United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 93478
Las Vegas NV 89193-3478
EPA 600/R-94/031
March 1994
Research and Development
EPA
Application of Microwave
Energy to the Extraction
of Organic Compounds
from Solid Samples
0174qad94.cov
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APPLICATION OF MICROWAVE ENERGY
TO THE EXTRACTION OF ORGANIC
COMPOUNDS FROM SOLID SAMPLES
By
Viorica Lopez-Avila* and Richard Young
Midwest Research Institute
California Operations
625-B Clyde Avenue
Mountain View, California 94043
USA
Contract Number 68-C1-0029
Project Officer: Werner F. Beckert
Quality Assurance and Methods Development Division
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89119
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89119
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NOTICE
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development (ORD), partially funded and managed the extramural research described here. It has
been peer reviewed by the Agency and approved as an EPA publication.
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PREFACE
This is the final report for research performed under Work Assignment 3-18, EPA Contract
68-C1-0029, conducted by the Midwest Research Institute, California Operations (MRI-CO). The
MRI-CO project was directed by Dr. Viorica Lopez-Avila.
This report was written by Dr. Lopez-Avila. Technical support for the project was provided
by Richard Young. Nikhil Shah and Robert Kim were involved with some early experiments under
this work assignment.
The authors would like to thank the CEM Corporation (Matthews, NC) for the loan of the
microwave unit used in this study and Bob Revesz from CEM Corporation for helpful technical
discussions. The authors also acknowledge Steven Hawthorne of the Energy & Mineral Research
Center of the University of North Dakota (Grand Forks, ND) for reviewing this report and for
providing helpful comments.
111
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ABSTRACT
As part of an ongoing evaluation of novel sample-preparation techniques by the U.S.
Environmental Protection Agency (EPA), especially techniques that minimize generation of waste solvents,
we evaluated microwave-assisted extraction (MAE) of organic compounds from solid materials (or
"matrices"). Six certified reference materials containing polynuclear aromatic hydrocarbons (PAHs) and
some base/neutral/acidic compounds, all of which are pollutants of interest to the EPA, were subjected to
MAE in a closed-vessel microwave system with hexane-acetone (1:1) at different temperatures (80°C,
115°C, or 145°C) and for different periods of time (5, 10, or 20 min). For comparison, the same samples
were subjected to room-temperature extraction by allowing the same solvent mixture to stay in contact with
the solid matrix the same amount of time as the microwave-extracted sample (including any cooling time).
Two matrices were also heated in a convection oven at 115°C, for different periods of time, with the same
solvent and in the same vessel as the microwave-extracted samples. Whereas the average recovery at room
temperature was about 54 percent, the MAE recoveries for 17 PAHs (three of which were deuterated
PAHs that were spiked into the matrices) from the six matrices were 72 percent at 80°C, 78 percent at
115CC, and 77 percent at 145'C. The recoveries for the oven-heated samples were similar to those
obtained by MAE. MAE was, however, exclusively used in this study because of its easy controllability
and convenience. Although the average recoveries by MAE increased slightly with extraction time, the
increase was not statistically significant. The performance of the MAE technique varied with the matrix
and the analytes. Eleven PAHs had average recoveries in the 65- to 111-percent range, and three
compounds [benzo(a)pyrene, benzo(ghi)perylene, and fluorene] had recoveries of 51 percent, 64 percent,
and 62 percent, respectively. The spiked-compound recoveries by MAE were 77 percent for anthracene-
d,0, 104 percent for benzo(a)anthracene-d,2, and 84 percent for fluoranthene-d,0. Additional experiments
with 14 phenols and 20 organochlorine pesticides indicated that MAE is a viable alternative to the
conventional Soxhlet/Soxtec and sonication extraction techniques. MAE requires smaller amounts of
organic solvents, and sample throughput is increased by shorter extraction times (10 min) and because
simultaneous extraction of up to 12 samples is possible.
IV
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CONTENTS
Notice ii
Preface iii
Abstract iv
Tables vi
Figures viii
1. Introduction 1
2. Conclusions 2
3. Recommendations 3
4. Experimental 4
5. Results and Discussion 16
References 43
Appendices
A. Percent-recovery results of the GC/MS analyses for the six certified reference
materials 44
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TABLES
Number Page
1 Compounds investigated in this study 5
2 Certified values and concentrations measured in this study by sonication-
GC/MS and Soxtec-GC/MS for compounds known to be present in the HS-3,
HS-4, and HS-5 marine sediments 7
3 Certified values and concentrations measured in this study by sonication-
GC/MS for compounds known to be present in the SRM1941 marine sediment . . 8
4 Certified values and concentrations measured in this study by Soxtec-
GC/MS for compounds known to be present in the SRS 103-100 soil 9
5 Time required to reach the maximum temperature under various extraction
conditions 17
6 Recoveries of pesticides from freshly spiked sand using MAE and room-
temperature extraction with hexane-acetone (1:1) 18
7 Average recoveries and percent RSDs for dry and wet SRS 103-100 soil 26
8 Percent recoveries of "native" and spiked compounds from ERA soil
Lot No. 321 with hexane-acetone (1:1) using room-temperature extraction
and MAE at different temperatures and pressures 30
9 Average recoveries and percent RSDs for dry and wet ERA soil Lot
No. 323 32
10 Average recoveries and percent RSDs for phenols after microwave heating - solvent
versus solvent/soil suspension 33
11 Average recoveries and percent RSDs for organochlorine pesticides after microwave
heating - solvent versus solvent/soil suspension ' 34
12 Average recoveries and percent RSDs for PAHs and selected base/neutral
compounds after microwave heating - solvent versus solvent/soil suspension ... 35
13 Comparison of analyte concentrations in extracts generated by sonication, Soxtec,
and MAE with the certified values for the HS-3 marine sediment 37
vi
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TABLES (concluded)
Number Page
14 Comparison of analyte concentrations in extracts generated by sonication, Soxtec,
and MAE with the certified values for the HS-4 marine sediment 38
IS Comparison of analyte concentrations in extracts generated by sonication and MAE
with the certified values for the HS-5 marine sediment 39
16 Comparison of analyte concentrations in extracts generated by sonication and MAE
with the certified values for the SRM1941 marine sediment 40
17 Comparison of analyte concentrations in extracts generated by Soxtec and MAE with
the certified values for the SRS103-100 soil 41
18 Correlation of the data obtained from MAE extracts for different matrices with the
certified values and the values obtained from sonication or Soxtec extracts 42
VII
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FIGURES
Number Page
1 Schematic diagram of the temperature/pressure control system for the MDS-2000
microwave system 11
2 View of the 12 lined digestion vessels, containment vessel, and temperature and
pressure probes 12
3 (a) Lined digestion vessel with the temperature and pressure control; (b) lined
digestion vessel without the temperature and pressure control 13
4 Percent recovery as a function of temperature for the 17 PAH compounds 20
5 Percent recovery as a function of time for the 17 PAH compounds 21
6 Percent recovery as a function of matrix for the 17 PAH compounds 22
7 Spiked versus native compound percent recoveries 23
8 Percent recovery as a function of compound for the 17 PAH compounds 25
9a GC/MS chromatogram of the extract obtained by MAE of the HS-3 marine sediment
with hexane-acetone (1:1) 27
9b GC/MS chromatogram of the extract from a second extraction performed on the
HS-3 marine sediment using microwave energy and fresh solvent 28
9c GC/MS chromatogram of the sonication extract from the HS-3 marine sediment that
was first extracted using microwave energy before extraction with fresh solvent
using a sonic probe 29
vui
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SECTION 1
INTRODUCTION
Use of microwave energy to enhance extraction of organic compounds from solid matrices such as
soil, seeds, foods, and feeds was reported by Ganzler and coworkers in two publications in 1986 and 1987
(1,2). These researchers used a conventional, household microwave oven to irradiate solvent/sample
suspensions for 30 sec up to seven times each. They reported that the microwave extraction method was more
efficient than Soxhlet extraction for polar compounds (1). Recently, Onuska and Terry (3) used microwave
energy to extract organochlorine pesticides in open vessels from spiked sediment samples; they reported
quantitative recoveries and no compound breakdown due to exposure to microwaves. Extraction of essential
oils and other oils from biological materials such as plant and fish tissue by exposure to microwave energy
was recently described in a patent application (4). In a U.S. patent (5), use of microwave energy for the
extraction of natural products from mint, sea parsley, cedar foliage, and garlic with hexane, methylene
chloride, or ethanol in open vessels in two or more stages is described. Other researchers have reported use
of microwave energy to extract stabilizers from polyolefins (6).
As part of an ongoing U.S. Environmental Protection Agency (EPA) program addressing sample
preparation techniques that prevent or minimize pollution and generation of waste solvents in analytical
laboratories, this study, which was started in mid-1992 by the Environmental Monitoring Systems Laboratory,
Las Vegas (EMSL-LV), addresses the extraction of organic compounds using a closed-vessel microwave-
assisted extraction (MAE) technique. Six standard reference soils and sediments containing polynuclear
aromatic hydrocarbons (PAHs) and some other base/neutral/acidic compounds of interest to the EPA were
subjected to MAE in hexanc-acctone (1:1) at various temperatures and for different periods of time to
establish whether this technology has merit as a method to extract such pollutants from solid samples. For
comparison, extractions were performed using conventional techniques (e.g., Soxhlet/Soxtec and sonication
extraction), room-temperature extraction (as defined later), and simple heating with solvent in a closed
container using a convection oven. The results indicated that MAE could be a viable alternative to the
conventional Soxhlet and sonication methods. This technique uses smaller amounts of organic solvents, and
sample throughput is increased because shorter extraction times (10 min) are required, and simultaneous
extraction of up to 12 samples is possible (in this study, up to six samples were extracted simultaneously).
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SECTION 2
CONCLUSIONS
A MAE technique for extracting organic compounds from soils and sediments was developed
and evaluated with representative matrices and compounds of environmental significance (PAHs,
selected base/neutral compounds, phenols, and organochlorine pesticides). All extractions were
performed with hexane-acetone (1:1) in a closed-vessel microwave system that is commercially
available. Our results indicated that recoveries of 17 PAHs (three of which were deuterated spikes)
from six matrices averaged 72 percent at 80°C, 78 percent at 115°C, and 77 percent at 145°C. The
average recoveries increased slightly with extraction time, and a 10-min extraction at 115°C is
recommended for these types of compounds and matrices when hexane-acetone (1:1) is used as the
extraction solvent.
Other solvent mixtures that appeared to work well include methylene chloride-acetone (1:1)
and toluene-methanol (1:10). Methylene chloride alone and toluene-methanol (10:1) take 10 to 14 min
for 30 mL solvent to heat to maximum temperature in the microwave system.
A 5- to 10-g soil or sediment sample and 30 mL solvent seem to work well when a 110-mL
closed extraction vessel is used since the mixture reaches the maximum operating temperature of 151°
to 157°C (at 100 percent power) in about 2 min, regardless of matrix.
From all compounds investigated in this study (17 PAHs, 13 base/neutral compounds, 14
phenols, and 20 organochlorine pesticides), only two compounds (2,4-dinitrophenol and 2-methyl-4,6-
dinitrophenol) exhibited low recoveries when soil/solvent suspensions were heated for 10 min at 115°C.
We concluded that catalytic reactions in the presence of soil or strong adsorption of the compounds
on soil may have been the cause of low recoveries. Since the temperatures used during MAE are
typically close to and above 100°C, very temperature-sensitive compounds may partially decompose.
Stability of the target analytes under MAE conditions must therefore be demonstrated.
MAE of organic compounds from soil and sediment samples seems to be a viable alternative
to the conventional Soxhlet and sonication extraction techniques since MAE recoveries are in general
equal to or better than those achieved with conventional extraction techniques. The main advantages
of MAE over the conventional Soxhlet and sonication methods or the simple heating of sample/solvent
suspensions in a closed container are the ease with which uniform conditions can be maintained in the
microwave system (temperature and pressure are being continously monitored), the reduced extraction
time (typical sample preparation time for this technique is 10 min for extraction and 40 min for extract
cooling, centrifugation, and extract concentration), and reduced solvent use (30 mL in the MAE versus
300 mL in the Soxhlet extraction). Up to 12 samples can be extracted simultaneously in a few
minutes, resulting in increased sample throughput compared to Soxhlet and sonication extraction.
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SECTION 3
RECOMMENDATIONS
The data presented in this report were obtained in a single-laboratory study and \vith a few relevant
solid materials. MAE should now be evaluated with additional matrices and target analytes and then subjected
to an intcrlaboratory performance study.
MAE of other classes of compounds, including organophosphorus pesticides, chlorophenoxy acid
herbicides, and carbamate pesticides, should be investigated. It may be possible to extract the compounds
with a buffer solution (e.g., 0.2 M KC1/0.2 M KOH buffer at pH 12 for the chlorophenoxy acid herbicides)
thus eliminating or further minimizing the use of organic solvents in the extraction process.
Future studies should also address the effect of moisture upon compound recovery.
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SECTION 4
EXPERIMENTAL
Standards
Analytical reference standards of 14 non-labeled PAHs (concentration: 2 mg/mL per
compound; solvent: methylene chloride-benzene, 50:50), 14 phenols (concentration: 1 mg/mL per
compound; solvent: acetonitrile), and 20 organochlorine pesticides (concentration: 2 mg/mL per
compound; solvent: toluene-hexane, 50:50) (Table 1) were purchased as composite solutions from
Supelco, Inc. (Bellefonte, PA). The three deuterated PAHs were purchased as neat materials from
Cambridge Isotope Laboratory (Woburn, MA). The base/neutral compounds in Table I (except
dibenzofuran, which was bought from Supelco as neat material) were purchased as individual stock
solutions from ChemService (West Chester, PA) and Supelco, Inc., and were combined with the PAH
stock solution to make the working calibration standards for the GC/MS analysis. Dibenzofuran was
dissolved separately in methanol at 5 mg/mL and was combined with the PAH stock solution to make
the working calibration standards. The purities of all compounds were stated to be greater than
96 percent. The spiking solution and the working calibration standards were prepared by serial
dilution of the composite stock solution containing either the phenols, organochlorine pesticides,
PAHs, or base/neutral compounds; for the analysis of the ERA soil samples (defined below), the
calibration standards contained the PAHs, the base/neutral compounds, and selected phenols.
