/kg, micrograms per kilogram; NR, not reported; –, no data; number of analyses=7]

Compound Measured mean 

concentration (μg/kg)

Standard deviation 

(μg/kg)

Relative standard 

deviation (percent)

C1-alkylated naphthalene

C2-alkylated naphthalene

C3-alkylated naphthalene

C4-alkylated naphthalene

C5-alkylated naphthalene

C1-alkylated phenanthrene/anthracene

C2-alkylated phenanthrene/anthracene

C3-alkylated phenanthrene/anthracene

C4-alkylated phenanthrene/anthracene

C5-alkylated phenanthrene/anthracene

C1-alkylated fluoranthene/pyrene

C2-alkylated fluoranthene/pyrene

C3-alkylated fluoranthene/pyrene

C4-alkylated fluoranthene/pyrene

C5-alkylated fluoranthene/pyrene

C1-alkylated benzo[a]anthracene/chrysene

C2-alkylated benzo[a]anthracene/chrysene

C3-alkylated benzo[a]anthracene/chrysene

C4-alkylated benzo[a]anthracene/chrysene

C5-alkylated benzo[a]anthracene/chrysene

C1-alkylated benzopyrene/perylene

C2-alkylated benzopyrene/perylene

C3-alkylated benzopyrene/perylene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

464

450

750

197

NR

540

429

3.5

128

NR

622

123

NR

NR

NR

307

185

NR

NR

NR

386

NR

NR

NR

NR

13.8

44.1

52.8

94.0

–

6.8

16.2

16.2

20.0

–

27.8

19.6

–

–

–

13.6

19.6

–

–

–

27.0

–

–

–

–

2.97

9.80

7.04

48.0

–

1.25

3.78

5.29

16.0

–

4.47

16.0

–

–

–

4.41

16.0

–

–

–

7.00

–

–

–

–
42 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

Table 22 lists mean concentrations of alkylated PAH 

homolog groups present, but which are not reported in the 

SRM certification documents supplied with SRM 1944. 

The RSDs are all less than 17.7 percent, thereby showing 

good agreement between measurements. Many of the 

alkylated PAH homolog groups were not present. 

CRM 354—CRM 354 is a reference material certified 

through Environmental Resources Associates in Denver, 

Colorado. Its soil characterization contained about 91.4 

percent sand, 4.4 percent silt, and 4.3 percent clay. 

A certified SRM/CRM sample was prepared and 

analyzed with each set of environmental samples. Results 

for Certified Reference Material (CRM) 354 analyzed are 

listed in table 23 for 2001. It can be seen that, with the 

exception of anthracene, all results fell within the acceptance limits of the CRM. Mean recovered anthracene concentrations were slightly higher than the range of 

acceptance limits, which are statistically derived. Given 

that the spiked concentration of anthracene is more than 

three times the high limit of acceptance, this result suggests that for anthracene, this method performs better than 

the method or methods used to determine acceptance 

limits for the CRM. The mean PAH concentrations measured in the CRM by this method were greater than the 

midpoint of the acceptance limits. 

Comparing selected-ion monitoring (SIM) and 

full-scan ion monitoring (FS) acquisition using the 

F-test—Until recently (2002), achieving a 5-μg/kg 

laboratory reporting level was possible only under SIM 

conditions. Improvements in GC/MS instrumentation, 

such as the Agilent Technologies 5973 MSD, can provide 

comparable reporting levels between SIM and FS.

 Lower method detection levels by about a factor of 

two can be achieved using SIM analysis (table 16) as 

opposed to full-scan monitoring (table 7). SIM scans on 

average only 20 to 30 ions during a specified time 

interval. It can eliminate or reduce many background 

interferences because many interfering ions are not 

monitored. Conversely, potential interferences might be 

missed that contribute to false positive identification. 

There are benefits when using full-scan data 

acquisition. First, there is greater confidence in the 

qualitative identification of compounds because the mass 

spectrometer scans across the range of 45 to 450 atomic 

mass units (amu), which results in more spectral 

information than the few ions monitored under SIM 

conditions. Because of the greater number of ions 

monitored for each compound, there is greater confidence 

in compound identification. In this method with the lack 

of standard material for many of the isomers in the 

alkylated PAH homolog groups, the additional detection 

of fragment ions results in greater confidence in their 

detection. Secondly, FS data allow for investigation

Table 21. Polycyclic aromatic hydrocarbon concentrations certified by the National Institute of Standards and Technology for Standard

Reference Material 1944 and determined using selective-ion monitoring.

