United States
Environmental Protection
Agency
Industrial
Laboratory
Cincinnati OH 4S2W
EPA-600/2-80-157
June 1980
Research and Development
Dioxins
Volume II.
Analytical Method for
Industrial Wastes
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL MONITORING series,
This series describes research conducted to develop new or improved methods
and instrumentation for the identification and quantification of environmental
pollutants at the lowest conceivably significant concentrations. It also includes
studies to determine the ambient concentrations of pollutants in the environment
and/or the variance of pollutants as a function of time or meteorological factors.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-80-157
June 1980
DIOXINS:
VOLUME II.
ANALYTICAL METHOD FOR INDUSTRIAL WASTES
by
T. 0. Tiernan, M. L. Taylor, S. D. Erk,
0. 6. Solch, G. Van Ness, and J. Dryden
The Brehm Laboratory and Department of Chemistry
Wright State University
Dayton, Ohio 45435
Contract No. 68-03-2659
Project Officer
David R. Watkins
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.
n
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory-
Cincinnati (lERL-Ci) assists in developing and demonstrating new and im-
proved methodologies that will meet these needs both efficiently and
economically.
This report is one of a three-volume series dealing with a group of
hazardous chemical compounds known as dioxins. The extreme toxicity of one
of these chemicals, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), has
been a concern of both scientific researchers and the public for many years.
The sheer mass of published information that has resulted from this concern
has created difficulties in assessing the overall scope of the dioxin
problem. In this report series the voluminous data on 2,3,7,8-TCDD and
other dioxins are summarized and assembled in a manner that allows compari-
son of related observations from many sources; thus, the series serves as a
comprehensive guide in evaluation of the environmental hazards of dioxins.
Volume I is a state-of-the-art review of dioxin literature. Detailed
information is presented on the chemistry, sources, degradation, transport,
disposal, and health effects of dioxins. Accounts of public and occupa-
tional exposure to dioxins are also included. Volume II details the devel-
opment of a new analytical method for detecting part-per-trill ion levels of
dioxins in industrial wastes. It also includes a review of the analytical
literature on methods of detecting dioxins in various types of environmental
samples. Volume III identifies various routes of formation of dioxins in
addition to the classical route of the hydrolysis of chlorophenols. The
possible presence of dioxins in basic organic chemicals and pesticides is
addressed, and production locations for these materials are identified.
For further information, contact Project Officer David R. Watkins,
Organic and Inorganic Chemicals Branch, lERL-Ci. Phone (513) 684-4481.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
m
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PREFACE
This report is Volume II in a series of three reports dealing with a
group of hazardous chemical compounds known as dioxins. This volume dis-
cusses the development of a new analytical technique for identifying dioxins
in industrial wastes, and presents a bibliography of other analytical
methods for determining dioxins in various types of environmental samples.
Other volumes of this series examine the occurrence, environmental trans-
port, toxicity, and disposal of this class of compounds, the detailed
chemistry of dioxin formation, and the commercial products with potential
for containing dioxin contaminants.
An extensive body of published literature has appeared during the past
25 years that has been concerned primarily with one extremely toxic member
of this class of compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin. Often
described in both popular and technical literature as "TCDD" or simply
"dioxin," this compound is one of the most toxic substances known to
science. This report series is concerned not only with this compound, but
also with all of its chemical relatives that contain the dioxin nucleus.
Throughout these reports, the term "TCDD's" is used to indicate the family
of 22 tetrachlorodibenzo-p-dioxin isomers, whereas the term "dioxin" is used
to indicate any compound with the basic dioxin nucleus. The most toxic
isomer among those that have been assessed is specifically designated as
"2,3,7,8-TCDD."
The objective in the use of these terms is to clarify a point of tech-
nical confusion that has occasionally hindered comparison of information
from various sources. In particular, early laboratory analyses often
reported the presence of "TCDD," which may have been the most-toxic
2,3,7,8-isomer or may have been a mixture of several of the tetrachloro
isomers, some of which are relatively nontoxic. Throughout this report
series, the specific term 2,3,7,8-TCDD is used when it was the intent of the
investigator to refer to this most-toxic isomer. Since early analytical
methods could not dependably isolate specific isomers from environmental
samples, the generic term "TCDD's" is used when this term appears to be most
appropriate in light of present technology.
IV
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ABSTRACT
The overall objective of this research project was to develop a unified
analytical approach for use in quantifying part-per-trill ion levels of
tetrachlorodibenzo-p-dioxins (TCDD's) in various chemical wastes.
The EPA provided Brehm Laboratory of Wright State University with 17
waste samples from plants manufacturing trichlorophenol, pentachlorophenol,
and hexachlorophene, and from plants processing wood preservatives.
The extraction procedure developed for isolating the TCDD's from the
various types of sample matrices is fully described. Analysis was accom-
plished using highly specific and sensitive coupled gas chromatographic-mass
spectrometric (GC-MS) methods. Both low and high resolution MS techniques
were employed. This methodology is also described in detail. The pro-
cedures presented in this report were acceptable for most of the industrial
process samples provided. TCDD's were detected and quantitatively deter-
mined in several of the samples at levels in the ppt to ppm range. One
sample, identified as a trichlorophenol stillbottom, was found to contain
40 ppm TCDD's. This method was not applicable for wood or woodlike products
and difficulties were also encountered with some samples that were suscep-
tible to emulsion formation in the preparation stages.
The Brehm Laboratory submitted this report in fulfillment of a subcon-
tractual effort with Battelle Columbus Laboratories, supported through a
prime contract between Battelle and the U.S. Environmental Protection Agency
(Contract No. 68-03-2659). This report covers the period October 1, 1978 to
March 31, 1979 and work was completed as of March 3, 1979.
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CONTENTS
Foreword
Preface
Abstract
Figures
Tables
List of Abbreviations
Acknowledgment
I. Introduction
2. Analytical Background
3. Analytical Method
4. Discussion and Results
5. Conclusions and Recommendations
References
Appendix A. Principles of GC-MS
Appendix B. Other Instrumental Methods
Appendix C. Literature Review
Page
i i i
iv
v
viii
ix
x
xi
I
4
8
13
43
45
49
57
60
vii
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FIGURES
Number Page
1 Mass chrotnatogram of extract of EPA sample 2 at m/e 322
obtained with GC-QMS. 16
2 High pressure liquid chromatogram of sample 2. 23
3 High pressure liquid chromatogram of 2,3,7,8-TCDD standard. 24
4 Four-ion mass fragmentogram of benzene solvent blank
obtained with GC-MS-30. 26
5 Four-ion mass fragmentogram of 50 pg of 2,3,7,8-TCDD
and 1 ng 37Cl4-2,3,7,8-TCDD obtained with GC-MS-30. 27
6 Four-ion mass fragmentogram of sample 12700 obtained
with GC-MS-30. 28
7 Four-ion mass fragmentogram of sample 5 obtained
with GC-MS-30. 29
8 Dual-ion mass fragmentogram of sample 2, obtained
with GC-MS-30, mass resolution 1:12,500. 35
9 Dual-ion mass fragmentogram of 150 pg of 2,3,7,8-TCDD
standard obtained with GC-MS-30, mass resolution 1:12,500. 36
10 Mass fragmentograms using GC-MS-30 of mixtures of
2,3,7,8-TCDD with other chlorinated compounds. 38
11 Mass spectrum of 2,3,7,8-TCDD standard and sample 2
(mass range m/e 330 to m/e 250). 41
12 Mass spectrum of 2,3,7,8-TCDD standard and sample 2
(mass range m/e 250 to m/e 150). 42
viii
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TABLES
Number Page
1 Samples Used in Development of Analytical Method for
TCDD's in Industrial Wastes 14
2 Elution of TCDD's in Extracts of Sample 2 17
3 Content of TCDD's in Column Fractions for Sample 2 19
4 Elution of TCDD's in Extracts of Sample C04131 20
5 Results of GC-MS-30 Analyses of EPA Samples for TCDD's 25
6 TCDD Isomer Content of Column Fractions of 2,3,7,8-TCDD
Spiked Samples 31
7 Recoveries of 2,3,7,8-TCDD Spiked Samples Following
Alumina Column Chromatography 33
8 Results of GC-MS-30 Analyses of 37Cl4-2,3,7,8-TCDD
Spiked Samples . 34
9 Relative Intensities of Major Ions Observed in Mass
Spectral Scans 40
ix
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LIST OF ABBREVIATIONS
cm centimeter
DDE 2,2-bis-(p-chlorophenyl)-l,l-dichloroethylene
GC-EC gas chromatography-electron capture
eV electron volt
9 gram
GC gas chromatography
GC-MS gas chromatography-mass spectrometry
GC-MS-30 gas chromatography-mass spectrometry (high resolution)
GC-QMS gas chromatography-quadrupole mass spectrometry (low
resolution)
HPLC high-pressure liquid chromatography
I.D. inside diameter
kg kilogram
LD50 lethal dose to 50% of test group
m meter
m/e mass to charge ratio
ml milliliter
ml/min milliliter/minute
mm millimeter
MS mass spectrometry
ng nanogram
PCP pentachlorophenol
PCB polychlorinated biphenyl
pg picogram
ppb parts per billion (ug/1 or ng/ml)
ppm parts per million (mg/1 or ug/ml)
ppt parts per trillion (ng/1 or pg/ml)
PSIG pounds per square inch gage
2,4,5-TCP 2,4,5-trichlorophenol
TCDD's tetrachlorinated dibenzo-p-dioxins; 22 possible isomers
ug microgram
UV ultraviolet
V volt
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ACKNOWLEDGMENT
This report was prepared for the U.S. Environmental Protection Agency
by the Brehm Laboratory and Chemistry Department of Wright State University,
Dayton, Ohio. Dr. T.O. Tiernan was the Principal Investigator with Dr. M. L.
Taylor and S.D. Erk as Co-Principal Investigators. Mr. Dave Watkins was the
Project Officer for the U.S. Environmental Protection Agency.
A review of the analytical literature for determination of TCDD's in
various sample matrices was compiled by Battelle Columbus Laboratories,
Columbus, Ohio, and constitutes a significant addition to this report. This
material was used to develop Appendices B and C.
Final compilation of this report for integration into the three-volume
dioxin series was done by PEDCo Environmental, Inc., Cincinnati, Ohio, with
Ms. M. Pat Esposito as Project Manager. Technical assistance was provided
by Ms. Diane N. Albrinck.
xi
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SECTION 1
INTRODUCTION
A dioxin is any of a family of compounds known chemically as dibenzo-
para-dioxins. Each of these compounds has as a nucleus a triple-ring struc-
ture consisting of two benzene rings interconnected to each other through a
pair of oxygen atoms. Shown below are the structural formula of the dioxin
nucleus and also the abbreviated structural convention used throughout the
report series.
Most environmental interest in dioxins and most studies of this family
of compounds have centered on chlorinated dioxins, in which the chlorine
atom occupies one or more of the eight substitution positions (Blair 1973;
Lee et al. 1973; Nicholson and Moore 1979).
The interest of health and environmental researchers in chlorodioxins
arose principally because of the toxicity and distribution of one of these
compounds, 2,3,7,8 tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD),* whose struc-
tural formula is as follows:
Throughout this report, the 2,3,7,8-tetrachloro isomer is specifically
noted as 2,3,7,8-TCDD to differentiate it from the other tetrachloro
isomers. In many cases, however, general reference is made to the family
of tetra isomers as TCDD's because of the difficulty in isolating specific
isomers. Refer to preface for further explanation.
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This is an unusual organic chemical, symmetrical across both horizontal and
vertical axes. It is remarkable for its lack of reactive functional groups
and its chemical stability. It is a lipophylic molecule, virtually insol-
uble in water and only sparingly soluble in most organic liquids; it is a
colorless crystalline solid at room temperature.
Although 2,3,7,8-TCDD was first reported in the chemical literature in
1872, no major investigations into its toxicity were begun until the 1950's.
Because of the remarkable stability of this substance in biological systems
and its extreme toxicity, cumulative effects of extremely small doses are a
major concern. For example, the ID™* of 2,3,7,8-TCDD for the male guinea
pig has been shown to be only 0.6 ug/kg or 0.6 part per billion body weight
(McConnell et al., 1978). Fetal mortality has been observed in rats that
had been fed 10 consecutive doses of 2,3,7,8-TCDD at the level of 0.125
(jg/kg per day (World Health Organization 1977). It is reasonable to pre-
sume, therefore, that the slightest trace of 2,3,7,8-TCDD in the environment
may have adverse effects on the health of both human and animal populations.
