Trace Environmental Quantitative Analysis: Principles, Techniques, and Applications - Chapter 1 pps

The second edition attemptsto move the reader from the most elementary of principles of trace environmentalquantitative analysis TEQA to those techniques and applications currently being

Trace Environmental Quantitative Analysis

Principles, Techniques, and Applications

E D I T I O N

A CRC title, part of the Taylor & Francis imprint, a member of the Taylor & Francis Group, the academic division of T&F Informa plc.

Trace Environmental Quantitative Analysis

6000 Broken Sound Parkway NW, Suite 300

Boca Raton, FL 33487-2742

© 2006 by Taylor & Francis Group, LLC

CRC Press is an imprint of Taylor & Francis Group

No claim to original U.S Government works

Printed in the United States of America on acid-free paper

10 9 8 7 6 5 4 3 2 1

International Standard Book Number-10: 0-8247-5853-6 (Hardcover)

International Standard Book Number-13: 978-0-8247-5853-0 (Hardcover)

Library of Congress Card Number 2005048512

This book contains information obtained from authentic and highly regarded sources Reprinted material is quoted with permission, and sources are indicated A wide variety of references are listed Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use.

No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers

Danvers, MA 01923, 978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged

Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only

for identification and explanation without intent to infringe.

Library of Congress Cataloging-in-Publication Data

Loconto, Paul R.,

1947-Trace environmental quantitative analysis : principles, techniques, and applications / Paul

R Loconto. 2nd ed.

p cm

Includes bibliographical references and index.

ISBN 0-8247-5853-6 (alk paper)

1 Environmental chemistry 2 Trace analysis 3 Chemistry, Analytic Quantiative I.

Title.

TD193.L63 2005

Visit the Taylor & Francis Web site at

and the CRC Press Web site at

Taylor & Francis Group

is the Academic Division of T&F Informa plc.

For permission to photocopy or use material electronically from this work, please access www.copyright.com

( http://www.copyright.com/ ) or contact the Copyright Clearance Center, Inc (CCC) 222 Rosewood Drive,

http://www.taylorandfrancis.com http://www.crcpress.com

To my five points of light Each added a new dimension to my life.

Jennifer Ann Michelle Ann Allison Marie Julia Marie Elizabeth Marie

In memory of Taylor Renee Hamel

(1995–2005) whose light was extinguished

much too early.

The rapid pace in which trace analysis is changing has warranted the writing of asecond edition in a relatively short period What is new? The second edition attempts

to move the reader from the most elementary of principles of trace environmentalquantitative analysis (TEQA) to those techniques and applications currently beingpracticed in analytical laboratories dedicated to trace environmental chemical andtrace environmental health quantitative analysis while adding new significant topics.The increasing importance of mass spectrometry will become apparent to thereader primarily as a low-resolution hyphenated technique The principles that under-determinative techniques

alternatives to liquid–liquid extraction are introduced Column chromatographiccleanup, virtually ignored earlier, and gel permeation chromatography have beenintroduced along with additional applications to biological sample matrices of envi-ronmental health and toxicological interest Matrix solid-phase dispersion as applied

to the isolation and recovery of persistent organic pollutants from fish tissue hasbeen added The prolific growth of SPME as evident in the analytical literature overthe past 5 years has warranted an enlarged section on this technique

More than two dozen new topics not previously discussed in the original bookhave been added to the second edition

Any author, upon reviewing the finished product of a first book, has a mostimmediate desire to rewrite all of it I have resisted this temptation and have modifiedonly those sections of the original book that I felt enlarge and enhance the environ-mental analytical chemist’s understanding of TEQA

Who should read the second edition? Scientists, in addition to analytical ists, such as organic chemists, biochemists, molecular biologists, geologists, toxi-cologists, epidemiologists, food scientists, and chemical and environmental engi-neers will find that the second edition might enhance their understanding of TEQA.Laboratory technicians of various skill and knowledge levels should also find thecontent of this edition beneficial

chem-The style for the second edition has remained the same Section headingscontinue to be cast in the form of a question New terms have been italicized whenthey appear for the first time Beneath each chapter title is a brief “Chapter at aGlance” so that the reader can more quickly find topics of immediate interest Figuresand tables are both separated and numbered in sequence and integrated in the textwithout numbering, as before Digressions from the main topics have also occurred

in a manner similar to that in the original book Graphs are either sketches that Idrew to illustrate a principle or carefully drawn from experimental data (I’m a prettygood chemist; an artist, I am not) To reiterate from the preface to the original book,lie GC-MS, GC-MS-MS, LC-MS, and ICP-MS can now be found in Chapter 4 onChapter 3 on sample preparation techniques has been enlarged so that even more

