xvEPA
United States Office of Research and EPA 600/R-04/043
Environmental Protection Development May 2004
Agency Washington DC 20460
Identification of Time-integrated
Sampling and Measurement
Techniques to Support Human
Exposure Studies
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Identification of Time-integrated Sampling
and
Measurement Techniques to Support Human
Exposure Studies
By
J. D. McKinney, Ph.D.
Research Triangle Institute
Analytical and Chemical Sciences
Post Office Box 12194
Research Triangle Park, NC 27709
Stephen N. Hern, Gary L. Robertson
National Exposure Research Laboratory
Las Vegas, NV 89193
Contract Number 68-D-99-012
EPA Project Officer
Ellen W. Streib
National Exposure Research Laboratory (MD-56)
Research Triangle Park, North Carolina 27711
National Exposure Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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Notice
The information in this document has been funded and managed by the United States
Environmental Protection Agency under Contract 68-D-99-012 to Research Triangle Institute. It has
been subjected to the Agency's peer and administrative review and has been approved for publication as
an EPA document. Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
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Foreword
The mission of the National Exposure Research Laboratory (NERL) is to provide scientific
understanding, information, and assessment tools that will quantify and reduce the uncertainty in EPA's
exposure and risk assessments for environmental stressors. These stressors include chemicals,
biologicals, radiation, and changes in climate, land use, and water use. The Laboratory's primary
function is to measure, characterize, and predict human and ecological exposure to pollutants. Exposure
assessments are integral elements in the risk assessment process used to identify populations and
ecological resources at risk. The EPA relies increasingly on the results of quantitative risk assessments to
support regulations, particularly of chemicals in the environment. In addition, decisions on research
priorities are influenced increasingly by comparative risk assessment analysis. The utility of the risk-
based approach, however, depends on accurate exposure information. Thus, the mission of NERL is to
enhance the Agency's capability for evaluating exposure of both humans and ecosystems from a holistic
perspective.
The National Exposure Research Laboratory focuses on four major research areas: predictive
exposure modeling, exposure assessment, monitoring methods, and environmental characterization.
Underlying the entire research and technical support program of the NERL is its continuing development
of state-of-the-art modeling, monitoring, and quality assurance methods to assure the conduct of
defensible exposure assessments with known certainty. The research program supports its traditional
clients - Regional Offices, Regulatory Program Offices, ORD Offices, and Research Committees - and
ORD's Core Research Program in the areas of health risk assessment, ecological risk assessment, and risk
reduction.
Gary J. Foley
Director
National Exposure Research Laboratory
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Abstract
Accurate exposure classification tools are required to link exposure with health effects in
epidemiological studies. Long-term, time-integrated exposure measures would be desirable to address the
problem of developing appropriate residential childhood exposure classifications. Screening techniques
are also of interest that could focus attention on the most highly exposed (to indicator compounds)
populations for which costly multiroute, multimedia monitoring would be most informative. This report
presents the results of a literature review that was designed to investigate and/or evaluate methods used in
classifying exposure, both long-term, time-integrated and screening methods for assessing exposures to
relatively short half-life contaminants
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CONTENTS
Section Page
Glossary vi
Acronyms ix
1.0 INTRODUCTION 1-1
1.1 Background Information 1-1
1.2 Objectives 1-3
2.0 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS 2-1
3.0 TECHNICAL APPROACH AND RESULTS 3-1
3.1 Search Routines and Approaches to Review of Current Literature
Materials 3-1
3.2 Some Current Methods and Technologies 3-3
3.3 Emerging Technology Including Applications from Other Fields 3-5