In view of these considerations, it is vitally important to scrutinize
carefully the probable avenues of contamination of the environment with
2,3,7,8-TCDD. It has been recognized for some time that 2,3,7,8-TCDD can be
produced in the manufacture of 2,4,5-trichlorophenol. Other dioxins are
similarly produced in the manufacture of other chlorophenols. The amounts
of dioxins produced depend on process controls such as temperature and
pressure. Since dioxins may be present in these and other manufactured
chemical products, it is also likely that they may be present in the chemi-
cal wastes and sludges remaining from these processes. If this is the case,
indiscriminate discharge of these wastes into the environment, or the use of
improper disposal procedures could lead to the contamination of water, air,
or foodstuffs. This might, in turn, result in widespread exposure of the
population to TCDD's and other dioxins.
Since 1972 the personnel of the Brehm Laboratory of Wright State
University have been performing sensitive dioxin analyses under programs
supported by several government agencies (U.S. Air Force, U.S. Environmental
Protection Agency (EPA), U.S. Department of Agriculture), and the states of
Michigan, New York, and Arkansas. In these investigations Brehm Laboratory
has developed and applied complex analytical methodology for the determina-
tion of TCDD's in many types of samples, including herbicides, industrial
chemicals, soils, water, air, biological tissues and fluids (both human and
other animal), and combustion products and related samples (Taylor et al.
1973; Taylor, Hughes, and Tiernan 1974a,b,c; Fee et al. 1975; Hughes et al.
1975; Taylor, Tiernan, and Hughes 1974; Tiernan 1975a,b; Tiernan, Taylor,
and Hughes 1975; Taylor et al. 1975, 1976, 1977, 1979; Tiernan et al. 1979;
Erk, Taylor, and Tiernan 1979; Yelton, Taylor, and Tiernan 1977; Wright
State University 1976). The levels of TCDD's in these samples have ranged
from high parts per million (ppm) to low parts per trillion (ppt). A sig-
nificant number of samples examined have been found to contain
LD
ce
3™: The administered dose of a substance which is lethal to 50 per-
irtr of a test group of animals.
-------
detectable amounts of TCDD's. On the basis of these findings many investi-
gators believe that TCDD's may already be widespread contaminants in the
environment.
The analytical techniques applied by Brehm Laboratory in these earlier
dioxin programs have varied widely in terms of the complexity of equipment,
sample preparation, and the overall sensitivity and specificity of the
procedures. It is now apparent that a single basic technique, amenable to
minor modifications, would be desirable for the purpose of characterizing
various types of chemical samples, provided that such a technique could
satisfy all the specified criteria for sensitivity, specificity, and other
analytical factors.
Sensitivity in the ppt range is required because of the potent toxicity
of 2,3,7,8-TCDD. The current detection capability is approaching 1 ppt in
at least some sample matrices and must be developed in others, particularly
chemical process wastes and sludges. Accuracy is also important in these
determinations, owing to current and potential regulatory actions that hinge
on the analytical data.
The Brehm Laboratory, in a subcontractual effort with Battelle Columbus
Laboratories, supported through a prime contract between Battelle and the
U.S. EPA, has undertaken development of new analytical techniques for use in
quantitating ppt levels of TCDD's in various chemical wastes. The goal in
this work was to develop a unified analytical approach to the handling of a
variety of chemical waste sample types and matrices.
The U.S. EPA supplied 17 test samples representing various types of
chemical wastes or residues generated during the manufacture of chloro-
phenols and related chemicals. These samples were expected to contain
TCDD's and were used in methods development by the Brehm Laboratory ana-
lysts. Presented herein are the final results of this work. This volume
includes a background discussion of various analytical approaches to the
detection of TCDD's, the newly developed and validated analytical method, a
description of the procedures used in development of the method, and the
analytical data obtained in applying the method to various industrial
samples. Appendix A of this report discusses general principals of gas
chromatography and mass spectrometry. Appendix B discusses other methods
and procedures found in current literature which may be used to detect
TCDD's in a variety of sample matrices. Appendix C is a compilation of
references on analysis of TCDD's, categorized by sample type.
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SECTION 2
ANALYTICAL BACKGROUND*
Analytical methods for detecting TCDD's in various types of samples
involve extensive sample preparation procedures followed by highly complex
instrumental analysis. This section discusses various approaches to the
detection and quantitative measurement of TCDD's, which had been used prior
to the inception of the present study in 1978.
SAMPLE PREPARATION
Because TCDD's may be found in a variety of matrices many different
sample extraction/ preparation methods have been developed. Although they
differ in complexity, most of these methods may be classified into two major
categories: first, those characterized by a highly basic extraction step,
and second, those involving only neutral extraction. The neutral extraction
technique was developed to preclude the possibility that treatment with a
strong base might generate compounds that could form chlorinated dioxins in
the mass spectrometer. Following extraction, the sample preparation steps
are similar for both techniques, differing only in the method of application
and complexity. Both extraction procedures are described in detail below.
Basic Extraction Method
Historically basic extraction methods were first developed for the
determination of TCDD's in environmental samples (Crummett and Stehl 1973;
Baughman and Meselson 1973a; Baughman and Meselson 1973b). Such sample
preparation techniques begin with digestion of a sample aliquot using
alcohol and a strong base. This is followed by a series of organic solvent
extractions to separate the TCDD's from the alkaline mixture. Solvents such
as ethanol, hexane, petroleum ether, and methylene chloride have been used,
either singly or in combination. The solvent extracts are combined and then
subjected to a series of washings with distilled water and strong acid. The
washed extract is then treated to remove all traces of water and passed
through one or more chromatographic columns for removal of some co-
extractants, primarily polar compounds. Instrumental analysis follows.
* Supplementary information on analytical methods for detecting dioxins in
various types of samples may be found in the appendices.
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An example of a typical basic extraction/preparation technique for
nonfat tissue consists of heating 10 g of sample with 10 ml of ethanol and
20 ml of 40 percent potassium hydroxide solution for 30 minutes. After the
solution cools, an additional 10 ml of ethanol is added and the solution is
extracted with four 10-ml portions of hexane. The preparation procedure
consists of washing the combined hexane extracts with concentrated sulfuric
acid until the acid fraction becomes only slightly colored. The acid wash
is followed by a 10 ml water wash, followed by evaporation to dryness at
room temperature with a stream of dry air. The sample is then redissolved
in hexane and further purified by elution chromatography using sorbents such
as alumina, silica gel, or Florisil, either singly or in combination. The
final eluate is concentrated prior to analysis.
Neutral Extraction Method
The neutral extraction and preparation technique was originally devel-
oped by O'Keefe, Meselson, and Baughman (1978). Albro and Corbett (1977)
describe an alternative neutral extraction method. A typical neutral ex-
traction technique for analysis of TCDD's consists of extracting the sample
with 10 ml of hexane. The hexane solution is then chromatographed with a
magnesia-Celite 545 column, an alumina column, an alumina minicolumn, and
finally a Florisil minicolumn. The Florisil column is eluted with methylene
chloride, and the eluate is concentrated in preparation for analysis. It
has been asserted that neutral extraction methods are particularly effective
for fish tissues and human milk (O'Keefe, Meselson, and Baughman 1978;
Harless and Dupuy 1979).
Chemical Composition of Extracts
The sample preparation techniques described above are useful for
destroying the integrity of the sample matrix and yield a small volume of
organically miscible/soluble residue. The net effect of these clean-up
procedures is the enrichment of the TCDD's relative to the natural compo-
nents of the sample matrix, as well as other chlorinated environmental
contaminants such as PCB's and DDE.* The latter compounds are often present
in the sample in significantly greater concentrations than the TCDD's
(larger by a factor of 106) and, therefore, may not be completely removed
from the extract at this point. In addition, it is unlikely that the fore-
going procedures result in separation of 2,3,7,8-TCDD from its other 21
TCDD isomers which may have been present in the sample.**
* DDE, or 2,2-bis-(p-chlorophenyl)~l,l-dichloroethylene, is commonly found
in environmental samples; it is a degradation product of the pesticide
DDT.
** Subsequent to the completion of the work described herein, reports have
appeared in the literature which describe methods for synthesis and isola-
tion of the 22 TCDD isomers (Nestrick 1979; Dow 1980). Using such new
analytical procedures it is now possible to isolate and quantitatively
determine 2,3,7,8-TCDD in environmental samples even in the presence of
the other 21 isomers.
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Consequently, detection and quantisation of TCDD's in general and
2,3,7,8-TCDD in particular in this "enriched" but still rather chemically
complex extract can only be accomplished by using a highly specific and
sensitive instrumental method. The method of choice, and that described
below, is coupled gas chromatography-mass spectrometry.
GAS CHROMATOGRAPHIC AND MASS SPECTROMETRIC METHODS OF ANALYSIS*
Because of its ready availability and relative ease of application, gas
chromatography has been extensively used for the detection and quantitation
of TCDD's (Elvidge 1971; Williams and Blanchfield 1971; Firestone et al.
1972; Williams and Blanchfield 1972; Crummett and Stehl 1973; Edmunds, Lee,
and Nickels 1973; Webber and Box 1973; Buser 1976; Bertoni et al. 1978). In
many instances, the authors cited above have found that the chromatographic
methods lack the required specificity for determining TCDD's in complex
samples. Consequently these researchers and others have sought more sensi-
tive and specific methods of detection.
At present the analytical method which is almost exclusively used for
the detection and quantitation of TCDD's is coupled gas chromatography-mass
spectrometry or GC-MS (Crummett and Stehl 1973; Tiernan et al. 1975; Taylor
et al. 1975; Buser and Bosshardt 1976; Harless 1976; Buser 1977; Gross
1978).
GC-MS is the only known method that can provide very high sensitivity
as well as the required selectivity for TCDD's. A particularly sensitive
and specific GC-MS technique which has been used entails low-resolution
selective ion monitoring. In the case of TCDD's, fragment ions at nominal
m/e 320 and m/e 322, as shown below, are monitored.
Cl
>
k
"a
t
70 eV
electrons
\l
>'
c M 35
%|.
>
i
C1«Y " *"
©
+ e
320)
©
+ e
321.8936 (non1n«l
322)
A discussion of the principles of gas chromatography and mass spectrom-
etry is presented in the Appendix.
-------
The intensities of these ions are recorded as the TCDD's elute from the gas
chromatograph. The ratio of the intensities of m/e 320 to m/e 322 is a
characteristic indicator of TCDD's. Unfortunately other compounds which may
also be present in the sample extract can also give rise to mass spectral
ions at the same nominal masses (m/e 320 and m/e 322) as TCDD's. Two
approaches can minimize this problem.
The first approach utilizes high resolution mass spectrometry (M/AM
>9000) to increase the selectivity. The ions appearing under low-resolution
MS conditions at nominal mass 322 may be produced from TCDD's which have
Ci2H4Cl402 as their elemental composition and thus have an "exact" mass of
321.8936. Interfering ions such as pentachlorinated biphenyls may also
appear at nominal mass 322, but their elemental composition is C12H3C15, and
therefore they have an "exact" mass of 321.8677. Thus, using high-
resolution MS these ions of slightly different mass are distinguishable, and
so the dioxin component having the exact mass of 321.8936 can be reliably
measured. Conceivably, ions having the C^^Cl^ composition can be
produced from other compounds, but proper selection of chromatographic
procedures maximizes the possibility of separating such compounds from
TCDD's. The achievement of detection limits in the low-ppt range at high MS
resolution generally requires the use of data acquisition methods which
entail signal averaging (Shadoff and Hummel 1978; Gross 1978; Taylor et al.
1976).
A second approach to the problem of separating TCDD's from closely
related interferences makes use of low-resolution mass spectrometry but
incorporates a more selective separation step prior to the mass spectro-
metric analysis. Capillary column gas chromatography is useful for this
purpose (Buser 1977), but liquid chromatography followed by capillary column
gas chromatography has proved even more fruitful (NestHck, Lamparski, and
Stehl 1979; Dow 1980).
In both the GC-high -resolution and the GC-low-resolution mass spec-
trometric methods, internal standards are frequently used for the quan-
tification of TCDD's. The analytical method developed in the present study
utilizes an internal standard, namely 37Cl4-2,3,7,8-TCDD.