Laboratories, Michigan Department of Community Health; the Michigan PublicHealth Institute; and the Biomonitoring Planning Grant, National Center for Envi-ronmental Health, Centers for Disease Control and Prevention These institutionsand grants enabled me to find the time to write, edit, and rewrite Barbara Mathieuand colleagues at Taylor & Francis have painstakingly, for a second time, turnedthis author’s rough draft into a book My wife, Priscilla, has graciously endured herhusband’s passion for writing And my motivation to write is rooted in and summa-rized by the ancient Chinese Proverb:

I hear and forget; I see and I remember; I write and I understand.

Paul R Loconto is currently a laboratory scientist specialist with the Michigan

Department of Community Health, Bureau of Laboratories, Lansing Dr Loconto

is the author of 24 peer-reviewed publications and 33 oral and poster presentations

in trace analysis and chemical education He combines various work experiencesthat include teaching at a community college, managing an environmental engineer-ing research laboratory within a large university, and conducting analytical methoddevelopment for an independent environmental testing laboratory All have giventhe author many unique insights over the years into the principles, techniques, andapplications of TEQA

1 Introduction to Trace Environmental Quantitative Analysis (TEQA) 1

2 Calibration, Verification, Statistical Treatment of Analytical Data,

Detection Limits, and Quality Assurance/Quality Control 37

3 Sample Preparation Techniques to Isolate and Recover Organics and

4 Determinative Techniques to Measure Organics and Inorganics 323

Appendix C: TEQA Applied to Drinking Water/Computer Programs

Appendix E: Useful Internet Links for Environmental Analytical Chemists 711

Appendix F: Useful Potpourri for Environmental Analytical Chemists 717

Environmental

Quantitative Analysis

(TEQA)

If you teach a person what to learn, you are preparing him for the past If you teach him how to learn, you are preparing him for the future.

—Anonymous

CHAPTER AT A GLANCE

Case study from trace enviro-health quantitative analysis 2

Case study from trace enviro-chemical quantitative analysis 4

Extent of chemical contaminants in humans 7

Analytical chemistry approaches to biomonitoring 11

Environmental chemistry 11

EPA regulations 15

Analytical methods that satisfy EPA regulations 20

Physical/chemical basis for EPA’s methods protocols 32

References 35

As we approached the new millennium, the news media and related mass media speculated on what would be different The 20th century was gone The 21st century was upon us The tragic events of 9/11 in the U.S provided one such answer Since 9/11, questions such as “If we have a terrorist event, can we measure trace concen-tration levels of terrorist-related chemical substances and attempt to evaluate expo-sure over relatively large numbers in the population?” have shifted the dialogue Public health laboratories are beginning to respond to this terrorist-related threat These laboratories are moving toward having a capability in trace environmental health quantitative analysis (also abbreviated TEQA) At the same time, biomonitoring-related initiatives are expanding Federal laboratories such as the National Center for Environmental Health and the Centers for Disease Control and Prevention (NCEH/CDC) are assisting state labs in the transfer of both bioterroism- and biomon-itoring-related analytical methods These methods are designed to measure trace

concentration levels of chemical substances that either persist (persistent organicpollutants (POPs)) or are eliminated rather quickly by the body, i.e., nonpersistentorganic pollutants (NPOPs).