4.0 REFERENCES 4-1
4.1 Air-Related 4-1
4.2 Water 4-4
4.3 Soil and Dust 4-5
4.4 Food 4-6
4.5 General 4-6
LIST OF TABLES
Number Page
1-1 Some Current Techniques for Time-Integrated Sampling and Analysis 1-4
3-1 Parameters for Major Searches 3-9
3-2 Summary Table of Some Method Papers by Group 3-11
3-3 Summary Table of Portable/Field-Ready Instruments from Gray Literature 3-53
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GLOSSARY
Active/passive samplingactive sampling depends on pumping or similar processes to collect the sample
whereas passive sampling involves non-mechanical processes like diffusion
Activity pattern
Acute/chronic effects
Aggregate exposure
Ambient monitoring
Chemical classes
Chemical/physical
Composite sampling
Continuous monitoring/
continuously direct reading
Cumulative exposure
Diffusive sampler
Discontinuous techniques
Environmental nervous
system
Epidemiological studies
Exposure assessment
Exposure classification
Grab sampling
Half-life
Halides
Headspace analysis
High sensitivity/cost/
burden methods
Intensity/frequency of
contact
Lab-on-a-chip
individual activity associated with daily events
short-term versus longer-term effects
total exposure from all routes for a particular time period
monitoring of the local/microenvironment of an individual/population;
generally refers to outdoor air monitoring
VOCs, SVOCs, PAHs, metals, pesticides, herbicides, flame retardants
transformation within media-processes that lead to multiple
forms/products of a given chemical to which one can be exposed
combining of samples of similar types to get an overall reading of
exposure, for example, combining different foods eaten at a meal
monitoring and displaying the concentration of a
chemical or the magnitude of a condition as opposed to a periodic or
cyclic monitoring process (also see discontinuous techniques)
exposure overtime that can lead to additive concentrations of chemicals
one that depends on the process of diffusion to collect the sample
parts done at different times, such as collection of the sample in the field
which is properly packaged and taken to the laboratory for analysis some
time later (also see continuous monitoring/direct reading)
term used to describe the wireless networking of lab-on-a-chip or
sensors for continuous monitoring of some environment of interest
the study of occurrence and distribution of disease
nature and extent of exposure
characterization of exposure in various terms to permit grouping of
individuals/populations in epidemiological and related studies
designed to capture a pollutant sample at a specific point in time (often
during "peak" exposure) for subsequent analysis
time at which the rate of disappearance of a chemical in the environment
leads to a 50% decrease in concentration
halogen (chlorine, bromine, etc.) anion
usually associated with the analysis of volatile chemicals in the defined
headspace above a confined sample of water, food, etc.
methods usually more complex and costly that may be required
for adequate sensitivity to characterize exposures for the general
population (also see low sensitivity/cost/burden/methods)
variables which define the nature and extent of exposure
understood to mean a small device integrating chemical reaction and
analysis functionalities
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Limit of detection
Long-term/time-integrated
measures
Low sensitivity/cost/
burden methods
Media of exposure
Metalloporphyrins
Method validation level
Microenvironmental
Oxyanions
Pathways of exposure
Pattern recognition
PB-PK
Personal monitoring
Portable instruments
Preconcentration/
enrichment
Reactivity equivalents
Real-time method
Remote operation
Route of exposure
Scale of exposure
Screening techniques
Selectivity
Sensitivity
Sensors
lowest detectable concentration for an analyte at a given signal/noise
ratio
approaches to sampling to collect the pollutants over a specified
period of time
usually simpler and more cost effective; more suitable for
screening (also see high sensitivity/cost/burden methods)
air, water, dust, food, etc.
class of biomolecules with nearly planar/many electron structure used as
sensitive layers in sensors
E, EPA approved/accepted; F, field validated; L, laboratory validated; P,
proposed method
may be very specific and well-defined local environments such as in a
shower stall, or more general, such as indoor
common anions often associated with acidity like the sulfates, nitrates,
etc.