-------
SECTION 3
ANALYTICAL METHOD*
The analytical procedure ultimately developed and described herein for
determination of TCDD's in various industrial process waste samples utilizes
two separate GC-MS systems. A gas chromatograph coupled to a low-resolution
quadrupole mass spectrometer (GC-QMS) is used for preliminary identification
of TCDD's in the extracts of the waste samples. A second apparatus coupling
a gas chromatograph and a high-resolution mass spectrometer (GC-MS-30) is
used to confirm the results obtained with the GC-QMS technique. The
analysis method entails two steps, sample preparation and instrumental
analysis, as described below. It should be emphasized that, even with the
elaborate separation techniques employed here, the 2,3,7,8-TCDD isomer is
still not resolved from the other TCDD isomers if these are present in the
sample extracts. As a result, the quantitative data obtained here for
TCDD's must be considered an upper limit rather than an absolute level for
any individual TCDD isomer.
SAMPLE PREPARATION
The following procedures were developed as an approach to preparation
of industrial waste samples and have been successfully applied in this
study.
1. Place a 2.0 g aliquot of the sample in each of the two extraction
vessels. To each aliquot, add an appropriate quantity of 37C14-
2,3,7,8-TCDD dissolved in "distilled-in-glass" benzene as an
internal standard. Spike one of the two aliquots with an addi-
tional known quantity of authentic native 2,3,7,8-TCDD at a con-
centration equal to the nominal amount expected in the sample.
2. Add 30 ml "distilled-in-glass" petroleum ether to each sample and
mix thoroughly.
3. Extract each organic solution with 50 ml of double-distilled water
and discard the aqueous layer.
4. Extract each solution with 50 ml of 20 percent potassium hydroxide
and discard the aqueous basic layer.
This section presents the analytical method only; discussion of develop-
ment of the method follows in Section 4.
8
-------
5. Extract each solution with 50 ml of double-distilled water and
discard the aqueous portion.
G. Extract each solution with 50 ml of concentrated sulfuric aci,d and
discard the aqueous acidic layer.
7. Repeat step 6 until the acid layer is nearly colorless.
8. Extract each organic solution with 50 ml of double-distilled water
and discard the aqueous layer.
9. Dry each organic solution over anhydrous sodium sulfate.
10. Quantitatively transfer each organic solution to another vessel,
and concentrate to a volume of approximately 1 ml by passing a
stream of purified nitrogen over the surface of the liquid while
applying gentle heat (50°C) to the vessel.
11. Construct a chromatography column for each sample by packing a
disposable glass pipette (I.D.= 0.8 cm) with glass wool and 2.8 g
of Woelm basic alumina (previously activated by maintaining it at
600°C for a minimum of 24 hours, then cooled in a dessicator for
0.5 hour prior to use).
12. Quantitatively transfer each concentrated organic solution to the
top of a column.
13. Elute each column with 10 ml of 3 percent "distilled-in-glass"
methylene chloride in "distilled-in-glass" hexane, and discard the
entire column effluent.
14. Elute each column with 20 ml of 20 percent methyl ene chloride in
hexane and collect the eluate in four 5-ml fractions.
15. Elute each column with 10 ml of 50 percent methylene chloride in
hexane and retain the entire column eluate for analysis.
16. Elute each column with 3 ml of 50 percent methylene chloride in
hexane and retain the eluate for analysis.
17. Concentrate all six fractions in benzene to an appropriate volume
(usually 0.1 to 1.0 ml) and proceed with analysis.
INSTRUMENTAL ANALYSIS
The application of GC-MS instrumentation methods for analysis of TCDD's
requires knowledgeable and experienced personnel, dedication of the equip-
ment, and significant capital and operating costs. The requirement for
detecting low ppt levels of TCDD's in these analyses necessitates such a
sensitive and selective analytical method. Because this is currently the
-------
only known method which meets these criteria, the relatively high expense is
unavoidable.
The following is a brief description of the instrumentation required
for the analytical procedures developed herein.
GC-QMS System
The GC-QMS system consists of a Varian Model 2740 Gas Chromatograph
coupled directly (no helium separator is required) to an Extra-nuclear
Quadrupole Mass Spectrometer. The GC was adapted to include a sophisticated
system of remotely actuated high-temperature switching valves (Valco Co.)
and Granvilie-Phi Hips molecular leak valves, so that the column effluent
could be readily regulated (Tiernan et al. 1975a; Erk, Taylor, and Tiernan
1978).
With this arrangement, the total column effluent can be directed into
the mass spectrometer ion source, or the effluent flow can be split, one
portion going to the ion source and the other to a gas chromatographic
detector, as desired. The use of a differential high-speed pumping system
on the source vacuum envelope permits introduction of as much as 65 ml/min
of effluent from the gas Chromatograph into the mass spectrometer ion
source. Admitting the total Chromatograph effluent into the mass spec-
trometer source enhances the sensitivity of the analysis.
For purposes of instrument control and data acquisition, the GC-QMS
system is coupled to an Autolab System IV Computing Integrator. Additional
capacity for off-line data reduction is available with a Hewlett-Packard
2116C Minicomputer, which is programmed to accept data (punched paper tape)
from the system when necessary.
GC-MS-30 System
The GC-MS-30 system used in these studies consists of a Varian 3740 Gas
Chromatograph coupled through an AEI silicone membrane separator to an AEI
MS-30 Double-Focusing, Double-Beam Mass Spectrometer. The mass spectrometer
is equipped with a unique electrostatic analyzer scan circuit developed by
Wright State University, which permits the monitoring of as many as four
mass peaks, essentially simultaneously, by rapidly and sequentially stepping
and switching between the masses of interest, while maintaining picogram
sensitivity for TCDD's. The data are recorded by use of a Nicolet 1074
Signal Averaging Computer.
Sample Analysis
Analysis consists of three steps as described below.
1. Analyze each eluate fraction (collected in the elution chromatog-
raphy separation of the sample) on the low-resolution GC-QMS, using the
following operating parameters:
10
-------
Van"an 2740 Gas Chromatograph
Column:
Carrier gas:
2 m x 3 mm I. D. glass packed with 3 percent
OV-7 on Gas Chrom Q
Helium at 65 ml/min (the total chromatographic
column effluent is admitted to the mass spec-
trometer ion source)
Temperatures: Injector: 255°C
Column: 275°C
Transfer line: 295°C
Quadrupole mass spectrometer
Ionizing voltage:
Multiplier:
Resolution:
Source envelope pressure:
Analyzer envelope pressure:
Masses monitored:
Source temperature:
Analyzer temperature:
23.5 eV
3200 V
1:350
1.4 x 10"4 torr
8.0 x 10"6 torr
m/e 320, 322
250°C
120°C
2. Confirm any samples showing positive levels of TCDD's on the low-
resolution GC-QMS by analysis of the corresponding eluate fractions using
high-resolution GC-MS-30 and the following operating parameters:
Varian 3740 gas chromatograph
Column: 1.8 x 2 mm I.D. coiled glass column packed
with 3 percent Dexsil 300 on Supelcoport
(100/120 mesh)
Carrier gas: Helium at a flow rate of 30 ml/min
Temperatures: Injector: 250°C
Column: 240°C
Transfer line: 285°C
11
-------
AEI MS-30 mass spectrometer
Resolution 1:12,500
Ionizing voltage: 70 eV
Masses monitored: m/e 319.8966, 321.8936, 325.8805, and
327.8846
Temperatures: Membrane separator: 215°C
Transfer line: 270°C
Source: 250°C
3. Determine the overall recovery of the analytical procedure by
measuring the amount of internal standard (37Cl4-2,3,7,8-TCDD) recovered.
12
-------
SECTION 4
DISCUSSION AND RESULTS
For use in developing and demonstrating the analytical methodology for
determination of ppt levels of TCDD's in process wastes and related mate-
rials, samples were provided that were representative of wastes from several
different industrial chemical processes that might be expected to generate
chlorodioxins. The samples were obtained by the U.S. EPA from plants manu-
facturing trichlorophenol, pentachlorophenol, and hexachlorophene, and from
plants processing wood preservatives. Initially, the nature and identity of
each sample were unknown to the Wright State investigators, although infor-
mation was made available early in the program about two of the samples
originating from trichlorophenol manufacturing processes. Subsequently,
identifying data on most of the remaining samples were obtained and are
summarized in Table 1.
Because still bottom samples collected at a trichlorophenol manufac-
turing plant were considered of major interest, a sample of this type (EPA
sample 2) was selected for use in preliminary investigations.
The initial approach to analytical method development, based on the
experience of Wright State personnel in chlorodioxin analysis, is outlined
below.
1. If the sample is solid, dissolve a portion in an immiscible combi-
nation of aqueous and organic solvents, such as water and petro-
leum ether. If the sample is a liquid, extract a portion of the
material with a similar water-organic solvent system. In the
absence of any prior knowledge about the content of TCDD's in a
given sample, the quantity to be extracted must be selected on the
basis of sensitivity of the overall technique (as indicated by
previous experience) and the desired limits of detection.
2. Separate the aqueous component of the sample-solvent mixture from
the organic phase and discard the aqueous portion.
3. Extract the organic fraction with sequential washes of acid,
water, base, water, acid, and water (in that order), and discard
the washes.
4. Concentrate the remaining organic phase to near dryness and elute
through an alumina column, using appropriate solvents to separate
the TCDD's and other sample components.
13
-------
TABLE 1. SAMPLES USED IN DEVELOPMENT OF ANALYTICAL
METHOD FOR TCDD'S IN INDUSTRIAL WASTES
EPA No.
C04130
C04131
C04132
2
3
4
5
6
12700
12701
12702
11020
11021
11022
11023
11024
11025
Sample type
Liquid slurry
Solid
Liquid
Liquid/sol id
Slurry
Slurry
Liquid/solid
Liquid
Liquid/solid
Liquid
Solid
Liquid/solid
Liquid
Liquid/solid
Solid
Solid
Solid
Source and identity of sample
Givaudan: aqueous slurry of hexachlorophene
Givaudan: activated clay filter cake from
hexachlorophene manufacturing
Givaudan: ethyl ene di chloride recovery solutio
from hexachlorophene manufacturing
Transvaal: still bottom from trichlorophenol
(TCP) manufacturing
Transvaal: cooling tank bottom from TCP manu-
facturing
Transvaal: discharge line from TCP manufactur-
ing
Transvaal: sludge from TCP manufacturing
Transvaal: type unknown; presumably TCP proces
sample
Reichold Chemical: sludge from intake of settl
ing pond, pentachlorophenol (PCP) manufacturing
Reichold Chemical: sludge from discharge of
settling pond, PCP manufacturing
Reichold Chemical: PCP manufacturing
Baxter: retort solids residue from wood pre-
serving
Baxter: storage tank solution from wood pre-
serving
Baxter: cooling water solids from wood pre-
serving
Baxter: treated wood from wood preserving
Baxter: soil from neighborhood of wood preserv-
ing plant
Baxter: sludge from wood preserving
14
-------
5. Concentrate the fraction containing TCDD's and subject it to
preliminary screening analysis by use of the GC-QMS system,
operated in the selected-ion monitoring mode and adjusted to
detect m/e 322 and m/e 320, the two most abundant peaks in the
isotopic molecular ion cluster of 2,3,7,8-TCDD.
6. If the initial screening indicates a positive level of TCDD's,
then the level must be confirmed and quantitated by use of the
GC-MS-30 system.
This approach was used in analysis of sample 2. Subsequent modifica-
tions of this initial procedure and other observations are discussed in
following subsections.
DEVELOPING SAMPLE PREPARATION TECHNIQUE
Four aliquots of sample 2 were extracted with a mixture of water and
petroleum ether. The aqueous portion was discarded, and each organic frac-
tion was washed successively with acid, water, base, water, acid, and water.
The samples were then concentrated and transferred to a 2.8 g Woelm basic
alumina column (length 12 cm, internal diameter 0.8 cm).
Large quantities of a white crystalline substance appeared in the
column eluate. The column apparently was overloaded owing to the large
quantity of this material present in the sample. This substance possibly
accounted for interference in the mass chromatogram (Figure 1). Adjustments
of the column chromatography procedure were therefore made in an effort to
eliminate this crystalline contaminant in the fraction containing the
TCDD's.
A solvent screening study was done to evaluate the solubility of the
contaminant and the potential for its removal from the sample matrix.
Results are as follows:
Solvent tested Solubility of contaminant
100% methanol Slight solubility
3% methylene Solubility slightly greater than
chloride in hexane in 100% methanol
25% carbon tetra- Solubility slightly greater than
chloride in hexane in 3% methylene chloride in hexane
100% methylene Completely soluble
chloride
Next, elution characteristics of the alumina column were evaluated.
Table 2 presents the solvents and the discrete fractions collected in
determining the elution characteristics of the Woelm basic alumina column.