Standard Reference Materials
Six standard reference marine sediments and soils were used in this study. The HS-3, HS-4,
and HS-5 marine sediments, collected from three harbors in Nova Scotia, were purchased from the
National Research Council of Canada, Atlantic Research Laboratory (Halifax, Nova Scotia).
According to the certificate of analysis, these materials had been freeze-dried, sieved to pass a 125-/*m
sieve, homogenized in a cement mixer, and then subsampled into 200-g portions. The certified values
for the 16 compounds found in these samples are shown in Table 2, together with the values we
obtained in our study after extracting 10-g portions of these materials with hexane-acetone (1:1) in a
Soxtec extractor or 5-g portions with methylene chloride-acetone (9:1) using a sonic probe. The
SRS1941 marine sediment, purchased from NIST (Gaithersburg, MD), is a sediment collected from
the Chesapeake Bay at the mouth of the Baltimore Harbor. According to NIST, this sediment was
air-dried, pulverized, sieved (<150/*m), homogenized, and subsampled into 70-g portions. The
bottled samples were sterilized by ^Co radiation. Table 3 identifies the compounds certified by NIST
in this sample and the values that we obtained by extracting a 5-g portion of this material with
methylene chloride-acetone (9:1) using a sonic probe. Additional information about this sediment is
reported on the NIST Certificate of Analysis. The SRS103-100 standard reference material is a soil
contaminated with PAHs (natural material) and was purchased from Fisher Scientific (Fair Lawn, NJ);
the material was prepared by RT Corporation in Laramie, WY. The certified values and the values
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TABLE 1. COMPOUNDS INVESTIGATED IN THIS STUDY
Compound
no.
PAHs
Compound name
1 Acenaphthene
2 Acenaphthylene
3 Anthracene
4 Anthracene-d,0
5 Benzo(a)anthracene
6 Benzo(a)anthracene-d12
7 Benzo(a)pyrene
8 Benzo(b+k)fluoranthene
9 Benzo(ghi)perylene
10 Chrysene
11 Fluoranthene-d10
12 Fluorene
13 Fluoranthene
14 Indeno(l,2,3-cd)pyrene
15 Naphthalene
16 Phenanthrene
17 Pyrene
Base/Neutral Compounds
18 Dibenzofuran
19 1,2-Dichlorobenzene
20 1,3-Dichlorobenzene
21 N-Nitroso-di-n-propylamine
22 Nitrobenzene
23 1,2,4-TrichIorobenzene
24 2,4-Dinitrotoluene
25 9H-Carbazole
26 Di-n-butylphthalate
27 Bis(2-ethylhexyl)phthalate
28 Isophorone
29 4-Chlorophenyl phenyl ether
30 Butyl benzyl phthalate
(continued)
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TABLE 1 (Concluded)
Compound Compound name
no.
Phenols
31 Phenol
32 2-Chlorophenol
33 2-Methylphenol
34 3-Methylphenol
35 2-Nitrophenol
36 2,4-Dimethylphenol
37 2,4-Dichlorophenol
38 4-Chloro-3-methylphenol
39 2,4,6-Trichlorophenol
40 2,4-Dinitrophenol
41 4-Nitrophenol
42 2,3,4,5-Tetrachlorophenol
43 2-Methyl-4,6-dinitrophenol
44 Pentachlorophenol
Organochlorine pesticides
45 alpha-BHC
46 beta-BHC
47 gamma-BHC
48 delta-BHC
49 Heptachlor
50 Aldrin
51 Heptachlor epoxide
52 gamma-Chlordane
53 Endosulfan-I
54 aJpha-Chlordane
55 Dieldrin
56 4,4'-DDE
57 Endrin
58 Endosulfan-II
59 4,4'-DDD
60 Endrin aldehyde
61 Endosulfan sulfate
62 4,4'-DDT
63 Endrin ketone
64 Methoxychlor
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TABLE 2. CERTIFIED VALUES AND CONCENTRATIONS MEASURED IN THIS STUDY BY SONICAT1ON-GC/MS
AND SOXTEC-GC/MS FOR COMPOUNDS KNOWN TO BE PRESENT IN THE HS-3, HS-4, AND HS-5
MARINE SEDIMENTS
Compound name
Certified
value
(rag/kg)'
HS-3
Concentration
measured by
sonication
extraction and
GC/MS (mg/kg)b
Concentration
measured by
Soxtec extraction
and GC/MS
(rag/kg)b
Certified
value
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TABLE 3. CERTIFIED VALUES AND CONCENTRATIONS MEASURED IN THIS
STUDY BY SONICATION-GC/MS FOR COMPOUNDS KNOWN TO BE
PRESENT IN THE SRM1941 MARINE SEDIMENT
Compound name
Acenaphthenec
Acenaphthylenec
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(ghi)perylene
Chrysenec
Fluorene6
Fluoranthene
Indeno(l,2,3-cd)pyrene
2-Methylnaphthalenec
Naphthalene6
Perylene
Phenanthrene
Pyrene
Concentration
measured by
sonication
Concentration extraction and
(mg/kg)a GC/MS (mg/kg)b
0.052 ±
0.115 ±
0.202 ±
0.55 ±
0.67 ±
0.78 ±
0.444 ±
0.516 ±
0.702 ±
0.104 ±
1.22 ±
0.569 ±
0.406 ±
1.322 ±
0.422 ±
0.577 ±
1.08 ±
0.002
0.010
0.042
0.079
0.13
0.19 \
0.049 /
0.083
0.016
0.005
0.24
0.040
0.036
0.014
0.033
0.059
0.20
d
0.041
0.109
d
0.294
0.835
0.135
d
d
0.950
0.285
d
0.147
e
0.344
0.915
a Value reported by NIST.
b Single determinations.
c Concentration reported for this compound is not certified by NIST.
d ND - not detected; detection limit is approximately 0.1 mg/kg.
e NA - not analyzed for perylene.
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we measured after using Soxtec extraction are reported in Table 4. The ERA soils (Lot No. 321 and
323) are spiked materials and were purchased from Environmental Resource Associates (Arvada, CO).
The certified values for these materials are included in Tables 8 and 9 in the Results section.
The soil used in the preliminary experiments was a sandy loam soil (0.1 percent organic
matter) and was obtained from Sandoz Crop Protection (Gilroy, CA).
Solvents
All solvents used in this study were distilled-in-glass, pesticide grade. The solvent
mixture chosen for the MAE was hexane-acetone (1:1). Other solvents evaluated for the MAE include
tetrachloroethylene, methylene chloride-acetone (1:1), toluene-methanol (10:1), methylene chloride,
and toluene-methanol (1:10). The solvent mixture used for Soxtec extraction was hexane-acetone (1:1)
and that for sonication extraction was methylene chloride-acetone (9:1).
MAE Procedure
A 5-g portion of the sample was accurately weighed into an aluminum dish and was
transferred quantitatively to one of die Teflon-lined extraction vessels. To prepare the wet samples,
the calculated volume of water was added and allowed to equilibrate with the sample for
approximately 10 min. A solution containing the three deuterated PAHs was added to each sample
immediately before adding the hexane-acetone (1:1) solvent mixture (30 mL). The extraction vessel
was closed, after ensuring that a new rupture membrane was installed before each extraction.
Extractions were performed at 80°C, 115°C, or 145°C for 5, 10, or 20 min at 50 percent power.
After extraction, the vessels were allowed to cool to room temperature (approximately 20 min without
external cooling) before rney were opened. The supernatant and a 2- to 3-mL hexane-acetone rinse
of the Teflon extraction vessel containing the soil were combined and were filtered through precleaned
glass wool. The extract was concentrated to approximately 5 mL using nitrogen blowdown
evaporation, and then centrifuged twice for 10 min at 2,300 rpm to separate any fine particulates. The
extract was finally either concentrated to 1 mL or diluted for GC/MS analysis.
All MAEs were performed with a 950-watt MDS-2000 Microwave Sample Preparation
System (CEM Corporation, Matthews, NC) shown in Figure 1. This system was equipped with an
inboard pressure and fluoroptic" temperature control system for regulating sample extraction
conditions via magnetron power output control. Temperature- and pressure-control set points could
be programmed in five separate heating stages. The instrument controlled either pressure or
temperature, depending on which parameter reached its control set-point first.
The MAEs were performed in 110-mL lined digestion vessels. The turntable shown
in Figure 2 contained a control vessel and 11 standard vessels. The control vessel is illustrated in
Figure 3a. The outer body and cap consisted of microwave-transparent Ultem polyedierimide. The
removable inner liner, the liner cover, and the safety rupture membrane were made of Teflon PFA.
Gases could escape through the exhaust port if the safety rupture membrane broke or if the vessel
were hand-vented by turning the vent fitting. The liner cover of the control vessel had Teflon PFA
fittings to allow for pressure tubing connection and for insertion of a Pyrex tube that ran through the
cap into the vessel and ended close to the bottom of the vessel. The Pyrex tube, which housed the
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TABLE 4. CERTIFIED VALUES AND CONCENTRATIONS MEASURED IN THIS STUDY
FOR COMPOUNDS KNOWN TO BE PRESENT IN THE SRS103-100 SOIL
Compound name
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(k + b)fluoranthene
Chrysene
Fluorene
Fluoranthene
2-Methylnaphthalene
Naphthalene
Phenanthrene
Pyrene
Dibenzofuran
Pentachlorophenol
Concentration
Certified measured by
value Soxtec extraction and
(mg/kg)» GC/MS (mg/kg)b
591
16.3
425
249
97.5
156
310
475
1,307
56.7
23.6
1,450
961
306
884
± 104
± 11.1
± 67.5
± 56.8
± 26.6
± 40.1
± 62.9
± 101
± 396
± 21.0
± 28.1
± 570
± 428
± 74.8
± 692
683
21.0
553
240
78.0
179
272
456
1,041
78.9
41.1
1,315
714
378
1,070
a Value reported by Fisher Scientific.
b Single determinations.
10
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Fiberoptic
Temperature
Probe
II
II
n
ii
n
n
n
n
II
M
n
n
n
n
n
vi
Water Flush
'System
»h
i
t
LCD
t
Temperature
Control
Board
^m
^m
^m
1
Magn
CPU Board
Manual
Two-way
Valve
J
Signal
Pressure
Transducer
Printer
or PC
Figure 1.
Schematic diagram of the temperature/pressure control system for the MDS-2000
microwave system.
11
-------
0
Figure 2. View of the 12 lined digestion vessels, containment vessel, and temperature and
pressure probes.
12
-------
Temperature Port
Rupture Membrane
Vent Fitting
Exhaust Port
Prauuro Port
Backup Ring
Cov»r
Uiwr
Vessel Body
Teflon* Coated
Pyrex* Thermowell
V«nt Tub*
Rupture M«nbran«
Lbwr
VeuelBody
Figure 3.
(a) Lined digestion vessel with the temperature and pressure control.; (h) lined
digestion vessel without the temperature and pressure control.
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fluoroptic™ probe, provided a seal in the cap and protected the fluoroptic" probe from solvent attack.
The standard vessels, one of which is shown in Figure 3b, did not have temperature and pressure ports
but had only rupture membranes and vent stems. These vessel assemblies were rated for operation
up to 175 psi and 200°C.
All vessels shown in Figure 2 were connected to a containment vessel (shown in the center
of Figure 2) via 1/8-in Teflon tubes. The control vessel's temperature and pressure were monitored
for control purposes. The fluoroptic™ probe extended down through the center of the turntable and
was inserted into the control vessel. The 1/4-in diameter Teflon tube from the sealed containment
vessel passed through the oven cavity wall to provide a safe exhaust of any solvent vapor in case the
rupture membrane broke.
Other Extraction Procedures
Extractions using a Soxtec apparatus (Tecator, Silver Springs, MD) were performed by
extracting 10-g portions of the reference materials with 50 mL hexane-acetone (1:1); the immersion
time and the extraction time were 45 min each. The solvent was evaporated directly in the Soxtec
apparatus. Details of this procedure can be found elsewhere (7, 8).
Extractions using a sonic probe (Sonifier 450, Branson Ultrasonics, Danbury, CT) were
performed using 5-g portions of each reference material (except for the NIST 1941 material where
3.4 g was used). The solvent-soil suspensions were sonicated for 3 min at 50 percent power (output
setting 3.5) with 20 mL methylene chloride-acetone (9:1) and then again with another 10 mL
methylene chloride-acetone (9:1). The extracts were combined, the solvent was exchanged to hexane,
and the hexane solution was concentrated to 1 mL. A silica gel procedure using 1.8 g silica gel (100-
200 mesh, EM Science, Gibbstown, NJ), activated for 16 hrs at 130°C prior to use, was used to clean
up the extracts. The first fraction that was eluted with 10 mL hexane was discarded. PAHs were then
eluted from the silica gel column with 10 mL hexane-methylene chloride (60:40).
The room-temperature extractions of the reference soils and sediments were performed by
allowing the solvent mixture to stay in contact with the solid matrix the same amount of time that was
required for the temperature in the microwave-heated vessel (i) to reach the set point, (ii) to be
maintained at the set point (5, 10, or 20 min), and (iii) then to cool to room temperature.
The extractions using a convection oven were performed as described above for MAE except
that the vessels were heated in a convection oven (Baxter Scientific Products, McGaw Park, IL) for
15, 30, 60, and 120 min. Two matrices including SRS103-100 soil and the HS-5 marine sediment
were used in these experiments.