refers to specific ways an individual or population comes in contact with
an environmental agent, e.g., hand to mouth contact
statistical models used to aid in analysis of response patterns for sensors
physiologically based pharmacokinetics
monitoring clearly associated with an individual; usually conducted by
wearing a personal monitor
usually means small or miniaturized for field used and may be operated
remotely in some cases
some type of process usually designed to concentrate or enrich the
target analyte(s) before analysis to minimize problems with interferences
and improve detectability
used to describe chemicals of similar or ostensibly dissimilar structures
that have similar chemical reactivity properties
gives instantaneous (or nearly so) information at the point of sampling
usually means to describe field instruments that can be operated from a
distance
inhalation, ingestion, and dermal adsorption
extent of populations/individuals exposed
usually lower sensitivity/cost/burden methods to help in preclassifying
sample components
ability to discriminate
change in response (slope) as a function of incremental changes in
analyte concentration
understood to mean a device that contains a specific chemical
recognition element for identifying a molecule or class of molecules and
a means of signal transduction for quantifying the material
Sorbent material
activated charcoal, Carbotraptm, Carboxentm, Carbopacktm, Tenaxtr
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Sorbent tubes tubes containing some adsorbing/absorbing material for capturing and
preconcentrating/enriching target analytes
Spatial/temporal concentrations found over time and distance
concentration patterns
Spike exposure higher than normal exposure associated with some specific activity that
occurs infrequently
Time of exposure various aspects such as during certain stages of biological development,
daily activities, time of day, etc
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AAS
BCD
FID
FPD
GC
GC-AED
GC-MS
GC-NPD
GFAAS
HiVol PUF sampler
ICP-AES
ICP-MS
IR
ISE
LC-MS
LDPE
MIPs
MOSES II
MOS
MQL
NCI-MS
OP
PAHs
PBDE
PCA
PCBs
PID
POPs
PRC
PVC
RSD
SAW
ACRONYMS
atomic absorption spectroscopy
electron capture detector
flame ionization detector
flame photometric detector
gas chromatography
gas chromatograph with atomic emission detector
gas chromatograph coupled to mass spectrometer
gas chromatograph with nitrogen/phosphorus detector
graphite furnace atomic absorption spectroscopy
active sampling device containing polyurethane foam
plugs
inductively coupled plasma-atomic emission spectroscopy
inductively coupled plasma-mass spectrometer
infrared spectroscopy
ion selective electrode
liquid chromatography-mass spectrometer
low density polyethylene
molecularly imprinted polymers used for introducing molecular
recognition in sensors
a commercially produced electronic nose equipped with two
arrays of eight sensors
metal oxide semiconductor
method quantitative limit
negative chemical ionization mass spectrometry
organophosphate pesticides
polynuclear aromatic hydrocarbons
polybrominated diphenyl ethers
principle component analysis/computer routine used to aid in
analysis of response patterns from sensors
polychlorinated biphenyls
photoionization detector
persistent organic pollutants
performance reference compounds
polyvinyl chloride
relative standard deviation
surface acoustic wave
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SOP sensorial odor perception; also used in good laboratory practice
to mean standard operating procedure
SPMD semipermeable membrane device
SVOCS semivolatile organic chemicals
TCD thermal conductivity detector
TDS thermal desorption system
TLV threshold limit value
UV ultraviolet spectroscopy
VOCs volatile organic chemicals
XRF X-ray fluorescence spectroscopy
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SECTION 1.0
INTRODUCTION
1.1.1 BACKGROUND INFORMATION
Human exposure to environmental
chemicals can be defined as the condition which
exists when both the person and the chemical(s)
at "measurable concentrations" are present at the
same time and location. The dimensions of
exposure are generally expressed and specified
in terms of the media of exposure, time, route,
number of people, scale, microenvironment, and
activity pattern. Assessing total exposure of an
individual or population involves identifying the
contaminant, contaminant sources,
environmental media of exposure, transport
through each medium, chemical and physical
transformations, routes of entry into the body,
intensity and frequency of contact, and spatial
and temporal concentration patterns of the
contaminant. The accuracy and precision of
exposure assessments greatly influence the
reliability of decisions that depend upon such
assessments.
Accurate exposure classification tools
are required to link exposure with health effects
in epidemiological studies. Long-term, time-
integrated exposure measures are needed to
address the problem of developing appropriate
residential childhood exposure classifications.
Screening techniques are also of interest that
could focus attention on the most highly
exposed (to indicator compounds) populations
for which costly multiroute, multimedia
monitoring would be most informative. This
project was designed to investigate and/or
evaluate methods used in classifying exposure,
both long-term, time-integrated and screening
methods for assessing exposures to relatively
short half-life contaminants. Focus on single
chemicals by government regulatory agencies
has limited advancement of methods designed to
detect and quantitate classes or families of
chemicals that may be of interest in
environmental settings. However, this may
change in the future since there is growing
interest in assessing cumulative exposures to
various chemicals. An important part of this
task then is to also attempt to assess emerging
technologies and methods that have potential for
developments for these purposes.