Bioterrorism and biomonitoring are key initiatives that are currently driving thechanging nature of trace quantitative organics and inorganics analysis The secondedition of this book attempts to reflect these changes This new emphasis, when

analysis, has led this author to adopt a new term: trace enviro-chemical/enviro-health

quantitative analysis, whose acronym is also TEQA I have tried to add those

analytical concepts that are most relevant to conducting trace enviro-health tative analysis Sampling, sample preparation, determinative technique, and datareduction/interpretation are very similar to both trace enviro-chemical and tracethe enviro-health aspects of trace quantitative organics and inorganics analysis whilediscerning the similarities and differences in both One starts with an understanding

quanti-of the chemical nature quanti-of the sample or human or animal specimen received A clientneeds to understand just what analytes are to be measured and how these twopathways lead to four steps in the process shown in Scheme 1.1 There is no substitutefor effective communication between the client and the analytical laboratory Sam-

determinative techniques, often referred to as instrumental analysis (introduced in

data (introduced in Chapter 2) comprise the important aspects of successfully menting TEQA

imple-This second edition introduces principles and practices of trace enviro-healthquantitative analysis while expanding on the previous treatment of trace enviro-chemical quantitative analysis where the emphasis was placed only on environmentalsamples.1

Two case studies drawn from the recent literature introduce the practice ofcontemporary TEQA The first case study demonstrates that a possible endocrinedisrupter can be isolated and recovered from human urine

1 CAN AN EXAMPLE PROVIDE INSIGHT INTO TRACE

is to biomonitor, i.e., to measure, trace BPA in human urine Brock and coworkers2

at the NCEH/CDC have developed a quantitative analytical method to determinejust how much BPA might be present in a urine sample obtained from a personbelieved to be exposed to BPA.2 BPA is apparently excreted either unmetabolized

combined with the more established methods of trace environmental quantitative

enviro-health quantitative analysis Scheme 1.1 depicts both the enviro-chemical and

pling (introduced in Chapter 2), sample preparation (introduced in Chapter 3),Chapter 4), and data reduction, statistical treatment, and interpretation of analytical

or glucuronidated Urinary BPA glucuronide seems to be a longer-lived biomarker(12 to 48 h) After deglucuronidation using β-glucuronidase, BPA was isolated andrecovered by reversed-phase solid-phase extraction The isolate was converted to itspentafluorobenzyl ether The pentafluororbenzyl ether of BPA was quantitated usingisotope dilution gas chromatography-mass spectrometry (GC-MS) A method detec-two different mass spectra for the pentafluorobenzyl ether of BPA that eluted fromthe gas chromatographic column at ∼26.4 min The top mass spectrum in Figure 1.1was obtained via electron-impact mass spectrometry and reflects positive fragmentions, while the bottom mass spectrum was obtained via negative chemical ionizationmass spectrometry Pooled human urine samples showed no detectable BPA beforethe urine was treated, while BPA concentration levels varied from 0.11 to 0.51 parts

SCHEME 1.1

What is the chemical nature

of the sample or human specimen?

Blood, plasma, serum, urine, breast milk, adipose tissue, saliva, other body fluids

non-of interest

Application of appropriate determinative techniques (instrumental analysis)

Data reduction, statistical treatment of analytical data and interpretation; detection limit calculations; QA/QC

Reporting of analytical results

to client

Sampling, sample preparation

Trace Enviro-health quantitative analysis

tion limit (MDL) was reported to be 120 parts per trillion (ppt) Figure 1.1 shows

per billion (ppb) for the treated urine Molecular structures for Bisphenol A and forpentafluorobenzyl bromide (α-bromo-2,3,4,5,6-pentafluorotoluene) are shown below:

The second case study demonstrates that an emerging pharmaceutical can beisolated and recovered from wastewater

2 CAN AN EXAMPLE PROVIDE INSIGHT TO TRACE

ENVIRO-CHEMICAL QA?

Yes indeed, and we start with a published report on the isolation and recovery of clofibricacid from wastewater.3 Clofibric acid [2-(4-chlorophenoxy)-2-methyl-propanoic]

FIGURE 1.1 Electron impact (top) and negative chemical ionization (bottom) mass spectra

of the pentafluorobenzyl ether of Bisphenol A.