Analysis of Extracts
Analyses of the extracts from the reference soil and sediment samples and from those samples
containing PAHs and selected base/neutral compounds were performed on a 5890 Series II gas
chromatograph interfaced to an HP 5971A mass spectrometer MSD/DOS Chemstation (Hewlett-
Packard Company, Palo Alto, CA) and equipped with a 5973A autoinjector. The samples were
introduced via a 30-m length x 0.25-mm ID x 0.25-/xm film thickness PTE-5 fused-silica open tubular
column (Supelco, Inc.) with helium carrier gas at a linear velocity of 39 cm/sec. The column
temperature was held at 75°C for 3 min, then programmed to the final temperature of 300°C at
14
-------
12°C/min, where it was held for 13 min. The injection volume was 2 /xL, and the injector
temperature was 250°C. The injector was set in the splitless mode for 1 min after the injection. The
electron energy was set at 70 eV and the electron multiplier voltage was set at 2,160 V. Spectral data
were acquired at a rate of 1.2 sec/scan (scanning range was 40 to 500 amu). The instrument was
tuned daily with PFTBA introduced via the calibration gas valve; the ion intensity was verified using
DFTPP introduced via the GC inlet. A 5-point internal standard calibration was performed initially
to establish the GC/MS linear range. Six internal standards including 1,4-dichlorobenzene-d4 (IS-1),
naphthalene-d8 (IS-2), acenaphthene-d10 OS-3), phenanthrene-d,0 (IS-4), chrysene-d,2 (IS-5), and
perylene-d12 (IS-6) were spiked into every extract that was analyzed by GC/MS.
Analyses of the extracts containing the 14 phenols or the 20 organochlorine pesticides were
performed by gas chromatography. For phenol analysis, we used a 5890 Series II gas chromatograph
equipped with a flame ionization detector and a 5973A autoinjector. Samples were introduced via a
15-m length x 0.53-mm ID x 0.88-fun film thickness HP-5 fused-silica open tubular column (Hewlett-
Packard Company) with helium carrier gas at a flow rate of 7.1 mL/min. The column temperature
was held at 65°C for 3 min, then programmed to 185°C (1-min hold) at 10°C/min, then to 275°C
(5-min hold) at 30°C/min. The injection volume was 2 /iL, and the injector temperature was 200°C.
For organochlorine pesticide analysis, we used a 5890 Series II gas chromatograph equipped
with an electron capture detector and a 5973A autoinjector. Samples were introduced via a 15-m
length x 0.53-mm ID x 0.88-/im film thickness HP-5 fused-silica open tubular column (Hewlett-
Packard Company) with helium carrier gas at a flow rate of 7.5 mL/min. The column temperature
was held at 150°C for 0.5 min, then programmed to 275°C at 5°C/min. The injection volume was
1 /xL, and the injector temperature was 200°C.
Safety
The microwave unit should be operated in accordance with CEM's recommended operating
safety instructions. The MDS-2100 microwave unit used in this study was modified by CEM
Corporation to incorporate additional safety features: (a) a Teflon ceiling, held in place with
polypropylene clips, was mounted in the cavity underneath the mode stirrer so that any sparks from
the stirrer would not ignite organic vapors that might leak into the cavity; (b) an air-flow sensor was
installed in the exhaust line from the microwave unit (should the sensor detect a decrease in the air
flow, then the microwave energy would be shut off); (c) the maximum operating pressure was set to
150 psi; and (d) the lined digestion vessels were modified so that in case of membrane rupture, the
solvent vapors would be retained in the containment vessel and would not escape into the cavity.
15
-------
SECTION 5
RESULTS AND DISCUSSION
Preliminary Experiments
Pure hydrocarbon solvents (e.g., hexane) do not absorb microwave energy. Therefore, a
certain percentage (> 10 percent) of a polar component (e.g., acetone) must be added. In our
preliminary MAE experiments, we tried several solvents and solvent mixtures that are commonly used
with conventional extraction techniques using the control vessel to establish the time required to reach
the maximum temperature. Methylene chloride-acetone (1:1), hexane-acetone (1:1), and toluene-
methanol (1:10) reached maximum temperature within 1 to 3 min (Table 5). We chose hexane-acetone
(1:1) in subsequent experiments since this solvent mixture was compatible with electron capture
detection. Next, we investigated the effect of solvent volume by varying the volume of hexane-
acetone (1:1) from 5 to 30 mL. The results indicated that a 30-mL volume was desirable since the
solvent could reach the maximum temperature (156-160°C) in 2.5 min (Table 5). Various solid
matrices were added to the solvent, but the effect of the matrix on the heating rate appeared to be
insignificant; the time required for the temperature to reach maximum was still about 2 min (Table 5).
When both the solvent volume and the mass of the sample were varied, while keeping their
ratio constant, we found that a 30-mL volume and a 6-g sample were giving the shortest heating time
(Table 5). When the water content of the sample was adjusted to 10 or 30 percent, the time required
to reach the maximum temperature almost doubled, and the Tmax was about 15 °C lower than in the
case of the dry matrix. When we performed experiments using solvent only, with 6 and 12 vessels,
we found that the time required to heat the solvent in the vessels to Tmax increased to 5 min for 6
vessels and to 9.5 min for 12 vessels (Table 5).
Sand freshly spiked with seven of the organochlorine pesticides listed in Table 1 was
extracted for 5, 10, or 20 min using microwave energy; another spiked sand sample was left in contact
with the solvent at room temperature (no microwave energy) for about 5 min. Recoveries (Table 6)
were all above 95 percent, and we could not draw conclusions about how well the MAE technique
performed because simple soaking of the sample with solvent also resulted in quantitative recoveries.
The results indicated, however, that the spiked compounds did not degrade when microwave energy
was applied. The recoveries ranged from 95 to 134 percent; the high values may have been due to
partial evaporation of the solvent upon opening the vessel too soon after extraction. In subsequent,
more carefully monitored experiments, we measured the volume of the solvent after extraction and
found no changes in the solvent volume when we extracted dry matrices and allowed adequate time
for cooling.
16
-------
TABLE 5. TIME (MIN) REQUIRED TO REACH THE MAXIMUM TEMPERATURE UNDER
VARIOUS EXTRACTION CONDITIONS
Solvent type
Effect of solvent
Tetrachloroethylene
Methylene chloride-acetone (1:1)
Hexane-acetone (1:1)
Toluene-methane! (10: 1)
Methylene chloride
Toluene-methanol (1:10)
Effect of solvent volume
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Effect of matrix
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Effect of solvent
volume and sample weight
Hexane-acetone (1:1)
Hexane-acetone (1 : 1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Effect of number of vessels
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Effect of sample moisture
Hexane-acetone (1:1)
Hexane-acetone (1:1)
Solvent
volume
(mL)
10, 20, 30
30
30
30
30
30
5
10
15
20
30
30
30
30
30
10
15
20
30
30
30
30
30
30
Matrix type
Solvent only
Solvent only
Solvent only
Solvent only
Solvent only
Solvent only
*
Solvent only
Solvent only
Solvent only
Solvent only
Solvent only
Sand
Sediment
Sandy loam
Clay loam
Clay loam
Clay loam
Clay loam
Clay loam
Solvent only
Solvent only
Solvent only
Sand (10% water)
Sand (30% water)
Sample
weight
(g)
0
0
0
0
0
0
0
0
0
0
0
10
5
10
6
2
3
4
6
0
0
0
5
5
Number
of
vessels
1
1
1
1
1
1
1
1
1
1
1
1
1
1
I
1
1
1
1
1
6
12
1
1
Time required to
reach maximum
temperature
(min)
a
1:15
2:30
13:45
9:45
1:15
17:00
7:45
7:30
5:00
2:30
2:30
2:00
1:45
2:15
14:00
8:30
4:45
2:15
2:30
5:00
9:30
4:30
3:30
*max
CO
—
160-161
157-159
110-112
135-136
146-147
146
147-148
145
145
156-160
156-157
154-155
152-153
151-152
155
153
152
151
156-160
156-160
156-160
142-143
137-138
a Temperature did not exceed 70°C.
17
-------
TABLE 6. RECOVERIES OF PESTICIDES FROM FRESHLY SPIKED SAND USING
MAE AND ROOM-TEMPERATURE EXTRACTION WITH HEXANE-
ACETONE (!:!)•
Compound name
MAE recoveries (percent)
5 min
10 min
20 min
Room temperature
extraction
recoveries (percent)
5 min
alpha-BHC
gamma-BHC
Heptachlor
Aldrin
4,4'-DDE
Endosulfan II
4,4'-DDT
99.2
96.8
94.6
102
106
97.0
100
116
116
117
120
130
122
134
108
107
111
107
125
116
129
96.6
95.0
96.2
95.4
103
102
114
a Single determinations. The spike level was 600 ng/g. The sample weight was 5 g; the extraction
was performed with 30 mL hexane-acetone (1:1) at 155°C and 100 percent power.
18
-------
MAE of PAHs from Standard Reference Materials
Four standard reference marine sediments (HS-3, HS-4, HS-5, and NIST SRM1941) and two
certified contaminated soils (SRS103-100 and ERA Lot No. 321) were subjected to MAE with hexane-
acetone (1:1) for 5, 10, or 20 min after reaching the set temperature (80°C, 115°C, or 145°C). In
parallel, we performed room-temperature extractions of the same materials by allowing the solvent
mixture to stay in contact with the solid matrix for the same combined amounts of time that were
required for the temperature in the microwave-heated vessel to reach the set point, to be maintained
at the set point (5, 10, or 20 min), and then to cool to room temperature. Before extraction, three
deuterated compounds were spiked onto these samples at levels comparable to those of their
undeuterated counterparts. This allowed us to compare the recoveries of the "native" compounds and
the spiked compounds.
The recovery data for the 17 compounds listed under PAHs in Table 1 (14 of which were
native compounds and three were spikes) are summarized in Figures 4 through 8. These recoveries
were determined from the values obtained from the analysis of the extracts by GC/MS in relation to
the certified values provided by the manufacturers. Not all reference materials contained all 17
compounds; therefore, the summarized recovery data pertain to recovery results from four to six
matrices, depending on the compound.
Figure 4 shows the average recoveries and the 95-percent confidence intervals as a function
of temperature across the 17 compounds and the six matrices. The average recovery at room
temperature was approximately 54 percent, which was significantly lower than the average recoveries
achieved at 80°C, 115°C, and 145°C (72 percent, 78 percent, and 77 percent, respectively). Since
the average recoveries at 115°C and 145°C were almost identical, subsequent experiments to
determine method precision and accuracy were carried out at 115°C.
Figure 5 shows the average recoveries (for data generated for four to six matrices per
compound and at three temperatures, 80°C, 115°C, and 145°C) and the 95-percent confidence
intervals as a function of time. The average recovery increased slightly with extraction time, but the
increase was not statistically significant. Thus, a 5-min extraction (at 115°C) was deemed sufficient
for recovering 11 "native" PAHs from a soil or sediment matrix.
Figure 6 shows the average recoveries (for data generated for the 17 compounds at three
temperatures and three extraction times) and the 95-percent confidence intervals as a function of
matrix. These data indicate that, just as with other extraction methods, method performance was also
a function of the matrix. It is difficult to establish whether the recovery was also a function of analyte
concentration; the results in Figure 6 did not support this. For example, the HS-4 marine sediment
matrix had the lowest PAH concentrations (ranging from 0.15 to 1.25 mg/kg), yet the average
recovery across the 17 compounds was higher than for the HS-5 marine sediment where the PAH
concentrations ranged from 0.2 to 8.4 mg/kg. The NIST sediment material, which had some PAHs
at levels that were comparable to those in the HS-4 marine sediment, gave even higher recoveries.
The ERA soil, which is not a naturally occurring soil material, but a soil that has been spiked,
homogenized, and weathered, exhibited recoveries averaging 83 percent, which were approaching
those measured for the spikes (Figure 7). This seems to indicate that even after weathering, the ERA
spikes behaved almost like fresh spikes.
19
-------
81
78
71
g 68
u
V
at
81
SB
51
29
95 Percent LSD
Intervals for Factor Means
115 145
Temperature (°C)
Figure 4. Percent recovery as a function of temperature for the 17 PAH compounds (four to
six matrices).
20
-------
78
78
74
72
78
95 P«pc«nt LSO
Intervals •for Factor H«*n»
10 20
Time (min)
Figure 5. Percent recovery as a function of time for the 17 PAH compounds (four to six
matrices).
21
-------
95 P«rc«nt LSO
Intervals for Factor Mean*
184
94
84
31
I
74
64
54
I I
I I
I
HS3 SRS103188 HS4
NIST1941 HSS ERft
Matrix
Figure 6. Percent recovery as a function of matrix for the 17 PAH compounds (four to six
matrices).
22
-------
95
91
87
31
C
u
£
83
79
75
71
95 Percent LSD
Interval* for Factor Means
Nat i ve
SP i ked
Compound state
Figure 7. Spiked versus native compound percent recoveries (four to six matrices).
23
-------
Figure 8 shows the average recoveries (for data generated from four to six matrices per
compound at three temperatures and three extraction times) and the 95-percent confidence intervals
as a function of compound. Of the native compounds, 11 gave average recoveries within 65 to
111 percent, and three compounds [benzo(a)pyrene, benzo(ghi)perylene, and fluorene] had recoveries
of 51 percent, 64 percent, and 62 percent, respectively. The spiked-compound recoveries were
77 percent (compound no. 4), 104 percent (compound no. 6), and 84 percent (compound no. 11).