1.1.2 Indoor Pollutant Problem Area
The use of building materials, furniture,
carpets, and various household products
invariably releases pollutants to the air or
surfaces. These pollutants may then be
transferred to humans by inhalation, dermal
contact or ingestion. Assessing an individual's
exposure to such indoor pollutants is best done
through personal monitoring methods which
can also include assessments of daily activity
patterns and the potential for exposure.
However, active personal monitoring methods
tend to place a high burden on the individual.
Ambient monitoring designed to map
microenvironments and the activity patterns of
individuals are useful surrogates in assessing
personal exposures.
A wide range of chemicals is of interest
as indoor pollutants including physiochemical
classes/families such as the VOCs, SVOCs,
PAHs and metals. Use groupings like the
pesticides, flame retardants and cleaning
solvents are also of interest. Methods that
permit detection of chemical classes and families
in one collected sample can be helpful for
human exposure screening and preclassification
purposes. Real-time methods designed to detect
specific prototype chemicals for the various
classes are a possibility, but such approaches
have received relatively little attention.
However, real-time methods are not generally
useful for media/samples like food and surfaces
where it is difficult to quickly and effectively
transfer target analytes to measuring devices or
sensors. .
1.1.3 Brief Overview of Current Technology
And State-of-the Art
Monitoring of environmental pollutants
(organic and inorganic) represents an ongoing
challenge for the environmental chemist. Since
most environmental pollutants are present at
low concentrations, highly sensitive detection
methods as well as efficient separation methods
are needed to quantify environmental samples.
1-1
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Some current techniques that have been
reviewed (see reference 120) for time integrated
sampling and analysis are listed in Table 1-1.
Continuously operating analytical devices offer
a high time resolution, but often lack sufficient
sensitivity and selectivity. Application of such
devices for assessing the presence of classes or
families of chemicals can be even more difficult
since it is necessary to fine tune both qualitative
and quantitative analytical parameters for
multiple chemicals. Therefore, discontinuous
techniques with a (pre)concentration step during
or after the sample collection are still preferred,
especially in the case of toxic substances where
the ability to detect low concentrations is
demanded. To evaluate exposures over time,
various methods have included time-integrated
approaches in which the sampled medium passes
through an absorbing or adsorbing material that
removes the desired pollutants during a specified
period of time, grab sampling designed to permit
one to measure pollutants at a specific point in
time and evaluate "peak' exposures, and direct
reading monitoring devices designed to collect
and analyze samples continuously.
Most integrated sampling methods
appear to use active sampling techniques in
which the pollutants are collected by forced
movement (e.g., use of a pump) through an
appropriate collection device such as a sorbent
tube, treated filter, or impinger containing a
liquid media. The availability of an acceptably
low burden active personal air exposure sampler
for use by children that is also suitable for a
wide range of chemical classes or families of
interest in indoor environments is generally
lacking. Passive sampling/monitoring devices
appear to be the currently accepted technology
where collection of sample is controlled by a
physical process such as diffusion through a
static air layer or permeation through a
membrane without the active movement of the
medium. A passive sampler can be used over a
long sampling period, integrating the pollutant
concentration over time. Since only a few
analyses are possible over the sample-collection
period, analytical costs (usually associated with
expensive dynamic sample isolation and
preconcentration techniques) can be
substantially reduced. Because of their ease of
use, passive dosimeters (such as organic vapor
monitors) are attractive alternatives to active
samplers for monitoring personal exposures to
air contaminants and are receiving more study
(see references 40-41 for recent studies) for
personal, indoor and outdoor air monitoring of
VOCs in community and office environments
with sampling times ranging from days to
weeks. Because of the limited capacity and
"breakthrough" problem of some of these
badges, sequential sampling with several
monitors may be necessary for time-integrated
studies. Semipermeable membrane devices
(SPMDs) have received some attention for
indoor studies involving air, but the devices
have received more detailed study in the context
of water sampling and analysis.
In both cases (active and passive), the
actual sample collection and analysis steps are
usually discontinuous, although validated
methods exist that have combined the two steps
into a single method. Real-time methods with
immediate results offer advantages, but have
other limitations. For example, real-time
methods are usually designed for a specific
target analyte (such as may be present in an
occupational setting) and are not generally
useful for detecting classes or families of
chemicals, an important consideration for
environmental monitoring. However, there are
exceptions to this such as the aerosol-based total
PAH real-time monitor that has been in use for a
number of years to measure indoor
concentrations of PAHs (see for example
reference 46). It may be possible to adapt
monitors of this type to other classes of indoor
pollutants that may be detected using
photoelectric ionization instruments.