15
-------
TCDD'S
TIME-
Figure 1. Mass chromatogram of extract of
sample 2, at m/e 322 obtained with GC-QMS.
16
-------
TABLE 2. ELUTION OF TCDD'S IN EXTRACTS OF SAMPLE 2
Set No.
Eluting solvent
Total volume
of column
effluent, ml
Volume of
fraction(s)
collected
Al
A2
Bl
B2
Cl
C2
Dl
02
3% methylene chloride in
hexane
50% methylene chloride
in hexane
3% methylene chloride in
hexane
20% methylene chloride
in hexane
10
13
10
18
25% carbon tetrachloride
in hexane
50% methylene chloride
in hexane
25% carbon tetrachloride
in hexane
20% methylene chloride
in hexane
10
13
10
18
total 10 ml
1st 5 ml in one
sample; 6th through
13th ml in separate
1-ml fractions
total 10 ml
1st 5 ml in one
fraction 6th through
13th ml in separate
1-ml fractions; 14th
through 18th ml in
one fraction
total 10 ml
1st 5 ml in one
fraction; 6th through
13th ml in separate
1-ml fractions
total 10 ml
1st 5 ml in one
fraction; 6th through
13th ml in separate
1-ml fractions; 14
through 18th ml in
one fraction
17
-------
Selection of the solvents and the eluate fractions was based on earlier
experience of Brehm Laboratory personnel in column chromatography with
similar sample matrices.
The eluate fractions were analyzed for TCDD's by use of the GC-QMS
system. The results, presented in Table 3, show clearly that the best
elution sequence involves the use of 10 ml of 3 percent methylene chloride
in hexane, followed by 18 nfl of 20 percent methylene chloride in hexane.
This sequence yields TCDD's in a well-defined fraction containing few other
contaminants. Use of all the other solvent pairs yielded fractions that
generated interferences in the dioxin mass chromatogram which were as great
as those shown in Figure 1 or greater.
Application of Initial Procedure to EPA Samples
The extraction and sample preparation procedure developed for sample 2
was applied to ten of the other industrial samples supplied by EPA. In
these analyses some interferences were still present in the extract fraction
which was thought to contain the TCDD's; the interferences resulted in a
higher minimum detection limit (ppb) than was desired. Portions of these
samples were also spiked with known quantities of 2,3,7,8-TCDD so that
recoveries for the procedure could be determined. The recovery in GC-QMS
analysis of sample 2 was 127 percent.
Surprisingly, in analysis of the other ten samples by the same pro-
cedure, none of the added 2,3,7,8-TCDD was recovered. The same procedure
was then applied in analyses of spiked aliquots of these samples, but this
time all the eluate fractions from the alumina columns were retained and
analyzed for TCDD's. Again, no 2,3,7,8-TCDD was detected. It was necessary
to further investigate the sample preparation procedures.
Optimizing Sample Preparation Procedure
Another sample (C04131) was subjected to the general preparation pro-
cedure already described, up to the point of elution of the column. Then
the sample was spiked with a large quantity of 2,3,7,8-TCDD by introducing
it directly onto the alumina column. The column elution characteristics
were then evaluated as before and the results are shown in Table 4. This
procedure was repeated for all other samples and their column elution pro-
files were determined.
This study indicated that a general extraction and preparation pro-
cedure must include a provision for assessing the elution characteristics of
the alumina column for each type of sample matrix. Apparently, each type of
sample conditions or deactivates the column in a manner peculiar to its
matrix, and this conditioning in turn, determines the elution characteris-
tics of TCDD's, which may differ markedly in different sample types.
18
-------
TABLE 3. CONTENT OF TCDD'S IN COLUMN FRACTION FOR SAMPLE 2a
Solvent
set No.
AT
A2
Bl
B2
Cl
C2
Dl
D2
Eluate fraction no.
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
TCDD's detected
_*
+*
-
+*
0
+*
0
+*
_*
+*
-
+*
0
+*
0
+*
_*
+*
-
+*
0
+*
0
+*
_*
+*
-
+*
0
+*
0
+*
_*
+*
-
+*
0
+*
0
+*
_*
+*
-
+
0
+*
0
+*
_*
+*
-
+
0
+*
0
+*
_*
+*
-
+
0
+*
0
+
_*
+
-
+
0
+*
0
+
_*
-
-
+
0
+*
0
+
0
-
0
+
+*
+
0
-
0
+
+*
+
0
-
0
+
+*
+
0
0
0
+
0
+
0
0
0
+
0
+
0
0
0
+
0
+
0
0
0
+
0
+
0
0
0
+
0
+
. Aliquots of EPA sample 2.
Fraction numbers refer to those collected from each of the columns, as indicated in Table 2.
+ =
0 =
* =
TCDD's present in fraction.
No TCDD's detected in fraction.
Fraction not analyzed.
Two or more peaks evident in mass chromatogram near 2,3,7,8-TCDD retention time.
-------
TABLE 4. RECOVERY OF 2,3,7,8-TCDD SPIKE FROM ELUATES OF SAMPLE C04131
Solvent
10 ml 3%
methyl ene
chloride in
hexane
20 ml 20%
methyl ene
chloride in
hexane
10 ml 50%
methyl ene
chloride in
hexane
No. of
fractions
collected
1
4
1
Volume
of each
fraction
10 ml
5 ml
10 ml
Action
Discarded
Analyzed by
GC-QMS
Analyzed by
GC-QMS
Results
No 2,3,7,8-
TCDD
80% 2,3,7,8-
TCDD
recovered
20
-------
ANALYTICAL PROCEDURE
Research workers in several laboratories, including the Brehm Labora-
tory, have analyzed various types of samples for dioxin content. Generally,
the analytical approach to determining a chlorinated hydrocarbon of this
type in a complex sample matrix has involved quantitation of the chloro-
carbon by use of electron capture-gas chromatography (EC-GC) or gas chroma-
tography-mass spectrometry (GC-MS). The studies at Brehm Laboratory
entailed use of GC-MS and high-performance liquid chromatography (HPLC).
GC-MS System
As described in Section 3, the GC-QMS system was used for initial
detection of TCDD's in the fractionated sample. Then the GC-MS-30 was used
to confirm the positive levels of TCDD's detected in the GC-QMS.
In one procedural modification, a labelled internal standard, 37C14-
2,3,7,8-TCDD, was added to all samples. Also, the MS-30 high-resolution
mass spectrometer was modified to permit essentially simultaneous step-
scanning of four ions in the high-resolution mode. The ions typically
monitored were:
m/e 319.8966, a major molecular ion in the mass spectrum of 2,3,7,8-
TCDD
m/e 321.8936, a major molecular ion in the mass spectrum of 2,3,7,8-
TCDD
m/e 325.8805, a molecular ion indicative of interfering PCB's
m/e 327.8846, a major molecular ion in the mass spectrum of 37C14-
2,3,7,8-TCDD.
High-Performance Liquid Chromatography (HPLC)
In earlier studies aimed at determining TCDD's in environmental
samples, concern has been raised that the presence of the so-called pre-
dioxins (for example, polychlorinated phenoxyphenols) in the samples would
lead to false positive determinations of TCDD's because the latter can be
formed by cyclization reactions of the predioxins in the hot injection port
of gas chromatographs. The present investigation ruled out potential false
positive effects of predioxins by applying an HPLC analytical technique as a
quality assurance measure. HPLC does not entail injection of the sample
into a heated port and therefore minimizes the possibility of thermal
cyclization of predioxins.
The HPLC instrument used in these studies is the Model LC 5021 Varian.
This microprocessor-controlled HPLC is both completely automatic and pro-
grammable and incorporates a multiple solvent system. Three detectors are
available: a fixed-wavelength UV (254 nm) detector, a variable-wavelength
UV detector, and a fluorescence detector. A cathode ray tube (CRT) keyboard
21
-------
unit displays operating parameters while a micropressor -based computing
integrator (DCS-111L) stores the data and performs appropriate calculations.
The parameters applicable to the instrument as it was used in this study are
listed below:
Column: DuPont Zorbax ODS (25 cm x 6.2 mm)
Temperature: 50°C
Starting Pressure: 952 psig
Solvent: 100% Methanol
Flow rate: 2.5 ml/min
Detector: UV (235 nm)
Sensitivity: 0.02 absorbance units full scale/15 ng TCDD's
Upon injection of a 10 ul aliquot of the sample 2 extract into the HPLC, a
chromatographic peak having a retention time which was the same as that
observed with the 2,3,7,8-TCDD standard was observed. Representative HPLC
chromatograms are shown graphically in Figures 2 and 3, and these results
indicate a readily detectable level of TCDD's in the sample 2 extract. It
is apparent that the TCDD's detected cannot have been formed by cyclization
of predioxins.
Analytical Results
Attempts were made to extract 15 of the 17 EPA samples by the pro-
cedures described in section 3. The remaining two samples, 11023 and .12702,
were not subjected to these methods. Sample 11023 was a section of wood,
which the earlier experience of Wright State had shown is not amenable to a
potassium hydroxide digestion process. Sample 12702 was not analyzed
because of insufficient time during the contract period.
Twelve of the fifteen samples were successfully analyzed by the Wright
State procedure, with results as shown in Table 5. These data show that the
procedure is applicable to samples exhibiting a wide range of concentrations
of TCDD's from ppt to ppm (a factor of 106). For those samples in which no
TCDD's were detected, the minimum detectable concentration of TCDD's was in
the low ppt range (45 to 140 ppt).
Examples of mass fragmentograms obtained with the GC-MS-30 high resolu-
tion mass spectrometer are shown in the following figures. Figure 4 shows a
four-ion step-scan mass fragmentogram of benzene, the solvent used for
dilution of the final sample residue. Analysis of a solvent blank is
repeated before analysis of each sample in order to ensure that no TCDD's
are carried over in the injection syringe. Figure 5 illustrates similar
data obtained from injection of a sample consisting of 50 pg of native
2,3,7,8-TCDD and 1 ng of 37Cl4-2,3,7,8-TCDD. Note that different attenua-
22
-------
[1
TCDD'S
I
I I 1
TIME
Figure 2. High pressure liquid chromatogram of sample 2,
23
-------
2,3,7,8-TCDD
I
TIME
Figure 3. High pressure liquid chromatogram of
2,3,7,8-TCDD standard.
24
-------
TABLE 5. RESULTS OF GC-MS-30 ANALYSIS OF EPA SAMPLES FOR TCDD'S
EPA sample no.
C04130
C04131
C04132
2
3
4
5
6
12700
12701
12702
11020
11025
11021
11022
11023
11024
Origin
Givaudan
Givaudan
Givaudan
Transvaal
Transvaal
Transvaal
Transvaal
Transvaal
Reichold
Reichold
Reichold
Baxter
Baxter
Baxter
Baxter
Baxter
Baxter
Quantity of
TCDD's found
ng/g (ppb)
NDa
ND
ND
40,000
675
22
070
ND
ND
ND
b
ND
ND
c
c
b
d
Minimum detectable
concentration
pg/g (ppt)
140
70
50
e
e
e
e
50
80
75
140
45
. ND: no TCDD's detected in excess of the minimum detectable concentration.
Not processed.
^ General procedure could not be successfully applied to these samples.
a Not analyzed on GC-MS-30.
e An exact minimum detectable concentration was not recorded for these
analyses; however the reported values for quantity of TCDD's found are
well above the criterion of 2.5X noise.
25
-------
ATTENUATION: 512
m/e 319.8966
Figure 4. Four-ion mass fragmentogram of
benzene solvent blank obtained with GC-MS-30.
26
-------
ATTENUATION: 256
m/e 321.8936
I
m/e 319.8966
m/e 327.8846
ATTENUATION: 8192
Figure 5. Four-ion mass fragmentogram of 50 pg 2,3,7,8-TCOD and
1 ng 37Cl4-2,3,7,8-TCDD obtained with GC-MS-30.
27
-------
tions have been applied to the various peaks displayed in Figure 5. Figures
6 and 7 demonstrate similar four -ion step -scan mass fragmentograms obtained
for two of the EPA samples. Although the fragmentogram for sample 12700
shows peaks at m/e 319.8966 and m/e 321.8936, their intensities are not
greater than 2.5 times the background; this is one of the criteria applied
for establishing the presence of TCDD's in a sample.
of 37Cl4-2,3,7,8-TCDD from sample 12700, the minimum
tion (MDC) of TCDD's is 80 pg/g.