To determine method accuracy and precision, six 5-g portions of the SRS103-100 standard
reference soil were extracted simultaneously for 10 min at 115°C. The average recoveries and percent
RSDs for the 16 compounds known to be present in the sample are presented in Table 7. The
repeatability of the injection technique was 1.3 percent or better (as determined from the six
consecutive injections of a calibration standard at a concentration of 50 ng//*L). When one of the soil
extracts was injected six times, the percent RSDs were comparable to those obtained for the calibration
standard with the exception of pentachlorophenol (percent RSD 11.9). The percent RSDs calculated
for the six extracts were higher, as expected; but they were under 10 percent for 14 of the 16
compounds. Naphthalene and pentachlorophenol were the two compounds for which we obtained
percent RSDs in the 12 to 14 percent range. Percent recoveries established relative to the certified
values were greater than 80 percent and did not appear to be affected by the presence of water in the
sample. The high recoveries of naphthalene and phenanthrene that we found for the MAE may be
due to a certified value that is biased low, since in both cases the standard deviation for the certified
concentration is quite high (Table 4).
To verify that a 10-min MAE was sufficient to extract the compounds of interest from a soil
or sediment matrix, we reextracted the material (remaining after the first extraction) with fresh solvent
using the same conditions. Figures 9a and 9b show GC/MS chromatograms of the HS-3 extracts from
the first and second extraction, respectively. Since we did not recover any compounds in the second
extraction, we reextracted a separate portion of the material (that had already been extracted once
using microwave energy) with methylene chloride-acetone (9:1) using sonication extraction. A
GC/MS chromatogram of the extract obtained by sonication extraction is shown in Figure 9c. Except
for three compounds (phenanthrene, fluoranthene, and pyrene) that represented less than 5 percent of
their original concentrations, the extract was clean. Thus, we concluded that a 10-min MAE was
sufficient for the types of matrices we investigated.
Extraction of Other Organic Compounds
The recovery data for 20 compounds of interest to the EPA that were known to be present
in the ERA soil Lot No. 321 are included in Table 8. The recoveries follow the same trend as in the
case of the PAHs. The recoveries obtained at room temperature were significantly lower than those
achieved using microwave energy; the 5-min, 10-min, and 20-min extraction results were very similar;
and there was a significant improvement in recovery when extractions were done at either 115°C or
145°C as compared with the 80°C extraction. Compounds that gave recoveries above 80 percent at
115°C/10min included naphthalene, dibenzofuran, N-nitroso-di-n-propylamine, nitrobenzene,
2,4-dichlorophenol, 2,4,6-trichlorophenol, fluoranthene, chrysene, 2,4-dinitrotoluene, carbazole, and
di-n-butylphthalate. Pentachlorophenol gave a recovery of 67 percent and bis(2-ethylhexyl)phthalate
a recovery of 79 percent. 1,2,4-Trichlorobenzene recovery was only 56 percent, and the more volatile
compounds such as 1,2-dichlorobenzene and 2-methylphenbl gave low recoveries, even when extracted
at room temperature.
24
-------
95 Ptrccnt LSD
Intervals for Factor rt««n»
125
IBS
85
65
45
I I I I I I
I I I
I
i i i i i i
i i i
_L
1234
(4) (4) (6) -
5
(5)
6789
- (5) (6) (4)
10
(5)
11 12 13 14 15 16 17
- (4) (6) (4) (5) (5) (6)
Compound
Figure 8. Percent recovery as a function of compound for the 17 PAH compounds (four to
six matrices). Refer to Table 1 for compound number and to Tables 2 through 4
for the list of certified compounds in each matrix. The numbers in parentheses
indicate the number of matrices that contained the individual compounds.
25
-------
TABLE 7. AVERAGE RECOVERIES AND PERCENT RSDs FOR DRY AND WET SRSI03-100 SOIL
to
MAE'
Compound name
Naphthalene
2-Methylnaphthalene
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a + k)fluoranihene
Benzo(a)pyrene
Chrysene
Fluorene
Fluoranlhene
Phenanthrene
Pyrene
Dibenzofuran
Penlachlorophenol
Certified
value
(mg/kg)
23.6
56.7
590.9
16.3
424.8
249.4
156.1
97.5
310.4
475.5
1,306.6
1,449.5
961.2
305.6
884.0
Dry matrix percent
recovery
(percent RSD)b
150
98.0
112
80.9
107
87.9
114
93.3
95.5
97.3
109
137
117
109
80.3
(11.7)
(6.4)
(4.6)
(5.9)
(4.5)
(6.2)
(5.0)
(4.6)
(6.3)
(4.4)
(4.8)
(4.5)
(4.0)
(4.6)
(14.3)
Wet matrix percent
recovery
(percent RSD)b
143
95.0
111
79.0
105
84.2
111
87.3
92.8
96.3
106
135
115
108
104
(13.5)
(6.8)
(6.9)
(6.0)
(7.6)
(6.4)
(7.6)
(7.0)
(7.6)
(6.3)
(8.0)
(7.5)
(7.5)
(6.5)
(11.8)
Percent RSD for
extract injection
0.3
0.5
0.6
0.9
1.4
1.5
1.4
2.2
1.8
1.8
0.7
0.3
0.7
0.6
11.9
Percent RSD for
standard injection**
0.5
NAC
1.1
0.8
0.3
1.0
0.4
0.6
1.2
1.3
0.5
0.3
1.0
1.0
1.1
* Six vessels were extracted simultaneously for 10 min at 115°C. The wet matrix contained 20 percent water.
b The number of determinations was six.
c Data not available.
-------
Abundance
I 2.46+07
' 2.26+07
I
i
: 26+07
1.86+07
| 1.66+07
i
j
• 1.46+07
I 1.26+07
!
16+07
i
i
j 8000000
| 6000000
: 4000000 -
i |
| 2000000 -j
TIC: MWEHS33A.D
IS-3
IS-2
IS-4
IS-S
IS-6
.Time — > 5.00
10.00
15.00
20.00 25.00
30.00
Figure 9a. GC/MS chromatogram of the extract obtained by MAE of the HS-3 marine
sediment with hexane-acetone (1:1) (1S-1 through IS-6 are internal standards).
27
-------
Abundance
6500000 -•
IS-3
TIC: MWEHS35.D
6000000 -
1
5500000 -
| 5000000 -
4500000 -
4000000 -
3500000
I
3000000 -
2500000 -
2000000 -
)
; 1500000 -
IS
1000000 -
1
500000 -j
1
J
j
Time — > 5.
IJ
-1
V
00
5-2
10.00
1
15.
IS-4
.. L i i
00 20. 0(
IS-5
1 . .
) 2
IS-6
1
5.00 30.00
Figure 9b. GC/MS chromatogram of the extract from a second extraction performed on the
HS-3 marine sediment using microwave energy and fresh solvent (IS-1 through
IS-6 are internal standards).
28
-------
Abundance
TIC: SONHS31.D
; eoooooc
1
! 5500000
i
i
J 5000000
i
i
i 4500000
1
i
i
I
1 4000000
i
i
i
! 3500000
1
: 3000000
2500000
I
2000000
1
1
1500000
I
1000000 -
500000-
0 -
Time — >
IS
5.
I!
-1
\
00
IS-
5-2
10.00
3
, L
15.
IS-
^
00
4
x.
jLJ
2o:oc
IS-5
t u
) 2
IS-6
t
5.00 30.00
Figure 9c. GC/MS chromatogram of the sonication extract from the HS-3 marine sediment
that was first extracted using microwave energy before extraction with fresh
solvent using a sonic probe (IS-1 through IS-6 are internal standards).
29
-------
TABLE 8. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM ERA SOIL LOT NO. 321
WITH HEXANE-ACETONE (1:1) USING ROOM TEMPERATURE EXTRACTION AND MAE AT
DIFFERENT TEMPERATURES AND PRESSURES"
Compound name
"Native" compounds
Anthracene
Benzo(b)fluoranlhene
1 ,2-Dicblorobenzene
Chrysene
Fluoranlhene
Naphthalene
Dibenzofuran
Pyrene
2-Methylphenol
N-Nitroso-di-n-propylamine
Nitrobenzene
2,4-Dichlorophenol
1 ,2,4-Trichlorobenzene
2,4,6-Trichlorophenol
2,4-Dinitrotoluene
Carbazole
Di-n-butyl-phthalate
Bis(2-ethylhexyl)phlhalate
Penlachlorophenol
Spikes
Anthracene-d|o
Fluoranthene-d|0
Benzo(a)anth race ne-d ( 2
Certified
value
(mg/kg)
3.52
2.03
10.0
4.47
8.09
2.96
1.70
3.78
5.46
5.01
7.87
5.52
9.36
2.82
4.86
5.00
3.43
7.62
6.68
5.00
5.00
5.00
Room temperature
5 min
44.0
44.6
33.4
70.7
65.2
58.6
67.4
48.7
20.3
93.7
90.2
65.0
52.5
59.1
139
79.4
129
53.5
36.3
87.6
98.8
99.2
10 min
41.6
43.4
30.5
65.5
62.7
50.5
59.9
48.5
19.2
89.2
87.9
64.0
49.4
58.2
123
74.8
121
51.4
34.1
86.4
89.0
94.5
20 min
39.6
47.6
25.5
61.6
61.1
46.4
53.8
44.6
16.7
79.7
74.7
57.8
43.7
48.6
112
65.6
112
54.9
35.3
89.2
105
103
80°C/22 psi
5 min
49.3
50.0
31.3
66.0
70.2
53.9
71.4
55.6
20.7
78.0
79.4
78.7
53.0
71.1
123
87.6
113
59.7
47.6
86.2
95.2
98.2
10 min
48.9
51.0
33.8
69.3
72.3
56.8
74.1
55.6
21.1
81.9
83.7
80.9
54.6
70.8
122
95.3
117
62.2
45.7
82.3
91.3
91.6
20 min
54.5
62.1
32.4
83.7
83.5
64.9
80.7
66.7
23.2
84.3
84.3
79.6
55.7
82.4
140
107
141
73.2
56.8
84.4
97.1
97.7
US°C/72 psi
5 min
64.5
74.7
37.6
106
102
71.4
91.6
81.2
25.4
98.7
104
112
67.0
94.8
143
136
166
92.4
52.5
83.9
92.6
98.2
10 min
61.3
68.9
32.7
87.2
89.3
105
82.2
78.8
17.9
80.7
82.6
87.1
55.7
90.9
142
113
125
79.1
67.5
87.9
98.0
96.8
20 min
64.8
73.4
33.4
100
96.6
113
84.4
79.4
23.8
85.6
88.6
93.2
59.4
100
144
120
145
88.6
76.6
88.4
101
96.6
145'C/ISO
5 min
69.5
74.8
29.6
89.7
91.1
160
83.6
78.3
24.5
85.9
96.3
96.4
54.1
109
140
125
134
85.7
76.8
96.0
104
99.6
10 min
78.9
80.9
32.3
104
102
69.3
92.7
92.1
28.0
85.7
98.2
103
61.9
129
159
142
146
89.8
83.6
93.8
100
101
psi
20 min
63.6
68.8
27.6
84.3
89.4
66.8
81.3
79.7
20.6
74.9
83.4
85.7
52.5
91.1
125
118
130
76.7
76.0
85.7
93.1
92.2
1 Single determinations. The sample size was 5 g; the solvent volume was 30 mL. The extracts were concentrated 30-fold prior to GC/MS
analysis.
-------
The average recoveries and the percent RSDs were also determined for this matrix using six
5-g portions of the ERA soil Lot No. 323 (both dry and wet). We could not use material from Lot
No. 321, since it was no longer available from ERA. However, the ERA soil Lot No. 321 matrix
was the same as in the new Lot No. 323, and the spike levels (certified values) were comparable to
those in Lot No. 321. Table 9 identifies the 20 compounds known to be present in ERA soil Lot
No. 323 and gives their certified values, the typical recoveries achieved using the EPA-approved
methodology (Soxhlet or sonication techniques), and the recoveries that we achieved using MAE. In
addition, the percent RSDs are shown for six consecutive injections of one of the extracts and of a
calibration standard. The repeatability of the injection technique was better than 1.4 percent (except
for two of the 23 values at 2.9 percent) for the calibration standard and better than 1.1 percent for the
ERA extract (except for two of the 23 values at 4.3 and 5.3 percent). There was more spread in the
average recoveries for the ERA soil since the compounds covered a wider range of volatilities.
However, the recoveries that we achieved using MAE were for the most part higher than those
achieved by the EPA-approved methodology. When comparing the typical recoveries achieved with
the EPA-approved methodology and those achieved with the MAE for the dry sample (Table 9), we
found that 11 compounds exhibited an increase in recovery greater than 10 percent (the range was 10
to 56 percent), two compounds exhibited a 6 to 7 percent increase, two compounds showed no change
in recovery, and five compounds exhibited a decrease in recovery (10 to 15 percent). In the case of
the wet matrix, the recoveries for the MAE were higher than those for conventional extraction for 14
of the 20 compounds and lower (but not exceeding 15 percent) for six compounds.
Stability Studies
To test for possible compound degradation during the extraction, we performed experiments
in which we heated solvent (hexane-acetone, 1:1) and solvent-soil suspensions, spiked with the target
compounds, at 115°C for 10 min using microwave energy at 50 percent power. To account for
possible losses during the nitrogen blowdown evaporation, we took an equivalent volume of hexane-
acetone (1:1) and spiked it with the target compounds at the same concentrations as the samples
subjected to MAE. The spiked solvent was then concentrated to 1 mL for phenols and PAHs and was
analyzed as is for organochlorine pesticides. The results are presented in Tables 10 through 12.
For the 14 phenols tested (Table 10), we did not find any degradation when using solvent
only (recoveries ranged from 80.3 to 111 percent). When soil was present, we found slightly lower
but acceptable recoveries (> 70 percent) for 10 compounds, two compounds had borderline recoveries
(2-nitrophenol at 66.7 percent and pentachlorophenol at 55 percent), and two compounds
(2,4-dinitrophenol and 2-methyl-4,6-dinitrophenol) appeared to have degraded since their recoveries
were 9.4 percent and 17.1 percent, respectively. Catalytic reactions in the presence of the soil or
simply strong adsorption to soil particles may have been the cause for these low recoveries.