1.2 OBJECTIVES
The primary objective of this project is
to identify the time-integrated sampling and
analytical methods and technology that are
currently available (or will be validated field-
ready in the next two years) or that can
reasonably be adapted from other applications to
interrogate air, water, soil, and surfaces in
indoor environments for target
compounds/compound classes (VOCs, metals,
pesticides, etc). Long-term time-integrated
1-2
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exposure measures are needed in order to
develop an appropriate exposure classification
for a given individual which then can be linked
to that same individual's health outcome data for
epidemiological studies involving general
population exposures. Health outcomes can be
short-term , acute or more long-term, chronic in
nature, so it is important to assess both short
term and long term exposures. Most previous
multimedia human exposure studies have made
microenvironmental or personal pollutant
measurements for only a brief duration (e.g., one
day or one hour). These types of studies could
easily miss a key exposure event (i.e., a short
duration event with high microenvironmental
concentrations) in a given individual's life
because of the brief temporal monitoring regime.
Missing such a key exposure event could lead to
misclassification of an individual's exposure. In
addition, since pollutant concentrations in the
home are generally expected to be low with only
occasional sporadic acute spikes, the merits of
continuous-long-term or composite sampling
methods should be considered. Therefore, long-
term time-integrated monitoring techniques as
well as techniques that will permit detection and
recording of "spike" exposures must be
identified to improve the accuracy of exposure
classifications. Methods that may have potential
for use as screening techniques (such as for
chemical/structural classes and/or reactivity
families) are also identified where possible.
In addition, selected sampling/analysis
methods should have appropriate detection
sensitivities and operate in a time frame
consistent with study objectives. Methods
should also be sufficiently rugged and
transferable to provide comparable data for large
numbers of samples, sufficiently selective to
prevent misidentifications of chemicals and
provide pollutant concentration data that meet a
study's accuracy and precision objectives.
Furthermore, the collection methods must place
as small a burden as possible on the study
population. Finally, because large numbers of
samples must often be collected and analyzed,
both the collection and analysis methods should
be as efficient and cost effective as possible.
1-3
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TABLE 1 -1. SOME CURRENT TECHNIQUES FOR TIME INTEGRATED SAMPLING AND
ANALYSIS
Sampling Techniques
» metal oxide sensors
Passive Devices * thermal conductivity sensors
Collection by diffusion (for gases > portable instruments, (i.e.,
and vapors) GC, GC-MS, XRF, etc.)
» activated charcoal Techniques for aerosols
* silica gel * light-scattering photometers
» Tenax » light-scattering particle
* Chromosorb* counters
* Amberlite XADta resins * condensation nucleus
* molecular imprinted counters
polymers > single particle aerosol mass
* SPMDs monitors
Collection by sediment (for » piezoelectric crystal
aerosols) microbalance
» weigh boats > trapped element oscillating
Collection by wiping microbalance
» surface wipes Biosensors
* EL press * immunosensors
* PUF roller * enzymatic biosensors
* hand rinse * molecular probe
» body dosimeter Other
Active Devices * fiber optic sensors
Solid Sorbents » affinity sensors/molecular
* activated charcoal imprinted polymers
* silica gel
» porous polymers
» Tenaxtm
» Porapaksta
* Chromosorbstm
» Amberlite XADtm resins
Chemically treated filters
Liquid absorbers
Sampling bags/evacuated rigid
containers
* Teflontm bags, etc.