500 400

300 200

O

F F F

408 407

acid is the bioactive metabolite of various lipid-regulating prodrugs Acidic olites of pharmaceuticals present one type of analyte that appears in the effluent ofmany municipal treatment facilities The isolation and recovery of clofibric acid isconsistent with the Environmental Protection Agency’s (EPA) Division of Environ-mental Sciences, Environmental Chemistry Branch’s mission to study the fate andtransport of chemical compounds derived from pharmaceuticals, their metabolites,and personal care products Patterson and Brumley approached the need to quantitateclofibric acid by comparing two major types of sample preparation, liquid–liquidextraction (LLE) and reversed-phase solid-phase extraction (RP-SPE), using a sty-rene/divinyl benzene adsorbent The determinative technique used was electron-impactgas chromatography-mass spectrometry (EI-GC-MS) after conversion of clofibricacid to its methyl ester by derivatizing with trimethyl silyl diazomethane An internal

metab-a trmetab-ace qumetab-antitmetab-ative metab-anmetab-alysis of smetab-amples of sewmetab-age effluent to determine how muchclofibric acid is present Shown below are the molecular structures for clofibric acidand two organic compounds, 3,4-D and PCB 104 (2,2′,4,6,6′-pentachlorobiphenyl),used by the authors to calibrate the instrument based on the internal standard mode:

Since EI-GC-MS was the only instrumental determinative technique

(determina-subtracted standard or clofibric acid methyl ester, while the mass spectrum shownbelow is for a background-subtracted mass spectrum obtained from the effluent

Cl

Cl O

O H

Cl Cl

Cl

Cl Cl

sample extract at the retention time of clofibric acid methyl ester The disputablefact that both mass spectra are identical demonstrates the unequivocal nature of

identification, sometimes referred to in EPA methods as confirmation Figure 1.2 illustrates trace environmental qualitative analysis Using all abundant fragment ions

or even one or more selected fragment ions with which to build a calibration curve,and from this curve to interpolate and thus to find how much clofibric acid is present

in the unknown extract from the waste effluent, nicely illustrates the science of traceenvironmental quantitative analysis

Let us summarize some regulatory issues, first from this emerging enviro-healtharena We then complete this introductory chapter with an emphasis on the well-established enviro-chemical arena, largely reviewing the significant environmentalregulations We then show just how the EPA methods fit in A significant question

is before us with respect to enviro-health

FIGURE 1.2 EI mass spectra for clofibric acid methyl ester.

100 80 60 40 20

3 TO WHAT EXTENT DO ENVIRONMENTAL

CONTAMINANTS ENTER HUMANS?

the first National Report on Human Exposure to Environmental Chemicals,

con-ducted by the CDC This report provides exposure information about people ipating in an ongoing national survey of the general U.S population — the NationalHealth and Nutrition Examination Survey (NHANES) The survey was conducted

partic-by the National Center for Health Statistics of the CDC This first report presentsdata for the general U.S population from the 1999 NHANES According to thereport, this survey was conducted in only 12 locations across the country Mostanalyses were conducted in subsamples for the population More data would beneeded to confirm these findings and to allow more detailed analysis to describeexposure levels in population subgroups.4

All the metals determined are listed in Table 1.1, while just those organics thatreveal a level above the limit of detection are shown in Table 1.2 The report makes

TABLE 1.1

Geometric Mean of Blood and Urine Levels of Environmental Metals

Metal

Human Specimen

No of People Sampled Units

Geometric Mean (95% Confidence Interval)

Source: Adapted from the National Health and Nutrition Examination Survey (NHANES), U.S., 1999.

CDC, National Report on Human Exposure to Environmental Chemicals, CDC, Atlanta, GA, March

2001.

Table 1.1 (metals) and Table 1.2 (organics) highlight selected analytical results from

it very clear that the presence of detectable concentration levels of chemical stances does not indicate that the chemical causes disease Since 1976, CDC hasthat the geometric mean blood Pb levels for children aged 1 to 5 have decreased to2.0 from 2.70 µg/dL, the geometric mean for the period 1991–1994 These decreases

sub-in blood Pb levels sub-indicate a success sub-in public health efforts to decrease the exposure

of children to Pb

Not shown in either Table 1.1 or Table 1.2 are the results for reduced exposure

of the U.S population to environmental tobacco smoke (ETS) Cotinine is a olite of nicotine that tracks exposure to ETS Molecular structures for both cotinineand its precursor, nicotine, are shown below:

metab-A decrease in serum cotinine concentration levels from 0.20 ng/mL obtainedduring the period 1988–1991 to 0.050 ng/mL (obtained in this study) among peopleaged 3 years and older (a 75% decrease) indicates a dramatic reduction in exposure

of the general population to ETS over the past decade

Table 1.2 reveals some surprising results CDC scientists measured metabolites

of seven major phthalates Di-2-ethylhexyl phthalate and di-iso-nonyl phthalate aretwo phthalates produced in greatest quantity; however, metabolites of diethyl and