Based on the recovery
detectable concentra-
The mass fragmentogram for sample 5 (Figure 7) shows peaks at both m/e
319.8966 and m/e 321.8936, and the intensities are well in excess of 2.5
times the background levels. After application of a recovery correction on
the basis of the internal standard, these data indicate that sample 5 con-
tains 70 pg TCDD's per gram of sample. Data similar to those shown in
Figures 4 through 7 were obtained for the other samples analyzed in this
program.
Analyses of samples 11021 and 11022 were not completed owing to the
formation of an intractable emulsion at the petroleum/ ether interface.
Analysis of sample 11024 on the GC-MS-30 system was not attempted because a
colored residue was visible in the final extract. Earlier experience had
shown that such residues indicate that the sample extract contains gross
quantities of compounds other than TCDD's, which lead to serious contamina-
tion of the high-resolution mass spectrometer.
All data in Table 5 were derived from analyses with the high resolution
GC-MS-30 system. For each of the industrial process samples, the appro-
priate elution chromatogram fractions to be analyzed were determined in
advance in a series of alumina column elutions using an aliquot of the
sample spiked with 2,3,7,8-TCDD standard; these elutions were accomplished
in a manner similar to that described for sample 2. These elution test
samples were analyzed with the low resolution GC-QMS system. Data pertinent
to the determination of the elution characteristics of TCDD's in the various
samples are shown in Table 6. The fractions collected for each sample in
the elution experiments are as follows:
1.
2.
3.
4.
5.
6.
Fraction
chloride
I
in
- First
hexane.
5-ml portion eluted with 20 percent methylene
Fraction II - Second 5-ml portion eluted with 20 percent methylene
chloride in hexane.
Fraction III - Third 5-ml portion eluted with 20 percent methylene
chloride in hexane.
Fraction IV - Fourth 5-ml portion eluted with 20 percent methylene
chloride in hexane.
Fraction V - First TO-ml portion eluted with 50 percent methylene
chloride in hexane.
Fraction VI - Last 3-ml portion eluted with 50 percent methylene
chloride in hexane.
28
-------
m/e 327.8846
10
ATTENUATION: 512
m/e 321.8936
m/e 319.8966
ATTENUATION: 8192
m/e 321.8966
m/e 319.8966
1
Figure 6. Four-ion mass fragmentogram of sample 12700 obtained with GC-MS-30.
-------
co
o
ATTENUATION: 512
m/e 319.8966
m/e 321.8936
m/e 327.8846
I
t
ATTENUATION: 4096
Figure 7. Four-ion mass fragmentogram of sample 5 obtained with GC-MS-30.
-------
TABLE 6. TCDD ISOMER CONTENT OF COLUMN FRACTION
SAMPLES SPIKED WITH 2,3,7,8-TCDD
EPA
samples
C04130
3
12700
12701
11020
11024d
11025
Eluate .
fraction
IV
V
VI
V
III
IV
V
VI
IV
V
VI
IV
V
IV
V
VI
IV
V
VI
IV
V
Quantity
of 2,3,7,8-TCDD
added to
sample,
ng/g
10.42
10.35
50.64
12.14
12.84
9.86
3.71
6.54
Quantity
of 2,3,7,8-TCDD
detected in
fraction,
ng/g
ND
10.62
ND
597
ND
46
625
ND
ND
8.4
ND
ND
10.12
0.56
8.68
ND
0.29
1.09
ND
ND
5.63
Minimum
detectable
concentration,
ng/g
0.5
0.5
3.0
3.0
0.3
0.57
0.28
-
0.23
0.08
0.14
Recovery, %
102
69
79
6
88
8
29
86
. See Table 4-1 for description of sample.
Designation of eluate fractions:
III Third 5-ml aliquot eluted with 20% methylene chloride in hexane.
IV Fourth 5-ml aliquot eluted with 20% methylene chloride in hexane.
V First 10-ml aliquot eluted with 50% methylene chloride in hexane.
VI Last 3-ml aliquot eluted with 50% methylene chloride in hexane.
ND: no 2,3,7,8-TCDD detected in excess of the minimum detectable concentration.
Portion of sample was lost during preparation.
31
-------
These fractions were analyzed with the GC-QMS in reverse order, begin-
ning with the last fraction and continuing backward until the quantity of
TCDD's detected in the several fractions was a reasonably large percentage
of that originally added as the spike, or until a fraction was reached that
contained no TCDD's. The data in Table 6 show that TCDD's are completely
eluted from all samples prior to Fraction VI. In most cases the bulk of the
TCDD's appeared in Fraction V, although in samples 11020 and 11024 the
TCDD's were detected in Fraction IV.
Table 7 summarizes the total recoveries of the added 2,3,7,8-TCDD
spikes achieved by collecting the optimum column chromatography fractions of
the various industrial process samples. These recoveries range from 60 to
102 percent, with a mean value of 85 percent.
Except for sample 2, all of the samples processed in this investigation
were also spiked with 37Cl4-2,3,7,8-TCDD. This compound was added as an
internal standard in the analyses with the GC-MS-30 system. The mean
recovery of 37Cl4-2,3,7,8-TCDD for the samples analyzed herein was 74
percent with a standard deviation of 16.8 percent. The recovery data are
shown in Table 8.
Confirmation of TCDD's in Sample 2
Measurements in which m/e 320 and m/e 322 were monitored by the low-
resolution GC-QMS system indicated that sample 2 contained approximately 40
ug TCDD's per gram of sample. The report of this high level of TCDD's
prompted considerable concern both at EPA and state regulatory organiza-
tions.
This finding was also controversial because an earlier examination of
this sample in an EPA laboratory had yielded no indication of the presence
of TCDD's. It was obviously important, therefore, to more definitively
confirm the initial Wright State analyses of sample 2; this was done by a
procedure essentially the same as that which is described as the final
method (Section 3).
The sample was extracted, and the extract was subjected to liquid
chromatography preparation. As mentioned earlier, the fraction of sample 2
that was eluted from the alumina column with 20 percent methylene chloride
in hexane was determined to contain the bulk of the TCDD's. Accordingly,
this fraction was analyzed for TCDD's by the GC-MS-30 system operated in the
dual-ion monitoring mode (m/e 319.8966 and 321.8936 were monitored). The
resolution of the MS-30 mass spectrometer was adjusted to 1:12,500 for this
measurement.
The dual-ion step-scan mass fragmentogram obtained with this sample
extract is shown in Figure 8 and corresponding data obtained with an
authentic 2,3,7,8-TCDD standard are shown in Figure 9. For EPA sample 2,
32
-------
TABLE 7. RECOVERIES OF 2,3,7,8-TCDD-SPIKED SAMPLES
FOLLOWING ALUMINA COLUMN CHROMATOGRAPHY
EPA
sample no.
C04130
4
5
6
12700
12701
11020
11024
11025
Quantity of 2,3,7,8-TCDD Quantity of 2,3,7,8-TCDD
added, ng/g (ppb)
10.4
12.0
12.2
10.4
12.1
12.8
9.9
3.7
6.5
detected, ng/g (ppb)
10.6
8.4
11.0
9.7
8.4
10.1
9.24
1.38
5.6
Recovery, %
,102
70
90
93
69
79
94
37a
86
Portion of sample lost during preparation.
33
-------
TABLE 8. RESULTS OF GC-MS-30 ANALYSES OF SAMPLES
SPIKED WITH 37Cl4-2,3,7,8-TCDD
EPA
sample no.
C04130
C04131
C04132
5
6
4
12700
12701
11020
11025
WSU
sample no.
B-001C
B-002A
B-003A
B-006A
B-007A
B-008A
B-009E
B-010E
B-012F
B-017B
Quantity of
37Cl-2,3,7,8-TCDD
added, ng/g (ppb)
1.11
0.93
0.96
1.21
1.09
1.09
1.23
1.29
1.19
0.67
Quantity of
37Cl-2,3,7,8-TCDD
detected, ng/g (ppb)
0.78
0.91
0.61
0.48
0.67
0.75
1.06
1.14
0.93
0.58
Recovery, %
70
98
64
40
61
69
86
88
78
86
Data for samples 2 and 3 are not included because the ratio technique
could not be used with samples containing high levels of TCDD. Sample
11024 is also omitted because the extract was not clean enough for
analysis by GC-MS-30.
34
-------
m/e 321.8936
m/e 319.8966
I
Figure 8. Dual-ion mass fragmentogram of sample 2
obtained with GC-MS-30, mass resolution 1:12,500.
35
-------
m/e 321.8936
m/e 319.8966
Figure 9. Dual-ion mass fragmentogram of 150 pg of
2,3,7,8-TCDD standard obtained with GC-MS-30,
mass resolution 1:12,500.
36
-------
the ratio of m/e 319.8966 to m/e 321.8936 in the mass fragmentogram is 0.79,
while that for the 2,3,7,8-TCDD standard is 0.84. Both of these values
agree well with the theoretically predicted ratio of these two peaks, £.77,
which is calculated on the basis of the relative abundance of 35C1 and 37C1
isotopes.
Further confirmation that the unknown component in sample 2 is indeed a
quantity of TCDD isomers is provided by the observation that the GC reten-
tion time of the unknown component was identical to that of the 2,3,7,8-TCDD
standard. This criterion is applied in all determinations of TCDD's in
Wright State's Brehm Laboratory.
The mass spectrometric resolution achieved in this program with the
MS-30 Mass Spectrometer can be demonstrated experimentally by using the
specialized step-scan circuitry developed by Wright State. The practical
method of demonstrating the resolution is to obtain a narrow mass scan for a
sample consisting of TCDD's in a mixture of other compounds that yield mass
spectral ions whose mass is very close to that of TCDD's. In earlier
studies we utilized a mixture of 2,3,7,8-TCDD, PCB's such as Aroclor 1254,
and DDE* for this purpose. The latter compounds yield mass spectral peaks
that are very near the mass of the TCDD's major ion (Aroclor 1254 m/e
321.8679, DDE m/e 321.9290, 2,3,7,8-TCDD m/e 321.8936).
In order to obtain ions of approximately equal intensity from all these
compounds, however, the quantities of PCB and DDE must be quite large rela-
tive to the quantity of TCDD's. Figure 10 shows a typical mass fragmen-
togram obtained during this investigation in analyses of two mixtures of
2,3,7,8-TCDD and DDE and a mixture of Aroclor 1254, 2,3,7,8-TCDD, and DDE.
On the basis of the data shown in Figure 10, the dynamk: resolution of the
mass spectrometer is calculated to be 14,000 with 20 percent valley defini-
tion.
The data on sample 2 which were described above were based on monitor-
ing only m/e 320 and m/e 322 in the mass spectrum of TCDD's. Our earlier
experience had shown that the low levels of TCDD's that are usually found in
environmental samples (low ppt) permit monitoring of no more than four mass
peaks for a single sample injection, even with the sophisticated step-scan
techniques developed in Brehm Laboratory. In this instance, however, the
level of TCDD's (40 ppm) in sample 2 was very high and it was feasible to
obtain an actual mass spectral scan as this component of the sample eluted
from the gas chromatograph.
Therefore the MS-30 Mass Spectrometer was set up in the normal magnetic
scanning mode, and an aliquot of the extract of sample 2 was injected into
the GC. At the appropriate retention time, the mass spectrum of the eluted
component was scanned. Before this, we obtained similar mass spectra of a
solution containing 10 ng of authentic 2,3,7,8-TCDD standard and of a
solvent blank (benzene). The instrumental parameters applicable to the
scans are as follows:
* As previously noted,DDE is a degradation product of the pesticide DDT.
37
-------
to
CO
AROCLOR 1254
lOOpg
.— 2,3,7,8-TCDD
2,-3,7,8-TCDO
f-70ng ODE
lOOpg
2,3,7,8-TCDD
m/e 319.8966x ^ m/e 319.9196
m/e 321.8936 m/e 321.9290
NO. 1 NO. 2
70ng DDE
m/e 321.8936^ ^ m/e 321.9290
NO. 3
Figure 10. Mass fragmentograms using GC-MS-30 of mixtures of
2,3,7,8-TCDD with other chlorinated compounds.
-------
Scan rate:
10 sec/decade, beginning 190 sec. after
sample injection
Mass range of scan: m/e 130 to m/e 350
Mass resolution: 1:1000
GC retention time
for TCDD:
195 sec.
Other parameters: Same as described in Section 3
The relative intensities of the more prominent mass spectral peaks
recorded in these runs are listed in Table 9. The mass spectra obtained for
the 2,3,7,8-TCDD standard and for the extract of sample 2 are shown in
Figures 11 and 12. These spectra obviously agree quite well. There is no
doubt that the unknown component in sample 2 is a TCDD isomer and that it is
present in a high concentration. Apparently some components of the extract
of sample 2, other than the TCDD's, also contribute to m/e 194, 257, and
259, but these are not of concern here.