[μg/kg, micrograms per kilogram; number of analyses=7]

Compound

Expected 

concentration

 (μg/kg)

Measured 

mean concentration 

(μg/kg)

Recovery 

(percent)

Relative standard 

deviation 

(percent)

Anthracene

Benz[a]anthracene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[g,h,i]perylene

Benzo[a]pyrene

Benzo[e]pyrene

Chrysene

Dibenz[a,h]anthracene

Fluoranthene

Indeno[1,2,3-cd]pyrene

Naphthalene

Perylene

Phenanthrene

Pyrene

1,770

4,720

3,870

2,300

2,840

4,300

3,280

4,860

424

8,920

2,780

1,650

1,170

5,270

9,700

1,890

4,180

2,900

2,810

1,340

3,210

1,940

3,980

614

7,290

2,440

830

697

4,160

7,070

107

88.6

74.9

122

47.2

74.8

59.2

81.9

145

81.7

87.9

49.8

59.6

78.9

72.9

7.60

6.01

9.27

5.79

6.08

7.31

6.14

6.75

 26.2

6.30

6.48

 10.3

6.64

6.00

6.29
Attachment 1 43

Table 22. Alkylated polycyclic aromatic hydrocarbon homolog groups detected in Standard Reference Material 1944 not reported by

the National Institute of Standards and Technology and determined using selective-ion monitoring.

[μg/kg, micrograms per kilogram; NR, not reported; –, no data; number of analyses=7]

Compound

Measured 

mean concentration 

(μg/kg)

Standard deviation 

(μg/kg)

Relative standard 

deviation (percent)

C1-alkylated naphthalene

C2-alkylated naphthalene

C3-alkylated naphthalene

C4-alkylated naphthalene

C5-alkylated naphthalene

C1-alkylated phenanthrene/anthracene

C2-alkylated phenanthrene/anthracene

C3-alkylated phenanthrene/anthracene

C4-alkylated phenanthrene/anthracene

C5-alkylated phenanthrene/anthracene

C1-alkylated fluoranthene/pyrene

C2-alkylated fluoranthene/pyrene

C3-alkylated fluoranthene/pyrene

C4-alkylated fluoranthene/pyrene

C5-alkylated fluoranthene/pyrene

C1-alkylated benz[a]anthracene/chrysene

C2-alkylated benz[a]anthracene/chrysene

C3-alkylated benz[a]anthracene/chrysene

C4-alkylated benz[a]anthracene/chrysene

C5-alkylated benz[a]anthracene/chrysene

C1-alkylated benzopyrene/perylene

C2-alkylated benzopyrene/perylene

C3-alkylated benzopyrene/perylene

C4-alkylated benzopyrene/perylene

C5-alkylated benzopyrene/perylene

1,300

2,780

7,111

4,790

NR

8,220

7,260

5,104

1,100

NR

9,350

3,400

NR

NR

NR

4,110

2,150

NR

NR

NR

4,400

NR

NR

NR

NR

130

299

754

670

–

506

595

423

194

–

766

369

–

–

–

324

183

–

–

–

282

–

–

–

–

10.0

10.7

10.6

14.0

–

6.15

8.19

8.29

 17.7

–

8.20

 10.9

–

–

–

7.90

8.50

–

–

–

6.40

–

–

–

–

Table 23. Polycyclic aromatic hydrocarbon concentrations detected in Certified Reference Material 354 using selected-ion 

monitoring for year 2001.

[μg/kg, micrograms per kilogram; number of analyses=8]

Spike compound

Concentration 

spiked 

(μg/kg)

Mean 

concentration 

recovered (μg/kg)

Performance 

acceptance limits 

(μg/kg)

Standard 

deviation 

(μg/kg)

Relative standard 

deviation 

(percent)

Anthracene

Benzo[k]fluoranthene

Chrysene

Fluoranthene

Naphthalene

Phenanthrene

Pyrene

4,440

5,170

1,660

11,500

9,770

6,150

6,580

1,525

3,690

1,284

8,061

4,054

4,112

4,321

799–1,368

2,171–4,601

681–1,494

3,795–10,350

1,466–9,282

2,398–5,781

2,106–5,922

156

359

116

922

816

493

375

10.20

9.73

9.05

11.40

20.10

12.00

8.68
44 Determination of Polycyclic Aromatic Hydrocarbon Compounds in Sediment

of compounds not specifically determined by the method 

(nonselected compounds). Nonselected compounds can 

be identified tentatively using computerized comparison 

of mass spectra with large reference mass-spectral 

libraries publicly available from USEPA or NIST. Such 

computerized nonselected searches can be a valuable tool 

in the search for potential emerging contaminants, a 

capability not possible with SIM data. 