In the case of the organochlorine pesticides (Table 11), we did not find any degradation when
using solvent only (recoveries ranged from 83 to 117 percent). When soil was present, recoveries
were still quantitative for all compounds but gamma-chlordane (recovery 74 percent). We found some
losses for three of the four BHC isomers; however, their recoveries were still almost quantitative (the
range was 82 to 88 percent).
In the case of the PAHs and a few base/neutral compounds (Table 12), we did not find any
degradation when using solvent only (recoveries ranged from 85.2 to 135 percent). When soil was
present, five compounds exhibited no change in recoveries but 21 compounds showed approximately
31
-------
TABLE 9. AVERAGE RECOVERIES AND PERCENT RSDs FOR DRY AND WET ERA SOIL LOT NO. 323
to
MAE'
Certified Typical recovery Dry matrix
value using approved percent recovery
Compound name (mg/kg)bEPA methodology6 (percent RSD)C
"Native" compounds
Anthracene
Benzo(a)anthracene
Benzo(k)fluoranthene
Chrysene
Naphthalene
Pyrene
Dibenzofuran
1 ,2-Dichlorobenzene
1 ,3-Dichlorobenzene
2-Methylphenol
3-MelhyIphenol
1 ,2,4-Trichlorobenzene
2,4,6-Trichlorophenol
2,4-Dinitrotoluenc
Bis(2-ethylhexyl)phthalate
Isophorone
4-Chlorophenyl phenyl ether
Butyl benzyl phthalate
Phenol
Penlachlorophenol
Spikes
Anihracene-d|0
Fluoranlhene-d|o
Benzo(a)anthracene-d|2
6.97
5.16
2.35
9.45
7.77
6.32
650
13.0
8.58
3.41
4.62
1.87
9.36
4.82
1.54
4.75
3.40
8.48
3.94
9.63
5.60
5.60
5.60
62
66
63
64
58
66
73
.6
.1
.4
.0
.7
0
.7
43.5
30
46
64
57
57
79
89
67
80
73
65
42
—
—
—
.5
6
9
.2
.1
.7
6
.2
6
6
0
7
72.6
74.2
49.1
85.2
60.3
74.7
80.8
39.1
26.2
34.6
72.2
59.2
89.0
106
74.7
76.5
79.4
90.0
72.2
646
83.1
82.4
85.2
(11.0)
(10.3)
(8.6)
(10.5)
(13.2)
(9.7)
(8.8)
(18.3)
(15.8)
(15.4)
(13.9)
(13.1)
(14.3)
(14.3)
(10.0)
(11.9)
(9.3)
(11.5)
(18.9)
(39.0)
(11.6)
(8.6)
(9.1)
Wet matrix
percent recovery
(percent RSD)"*
72.0
81.3
52.3
836
59.0
85.9
86.1
28.8
17.7
36.3
74.6
55.5
89.7
117
81.5
78.1
87.0
100
72.7
96.8
91.4
96.3
102
(2.7)
(5.3)
(4.0)
(2.8)
(6.1)
(4-9)
(2.9)
(9.6)
(13-5)
(5.1)
(2.9)
(5.7)
(21.8)
(9.2)
(5.8)
(2.4)
(4.3)
(8.1)
(3.8)
(9.4)
(2.7)
(5.0)
(8.7)
Percent
extract
0
0
RSD for
analysis0
.5
.3
0.6
0
0
0
0.
0
0
0
.7
4
9
5
.2
4
6
0.6
0.
1.
0.
0.
0.
1.
0.
0.
5.
0.
0.
4.
7
1
7
9
6
1
9
4
3
6
7
3
Percent RSD for
standard analysis1
0
1
.3
.0
2.9
1
.2
0.5
1
1
0
0
0
.4
0.3
0
.5
0.9
0
1
0
0
0
0
0
0
1.
2.
0
1.
3
0
5
4
5
3
9
g
1
9
5
4
* Samples in five to six vessels were extracted simultaneously for 10 min at 115°C. The wet matrices contained 20 percent water.
b Reported by ERA.
0 The number of determinations was six.
d The number of determinations was five.
-------
TABLE 10. AVERAGE RECOVERIES AND PERCENT RSDs FOR PHENOLS AFTER
MICROWAVE HEATING - SOLVENT VERSUS SOLVENT/SOIL
SUSPENSION"
Compound name
Phenol
2-Chlorophenol
2-Methylphenol
3-Methylphenol
2-Nitrophenol
2,4-DimethyIphenol
2,4-Dichlorophenol
4-Chloro-3-methylphenol
2,4,6-Trichlorophenol
2,4-Dinitrophenol
4-Nitrophenol
2,3,4,6-Tetrachlorophenol
2-Methyl-4,6-dinitrophenol
Pentachlorophenol
Solvent
Percent
average
recovery
80.3
87.4
85.0
91.1
100
86.9
87.2
89.4
90.4
106
86.7
91.1
111
93.4
only
Percent
RSD
22.9
14.6
12.5
11.5
20.9
7.0
9.3
8.0
8.8
21.0
10.8
8.9
18.7
9;8
Solvent
Percent
average
recovery
74.9
76.7
75.9
79.1
66.7
76.4
75.2
78.8
76.9
9.4
74.2
73.9
17.1
55.0
and soil
Percent
RSD
7.6
8.9
7.4
8.2
9.2
9.7
6.4
4.6
5.5
20.2
6.7
5.6
34.6
7.3
Slowdown
evaporation
84.5
87.1
83.0
86.9
85.4
71.3
84.1
85.2
84.7
82.7
82.6
84.4
85.7
81.6
a The number of determinations was three. The amount spiked was 50 ng per compound.
33
-------
TABLE 11. AVERAGE RECOVERIES AND PERCENT RSDs FOR ORGANOCHLORINE
PESTICIDES AFTER MICROWAVE HEATING - SOLVENT VERSUS
SOLVENT/SOIL SUSPENSION"
Compound name
alpha-BHC
beta-BHC
gamma-BHC
delta-BHC
Heptachlor
Aldrin
Heptachlor epoxide
gamma-Chlordane
Endosulfan-I
aJpha-Chlordane
Dieldrin
4,4'-DDE
Endrin
Endosulfan-II
4,4'-DDD
Endrin aldehyde
Endosulfan sulfate
4,4'-DDT
Endrin ketone
Methoxychlor
Solvent
Percent
average
recovery
104
103
104
107
105
107
107
83.0
110
99.3
108
107
109
106
111
117
109
105
107
115
only
Percent
RSD
1.6
1.5
1.7
1.5
1.5
1.3
2.3
2.3
4.0
0.5
2.7
0.9
0.6
1.4
2.0
1.0
1.5
1.0
1.2
6.0
Solvent
Percent
average
recovery
82.4
81.9
88.0
95.5
108
92.5
100
74.0
98.2
86.9
125
93.9
123
99.6
118
92.6
101
114
123
169
and soil
Percent
RSD
8.4
9.3
8.5
9.5
12.2
8.4
11.5
ll.O
11.4
9.6
14.8
9.6
14.4
8.4
15.4
11.9
11.0
22.7
14.9
17.4
a The number of determinations was three. The amount spiked was 1.5 /xg per
compound. The hexane-acetone extracts were not concentrated.
34
-------
TABLE 12. AVERAGE RECOVERIES AND PERCENT RSDs FOR PAHs AND SELECTED BASE/NEUTRAL
COMPOUNDS AFTER MICROWAVE HEATING - SOLVENT VERSUS SOLVENT/SOIL SUSPENSION*
Compound name
PAHs
Acenaphthene
Acenaphthylene
Anthracene
Anthracene-dlo
Benzo(a)anthracene
Benzo
-------
a 30-percent loss. Considering that losses during the blowdown step could be as high as 15 percent
for some of these compounds and that the measurement error could also be as high as 15 percent, we
concluded that the 30-percent loss is not unreasonable for these types of compounds. We believe some
of the more volatile compounds (e.g., chlorinated benzenes, naphthalene) may be partially lost during
the filtration step.
Comparison of MAE with Other Extraction Techniques
To compare MAE with other extraction techniques, we summarized in Tables 13 through 17
the concentrations of the various compounds (known to be present in each sample) in each matrix that
was extracted by sonication, Soxtec, and MAE at 115°C for 10 min. The data for the ERA soil are
not presented since we did not have enough material to extract by sonication or Soxtec extraction.
The Soxtec extractions and MAEs were performed with hexane-acetone (1:1), and the sonication
extractions were performed with methylene chloride-acetone (9:1); thus, the sonication data may not
be comparable to MAE data. In Table 18, we report the correlation coefficients and the regression
equations for each matrix.
Overall, the data indicate that there is significant correlation at the 95-percent significance
level between the MAE and the other extraction techniques. The slopes of the regression equations
ranged from 0.653 to 1.934. The various slopes indicated that the extraction efficiencies by MAE
were higher than those achieved by sonication for two matrices (HS-3 marine sediment and SRS103-
100 soil), almost identical for the HS-5 marine sediment, slightly lower for the HS-4 marine sediment,
and still reasonable for the SRM1941 marine sediment. MAE gave higher recoveries than Soxtec for
the HS-3 marine sediment and lower recoveries for the HS-4 marine sediment. When comparing
MAE data with the certified values (that were obtained either by sonication and/or Soxhlet extraction),
we found that MAE recoveries ranged from 70 percent for the HS-5 marine sediment to 112 percent
for the SRS103-100 soil.
The encouraging results obtained in this study with MAE indicate that efficient extraction of
analytes from a solid matrix could be achieved by heating the sample/solvent suspension in a closed
vessel for a defined period of time using microwave energy. Heating the sample/solvent in a
convection oven would undoubtedly be sufficient as we have seen from the two preliminary
experiments (data not shown) conducted here. However, the purpose of this study was not to develop
an extraction technique using a closed-vessel system in a convection oven but rather to evaluate the
use of a microwave system because of its easy controllability and convenience.
36
-------
TABLE 13. COMPARISON OF ANALYTE CONCENTRATIONS IN EXTRACTS
GENERATED BY SONICATION, SOXTEC, AND MAE WITH THE
CERTIFIED VALUES FOR THE HS-3 MARINE SEDIMENT
Certified
value
Compound name
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(ghi)perylene
Chrysene
Dibenzo(ah)anthracene
Fluorene
Fluoranthene
Indeno(l,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
(mg/kg)
4
0
13
14
7
7
2
5
14
1
13
60
5
9
85
39
.5
.3
.4
.6
.4
.7
.8
.0
.1
.3
.6
.4
.0
±
±
+
±
±
±
±
±
±
±
±
±
±
±
a
1.
0.
0.
2.
3.
1.
2.
2.
2.
0.
3.
9
1.
0.
5
1
4
0
6
2
0
0
0
5
1
3
7
± 20
±
9
Concentration
Concentration measured by
measured by Soxtec
sonication extraction and
extraction and
GC/MS
1
0
3
7
2
1 7
1
1
8
0
4
34
2
1
(mg/kg)b
.8
.18
.5
.6
.7
Q 1
J
.8
.8
.74
.9
.7
.2
.8
46.8
21
.6
GC/MS
(mg/kg)b
5
0
10
8
3
10
2
8
1
7
30
2
4
38
16
.8
.5
.1
.2
.6
.4
.8
.1
.2
.3
.8
.8
.3
.2
.8
Concentration
measured by
MAE and
GC/MS
(mg/kg)b
3.
0.
7.
10.
3.
1 11
J
3.
10.
2.
6.
53.
3.
7.
74.
32.
,c
4
38
0
8
7
3
9
8
0
7
0
8
7
2
7
a Value reported by the National Research Council of Canada.
b Single determinations.
c MAE at 115°Cfor 10 min.
37
-------
TABLE 14. COMPARISON OF ANALYTE CONCENTRATIONS IN EXTRACTS
GENERATED BY SON1CATION, SOXTEC, AND MAE WITH THE
CERTIFIED VALUES FOR THE HS-4 MARINE SEDIMENT
Compound name
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(ghi)perylene
Chrysene
Dibenzo(ah)anthracene
Fluorene
Fluoranthene
Indeno(l ,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
Certified
value
(mg/kg)a
0.15d
0.15d
0.14 ±0.07
0.53 ±0.05
0.65 ±0.08
0.70 ±0.15
0.36 ±0.05
0.58 ±0.22
0.65 ± 0.08
0.12 ±0.05
0.15d
1.25 ±0.10
0.51 ±0.15
0.15d
0.68 ±0.08
0.94 ±0.12
Concentration
measured by
sonication
extraction and
GC/MS (mg/kg)b
e
e
0.06
0.32
0.28
1 059
J
0.21
0.44
e
e
0.75
0.24
e
0.34
0.61
Concentration
measured by
Soxtec
extraction and
GC/MS
(mg/kg)b
e
e
0.18
0.38
0.38
1 0.98 1
I J
e
0.50
e
e
1.1
e
e
0.58
0.90
Concentration
measured by
MAE and
GC/MS
(mg/kg)b-c
0.02
0.06
0.10
0.75
0.29
0.58
0.48
0.41
d
0.04
0.92
0.57
0.06
0.43
0.82
a Value reported by the National Research Council of Canada.
b Single determinations.
c MAE at 115°C for 10 min.
d Upper limit; the amount present is not greater than 0.15 mg/kg.
e Not detected; the approximate detection limit was 0.1 mg/kg.