No of People Sampled Units

Geometric Mean (95% Confidence Interval)

Source: Adapted from the National Health and Nutrition Examination Survey (NHANES), U.S.,

1999 CDC, National Report on Human Exposure to Environmental Chemicals, CDC, Atlanta, GA,

March 2001.

N N

Nicotine

N N

O Cotinine

measured blood Pb levels as part of NHANES Results presented in Table 1.1 show

dibutyl phthalate were much higher in the population than levels of metabolites ofthe most ubiquitous phthalates found in the environment.

Trace enviro-health quantitative analysis, also abbreviated TEQA, is, in thisauthor’s opinion, an evolving subdiscipline of trace environmental quantitative anal-ysis The Clinical Laboratory Improvement Act of 1988 (CLIA’88) regulates thechemical laboratory and addresses those aspects of traditional clinical chemistry,such as determining the concentration of creatinine in blood Toxicological chemistryalso includes blood alcohol, digoxin, lithium, primidone, and theophylline assays.The concentrations in the blood and urine of these analytes are significantly higherthan those that would be considered at a trace level Our focus in this book is todiscuss how environmental pollutants can be quantitatively determined in humanspecimens However, environmental priority pollutants found in human specimensmay have entered the human domain via the various routes of exposure Figure 1.3

FIGURE 1.3 Routes of human exposure to environmental contaminants Types of body fluids

as human specimens for biomonitoring.

Respiratory tract

Inhalation Absorption

Sweat

Feces Developing

organs

Liver Hair

Urine

depicts routes of exposure to environmental priority pollutants along with the sible kinds of body fluids, shown as ovals, that could be defined as suitable humanspecimens for biomonitoring.5 Three routes of exposure include inhalation to therespiratory tract, ingestion to the gastrointestinal tract, and absorption through theskin, often termed dermal exposure The development of so-called biological markers

pos-(biomarkers) represents a very active research area involving toxicologists and

epidemiologists TEQA has a vital role to play in this research today A biomarkercan be either cellular, biochemical, or molecular in nature and can be measuredanalytically in biological media such as tissues, cells, or fluids A suitable biomarkercould be an exogenous substance or its metabolite It could also be a product of an

interaction between the xenobiotic agent and some target molecule Exposure and

dose are two terms that are further elaborated below:

• Exposure is contact of a biological, chemical, or physical agent with thesurface of the human body

• Dose is the time integral of the concentration of the toxicologically activeform of the agent at the biological target tissue

• Dose links exposure to risk of disease

• Exposure ≈ dose ≈ effect

The relationship between exposure, dose, and potential health effects is rized below:

summa-blood supply This model does not include adipose or other human tissue Bloodand urine are emerging as the most convenient human specimens to collect andconduct biomonitoring

Source

Pesticide use Air pollution Water pollution

Concentration: : Indoor air Outdoor air Surfaces Soil Food Drinking water

Potential

adverse health

effects

Exposure Personal air Diet Dermal rinse

Dose Biomarkers (urine, blood, hair)

Figure 1.3 depicts a biomonitoring scenario centered with respect to a person’s

Let us return to the concept of a biomarker as a key ingredient in biomonitoring.Biomarkers provide evidence of both exposure and uptake The concentration level

of a given biomarker is directly related to tissue dose Biomarkers account for allFactors that limit the usefulness of biomarkers include:5

• The fact that many biomarkers are still being developed

• The need for standardized protocols in both collection and analysis

• Variability in relationship with exposure

• Timing — each biomarker has a characteristic half-life

• Difficulty in interpreting

APPROACH TO BIOMONITORING LOOK LIKE?