» Summa1"1 canisters
Sample size-selective sampling for
aerosols
* filters for aerosols
» cyclone
* impaction
Sensors/Emerging Technologies
Direct-reading instruments for
gases and vapors
» combustion gas detectors
* colorimetric detectors
* electrochemical sensors
* infrared gas analyzers
1-4
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TABLE 1-1. (Continued)
Analytical Techniques
Conventional
Emerging
Organic
Metals
GC-MS
GC-ECD
LC-MS
GC-AED
ICP-MS
ICP-AES
XRF
AAS
ISE
ASV
Mostly organic
» immunoassays
* MlP-based sensors
» MOS-based sensors
* electronic nose
» electronic tongue
* lab-on-a-chip
» remote operated portable
instruments
1-5
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SECTION 2.0
SUMMARY, CONCLUSIONS, AND
RECOMMENDATIONS
Several approaches were used to identify
publications/materials relevant to meeting the
project objectives including scientific literature,
gray literature (gray literature is a term used for
articles in trade publications that have not
undergone the peer-review process used by
scientific journals), and internet resources, some
outside the traditional chemical and
environmental subject areas. Important works
were grouped primarily according to
methods/technologies that are currently in use,
to those that will be ready in 2-3 years, to
promising technologies that are further from
commercialization. Recent developments in
some of the emerging technologies are also
discussed. Information is also provided on some
of the more promising portable instruments that
were found in the gray literature. Unfortunately,
none of these systems/methods clearly meet the
objectives of this task in all respects. Limited
information was available on promising new
approaches that might be useful for personal
monitoring in indoor environments.
In general, air and water samples are more
amenable to the application of long-term, time-
integrated approaches to sampling and analysis,
and these matrices have been emphasized in this
report. Application to dust/surfaces and food
samples is more problematic, and the biggest
problem area is the preparation required to put
such samples into a form amenable to periodic
or continuous analysis. Dust/surface samples
may still require wiping/vacuuming approaches
with subsequent labor-intensive extraction and
clean-up procedures prior to analysis. Validated
methods are available for such purposes.
It is recommended that EPA consider
funding further developments in the areas of
passive monitors (especially the SPMDs and
sorbent tube type) for their own specific
applications. It would probably also be
worthwhile to follow new developments with
novel passive samplers for long-term
monitoring, such as described in reference 47,
since these appear to avoid the need for
laborious recovery of analytes from the samplers
(or sampling medium) after exposure by solvent
extraction or dialysis and the need for expensive
cleanup of the extracts before chromatographic
analysis. Also recent work (see abstract 37.01
from meeting, 12th Conference of the ISEA/14th
Conference of the ISEE, August 11-15, 2002,
Vancouver, BC, Canada, describes the
development of a passive sampler consisting of a
denuder made from sections of a multi-capillary
GC column which permits sampling rates about
100 times higher (increased surface area) than
the traditional badge and tube-type diffusive
samplers. Recent applications (see, for
example, reference 122) of commercially
available solid-phase microextraction devices
(SPMEs) as a diffusive sampler for time-
weighted average sampling of volatile s and
semivolatiles might also be of interest.
Although most of the emerging research on
sensors is well into the future in terms of real
application potential, it may be worth
considering their use for preclassifying pilot
studies before using the more expensive
methods. This might be particularly appropriate
for sensors that can be designed and applied to
detect a range/window of chemicals within
chemical classes/families of interest. Recent
developments using metalloporphyrins as
sensitive layers in electronic noses/tongues
appear to hold promise for such purposes since
there is considerable opportunity to design in
chemical class selectivity and sensitivity through
synthetic manipulations of the macrocyclic ring
and its peripheral groups and the metal center. It
might also be worthwhile to follow
developments in "lab-on-a-chip" technology, a
term understood to mean a device integrating
chemical reaction and analysis functionalities.
Since chemicals having similar structures
usually means similar reactivity and mechanisms
of toxic action, "lab-on-a-chip" approaches
might be useful for developing a kind of
"reactivity equivalents measure" that could
potentially provide an amplified signal (for a
specific kind of reactivity underlying a specific
2-1
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toxic effect) for use in exposure studies. A
recent perspective (reference 123; also see recent
reviews 124-125) on analytic chemistry
published in Science indicated that such
miniaturized chemical analysis systems have the
potential to revolutionize analytical chemistry
and that the uses for these systems could be
numerous with application to airborne
contaminants being one of the more promising.
It is further recommended that new
developments in portable GC and MS
instruments, especially those with
preconcentration devices at the front end, be
given serious consideration for certain
applications.
VOCs, PAHs, pesticides and other SVOCs
continue to receive attention as target analytes in
various long-term monitoring studies. Metals
have received less attention, probably as a result
of the increased complexity of sample collection
and analysis problems associated with their
study. Brominated flame retardants (for a
review see reference 121) are receiving
increased attention since they are used in a
variety of applications to reduce flammability of
computers and other electronic devices,
upholstered furniture, and other products.