39
-------
TABLE 9. RELATIVE INTENSITIES OF MAJOR IONS OBSERVED
IN MASS SPECTRAL SCANS
m/e
326
324
322
320
318
259
257
194
161
160
10 ng
2,3,7,8-TCDD
standard
10
50
100
80
30
23
34
18
21
17
Solvent blank
0
0
0
0
0
0
0
0
4
4
10 pi of
EPA sample 2 extract
(out of 2000 Ml total)
12
48
100
80
25
47
48
30
25
20
40
-------
ATTENUATION-
.1
m/e324 — '^
m/e 322
ATTENUATION
_uJ
1C
A
:
.
m/e 324--""^
m/e 322
)
^JL . A.VULU . J i . ^ , . i. , J
^^ m/e 318 m/e 259 '
m/e 320
J
J
MASS SPECTRUM OBTAINED FROM 10 ng of 2,3,7,8-TCDD STANDS
100 ATTENUATION: 10
. i . ..Lllil.i.l . -. «i
jl
u
IR[
1
LL_ J
^ — m/e 318 m/e 259-^
m/e 320
, .
^ m/e 257
)
il.jjiL-,
^m/e 257
MASS SPECTRUM OBTAINED FOR A PORTION (5y£ OUT OF 10 m£ EXTRACT) OF SAMPLE 2
Figure 11. « Mass spectra from scans of 2,3,7,8-TCDD standard and
sample 2 (mass range m/e 330 to m/e 250).
-------
ATTENUATION: 10
J.1.1. .,.... . .... I il
ill . . .Jlllj.ll!
m/e
1 JL
194 161^^160
MASS SPECTRUM OBTAINED FOR A PORTION (5 y£ OUT OF 10 mi EXTRACT) OF SAMPLE 2.
rv>
ATTENUATION: 1
m/e
uL
lull
194 161
MASS SPECTRUM OBTAINED FROM 10 ng of 2,3,7,8-TCDD STANDARD
Figure 12. Mass spectra from scans of 2,3,7,8-TCDD standard and
sample 2 (mass range m/e 250 to m/e 150).
-------
SECTION 5
CONCLUSIONS AND RECOMMENDATIONS
As a means of assessing the levels of the extremely toxic TCDD's in
process streams, wastes, and sediments from the manufacture of chemicals, a
method was developed that proved to be applicable to about 70 percent of the
industrial waste sample types examined in this study. These sample types
are typical of those that would be collected in a routine chemical plant
survey.
The analytical methodology implemented in this study is summarized in
the following five principal steps:
I. Preparation of a spiked and nonspiked aliquot of each sample in
liquid extractable form (organic phase).
2. A sample clean-up procedure that includes acid and base washes to
remove the bulk of the sample matrix.
3. An additional sample separation step using liquid chromatography.
4. Screening of samples for detectable levels of-TCDD's with a low-
resolution GC-QMS system. This step is repeated with a spiked
sample if positive levels of TCDD's are detected.
5. Confirmation and quantification of the level of TCDD's by analysis
of the samples with a high-resolution GC-MS-30 system.
There are four major advantages with the implementation of this method:
1. The procedure offers a relatively rapid method for qualitative
screening of a wide variety of materials for possible contamina-
tion by TCDD's, through the use of low-resolution mass spectrome-
try (GC-QMS showed a MDC of 1 ppb or less in 50 percent of the
samples).
2. Only samples in which the initial screening shows TCDD's need be
confirmed by use of GC with high -resolution mass spectrometry
(minimum resolution 1:10,000).
3. Analysis by high-resolution mass spectrometry yields extremely
high sensitivity as well as specificity. The need for both is
indicated by the finding of minimum detectable concentrations
below 100 ppt in more than half the samples tested.
43
-------
4. The method warrants a high level of confidence owing to the use of
an internal standard and application of the four-ion monitoring
technique. Recovery of 37Cl4-2,3,7,8-TCDD from spiked samples
indicates a recovery range of 40 to 98 percent for the method.
Further, by a procedure in which the quantity of native-TCDD1s
detected is proportionately related to the quantity of 37C14-
2,3,7,8-TCDD added, the data may be automatically corrected for
recovery.
Although the procedures outlined here are acceptable for analysis of
many industrial process samples, they are not applicable to all sample
types. Among those examined in this study, the samples that could not be
suitably analyzed are of two types. First are those of biological origin,
primarily wood and woodlike products. It is probable that for such samples
an acid digestion step is needed to effectively destroy cellular walls and
release any residue of TCDD's. Earlier work at Brehm Laboratory on wood and
other biological materials confirms the effectiveness of such an approach.
The other type of sample not amenable to the method is more difficult
to characterize. Samples of this type formed emulsions in the preparation
phase that could not be resolved. Use of several common emulsion-breaking
techniques such as addition of excess solvent, did not alleviate this
problem. Unfortunately, owing to the small number of samples of this type,
no further information was obtained. Additional work on such samples would
be desirable.
44
-------
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Baughman, R. , and M. Meselson. 1973a. An Analytical Method for Detecting
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Bertoni, G. , et al. 1978. Gas Chromatographic Determination of 2,3,7,8-
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Blair, E. H. , ed. 1973. Chlorodioxins - Origin and Fate. Advances in
Chemistry, Series 120, American Chemical Society, Washington, D.C.
Buser, H. R. 1976. High Resolution Gas Chromatography of Polychlorinated
Dibenzo-p-dioxins and Dibenzofurans. Anal. Chem., 48:1553-1557.
Buser, H. R. 1977. Determination of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in
Environmental Samples by High-Resolution Gas Chromatography and Low-
Resolution Mass Spectrometry. Anal. Chem., 49:918-922.
Buser, H. R. , and H. P. Bosshardt. 1976. Determination of Polychlorinated
Dibenzo-pdioxins and Dibenzofurans in Commercial Pentachlorophenols by
Combined GC-MS. Journal of the AOAC, 59(3):562.
Crummett, W. B. , and R. H. Stehl. 1973. Determination of Chlorinated
Dibenzo-p-dioxins and Dibenzofurans in Various Materials. Environmental
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Dow Chemical Co. 1980. Science, in press.
Edmunds, J. W. , D. F. Lee, and C. M. L. Nickels. 1973. Pestic. Sci.,
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-------
Elvidge, D. H. 1971. The Gas-chromatographic Determination of
2,3,7,8-Tetrachlorodibenzo-p-dioxin in 2,4,5-Trichlorophenoxyacetic Acid
(2,4,5-T), 2,4,5-T Esters and 2,4,5-Trichlorophenol. Analyst (London),
96:721-727.
Erk, S. D. , M. L. Taylor, and T. 0. Tiernan. 1978. Environmental Monitor-
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Material Spills, pp. 226-231.
Erk, S. D. , M. L. Taylor, and T. 0. Tiernan. 1979. Determination of
2,3,7,8-Tetrachlorodibenzo-p-dioxin Residues on Metal Surfaces by GC-MS.
Chemosphere, 8(1):7-14.
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and Related Compounds in Commercial Chlorophenols. Journal of the AOAC,
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Gross, M. L. 1978. Personal communication.
Harless, R. L. 1976. Presentation given at TCDD workshop held at the
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Harless, R. L. and A. Dupuy. 1979. Personal communication.
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Procedures for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Residues in Bovine Fat
and Milk. Journal of the AOAC, 61:621-626.
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Solch, J., et al. 1978. Development of GC-MS Methodology for Assaying
Bovine Tissue for Hexa-, Hepta-, and Octachlorodibenzo-p-dioxin Content.
Proceedings of the 26th Annual Conference on Mass Spectrometry and Allied
Topics, pp. 52-54.
Solch, J., et al. 1979. A Unique Scan Circuit for Use in Multiple Ion,
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Obtained with New GC-MS Procedures Developed for Determining Tetrachloro-
dibenzo-p-dioxin in Chlorophenoxy Herbicides. Dioxin Planning Conference,
EPA, Washington, D.C.
Taylor, M. L., B. M. Hughes, and T. 0. Tiernan. 1974c. Techniques for
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Methodology Developed for Characterization of Herbicide Orange, EPA,
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Taylor, M. L., T. 0. Tiernan, and B. M. Hughes. 1975. Analytical Tech-
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Taylor, M. L., J. G. Solch, and T. 0. Tiernan. 1979. Advances in
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Taylor, M. L., et al. 1975. Determination of Tetrachlorodibenzo-p-dioxin
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Tiernan, T. 0. 1975b. Applications of Mass Spectrometric Techniques for
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48
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APPENDIX A
BASIC PRINCIPLES OF GAS CHROMATOGRAPHY, MASS SPECTROMETRY,
AND COMBINED SYSTEMS
GAS CHROMATOGRAPHY (GC)
Gas chromatography is a special form of chromatography that is used to
separate the components of chemical mixtures. Several excellent references
describe the technique in detail (Dal Nogare and Juvet 1962; Littlewood
1970; Jones 1970; Ambrose 1971). In gas chromatography the mobile phase is
a gas and the stationary phase is either a liquid or a solid, hence the
terms gas-liquid chromatography and gas-solid chromatography. Gas-liquid
chromatography entails the use of a separation device, which is a column
containing the liquid phase (typically a high-boiling organic silicone
polymer) distributed on a highly inert solid support. Figure Al depicts a
typical gas chromatograph.
The column is maintained in an oven, in which the temperature can be
controlled precisely; through the column is passed an inert, high-purity gas
(e.g., helium), called the carrier gas. The carrier gas is the mobile phase
and the organic silicone polymer is the liquid phase. Typically, the
samples are introduced into the column in 0.1 to 10 ul amounts with a micro-
syringe through an injection port, which is a heated (100° to 250°C) inlet
system equipped with a silicone septum. The sample is vaporized immediately
upon injection, and The inert carrier gas passing through the injection port
sweeps the volatilized, injected sample out of the injection port and into
the gas chromatographic column. The volatilized constituents of the sample
migrate through the column at varying rates because of variations in the
physical and chemical properties of each component, such as boiling point,
absorptivity, and solubility. The components are thus separated and emerge
(elute) from the column at different times. In some samples the components
are highly similar and are not effectively separated or may necessitate the
use of extraordinary chromatographic procedures. More commonly, however,
the components of a chemical mixture can readily be separated by fairly
simple gas chromatographic techniques.
As each separated component elutes from the gas chromatographic column,
it is detected by one or more of several types of detectors. Among the
widely used detectors are flame ionization, thermal conductivity, and elec-
tron capture detectors. Other, more specific, types of detectors are also
used in conjunction with gas chromatography; in particular, the mass spec-
trometer has been used extensively. A discussion of the principles of mass
spectrometry follows.
49
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FINE ADJUSTMENT
VALVE
DRYING TUBE
KX1
9 MANOMETER OR
PRESSURE GAUGE
SAMPLE INJECTOR-
/"S PRESSURE
yj REGULATOR
CYLINDER CONTAINING
CARRIER GAS
FLOWMETER
DETECTOR
COLUMN
THERMOSTAT
Figure Al. Apparatus for gas chromatography
50
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MASS SPECTROMETRY (MS)
Mass spectrometry is described in detail in several references (Beynon
1960; McLafferty (ed.) 1963; Kiser 1965; Roboz 1968; McFadden 1973). Figure
A2 is a schematic diagram of a typical mass spectrometer; the principal
components of such a system are (1) an inlet system (2) an ion source, (3)
an accelerating system, (4) an analyzer system, (5) a detector, and (6) a
data acquisition system. The functions of these components are described
briefly.
The inlet system is the means of introducing the sample into the ion
source of the mass spectrometer. Inlet devices in common use include heated
direct insertion probes and heated gas inlet systems (batch inlets), which
are coupled to the mass spectrometer through a restricted fixed or variable
orifice, often called a "leak." In recent years the gas chromatograph has
been used often to introduce the sample and is coupled to the mass
spectrometer—hence the term "coupled GC-MS."
Because the ion source, the accelerating lens system, the mass
analyzer, and the detector of the mass spectrometer are all maintained under
vacuum by a pumping system, the inlet system must admit the sample (and the
carrier gas of a gas chromatograph) into the spectrometer at such a rate
that the pumping system maintains the specified internal operating pressure
of the instrument.