human specimen to analytical result” is listed in terms of five essential and sequential

steps, each linked by a chain-of-custody protocol The arrows show that the

rela-tionship between steps must include a chain-of-custody protocol This protocol mighttake the form of a written document If, however, a Laboratory Information Man-agement System (LIMS) is in place, the protocol takes the form of an entry into acomputer that utilizes a LIMS Referring to Figure 1.4, the sample prep lab maygive to the analyst a complete sample extract along with a signed chain-of-custodyform to provide evidence as to where the extract is headed next This five-stepapproach to biomonitoring is also applicable to trace enviro-chemical quantitativeanalysis

We leave for the moment trace enviro-health quantitative analysis and pick up trace enviro-chemical quantitative analysis Let us first define what we mean by

environmental chemistry

5 WHAT KIND OF CHEMISTRY IS THIS?

The academic discipline of environmental chemistry is a relatively recent ment Environmental chemistry can be defined as a systematic study of the nature

develop-of matter that exists in the air, water, soil, and biomass This definition could beextended to the plant and animal domains where chemicals from the environmentare likely to be found This discipline, which developed in the late 1960s, requiresthe knowledge of the traditional branches of organic, inorganic, physical, and ana-lytical chemistry Environmental chemistry is linked to biotechnology as well as tochemical, environmental, and agricultural engineering practices

Environmental analytical chemistry can be further defined as a systematic study

that seeks to answer two fundamental questions: What and how much matter exists

in the air, water, soil, and biomass? This definition could also be extended to theplant and animal domains just discussed This discipline, which developed in thepossible routes, as shown in Figure 1.3 Biomarkers account for differences in people

One such answer to this question can be found in Figure 1.4 The scenario “from

1970s, spearheaded by the first Earth Day in 1970 and the establishment of the U.S.EPA, requires a knowledge of traditional quantitative analysis, contemporary instru-mental analysis, and selected topics, such as statistics, electronics, computer software,

and experimental skill Environmental analytical chemistry represents the

fundamen-tal measurement science to biotechnology and to chemical, environmenfundamen-tal, andagricultural engineering practices That portion of environmental analytical chem-istry devoted to rigorously quantifying the extent to which chemical substances havecontaminated the air, water, soil, and biomass is the subject of this book

In its broadest sense, environmental chemistry might be considered to includethe chemistry of everything outside of the synthetic chemist’s flask The momentthat a chemical substance is released to the environment, its physico-chemical

FIGURE 1.4 From human specimen to analytical result; the analytical approach to

biomon-itoring.

• Sampling or human specimen collection

• Sample/specimen preservation and storage

Refrigeration Addition of preservatives Holding time considerations Archive unused specimens

• Sample/specimen preparation which includes

1 Addition to sample, prior to extraction, of

surrogates, labeled isotopes, and internal standards

2 Extraction of analyte(s) of interest from

matrix

3 Cleanup of matrix interferences

4 Concentration of sample extract

5 Addition of internal standard prior to

injection of the sample extract

• Optimization of determinative techniques and application of quantitative instrumental analysis

and includes:

6 Calibration and least squares regression

using an isotope dilution or internal standard mode of instrument calibration

7 Instrument calibration verification

8 Interpolation of the calibration applied to

sample extracts for all sample/specimens and QC samples

• Data reduction and interpretation of analytical

data; evaluation of percent recoveries, determining the instrument and method decision and detection limits; statistical treatment of replicate data

• Implementation of a QA/QC protocol; writing of a

QA document that addresses CLIA’88 guidelines

• Implementation of reporting protocols

• Preparation of summaries, spreadsheets, data bases

• Archival protocols

properties may have an enormous impact on ecological systems, including humans.Researchers have identified 51 synthetic chemicals that disrupt the endocrine system.Hormone disrupters include some of the 209 polychlorinated biphenyls (PCBs) andsome of the 75 dioxins and 135 furans that have a myriad of documented effects(p 81).6 The latter half of the 20th century has witnessed more synthetic chemicalproduction than any other period in world history Between 1940 and 1982, theproduction of synthetic chemicals increased about 350 times Billions of pounds ofsynthetic materials were released into the environment during this period U.S.production of carbon-based synthetic chemicals topped 435 billion pounds in 1992,

or 1600 pounds per capita (p 137).6

The concept of environmental contaminants as estrogenic “mimics” serves tobring attention to the relationship between chemicals and ecological disruption Thestructural similarity between DDT and diethyl stilbestrol is striking The formerchemical substance was released into the environment decades ago, whereas thelatter was synthesized and marketed to pregnant women during the 1950s and thenused as a growth promoter in livestock until it was banned by the Food and DrugAdministration (FDA) in 1979.7