In general, SIM analysis relative to FS analysis 

provides lower (about 2 times) detection capability and 

improved quantitation at low concentrations. Because the 

calculation of the MDL is based on the method variability, 

the F-test was applied to determine whether there were 

statistically significant differences in the precision 

between SIM and FS acquisition (table 24). The data of 

sodium sulfate matrix spikes fortified at 12.0 μg/kg were 

used in a two-tailed F-test. The critical value of F, based 

on 6 degrees of freedom, is 5.820 at the 5-percent 

probability level (Miller and Miller, 1993). 

At a 95-percent confidence level, the variances differ 

significantly for naphthalene, 2,6-dimethylnaphthalene, 

and 9H-fluorene. In these three cases, the FS variance is 

larger than its SIM counterpart, demonstrating higher 

variability in FS acquisition. The variability is greater in 

full-scan acquisition because of the greater background 

signal, lowering the signal-to-noise ratio and making data 

integration more difficult. 

In FS and SIM, as the spike level increases (24 μg/kg) 

the response increases, thus resulting in a larger 

signal-to-noise ratio. Appropriate peak integration 

becomes more obvious and variations in peak integration 

are smaller, which improves precision. At higher spike 

levels, the integration of the peak has greater uniformity 

between SIM and FS. This results in generally lower 

percent relative standard deviations than at lower spike 

concentrations and greater variability.

Table 24. Statistics for selected-ion monitoring and full-scan acquisition data fortified at 12.0 micrograms per kilogram. 

Confidence interval (P=0.05); F-test: 2-tailed, critical value=5.820

[Compounds designated with an (*) differ significantly between the two methods; SIM, selected-ion monitoring; number of analyses=7]

Compound Variance SIM Variance full scan F-test

Naphthalene

2-Ethylnaphthalene

2,6-Dimethylnaphthalene

1,6-Dimethylnaphthalene

Acenaphthylene

1,2-Dimethylnaphthalene

Acenapthene

2,3,6-Trimethylnaphthalene

9H-Fluorene

1-Methyl-9H-fluorene

Phenanthrene

Anthracene

2-Methylanthracene

4,5-Methylenephenanthrene

1-Methylphenanthrene

Fluoranthene

Pyrene

1-Methylpyrene

Benz[a]anthracene

Chrysene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[e]pyrene

Benzo[a]pyrene

Perylene

Indeno[1,2,3-cd]pyrene

Dibenz[a,h]anthracene

Benzo[g,h,i]perylene

0.198

.186

.160

.117

.173

.187

.228

.143

.193

.232

.368

.376

.236

.203

.240

.573

.289

.266

.247

.329

.337

.476

.606

.347

.318

.917

.576

.631

1.610

.746

.956

.236

.757

.672

.579

.110

1.146

.409

.886

.807

.282

.739

.426

.176

.767

1.383

.478

.288

.263

1.036

.585

.343

.987

1.473

.645

1.100

*8.125

4.018

*5.973

2.024

4.377

3.602

2.539

1.299

*5.941

1.760

2.408

2.147

1.196

3.643

1.779

3.260

2.652

5.195

1.938

1.142

1.281

2.178

1.036

1.011

3.102

1.607

1.119

1.742
Attachment 1 45

Conclusions

The custom method described in this attachment was 

originally implemented in 1996. It used the same 

methodology as the method in the body of this report 

except for two differences. The custom method used SIM 

data acquistion and included phenol, p-cresol, and 

coronene in its analyte list. Selected-ion monitoring 

originally was used to reach a 5-μg/kg reporting level. 

Full scan can now report at 10 μg/kg with the added 

benefits of greater confidence in detection of compounds 

and future analysis. 

Performance data were presented for three spike 

levels in three different matrices. MDLs were calculated. 

Standard reference material and certified reference 

material data provided additional performance data for the 

polycyclic aromatic hydrocarbons and precision data for 

the alkylated PAH homolog groups. A statistical F-test 

was used to compare the precision between full-scan data 

acquisition and selected-ion monitoring data acquisition. 

Variation between the two types of analysis was not 

significantly different except for three compounds: 

naphthalene, 2,6-dimethylnaphthalene, and 9H-fluorene. 
Olson and others—DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN SEDIMENT BY GC/MS—USGS WRIR 03-4318

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