Among the widely used brominated flame
retardants are the polybrominated diphenyl
ethers (PBDE) which are of concern because of
evidence for potential neurodevelopmental
toxicity and endocrine disruption. Commercial
technical PBDE mixtures generally contain less
than 10 congeners, while technical PCBs are
mixtures of about 80 congeners. Although the
PBDEs are less stable than their chlorinated
counterparts, degradation should be less of a
problem in indoor environments. Thus, their
analysis by highly sensitive techniques such a
negative chemical ionization-mass spectrometry
(NCI-MS) is promising. Very few methods
have been developed for air samples, although
some work with indoor air particles has been
reported (see reference 121 for discussion).
Another important class of brominated flame
retardants that has received less attention is
tetrabromobisphenol A. Other chemicals/classes
that have been detected in recent residential
indoor studies (see abstracts 16.21, 53.19 and
41.02 for example) from the Vancouver
Conference involving air and dust measures
include the phthalates, alkylphenols, herbicides
and aldehydes. The indoor aldehyde work
described in abstract 41.02 is also an example of
an effort to address a structurally related class of
contaminants using a sampling and analysis
approach common to all members of the class.
Other abstracts from this recent conference that
may be of interest include 21.04 (Repeated
personal monitoring versus microenvironmental
monitoring for assessing exposures to airborne
chemicals), 37.01 (Development of a sensitive
diffusion sampler for the measurement and
assessment of personal exposure to PAHs in air),
53.22 (Polycyclic aromatic hydrocarbon (PAH)
levels in house dust from homes with infants in
relation to maternal smoking behavior), and
44.28 (Brominated flame retardants: Policy
implications of the emerging science).
Finally, there is currently considerable
interest and effort to develop rapid
detection/monitoring systems for chemical and
biological warfare agents not only for use by the
military in the field but also for monitoring
environments occupied by the general
population including indoor settings. Since for
security reasons not all of these developments
are readily accessible and/or can be found in the
public domain, it may be necessary for EPA to
take other measures to gain access to
components of this work that might have a
bearing on the objectives of this task.
2-2
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SECTION 3.0
TECHNICAL APPROACH AND RESULTS
3.1 SEARCH ROUTINES AND
APPROACHES TO REVIEW OF
CURRENT LITERATURE
Several approaches were used to
identify publications/materials relevant to
meeting the project objectives. Published
literature (scientific and trade), gray literature,
and internet resources were searched to identify
promising technologies and methods. Both fee-
based databases and free internet sources were
searched. These resources included databases
such as Chemical Abstracts as well as databases
outside the traditional chemical and
environmental subject areas such as MEDLINE.
Both topic-specific and multi-disciplinary
databases and web links were searched to ensure
that a broad range of resources were used to
uncover relevant technologies and methods
across a variety of disciplines. Table 2-1
provides a list of key parameters/descriptors for
major searches performed in this task.
A broad based MEDLINE search to
identify references on the analysis of organic
and inorganic compounds, including pollutants,
noxae, and pesticides was performed. This
search specifically identified continuous and
time integrated sampling/monitoring techniques
as well as techniques using
sensors/microsensors. The searched resulted in
371 records, including a subset of 54 records
referencing time integrated techniques.
Continuous monitoring techniques were also
identified in the ScienceDirect database
including 58 initial references. Another 149
references were found on electronic nose/tongue
technologies using the following databases:
MEDLINE, ScienceDirect, NTIS, LC MARC,
and NLM LOCATORplus. References
identified in ScienceDirect from the journals
Sensors and Actuators (Part A & B) and
Biosensors and Bioelectronics have proven
particularly useful. Over 20 patents relating to
continuous and real-time monitoring were also
identified from the U.S. Patent and Trademark
database. Using standard web search engines
like Google [httg^/www-googlc^com],
potentially useful analytical methods-related
web sites including those at NIOSH
[http://www.cdc.gov/niosh/nmam/nmammenu.ht
mil. ASTM [htt
bin/SoftCart.exe/STORE/productsearch.htni?E+
mvstorel. and OSHA [http://www.osha-
slc.gov/dts/sltc/mcthods/indcx.htmll were
identified. Other useful web sites identified
include a comprehensive sensor site at the NSF
supported Long Term Ecological Research
Network
jA
]. Over 25 key authors were identified and other
relevant papers by these authors were sought
using the databases Ingenta and ScienceDirect,
among others.