At levels typically found in the environment, hormone-disrupting chemicals donot kill cells or attack DNA Their target is hormones, the chemical messengers thatmove about constantly within the body’s communication They mug the messengers

or impersonate them They jam signals They scramble messages They sow formation They wreak all manner of havoc Because messages orchestrate manycritical aspects of development, from sexual differentiation to brain organization,hormone-disrupting chemicals pose a particular hazard before birth and early in life(pp 203–204).6

disin-A more recent controversy has arisen around the apparent leaching of Bisphenol

A from various sources of plastics that are in widespread use among consumers.Earlier, the isolation and recovery of Bisphenol A from human urine was discussed.How could that method be changed to enable Bisphenol A to be isolated andrecovered from an environmental matrix such as plastic wrap? Molecular structuresfor p,p'-DDT and diethyl stilbestrol are shown below Compare these structures tothat shown earlier in this chapter for Bisphenol A The similarities in molecularstructure are striking

The EPA has released its plan for testing 15,000 chemicals for their potential todisrupt hormone systems in humans and wildlife These chemicals were chosenbecause they are produced in volumes greater than 10,000 pounds per year.9

Diethylstilbestrol

One usually hears about environmental catastrophes through the vast resources

of the mass media (i.e., radio, television, newspaper, popular magazines, newslettersfrom special interest organizations, etc.) The mass media usually assigns a name

to the disaster that also includes a geographic connotation Examples include theValdez Oil Spill in Alaska, Love Canal in New York, Seveso, Italy, and Times Beach,Missouri What is not so newsworthy, yet may have as profound an impact on theenvironment, is the ever-so-subtle pollution of the environment day in and day out.Both catastrophic pollution and subtle pollution require the techniques of TEQA toobtain data that enable society to continuously monitor the environment to ensureminimal ecological and toxicological disruption It is the combination of sophisti-

TEQA

This book provides insights and tools that enable an individual who either works

in an environmental testing lab or public health lab or anticipates having a career

in the environmental science or environmental health field to make a contribution.Individuals are thus empowered and can begin to deal with the problems of moni-toring and sometimes finding the extent to which chemicals have contaminated theenvironment or entered the human body

It is too easy to answer this question with “everyone.” The industrial sector of theU.S economy is responsible for the majority of chemical contamination released tothe environment Since the early 1970s, industry has been under state and federalregulatory pressures not to exceed certain maximum contaminant levels (MCLs) for

a variety of so-called priority pollutant organic and inorganic chemical substances.However, one of the more poignant examples of small-time pollution is that of drycleaning establishments located in various shopping plazas throughout the U.S.These small businesses would follow the practice of dumping their dry cleaningfluid into their septic systems It was not unusual, particularly during the 1980s, forlabs to analyze drinking water samples drawn from an aquifer that served theshopping plaza and find parts per billion (ppb) concentration levels of chlorinatedvolatile organics such as perchloroethylene (PCE)

The necessary sample preparation needed to modify a sample taken from anaquifer that is expected to contain PCE, so as to enable the sample to becomecompatible with the appropriate analytical instrument, will be described in Chapter 3.The identification and quantitative determination of priority pollutants like PCE indrinking water require sophisticated analytical instrumentation These so-calleddeterminative techniques will be described in Chapter 4 A laboratory exercise thatmight introduce a student to the technique involved in sample preparation andinstrumental analysis to quantitatively determine the presence or absence of a chlo-rinated volatile organic like PCE will be described in Chapter 5

cated analytical instruments (Chapter 4), sample preparation schemes (Chapter 3),mathematical treatment of analytical data (Chapter 2), and detailed practical proce-dures (Chapter 5) that enables a student or practicing analyst to effectively conduct