38
-------
TABLE 15. COMPARISON OF ANALYTE CONCENTRATIONS IN EXTRACTS
GENERATED BY SONICATION AND MAE WITH THE CERTIFIED VALUES
FOR THE HS-5 MARINE SEDIMENT
Concentration Concentration
measured by measured by
Certified sonication MAE and
value extraction and GC/MS
Compound name
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(ghi)perylene
Chrysene
Dibenzo(ah)anthracene
Fluorene
Fluoranthene
Indeno(l ,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
(mg/kg)a GC/MS (mg/kg)b (mg/kg)b'c
0.23 ±0.10
d
0.38 ±0.15
2.9 ± 1.2
1.7 ±0.8
2.0 ± 1.0 1
1.0 ±0.4 {
1.3 ±0.3
2.8 ±0.9
0.2 ±0.1
0.4 ±0.10
8.4 ±2.6
1.3 ±0.7
0.25 ± 0.07
5.2 ± 1.0
5.8 ± 1.8
0.03
0.06
0.16
1.1
0.58
1.9 1
I
0.19
1.9
0.12
0.11
5.5
0.55
0.04
2.8
3.2
0.04
0.45
0.25
2.2
0.38
1.3
0.47
1.4
d
0.13
5.9
0.66
0.15
3.2
3.8
a Value reported by the National Research Council of Canada.
b Single determinations.
c MAE at 115°Cfor 10 min.
d Not detected; the approximate detection limit was 0.1 mg/kg.
39
-------
TABLE 16. COMPARISON OF ANALYTE CONCENTRATIONS IN EXTRACTS
GENERATED BY SONIC ATION AND MAE WITH THE CERTIFIED VALUES
FOR THE SRM1941 MARINE SEDIMENT
Concentration Concentration
measured by measured by
Compound name
Acenaphthened
Acenaphthylened
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(ghi)perylene
Chrysened
Fluorene
Fluoranthene
Indeno(l,2,3-cd)pyrene
2-MethyInaphthaIened
Naphthalene*1
Perylene
Phenanthrene
Pyrene
Certified
value
(mg/kg)»
0.052 ± 0.002
0.115 ±0.010
0.202 ± 0.042
0.55 ±0.079
0.67 ±0.13
0.78 ±0.19
0.444 ± 0.049
0.516 ±0.08
0.702 ±0.016
0.104 ±0.005
1.22 ±0.24
0.569 ± 0.04
0.406 ± 0.036
1.322 ±0.014
0.422 ± 0.03
0.577 ± 0.059
1.08 ±0.20
sonication
extraction and
GC/MS (mg/kg)b
e
0.041
0.109
d
0.294
1 0.835 1
J I
0.135
e
e
0.950
0.285
e
0.147
f
0.344
0.915
MAE and
GC/MS
(mg/kg)b'c
0.042
0.098
0.186
0.376
0.396
0.990
0.454
0.454
0.056
1.03
0.398
0.254
f
f
0.494
0.604
8 Value reported by the National Research Council of Canada.
b Single determinations.
c MAE at 115°Cfor 10 min.
d Concentration reported for this compound is not certified by NIST.
e Not detected; the approximate detection limit was 0.1 mg/kg.
f Data not available.
40
-------
TABLE 17. COMPARISON OF ANALYTE CONCENTRATIONS IN EXTRACTS
GENERATED BY SOXTEC AND MAE WITH THE CERTIFIED VALUES
FOR THE SRS103-100 SOIL
Certified
value
Compound name
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(ajpyrene
Benzo(k + b)fluoranthene
Chrysene
Fluorene
Fluoranthene
2-Methylnaphthalene
Naphthalene
Phenanthrene
Pyrene
Dibenzofuran
Pentachlorophenol
Concentration
measured by
sonication
extraction and
(mg/kg)" GC/MS (mg/kg)b
591
16.3
425
249
97.5
156
310
475
1,307
56.7
23.6
1,450
961
306
884
± 104
± 11.1
± 67.5
± 56.8
± 26.6
± 40.1
± 62.9
± 101
± 396
± 21.0
± 28.1
± 570
±428
± 74.8
±692
683
21.0
553
240
78.0
179
272
456
1,041
78.9
41.1
1,315
714
378
1,070
Concentration
measured by
MAE and
GC/MS
(mg/kg)b'c
556
19.4
450
210
79.2
142
277
441
1,320
53.5
32.1
1,798
980
279
858
a Value reported by Fisher Scientific.
b Single determinations.
c MAE at 115°C for 10 min.
41
-------
TABLE 18. CORRELATION OF THE DATA OBTAINED FROM MAE EXTRACTS FOR DIFFERENT MATRICES
WITH THE CERTIFIED VALUES AND THE VALUES OBTAINED FROM SONICATION OR SOXTEC
EXTRACTS
Type of extraction
Reported certified value
Sonication extraction
Soxtec extraction
r
y
r
y
r
y
HS-3 marine
sediment
= 0.996
= -1.263+0.884x
= 0.997
= 0.436 +1.539x
= 0.983
= 4.026+1.934x
r
y
r
y
r
y
HS-4 marine
sediment
= 0.876
= -0.006 + 0.739x
= 0.779
= 0.183 + 0.916x
= 0.767
= 0.129 + 0.653x
r
y
r
y
a
HS-5 marine
sediment
= 0.985
= -0.285 +0.70U
= 0.969
= -0.099 +1.045x
r
y
r
y
a
SRMI94I marine
sediment
= 0.962
= -0.009 + 0.747x
= 0.889
= 0.178 + 0.779x
SRS103-100 soil
r
y
r
y
a
= 0.989
= -47.2+1.
= 0.954
= -75.9+1
122x
.2l3x
" Data not available.
-------
REFERENCES
1. Ganzler, K.; Salgo, A.; Valko, K. "Microwave Extraction - A Novel Sample Preparation
Method for Chromatography," J. Chromatogr. 371, 299-306 (1986).
2. Ganzler, K.; Salgo, A. "Microwave Extraction - A New Method Superseding
Traditional Soxhlet Extraction," Z. Lebensm.-Unters. Forsch. 184, 274-276 (1987).
3. Onuska, F. E.; Terry, K.A. "Extraction of Pesticides from Sediments Using a Microwave
Technique," Chromatographia 36, 191-194 (1993).
4. Pare, J. R. J., et al. "Microwave Extraction of Volatile Oils and Apparatus Therefor,"
Eur. Pat. Appl. EP485668 Al (1992).
5. Pare, J. R. J., et al. "Microwave-Assisted Natural Products Extraction," U. S. Patent
5,002,784 (1991).
6. Freitag, W.; John, O. "Fast Separation of Stabilizers from Polyolefins by Microwave
Heating," Angew. Makromol. Chem. 175, 181-185 (1990).
7. Lopez-Avila, V.; Bauer, K.; Milanes, J.; Beckert, W. F. "Evaluation of a Soxtec
Extraction Procedure for Extracting Organic Compounds from Soils and Sediments,"
J. AOAC Internal. 76, 864-880 (1993).
8. Lopez-Avila, V. "Development of a Soxtec Extraction Procedure for Extracting Organic
Compounds from Soils and Sediments," EPA Report 600/X-91/140, Environmental
Monitoring Systems Laboratory, Las Vegas, NV, October 1991.
43
-------
APPENDIX A
PERCENT-RECOVERY RESULTS OF THE GC/MS ANALYSES FOR THE
SIX CERTIFIED REFERENCE MATERIALS
44
-------
TABLE A-l. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-3 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) AT ROOM
TEMPERATURE"
Compound name
"Native" compounds
Naphthalene
Acenaphthyleneb
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l ,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
Fluoranthene-dj0
Benzo(a)anthracene-d t 2
Certified value
(mg/kg)
9.0 ±0.7
0.3 ±0.1
4.5 ± 1.5
13.6 ±3.1
85 ± 2.0
13.4 ±0.5
60 ±9.0
39 ±9.0
14.6 ±2.0
14.1 ±2.0
7.7 ± 1.2
2.8 ±2.0
7.4 ±3.6
5.4 ±1.3
1.3 ±0.5
5.0 ±2.0
25
25
25
Percent recovery
5 min
28.6
97.3.
47.1
33.8
53.8
32.9
54.7
50.3
40.6
49.4
1 67.1
38.1
43.1
97.7
49.0
55.6
68.7
60.4
10 min
29.0
101
44.7
31.8
49.0
33.9
49.1
45.8
36.8
46.4
1 59.9
33.1
40.7
85.4
45.2
48.5
55.1
49.2
20 min
44.6
101
54.9
40.7
62.1
39.9
67.3
59.8
48.4
56.1
1 77.6
38.9
49.4
106
54.4
70.0
83.1
69.4
a Cinnln Hatorminatir\ri Tho camnla CITO u/ac ^ O- fhp «r\lupnt Vf\llim<» U/3Q ^fl ml Thp
extract was concentrated sixfold prior to GC/MS analysis.
b The extract was concentrated 30-fold prior to GC/MS analysis.
45
-------
TABLE A-2. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-3 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING MAE
(TEMPERATURE 80°C; PRESSURE 22 PSI)a
Compound name
"Native" compounds
Naphthalene
Acenaphthyleneb
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
FluoranthenendjQ
Benzo(a)anthracene-d12
Certified value
(mg/kg)
9.0 ± 0.7
0.3 ± 0.1
4.5 ± 1.5
13.6 ± 3.1
85 ± 2.0
13.4 ± 0.5
60 ± 9.0
39 ± 9.0
14.6 ± 2.0
14.1 ± 2.0
7.7 ± 1.2
2.8 ± 2.0
7.4 ± 3.6
5.4 ± 1.3
1.3 ± 0.5
5.0 ± 2.0
25
25
25
Percent recovery
5 min
41.6
105
63.6
41.9
64.6
45.4
70.8
65.2
57.9
58.9
1 83.2
47.7
53.5
118
62.6
68.3
82.6
81.6
10 min
50.4
139
69.8
48.9
73.1
44.1
78.6
70.5
57.7
69.0
| 92.1
46.1
59.4
134
68.0
71.6
88.8
71.5
20 min
66.0
133
68.7
43.2
67.1
43.0
73.1
67.8
55.3
67.6
| 85.7
44.9
57.0
122
64.4
72.8
90.0
89.3
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated sixfold prior to GC/MS analysis.
b The extract was concentrated 30-fold prior to GC/MS analysis.
46
-------
TABLE A-3. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-3 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 115°C; PRESSURE 72 PSD*
Compound name
"Native" compounds
Naphthalene
Acenaphthyleneb
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(lc)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-dig
Fluoranthene-djQ
Benzo(a)anthracene-d12
Certified value
(mg/kg)
9.0 ± 0.7
0.3 ± 0.1
4.5 ± 1.5
13.6 ± 3.1
85 ± 2.0
13.4 ± 0.5
60 ± 9.0
39 ± 9.0
14.6 ± 2.0
14.1 ± 2.0
7.7 ± 1.2
2.8 ± 2.0
7.4 ± 3.6
5.4 ± 1.3
1.3 ± 0.5
5.0 ± 2.0
25
25
25
Percent recovery
5 min
50.4
118
66.9
40.5
65.6
45.9
68.0
63.1
57.0
59.1
| 80.7
41.2
55.4
122
61.8
72.2
85.2
80.5
10 min
85.2
125
75.6
49.3
86.3
52.0
88.4
83.8
74.2
76.7
| 108
55.0
70.2
152
78.4
83.7
106
105
20 min
61.1
158
72.4
50.9
33.2
49.0
73.5
67.7
54.7
66.2
1 86.9
44.1
57.8
126
66.4
70.0
88.4
86.3
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated sixfold prior to GC/MS analysis.
b The extract was concentrated 30-fold prior to GC/MS analysis.
47
-------
TABLE A-4. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-3 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 145°C; PRESSURE ISO PSI)a
Compound name
"Native" compounds
Naphthalene
Acenaphthyleneb
Acenaphthene
Fluorene
Phenanthrene .
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
D ibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
FIuoranthene-d10
Benzo(a)anthracene-d 12
Certified value
(mg/kg)
9.0 ± 0.7
0.3 ± 0.1
4.5 ± 1.5
13.6 ± 3.1
85 ± 2.0
13.4 ± 0.5
60 ± 9.0
39 ± 9.0
14.6 ± 2.0
14.1 ± 2.0
7.7 ± 1.2
2.8 ± 2.0
7.4 ± 3.6
5.4 ± 1.3
1.3 ± 0.5
5.0 ± 2.0
25
25
25
5 min
61.1
118
64.7
48.5
70.0
45.1
77.2
68.5
56.8
62.3
1 83.6
43.4
54.6
124
63.0
70.8
94.0
83.2
Percent recovery
10 min
123
163
53.1
36.7
55.8
43.0
56.4
50.1
40.5
48.7
} 60.8 1
33.8
40.4
86.9
47.0
57.2
66.1
54.1
20 min
73.8
188
66.4
51.0
68.5
50.0
81.4
60.8
52.5
58.5
73. 8
44.2
50.2
111
57.4
68.9
95.6
71.8
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated sixfold prior to GC/MS analysis.
b The extract was concentrated 30-fold prior to GC/MS analysis.
48
-------
TABLE A-S. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-4 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) AT ROOM
TEMPERATURE8
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
Fluoranthene-d10
Benzo(a)anthracene-d j 2
(mg/kg)
0.15b
0.15b
0.15b
0.15b
0.68 ± 0.08
0.14 ± 0.07
1.25 ± 0.10
0.94 ± 0.12
0.53 ± 0.05
0.65 ± 0.08
0.70 ± 0.15
0.36 ± 0.05
0.65 ± 0.08
0.51 ± 0.15
0.12 ± 0.05
0.58 ± 0.22
1.0
1.0
1.0
5 mm
b
b
b
b
26.8
32.9
27.4
38.7
49.4
39.4
1 21.9
5.5
22.4
c
3.8
53.2
29.2
40.0
10 mm
b
b
b
b
40.6
48.6
44.0
58.7
74.0
51.1
1 34.5
23.7
36.5
c
26.9
80.4
50.0
71.2
20 mm
b
b
b
b
40.6
41.4
43.8
56.2
90.2
43.4
1 32.3
28.6
52.5
c
29.0
66.6
57.2
99.2
Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
Not detected; the approximate detection limit was 0.1 mg/kg.