The ion source (shown schematically in Figure A3) is typically main-
tained at pressures of 10 3mm and lower (10 6mm) and at temperatures of 100°
to 250°C. The source is the region in which ions are generated from the
volatile sample molecules admitted through the inlet system. The ionization
of molecules in the gas phase is effected by bombarding them with electrons
emitted from a hot metal wire or ribbon (the filament) and drawn through a
set of slits for collection at an anode or electron trap. The energy of the
electrons is controlled by the potential difference between the filament and
the trap. As these energetic electrons either strike or pass close to the
sample molecules, ionization occurs, producing a molecular ion that usually
is fragmented further to yield other ions of smaller mass. The ion source
produces both positively charged and negatively charged ions, and many mass
spectrometers in use today are designed to detect both types.
The ions produced are electrically forced out of the ion source and
into the accelerating lens system, which generally imparts several kilovolts
of energy to the ions, which then enter the mass analyzer section.
The purpose of the mass spectrometer analyzer is to separate the ions
according to their mass:charge ratios. Various types of analyzer systems
are in use today, and the type of analyzer usually provides the descriptive
name for each mass spectrometer system. Thus there are, for example,
quadrupole mass spectrometers, single-focusing magnetic deflection mass
spectrometers, time-of-flight mass spectrometers, and double-focusing mass
spectrometers. Each of these systems is characterized by a distinct mode of
ion separation, and each provides different capabilities.
51
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SAMPLE
RESERVOIR
INLET
TO VACUUM
OSCILLOGRAPH
MOLECULAR
LEAKS
ION SOURCE
IONIZING ELECTRON BEAM
ACCELERATING REGION
RESOLVING
SLIT
ANALYZER
TUBE
RESONANT
ION BEAM
MAGNET
Figure A2. Schematic diagram of a Nier 60° sector mass spectrometer.
52
-------
en
CO
IONIZATION CHAMBER-
•REPELLER
^FILAMENT
r-ELECTRON SLIT
r-FIRST ACCELERATING
SLIT (-SECOND ACCELERATING SLIT
' IONIZING REGION
MOLECULAR LEAK-J
ELECTRON BEAM -I
ANODE —'
ION ACCELERATING
REGION
Figure A3. Electron-impact ion source and ion accelerating system.
Source: Merritt and Dean 1974.
-------
The ability of a mass spectrometer to effect a separation of adjacent
mass peaks (that is, to resolve these peaks) depends upon the analyzer.
Resolution is defined by the equation, R = M/AM, where M is the mass of the
first peak in a doublet and AM is the difference in the masses of the two
peaks. An increase in the value of R (denoting an increase in resolution)
indicates an increase in the ability to distinguish between very nearly
identical masses. Of the several mass spectrometers mentioned, the double-
focusing type affords the greatest mass spectral resolution, sometimes
exceeding 100,000. At this degree of resolution, masses appearing at m/e
99,999 and m/e 100,000 would be distinguishable. An instrument capable of
such high resolution is of course very complex and expensive and thus would
be used only when such high resolution is mandatory for effective analysis.
In contrast, a quadrupole mass spectrometer is much simpler to operate and
less expensive but can provide only low resolution (m/Am = 500 to 1000
typically).
Detection of the ions that have been separated is accomplished most
often by use of an electron multiplier, of which, again, various types are
in use. An electron multiplier produces current amplification of 103 to 108
with very low noise level and with negligible time constant or signal
broadening. The amplified analog signal resulting from the ion impacting on
the electron multiplier is finally routed to one of several possible data
acquisition devices; among those often used are the ocillographic recorder,
the analog recorder, a pulse counting device, or the digital computer.
The data from a mass spectrometer consist, in the analog format, of a
spectrum of peaks (the mass spectrum). The position of each peak on the
horizontal axis of a graphic display indicates its m/e ratio whereas the
amplitude of each peak indicates the number of ions (or abundance) of that
m/e. The data may also be displayed digitally in tabular form.
If more than one compound enters the mass spectrometer at a given time,
then the masses detected are generally attributable to any or all of the
compounds. Because it is difficult, and sometimes impossible, to interpret
the mass spectra obtained for mixtures of organic compounds, there is great
advantage in admitting the compounds separately. Thus a gas chromatograph
is used to introduce the separated components of a mixture sequentially into
the mass spectrometer. Following is a simplified description of a coupled
GC-MS system.
GAS CHROMATOGRAPHY/MASS SPECTROMETRY (GC-MS) SYSTEMS
In considering the coupling of the gas chromatograph to a mass spec-
trometer, one should recall that the source, analyzer, and detector of the
spectrometer are all typically maintained at pressures below 10 5mm.
Therefore, unless the mass spectrometer is equipped with a very high-
capacity pumping system, the gaseous effluent from a gas chromatographic
column cannot be admitted directly to the mass spectrometer source because
this would increase the pressure to a level that would prevent satisfactory
operation. Therefore, coupling is generally achieved by use of an inter-
54
-------
mediate device to reduce the rate of flow of the sample and carrier gas
stream. For this purpose several types of devices (called "separators1,1) are
used to achieve partial separation of the carrier gas (typically helium)
from the gaseous sample molecules. Among these devices are (1) a porous
barrier or effluent splitter, (2) a jet/orifice separator, and (3) a
molecular separator that includes a permeable membrane. Some gas chromato-
graph/mass spectrometer systems feature a direct coupling of the gas chrom-
atograph with the mass spectrometer by means of a very high capacity pumping
system.
A system that couples a chromatograph with a mass spectrometer is a
very powerful analytical tool, the only system that can provide definitive
analysis of complex chemical mixtures. The separation capabilities of the
gas chromatograph are complimented by the inherent specificity and sensi-
tivity of the mass spectrometer. During analysis of a complex mixture, the
components are separated gas chromatographically, each eluted component then
passes through the interface (separator) and into the mass spectrometer,
which provides and records a mass spectrum. Typically, the analysis of a
mixture could yield several hundred mass spectra, each containing 100 to 200
mass peaks. Therefore, the computer is an ideal means of acquiring the mass
spectra, reducing the data (converting the acquired data to actual mass
spectra by comparison with calibrated reference files), and displaying the
data. The minicomputer is an essential component of a modern GC/MS system
because the analyses generate such sizable quantities of data. Use of a
minicomputer can afford other advantages; for example, the computer can be
programmed to control the mass spectrometer so that it monitors only
selected masses typical of the compounds of interest. The computer also can
be programmed to allow monitoring of different masses- (corresponding to
different compounds) at different gas chromatographic retention times.
55
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APPENDIX A
REFERENCES
Ambrose, D. 1971. Gas Chromatography. Van Nostrand, New York.
Beynon, J. H. 1960. Mass Spectrometry and Its Applications to Organic
Chemistry. Elsevier, Amsterdam.
Dal Nogare, S. and R. S. Juvet. 1962. Gas Chromatography: Theory and
Practice. Wiley-Interscience, New York.
Jones, R. A. 1970. An Introduction to Gas-Liquid Chromatography. Academic
Press, New York.
Kiser, R. W. 1965. Introduction to Mass Spectrometry and Its Applications.
Prentice-Hall, Englewood Cliffs, New Jersey.
Littlewood, A. B. 1970. Gas Chromatography. 2nd Ed., Academic Press, New
York.
McFadden, W. 1973. Techniques of Combined Gas Chromatography/Mass Spec-
trometry. Wiley-Interscience, New York.
McLafferty, F. W. , ed. 1963. Mass Spectrometry of Organic Ions. Academic
Press, New York.
Merritt, W. H. , Jr. , and J. Dean. 1974. Instrumental Methods of Analysis.
5th Ed. Van Nostrand, New York.
Roboz, J. 1968. Introduction to Mass Spectrometry. Wiley-Interscience,
New York.
56
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APPENDIX B
OTHER INSTRUMENTAL METHODS FOR DIOXIN ANALYSIS
Most of the current technology for detection of TCDD's is based on gas
chromatography and/or mass spectrometry. However, a variety of other less
specific techniques have been used including ultraviolet spectroscopy
(Pohland and Yang 1972), electron spin resonance spectroscopy, and low-
temperature phosphorescence emission spectroscopy (Baughman 1974). None of
these methods provide both the high sensitivity and selectivity needed for
analysis of most environmental samples.
A resin sorption technique using XAD-2 resin has achieved a detection
limit of 1 ppt for TCDD's in water; because this technique required a large
quantity of sample for extraction, however, extension to other types of
samples is unlikely (Junk 1976).
Another technique uses PX21 powdered charcoal suspended on shredded
polyurethane foam as the sorbant (Huckins, Stalling, and Smith 1978). The
TCDD's were eluted from the charcoal column by use of a 50 percent solution
of toluene in benzene and finally were detected by electron-capture gas
chromatography. To enhance selectivity, an alumina column chromatography
step is usually included after elution from the charcoal column. The detec-
tion limit of this method ranges from 10 to 100 ppb.
Thin-layer chromatography has also been used for the detection of
TCDD's (Williams and Blanchfield 1971). Two-dimensional development with
two different solvents is used to increase selectivity. The spot corre-
sponding to 2,3,7,8-TCDD is removed from the plate, extracted with benzene,
and detected by electron -capture gas chromatography. This method has
achieved a detection limit in the low ppm region.
Steam distillation has also been tried (Storhen 1971), but was suitable
only for levels of TCDD's in the range of 1 to 3 ppm and lacked the selec-
tivity needed to avoid interferences.
Recently analytical methods involving chemical ionization mass spec-
trometry with negative ions have been published. An early communication by
Hunt and co-workers (Hunt, Harvey, and Russel 1975) reported a signal-to-
noise ratio of 50 from a 2-pg direct-probe insertion sample using oxygen as
the reagent gas. A sensitivity 25 times higher than the direct-probe inser-
tion method is reported for electron impact ionization. Hass et al. compare
the relative sensitivities of various chemical ionization modes, including
those of positive-ion versus negative-ion modes with methane, oxygen, and
57
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mixed methane/oxygen as reagent gases (Mass 1978). Positive-ion chemical
ionization affords the greater sensitivity, but does not produce ions
indicative of the molecular weight.
58
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APPENDIX B
REFERENCES
Baughman, R. W. 1974. Ph.D. Thesis, Harvard University, Cambridge,
Massachusetts.
Mass, J. R., et al. 1978. Anal. Chem., 50:1474.
Huckins, J. N., D. L. Stalling, and W. A. Smith. 1978. Journal of the
AOAC, 61:32.
Hunt, D. F., T. M. Harvey, and J. W. Russel. 1975. J.C.S. Chem. Comm.,
Vol. 151.
Junk, G. A., et al. 1976. J. Am. Water Works Assoc., 68-218.
Pohland, A. E., and G. C. Yang. 1972. J. Agric. Food Chem., 20:1093.
Storhen, R. W., et al. 1971. Journal of the AOAC, 54:218.
Williams, D. T., and B. J. Blanchfield. 1971. Journal of the AOAC,
55:93-95.
59
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APPENDIX C
LITERATURE REVIEW
This appendix is a compilation of references on dioxin analysis cate-
gorized by sample matrix. The categories are given below:
Air Hexachlorobenzene
Biological tissue Insecticides
Blood Milk or cream
Commercial chlorophenols Plant material
Fats or oils Soil
Fish and crustaceans Urine
Flue Gas Water
Fly ash Wipe samples
Grain Wood
Herbicide formulations
Air
Oswald, E. 1979. Toxicology Research Projects Directory, Vol. 04, Iss. 07.
Biological Tissue
Baughman, R., and M. Meselson. 1973. Environmental Health Perspectives,
5:27.
Bradlaw, J. A., et al. 1975. Proceedings of Society of Toxicology Meeting,
Williamsburg, Virginia, March.
Freudenthal, J. 1978. In: Dioxin: Toxicological and Chemical Aspects, F.
Cattabeni, A. Cavallaro, and G. Galli, eds. Spectrum Publications,
Inc., New York, Chapter 5:43-50.
Hass, J. R., et al. 1978. Anal. Chem. Vol. 50.
McKinney, J. D. 1978. In: Chlorinated Phenoxy Acids and Their Dioxins.
Ecol. Bull., 27:53-66.
60
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0-Keefe, P. W. 1978. In: Dioxin: Toxicological and Chemical Aspects. F.
Cattabenl, A. Cavallero, and G. Galli, eds. Spectrum Publications,
Inc., New York, Chapter 7:59-78.
Oswald, E. 1979. Toxicology Research Projects Directory, Vol. 04, Iss. 07.
Rose, J. Q., et al. 1976. Toxicol. Appl. Pharmacol., 36:209.
Shadoff, L. A., and R. A. Hummel. 1978. Biomed Mass Spectrom, 5(1):7-13,
January.