49
-------
TABLE A-6. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-4 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 80°C; PRESSURE 22 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
Fluoranthene^d10
Benzo(a)anthracene-d 12
(mg/kg)
0.15b
0.15b
0.15b
0.15b
0.68 ± 0.08
0.14 ± 0.07
1.25 ± 0.10
0.94 ± 0.12
0.53 ± 0.05
0.65 ± 0.08
0.70 ± 0.15
0.36 ± 0.05
0.65 ± 0.08
0.51 ± 0.15
0.12 ± 0.05
0.58 ± 0.22
1.0
1.0
1.0
5 mm
b
b
b
b
51.2
50.0
53.8
68.9
105
45.5
1 46.6
35.4
87.5
c
56.2
67.8
64.4
107
10 mm
b
b
b
b
57.6
57.1
62.9
76.4
123
52.3
1 49.4
52.0
76.1
c
54.5
67.4
74.4
128
20 mm
b
b
b
b
62.1
62.9
72.2
80.0
136
52.9
1 53.0
23.7
94.5
c
57.2
73.2
86.0
141
8 Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
c Not detected; the approximate detection limit was 0.1 mg/kg.
50
-------
TABLE A-7. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-4 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 115°C; PRESSURE 72 PSI)a
Compound name
Certified value
(mg/kg)
Percent recovery
5 min
10 min
20 min
"Native" compounds
Naphthalene 0.15b b
Acenaphthylene 0.15b b
Acenaphthene 0.15b b
Fluorene 0.15b b
Phenanthrene 0.68 ± 0.08 62.1
Anthracene 0.14 ± 0.07 65.7
Fluoranthene 1.25 ± 0.10 65.9
Pyrene 0.94 ± 0.12 75.7
Benzo(a)anthracene 0.53 ± 0.05 128
Chrysene 0.65 ± 0.08 52.9
Benzo(b)fluoranthene 0.70 ± 0.15 \ 52 3
Benzo(k)fluoranthene 0.36 ± 0.05 /
Benzo(a)pyrene 0.65 ± 0.08 42.2
Indeno(l,2,3-cd)pyrene 0.51 ± 0.15 83.9
Dibenzo(ah)anthracene 0.12 ± 0.05 c
Benzo(ghi)perylene 0.58 ± 0.22 52.8
Spikes
Anthracene-d|0 1.0 75.2
Fluoranthene-d,0 1.0 77.4
Benzo(a)anthracene-d|2 1.0 140
b
b
b
b
62.6
72.9
73.6
86.8
141
63.4
54.5
44.6
111
c
82.4
72.4
87.0
158
b
b
b
b
57.6
65.7
66.7
77.9
133
52.6
51.5
46.8
100
c
55.9
60.6
80.2
145
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
c Not detected; the approximate detection limit was 0.1 mg/kg.
51
-------
TABLE A-8. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-4 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 145°C; PRESSURE 150 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
D ibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d,0
Fluoranthene-d,0
Benzo(a)anthracene-d 12
(mg/kg)
0.15b
0.15b
0.15"
0.15b
0.68 ± 0.08
0.14 ± 0.07
1.25 ± 0.10
0.94 ± 0.12
0.53 ± 0.05
0.65 ± 0.08
0.70 ±0.15 1
0.36 ± 0.05 J
0.65 ± 0.08
0.51 ± 0.15
0.12 ± 0.05
0.58 ± 0.22
1.0
1.0
1.0
5 mm
b
b
b
b
74.7
85.7
66.1
82.3
134
55.7
50.4
44.3
80.4
c
52.4
71.2
79.2
141
10 mm
b
b
b
b
50.0
55.7
52.6
63.6
109
40.9
1 42.8
46.2
83.9
c
38.6
56.4
65.4
113
20 mm
b
b
b
b
50.0
55.7
52.6
63.6
109
40.9
1 42.8
65.8
72.9
c
50.0
72.0
69.4
130
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
c Not detected; the approximate detection limit was 0.1 mg/kg.
52
-------
TABLE A-9. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-5 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) AT ROOM
TEMPERATURE"
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l ,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d,0
Fluoranthene-d10
Benzo(a)anthracene-d 12
(mg/kg)
0.25 ± 0.07
0.15b
0.23 ± 0.10
0.4 ± 0.10
5.2 ± 1.0
0.38 ± 0.15
8.4 ± 2.6
5.8 ± 1.8
2.9 ± 1.2
2.8 ± 0.9
2.0 ± 1.0 \
1.0 ± 0.4 }
1.7 ± 0.8
1.3 ± 0.3
0.2 ± 0.1
1.3 ± 0.7
5.0
5.0
5.0
5 mm
28.8
b
13.0
19.5
39.4
48.4
40.2
39.4
41.2
32.3
21.8
22.9
28.9
c
24.8
50.2
54.2
94.6
10 mm
33.6
b
16.5
22.5
46.1
46.8
47.8
44.7
47.9
41.3
) 22.3
1
22.4
48.6
c
32.3
55.6
67.1
112
20 min
31.2
b
13.0
21.5
46.0
45.8
48.4
45.7
52.9
38.0
1 31 7
1
28.8
36.2
c
39.2
53.4
63.7
109
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
c Not detected; the approximate detection limit was 0.1 mg/kg.
53
-------
TABLE A-10. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-5 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 80°C; PRESSURE 22 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l ,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d,0
Fluoranthene-d10
Benzo(a)anthracene-d 12
(mg/kg)
0.25 ± 0.07
0.15°
0.23 ± 0.10
0.4 ± 0.10
5.2 ± 1.0
0.38 ± 0.15
8.4 + 2.6
5.8 ± 1.8
2.9 ± 1.2
2.8 ± 0.9
2.0 ± 1.0 1
1.0 ± 0.4 /
1.7 ± 0.8
1.3 ± 0.3
0.2 ± 0.1
1.3 ± 0.7
5.0
5.0
5.0
5 mm
53.6
c
13.9
29.5
56.4
46.3
61.5
56.8
71.4
36.9
43.1
27.3
51.2
d
37.4
55.3
68.1
130
10 mm
45.6
c
16.5
29.5
60.6
60.0
68.5
59.4
64.1
46.9
1 39.5
28.9
40.6
d
43.8
58.0
71.3
126
20 mm
419b
c
14.8
32.0
58.5
50.0
70.5
61.6
69.9
37.3
1 41.3
29.5
46.0
d
38.3
57.7
73.3
134
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Cannot explain high recovery.
c Upper limit; the amount is not greater than 0:15 mg/kg. Therefore the percent recovery
could not be calculated.
d Not detected; the approximate detection limit was 0.1 mg/kg.
54
-------
TABLE A-ll. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-5 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 115°C; PRESSURE 72 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d,0
Fluoranthene-d10
Benzo(a)anthracene-d 12
(mg/kg)
0.25 ± 0.07
0.15C
0.23 ± 0.10
0.4 ± 0.10
5.2 ± 1.0
0.38 ± 0.15
8.4 ± 2.6
5.8 ± 1.8
2.9 ± 1.2
2.8 ± 0.9
2.0 ± 1.0 1
1.0 ± 0.4 I
1.7 ± 0.8
1.3 ± 0.3
0.2 ± 0.1
1.3 ± 0.7
5.0
5.0
5.0
5 mm
416b
c
20.0
30.0
63.7
52.6
74.3
63.5
72.7
40.2
42.8
30.1
55.1
d
38.2
57.5
76.2
134
10 mm
61.6
c
18.3
32.5
61.3
65.8
69.8
65.1
77.3
48.4
1 41.8
22.4
50.8
d
35.8
56.9
73.2
141
20 mm
67.2
c
20.0
31.0
65.0
70.0
78.3
68.2
76.6
45.1
j 43.6
31.6
49.2
d
34.9
58.8
81.7
143
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Cannot explain high recovery.
c Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
d Not detected; the approximate detection limit was 0.1 mg/kg.
55
-------
TABLE A-12. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE HS-5 MARINE SEDIMENT WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 14S°C; PRESSURE 150 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Dibenzo(ah)anthracene
Benzo(ghi)perylene
Spikes
Anthracene-d10
Fluoranthene-d10
Benzo(a)anthracene-d j2
(mg/kg)
0.25 ± 0.07
0.15°
0.23 ± 0.10
0.4 ± 0.10
5.2 ± 1.0
0.38 ± 0.15
8.4 ± 2.6
5.8 ± 1.8
2.9 ± 1.2
2.8 ± 0.9
2.0 ± 1.0
1.0 ± 0.4
1.7 ± 0.8
1.3 ± 0.3
0.2 ± 0.1
1.3 ± 0.7
5.0
5.0
5.0
5 min
76.8
c
19.1
32.0
59.8
66.8
69.3
62.5
71.2
38.5
1 40.9
33.6
50.8
d
29.7
53.6
69.3
130
10 min
522b
c
15.7
31.0
64.0
62.1
70.5
65.4
83.7
38.1
1 45.9
37.4
59.2
d
45.1
56.4
70.6
133
20 min
73.6
c
22.6
33.0
67.8
63.2
73.0
69.6
85.2
42.6
1 43.6
22.2
63.1
d
39.1
60.0
74.0
154
8 Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b Cannot explain high recovery.
c Upper limit; the amount present is not greater than 0.15 mg/kg. Therefore the percent
recovery could not be calculated.
d Not detected; the approximate detection limit was 0.1 mg/kg.
56
-------
TABLE A-13. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS
FROM THE NIST SRM1941 MARINE SEDIMENT WITH HEXANE-
ACETONE (1:1) AT ROOM TEMPERATURE"
Compound name
"Native" compounds
NaphthaJeneb
2 -Methyl naphthal eneb
Acenaphthyleneb
Acenaphtheneb
FIuoreneb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chryseneb
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno( 1 ,2 ,3-cd)pyrene
Benzo(ghi)perylene
Spikes
Anthracene-d10
Fluoranthene-d10
Benzo(a)anthracene-d , 2
Certified value
(mg/kg)
1.322 ± 0.014
0.406 ± 0.036
0.115 ± 0.010
0.052 ± 0.002
0.104 ± 0.005
0.577 ± 0.059
0.202 ± 0.042
1.22 ± 0.24
1.08 ± 0.20
0.55 ± 0.079
0.702 ± 0.016
0.78 ± 0.19 1
0.444 ± 0.040 /
0.67 ± 0.13
0.569 ± 0.040
0.516 ± 0.083
0.6
0.6
0.6
Percent recovery
5 min
15.7
16.3
76.5
57.7
65.4
54.1
85.1
68.4
50.0
62.5
61.0
85.7
51.6
59.8
73.6
117
90.3
73.3
10 min
22.2
11.8
64.3
42.3
46.2
42.6
51.5
52.1
38.7
46.2
55.6
1 67 4 1
/ ' J
36.7
54.5
48.8
101
51.7
42.3
20 min
34.0
12.3
69.6
42.3
44.2
40.2
92.1
47.0
31.1
36.7
55.3
i 68.0
37.0
51.0
53.9
98.0
74.0
56.3
a Single determination. The sample size was 5 g; the solvent volume was
extract was concentrated 30-fold prior to GC/MS analysis.
b The concentration reported for this compound is not certified by NIST.
mL. The
57
-------
TABLE A-14.
PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS
FROM THE NIST SRM1941 MARINE SEDIMENT WITH HEXANE-
ACETONE (1:1) USING MAE (TEMPERATURE 80°C; PRESSURE
22 PSI)a
Compound name
"Native" compounds
Naphthalene1*
2-Methylnaphthaleneb
Acenaphthyleneb
Acenaphtheneb
Fluoreneb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chryseneb
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l ,2,3-cd)pyrene
Benzo(ghi)perylene
Spikes
Anthracene-d10
FluorantheneHdl0
Benzo(a)anthracene-d j 2
Certified value
(mg/kg)
1.322 ± 0.014
0.406 ± 0.036
0.115 ± 0.010
0.052 ± 0.002
0.104 ± 0.005
0.577 ± 0.059
0.202 ± 0.042
1.22 ± 0.24
1.08 ± 0.20
0.55 ± 0.079
0.702 ± 0.016
0.78 ±0.19 1
0.444 ± 0.049 J
0.67 ± 0.13
0.569 ± 0.040
0.516 ± 0.083
0.6
0.6
0.6
Percent recovery
5 min
23.9
22.2
83.5
53.8
73.1
70.7
90.1
76.7
51.3
68.7
82.1
82.7
50.4
65.4
74.4
103
95.7
98.7
10 min
24.1
25.1
76.5
76.9
78.8
76.9
92.1
71.0
45.7
74.5
63.8
1 78 1
J
49.9
63.3
75.2
102
70.7
77.7
20 min
162C
36.5
67.8
69.2
63.5
76.6
98.0
80.2
50.0
85.1
85.5
1 89.3
52.8
68.5
85.7
105
101
99.3
a Single determination. The sample size was 5 g; the solvent volume was 30 mL.
extract was concentrated 30-fold prior to GC/MS analysis.
b The concentration reported for this compound is not certified by NIST.
c Cannot explain high recovery.
The
58
-------
TABLE A-15.
PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS
FROM THE N1ST SRM1941 MARINE SEDIMENT WITH HEXANE-
ACETONE (1:1) USING MAE (TEMPERATURE 115°C; PRESSURE
72PSI)a
Compound name
"Native" compounds
Naphthalene6
2-Methylnaphthaleneb
Acenaphthyleneb
Acenaphtheneb
Fluoreneb
Phenanthrene
Anthracene
Fluoramhene
Pyrene
Benzo(a)anthracene
Chryseneb
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Benzo(ghi)perylene
Spikes
Anthracene-d|0
Fluoranthene-d10
Benzo(a)anthracene-d 12
Certified value
(mg/kg)
1.322 ± 0.014
0.406 ± 0.036
0.115 ± 0.010
0.052 ± 0.002
0.104 ± 0.005
0.577 ± 0.059
0.202 ± 0.042
1.22 ± 0.24
1.08 ± 0.20
0.55 ± 0.079
0.702 ± 0.016
0.78 ±0.19 \
0.444 ± 0.049 j
0.67 ± 0.13
0.569 ± 0.040
0.516 ± 0.083
0.6
0.6
0.6
Percent recovery
5 min
38.0
39.9
88.7
80.8
69.2
91.9
109
76.9
52.4
82.9
71.5
80.0
54.3
69.2
93.0
112
79.0
64.0
10 min
345b
62.6
85.2
80.8
53.8
85.6
92.1
84.6
55.9
68.4
64.7
1 80.9
59.1
69.9
88.0
100
85.0
61.3
20 min
488b
78.3
85.2
88.5
57.7
95.7
120
93.0
62.4
76.7
66.4
1 91.1
62.7
74.2
93.0
103
95.3
64.0
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was concentrated 30-fold prior to GC/MS analysis.
b The concentration reported for this compound is not certified by NIST.
c Cannot explain high recovery.