Tiernan, T. 0. 1976. EPA Contract No. 68-01-1959. December.
Woolson, E. A., R. F. Thomas, and P. D. J. Ensor. 1972. J. Agric. Food
Chem., 20:351.
Woolson, E. A., et al. 1973. Advanced Chemistry Series.
Young, A. L. 1974. Report No. AFATL-TR-74-12, Air Force Armament
Laboratory, Eglin Air Force Base, Florida.
Blood
Hummel, R.A. 1977. J. Agric. Food Chem., 25:1049-1053.
Oswald, E. 1979. Toxicology Research Projects Directory, Vol. 04, Iss. 07.
Commercial Chlorophenols
Blaser, W. W., et al. 1976. Anal. Chem., 48:984.
Buser, J. R. 1975. J. Chromatography, 107:295.
Buser, J. R., and H. P. Bosshardt. 1976. Journal of the AOAC, 59:562.
Crummet, W. B., and R. H. Stehl. 1973. Environmental Health Perspectives,
5:15.
Firestone, D., et al. 1972. Journal of the AOAC, 55:85.
Higginbotham, G. R., et al. 1968. Nature (London), 220:702.
Lamberton, J., et al. 1979. J. Amer. Ind. Hyg. Assoc., 40:816-822.
Langer, H. G., et al. 1971. 162nd Meeting, ACS, Washington, D.C., Pest.
Sec., No. 83.
Micure, J. P., et al. 1977. J. Chromatogr. Sci., 7:275.
61
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Pfeiffer, C. 1976. J. Chromatogr. Sci., 14:386.
Pfeiffer, C. D., T. J. Nestrick, and C. W. Kocher. 1978. Anal. Chem.,
6:800.
Fats or Oils
Campbell, J. C. , and L. Friedman. 1966. Journal of the AOAC, 49:824.
Firestone, D. 1976. Journal of the AOAC, 59:323-325.
Firestone, D. 1977. Journal of the AOAC, 60:354-356.
Higginbotham, G. R., et al. 1967. Journal of the AOAC, 50:874.
Horwitz, W., ed. 1975. Official Methods of Analysis of the Association of
Official Analytical Chemists, Association of Official Analytical
Chemists, Washington, D.C., 12th Ed., Sect. 28.118, pp. 511-512.
Hummel, R. A. 1977. J. Agric. Food Chem., 25:1049-1053.
Kocher, C. W., et al. 1978. Bulletin of Environmental Contamination and
Toxicology, 19:229.
O'Keefe, P. W., M. S. Meselson, and R. W. Baughman. 1978. Journal of the
AOAC, 61:621-626.
Ress, J. R., G. R. Higginbotham, and D. Firestone. 1970. Journal of the
AOAC, 53:628-634.
Shadoff, L. A., et al. 1977. Annali di Chimica, 67:583.
Shadoff, L. A., and R. A. Hummel. 1978. Bio. Mass Spec., 5:7.
Williams, D. T., and B. J. Blanchfield. 1971. Journal of the AOAC,
54:1429-1431.
Williams, D. T., and B. J. Blanchfield. 1972. Journal of the AOAC,
55:93-95.
Williams, D. T., and B. J. Blanchfield. 1972. Journal of the AOAC,
55:1358-1359.
Fish and Crustaceans
Baughman, R. W., and M. Meselson. 1973. 166th Nat. Meeting, ACS,
Chicago, Abstract Pest., 55.
Baughman, R. W., and M. Meselson. 1973. Environmental Health Perspectives,
Expt. Issue 5, 27-35.
62
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Baughman, R. W. 1974. Ph.D. Thesis, Harvard University, Cambridge,
Massachusetts.
Fukuhara, K., etal. 1975. J. of Hvg. Chem., 21:318.
Gross, M. L. 1978. Personal communication, November.
Lamparski, L. L., T. J. Nestrick, and R. H. Stehl. Anal. Chem.,
51(9):1453-1458.
Shadoff, L. A., and R. A. Hummel. 1975. 170th Nat. Am. Chem. Soc. Meeting,
Chicago, Ab. Anal., Vol. 80.
Shadoff, L. A., et al. Bull. Environ. Contain. Toxicol. In press.
Flue Gas
Frigerio, A., and M. C. Tagliabue. Impianti Incenerimento Rifuite Solidi:
Prelievo, Anal. Controllo Effluenti, [conv.]; 59-71.
Fly Ash
Buser, H. R., H. P. Bosshardt, and C. Rappe. 1978. Chemosphere, 2:165.
Grain
Hummel, R. A. 1977. J. Agric. Food Chem., 25:1053-1099
Isensee, A. R., and and G. E. Jones. 1971. J. Agric. Food Chem., 19:1210.
Shadoff, L. A., and R. A. Hummel. 1978. Biomed Mass Spectrom, 5(1):7-13,
January.
Herbicide Formulations
Brenner, K. S., K. Muller, and P. Sattel. 1972. J. Chromatography, 64:39.
Brenner, K. S., K. Muller, and P. Sattel. 1974. J. Chromatography,
90:382-387.
Buser, H. R., and H. P. Bosshardt. 1974. J. Chromatography, 90:71.
Crummett, W. B., and R. H. Stehl. 1973. Environmental Health Perspectives,
5:15.
Edmunds, J. W., D. F. Lee, and C. M. L. Nickels. 1973. Pestic. Sci.,
4:101.
Elvidge, D. A. 1971. Analyst (London), 96:721.
63
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Hackins, J. N., D. L. Stalling, and W. A. Smith. 1978. Journal of the
AOAC, 61:32.
Hohmstedt, B. 1978. In: Dioxin: Toxicological and Chemical Aspects. F.
Cattabeni, A. Cavallaro, and G. Galli, eds. Spectrum Publications,
Inc., New York, Chapter 3:13-25.
Hughes, B. M., et al. 1975. Natl. Tech. Inform. Serv., AD-A011, 597:Vol.
1.
Polyhofer, K. 1979. Levensm Unters Forsch. 168(1):21-4, January.
Ranstad, T., N. H. Mahle, and R. Matalon. 1977. Anal. Chem., 49:386.
Rappe, C., H. R. Buser, and H. P. Bosshardt. 1978. Chemosphere, 5:431.
Shadoff, L. A., etal. 1978. Anal. Chem., 50(11):1586-1588.
Tiernan, T. 0. 1976. EPA Contract No. 68-01-1959, December.
Tiernan, T. 0., M. L. Taylor, and B. M. Hughes. 1975. Proceedings 1975
International Controlled Release Pesticide Symposium.
Vogel, H., and R. D. Weeren. 1976. Anal. Chem., 280:9.
Woolson, E. A., R. F. Thomas, and P. D. Ensor. 1972. J. Agric. Food Chem.,
20:351.
Hexachlorobenzene
Villanueva, E. C., et al. 1974. J. Agric. Food Chem., 22:916.
Insecticides
Elvidge, D. A. 1971. Analyst, 96:721.
Storherr, R. W., et al. 1971. Journal of the AOAC, 54:218.
Webber, T. J. N., and D. J. Box. 1973. Analyst (London), 98:181.
Woolson, E. A., R. F. Thomas, and P. D. J. Ensor. 1972. J. Agric. Food
Chem., 20:351.
Shadoff, L. A., et al. Bull. Environ. Contam. Toxicol. In press.
Shadoff, L. A., and R. A. Hummel. 1978. Biomed Mass Spectrom, 5(1):7-13
January.
64
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Milk or Cream
Baughman, R., and M. Meselson. 1973. Environmental Health Perspectives,
Exp. Issue 5, 27-35.
Baughman, R. W. 1974. Ph.D. Thesis, Harvard University, Cambridge,
Massachusetts.
Hummel, R. A. 1977. J. Agric. Food Chem., 25:1049-1053.
Plant Materials
Buser, H. R. 1977. Anal. Chem., 49:918.
Buser, H. R. 1978. Monogr. Giovanni Lorenzini Found.; Vol 1, In: Dioxin:
lexicological and Chemical Aspects, 27-41.
Di Domenico, A., et al. 1979. Anal Chem; 51(6):735-740.
Hummel, R. A. 1977. J. Agric. Food Chem., 25:1049-1053.
Shadoff, L. A., and R. A. Hummel. Biomed Mass Spectrom, 5(1):7-13, January.
Soil
Bertoni, G. , et al. 1978. Anal. Chem., 6:732.
Buser, H. R. 1977. Anal. Chem., 49:918.
Buser, H. R. 1978. Monogr. Giovanni Lorenzini Found.; Vol 1, In: Dioxin:
lexicological and Chemical Aspects, 27-41.
Camoni, I. 1978. J. of Chromatography, 153:233-238.
Di Domenico, A., et al. 1979. Anal Chem., 51(6):735-740.
Gross, M. L. 1978. Personal communication, November.
Hummel, R. A. 1977. J. Agric. Food Chem., 25:1049-1053.
Kearney, P. C., E. A. Woolson, and C. P. Ellington. 1972. Environ. Sci.
Technol., 1017.
Nash, R. G. 1973. Journal of the AOAC, 56:728.
Shadoff, L. A., and R. A. Hummel. 1975. 170th National American Chemical
Society Meeting, Chicago, Illinois, Abst. Anal., 80.
Shadoff, L. A., et al. Bull. Environ. Contain. Toxicol. In press.
65
-------
Shadoff, L. A., and R. A. Hummel. 1978. Biomed Mass Spectrom, 5(1):7-13,
January.
Widmark, G. 1971. Tracer Cosmos, a Realistic Concept in Pollution
Analysis. In: International Symposium on Identification and
Measurement of Environmental Pollutants, B. Westley, ed. National
Research Council of Canada, Ottawa, p. 396.
Woolson, E. A., et al. 1973.' Advances in Chemistry Series, 120:112.
Urine
Oswald, E. 1979. Toxicology Research Projects Directory, Vol. 04, Iss. 07.
Water
Junk, G. A., et al. 1976. J. Am. Water Works Assoc., 68:218.
Shadoff, L. A., and R. A. Hummel. 1978. Biomed Mass Spectrom, 5(1):7-13,
January.
Wong, A. 1978. EPA Contract No. 68-03-2678, July.
Wipe Samples
Di Domenico, A., et al. 1979. Anal. Chem., 51(6):735-740.
Erk, S. D., M. L. Taylor, and T. 0. Tiernan. 1979. Chemosphere, 8(1):7-14.
Wood
Hass, J. R., et al. 1978. Anal. Chem., 50:1474.
Levin, J. D., and C. A. Nilsson. 1977. Chemosphere, 7:443.
66
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-80-157
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Dioxins: Volume II. Analytical Method
For Industrial Wastes
5. REPORT DATE
JUNE 1980 ISSUING DATE.
6. PERFORMING ORGANIZATION CODE
7.AUTHOR(s) y. 0. Tiernan, M. L. Taylor, S. D. Erk,
J. G. Solch, G. Van Ness, and J. Dryden
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
The Brehm Laboratories and Department of Chemistry
Wright State University, Dayton, Ohio 45435
1BB610
11. CONTRACT/GRANT NO.
Contract No. 68-03-2659
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final. 10/78 to 3/79
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
Volume II of a three-volume series on dioxins
16. ABSTRACT
The overall objective of this research project was to develop a unified analytical
approach for use in quantifying ppt levels of tetrachlorodibenzo-p-dioxins (TCDD's)
in various chemical wastes. Waste samples from plants manufacturing trichloro-
phenol, pentachlorophenol, and hexachlorophene, and from plants processing wood
preservatives were provided by the EPA.
The extraction procedure developed for isolating the TCDD's from the various types
of sample matrices is fully described. Analysis was accomplished using highly
specific and sensitive coupled gas chromatographic-mass spectrometric (GC-MS)
methods. Both low and high resolution MS techniques were employed. This method-
ology is also described in detail. The procedures presented in this report were
acceptable for most of the industrial process samples provided. TCDD's were detected
and quantitatively determined in several of the samples at levels in the ppt to ppm
range. One sample, identified as a trichlorophenol stillbottom, was found to con-
tain 40 ppm TCDD's. This method was not applicable for wood or woodlike products
and difficulties were also encountered with some samples that were susceptible
to emulsion formation in the preparation stages.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI l-ield/Group
Organic chemicals
Pesticides
Chemical analysis
Industrial wastes
Dioxins; 2,3,7,8-TCDD
Analytical chemistry
Hazardous waste disposal
07C
07D
13B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
79
20. SECURITY CLASS (This page I
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
*U.S. GOVERNMENT PRINTING OFFICE: 1981--657-165/0008
67
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