59
-------
TABLE A-l
-------
TABLE A-17.
PERCENT RECOVERIES OF "NATIVE" COMPOUNDS FROM THE
SRS103-100 SOIL WITH HEXANE-ACETONE (1:1) AT ROOM
TEMPERATURE"
Compound name
Naphthalene6
2-MethylnaphthaJeneb
Acenaphthyleneb
Acenaphthene
Dibenzofuran
Fluorene
Pentachlorophenolb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b + k)fluoranthene
Benzo(a)pyrene
Certified value
(mg/kg)
23.6
56.7
16.3
591
306
476
884
1,450
425
1,307
961
249
310
156
97.5
± 28.1
± 21.0
± 11.1
± 104
± 74.8
± 101
± 692
± 570
± 67.5
± 396
± 428
± 56.8
± 62.9
± 40.1
± 26.6
Percent recovery
5 min
64.6
54.0
73.6
59.1
67.9
66.2
60.5
91.7
71.2
63.9
81.1
65.7
68.0
48.8
48.0
10 min
64.1
56.3
76.6
54.9
61.1
54.8
59.5
86.1
72.2
62.1
74.7
67.1
57.6
48.8
45.5
20 min
75.8
59.0
86.9
63.8
75.2
71.7
68.7
101
74.0
74.6
94.3
82.5
67.4
59.6
58.5
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was diluted 10-fold prior to GC/MS.
b The extract was diluted twofold prior to GC/MS analysis.
61
-------
TABLE A-18. PERCENT RECOVERIES OF "NATIVE" COMPOUNDS FROM THE
SRS103-100 SOIL WITH HEXANE-ACETONE (1:1) USING MAE
(TEMPERATURE 80°C; PRESSURE 22 PSI)a
Compound name
Naphthalene1*
2-Methylnaphthalenet>
Acenaphthyleneb
Acenaphthene
Dibenzofuran
Fluorene
Pentachlorophenolb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b + k)fluoranthene
Benzo(a)pyrene
Certified value
(mg/kg)
23.6
56.7
16.3
591
306
476
884
1,450
425
1,307
961
249
310
156
97.5
± 28.1
± 21.0
± 11.1
± 104
± 74.8
± 101
± 692
± 570
± 67.5
± 396
± 428
± 56.8
± 62.9
± 40.1
± 26.6
Percent recovery
5 min
116
82.3
101
84.0
82.5
83.0
40.3
106
92.1
82.2
85.0
69.8
82.1
82.1
72.6
10 min
133
90.8
107
94.2
91.3
92.7
70.5
118
106
91.0
95.1
76.7
90.4
86.3
75.7
20 min
152
100
123
98.3
96.4
96.5
73.1
125
110
100
103
83.0
92.6
92.1
86.8
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was diluted 10-fold prior to GC/MS analysis.
b The extract was diluted twofold prior to GC/MS analysis.
62
-------
TABLE A-19. PERCENT RECOVERIES OF "NATIVE" COMPOUNDS FROM THE
SRS103-100 SOIL WITH HEXANE-ACETONE (1:1) USING MAE
(TEMPERATURE 11S8C; PRESSURE 72 PSI)a
Compound name
Naphthalene6
2-Methyloaphthaleneb
Acenaphthyleneb
Acenaphthene
Oibenzofuran
Fluorene
Pentachlorophenolb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b + k)fluoranthene
Benzo(a)pyrene
Certified value
(mg/kg)
23.6
56.7
16.3
591
306
476
884
1,450
425
1,307
961
249
310
156
97.5
± 28.1
± 21.0
± 11.1
± 104
± 74.8
± 101
± 692
± 570
± 67.5
± 396
± 428
± 56.8
± 62.9
± 40.1
± 26.6
Percent recovery
5 min
132
89.3
111
94.6
91.5
86.9
76.0
122
104
94.5
95.7
83.7
85.0
88.6
75.1
10 min
136
94.4
119
94.1
91.1
92.9
97.1
124
106
101
102
84.2
89.3
90.9
81.2
20 min
146
91.4
107
93.8
93.8
92.7
95.5
122
101
94.6
97.1
84.9
86.8
89.2
80.0
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was diluted 10-fold prior to GC/MS analysis.
b The extract was diluted twofold prior to GC/MS analysis.
63
-------
TABLE A-20. PERCENT RECOVERIES OF "NATIVE" COMPOUNDS FROM THE
SRS1Q3-100 SOIL WITH HEXANE-ACETONE (1:1) USING MAE
(TEMPERATURE 145°C; PRESSURE 150 PSI)'
Compound name
Naphthalene1"
2-MethyInaphthaleneb
Acenaphthyleneb
Acenaphthene
Dibenzofuran
Fluorene
Pentachlorophenolb
Phenanthrene
Anthracene
Fluoranthene
Pyrene
8enzo(a)anthracene
Chrysene
Benzo(b + k)fluoranthene
Benzo(a)pyrene
Certified value
(mg/kg)
23.6
56.7
16.3
591
306
476
884
1,450
425
1,307
961
249
310
156
97.5
± 28.1
± 21.0
± 11.1
± 104
± 74.8
± 101
± 692
± 570
± 67.5
± 396
± 428
± 56.8
± 62.9
± 40.1
± 26.6
Percent recovery
5 min
118
75.3
95.0
94.7
93.5
93.5
74.4
123
102
92.9
96.4
82.5
84.3
85.9
75.1
10 min
162
92.5
123
88.2
92.5
91.5
81.5 .
122
102
92.9
95.6
79.6
89.3
86.7
75.1
20 min
166
96.5
113
95.2
94.6
90.2
89.7
126
98
95.7
.102
82.0
92.0
92.1
79.4
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The
extract was diluted 10-fold prior to GC/MS analysis.
b The extract was diluted twofold prior to GC/MS analysis.
64
-------
TABLE A-21. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE ERA SOIL (LOT NO. 321) WITH HEXANE-ACETONE (1:1) AT ROOM
TEMPERATURE*
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Dibenzofuran
Pentachlorophenol
Anthracene
Fluoranthene
Pyrene
Chrysene
Benzo(b)fluoranthene
1 ,2-Dichlorobenzene
2-MethyIphenol
N-Nitroso-di-n-propylamine
Nitrobenzene
2,4-Dichlorophenol
1 ,2,4-TrichIorobenzene
2,4,6-Trichlorophenol
2,4-Dinitrotoluene
Carbazole
Di-n-butyl-phthalate
Bis(2-ethylhexyl)phthaJate
Spikes
Anthracene-djQ
Fluoranthene-djQ
Benzo(a)anthracene-dt2
(mg/kg)
2.96
1.70
6.68
3.52
8.09
3.78
4.47
2.03
10.0
5.46
5.01
7.87
5.52
9.36
2.82
4.86
5.00
3.43
7.62
5.00
5.00
5.00
5 mm
58.6
67.4
36.3
44.0
65.2
48.7
70.7
44.6
33.4
20.3
93.7
90.2
65.0
52.5
59.1
139
79.4
129
53.5
87.6
98.8
99.2
10 mm
50.5
59.9
34.1
41.6
62.7
48.5
65.5
43.4
30.5
19.2
89.2
87.9
64.0
49.4
58.2
123
74.8
121
51.4
86.4
89.0
94.5
20 mm
46.4
53.8
35.3
39.6
61.1
44.6
61.6
47.6
25.5
16.7
79.7
74.7
57.8
43.7
48.6
112
65.6
112
54.9
89.2
105
103
a Single determination: The sample size was 5 g; the solvent volume was 30 mL. The extract
was concentrated 30-fold prior to GC/MS analysis.
65
-------
TABLE A-22. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE ERA SOIL (LOT NO. 321) WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 80°C; PRESSURE 22 PSI)a
Compound name
"Native" compounds
Naphthalene
Dibenzofuran
Pentachlorophenol
Anthracene
Fluoranthene
Pyrene
Chrysene
Benzo(b)fluoranthene
1 ,2-Dichlorobenzene
2-Methylphenol
N-Nitroso-di-n-propylamine
Nitrobenzene
2,4-Dichlorophenol
1 ,2,4-Trichlorobenzene
2,4,6-Trichlorophenol
2,4-Dinitrotoluene
Carbazole
Di-n-butyl-phthalate
Bis(2-ethylhexyl)phthaJate
Spikes
Anthracene-d10
Fluor anthene-d,0
Benzo(a)anthracene-d,2
Certified value
(mg/kg)
2.96
1.70
6.68
3.52
8.09
3.78
4.47
2.03
10.0
5.46
5.01
7.87
5.52
9.36
2.82
4.86
5.00
3.43
7.62
5.00
5.00
5.00
Percent recovery
5 min
53.9
71.4
47.6
49.3
70.2
55.6
66.0
50.0
31.3
20.7
78.0
79.4
78.7
53.0
71.1
123
87.6
113
59.7
86.2
95.2
98.2
10 min
56.8
74.1
45.7
48.9
72.3
55.6
69.3
51.0
33.8
21.1
81.9
83.7
80.9
54.6
70.8
122
95.3
117
62.2
82.3
91.3
91.6
20 min
64.9
80.7
56.8
54.5
83.5
66.7
83.7
62.1
32.4
23.2
84.3
84.3
79.6
55.7
82.4
140
107
141
73.2
84.4
97.1
97.7
8 Single determination. The sample size was 5 g; the solvent volume was 30 mL. The extract
was concentrated 30-fold prior to GC/MS analysis.
66
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TABLE A-23. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE ERA SOIL (LOT NO. 321) WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 115°C; PRESSURE 72 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Dibenzofuran
Pentachlorophenol
Anthracene
Fluoranthene
Pyrene
Chrysene
Benzo(b)fluoranthene
1 ,2-Dichlorobenzene
2-Methylphenol
N-Nitroso-di-n-propylamine
Nitrobenzene
2,4-Dichlorophenol
1 ,2,4-Trichlorobenzene
2,4,6-Trichlorophenol
2,4-Dinitrotoluene
Carbazole
Di-n-butyl-phthalate
Bis(2-ethylhexyl)phthalate
Spikes
Anthracene-d10
Fluoranthene^d10
Benzo(a)anthracene-d , 2
(mg/kg)
2.96
1.70
6.68
3.52
8.09
3.78
4.47
2.03
10.0
5.46
5.01
7.87
5.52
9.36
2.82
4.86
5.00
3.43
7.62
5.00
5.00
5.00
5 mm
71.4
91.6
52.5
64.5
102
81.2
106
74.7
37.6
25.4
98.7
104
112
67.0
94.8
143
136
166
92.4
83.9
92.6
98.2
10 mm
105
82.2
67.5
61.3
89.3
78.8
87.2
68.9
32.7
17.9
80.7
82.6
87.1
55.7
90.9
142
113
125
79.1
87.9
98.0
96.8
20 min
113
84.4
76.6
64.8
96.6
79.4
100
73.4
33.4
23.8
85.6
88.6
93.2
59.4
100
144
120
145
88.6
88.4
101
96.6
a Single determination. The sample size was 5 g; the solvent volume was 30 mL. The extract
was concentrated 30-fold prior to GC/MS analysis.
67
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TABLE A-24. PERCENT RECOVERIES OF "NATIVE" AND SPIKED COMPOUNDS FROM
THE ERA SOIL (LOT NO. 321) WITH HEXANE-ACETONE (1:1) USING
MAE (TEMPERATURE 14S°C; PRESSURE 150 PSI)a
Certified value
Percent recovery
Compound name
"Native" compounds
Naphthalene
Dibenzofuran
Pentachlorophenol
Anthracene
Fluoranthene -
Pyrene
Chrysene
Benzo(b)fluoranthene
1 ,2-Dichlorobenzene
2-Methylphenol
N-Nitroso-di-n-propylamine
Nitrobenzene
2,4-Dichlorophenol
1 ,2,4-Trichlorobenzene
2,4,6-TrichJorophenol
2,4-Dinitrotoluene
Carbazole
Di-n-butyl-phthalate
Bis(2-ethylhexyl)phthalate
Spikes
Anthracene-d10
Fluoranthene-d10
Benzo(a)anthracene-d 12
(mg/kg)
2.96
1.70
6.68
3.52
8.09
3.78
4.47
2.03
10.0
5.46
5.01
7.87
5.52
9.36
2.82
4.86
5.00
3.43
7.62
5.00
5.00
5.00
5 mm
160
83.6
76.8
69.5
91.1
78.3
89.7
74.8
29.6
24.5
85.9
96.3
96.4
54.1
109
140
125
134
85.7
96.0
104
99.6
10 mm
69.3
92.7
83.6
78.9
102
92.1
104
80.9
32.3
28.0
85.7
98.2
103
61.9
129
159
142
146
89.8
93.8
100
101
20 mm
66.8
81.3
76.0
63.6
89.4
79.7
84.3
68.8
27.6
20.6
74.9
83.4
85.7
52.5
91.1
125
118
130
76.7
85.7
93.1
92.2
a Cinrrla Hotorminot inn Th» eomnlo C'ITO u/ac S o- th(> cnlvpnt vnliimp. was ^0 ml. The extract
was concentrated 30-fold prior to GC/MS analysis.
68
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