A search of fee-based engineering,
technology, health, and environmental/pollution
databases for references on real-time monitoring
and on SPMDs was performed. The search
resulted in 54 relevant citations. A larger search
of this same database set, along with a search of
the EPA and Library of Congress online
catalogs was performed with an emphasis on
long-term monitoring as well as conventional
sampling/analytical techniques. This search
resulted in 73 relevant citations. These searches
have also included a database that indexes
conference papers from all scientific disciplines,
as well as a food science database and an
engineering database, along with the above
mentioned Library of Congress database. The
use of these resources broadened the search to
include references from outside the
chemistry /environmental literature. In addition
to searching by keywords, over 50 relevant
papers were identified from searching 19 authors
considered prominent in this field. A search of
Chemical Abstracts and Analytical Abstracts for
predominantly review articles identified 39
references. State-of-the-art research and
applicable research from outside the
chemistry/environmental disciplines was
examined by searching over 15 web sites
identified by the TOPO. These sites include
trade journals [some examples are Chemical
3-1
-------
Equipment fhttp:7/www.chcmcquipmag.coml
and Hazardous Materials Management
rhttj3i//Wj₯w^^ gray literature
indexes such as the GrayLIT Network
[http://www.osti .gov/graylit].
A search of technology, health,
environmental/pollution and multi-disciplinary
databases for references on flame retardants in
indoor environments was also performed. This
search resulted in the identification of 10
relevant citations. Two searches were made of
the Dissertation Abstracts database, an index of
international doctoral dissertations and masters'
theses. The first search concentrated on
references in the field of chemistry and
environmental science. This resulted in 41
relevant citations. A second search of
Dissertation Abstracts concentrated on
disciplines outside of the chemical and
environmental sciences. This search produced
46 relevant citations. Fourteen multi-
disciplinary trade magazine/trade magazine
publisher web sites [See Above] were searched
and 24 relevant citations were identified.
Additionally, the GrayLIT Network
[http://www.osti.gov/graylitl, a web portal to
Federal gray literature from the Department of
Energy's Office of Scientific and Technical
Information, was searched and 8 key references
were identified. An additional 14 notable
references were identified from databases
covering the fields of aerospace, agriculture,
biotechnology, energy, safety, pharmacology,
materials science, and electrical engineering.
Reference 121 provides a brief overview of the
analytical methodology used for the
determination of brominated flame retardants in
environmental samples and concentrations found
in the samples.
A search for information on the topic of
"lab-on-chip" was also conducted. This resulted
in 21 relevant references, including a web
information portal on the subject at
[http ://www iab-on-a-
chip.com/home/index.htmll. Special attention
was given to coverage of the gray literature,
instrumentation/equipment supplier application
notes, etc. In considering efforts toward the
development of autonomous environmental
monitoring systems, the concept of total
analysis systems or Lab-on-a-Chip, which is
based on the twin strategies of integration and
miniaturization that have been so successful in
the electronics industry, was also considered. A
recent paper (M Sequeira et al., Talanta 2002,
56, 355-363) may be of interest. The article
looks at the materials issues, particularly with
respect to new polymeric materials that are
becoming available, and strategies for
integrating optical (colorimetric) detection. It is
indicated that for environmental monitoring, the
further integration of wireless communications
with micro-dimensioned analytical instruments
and sensors will become the driving force for
new developments in the field, and that the
emergence of these compact, self-sustaining,
networked instruments will have enormous
impact on all field-based environmental
measurements. It is further indicated that the
ultimate manifestation of this concept is to
develop an 'environmental nervous system'
through the distribution of a multitude of
devices in waterways, airways, etc. However,
these systems, as promising as they appear to be,
are still in the future.
In trying to address the objectives of
identifying methods/equipment that are either
currently in use or will be validated field ready
within the next two years, developments
reported in the gray literature, supplier
application notes, etc. have received some
attention. Using a freely available search
engine [am/a^gcxiglixixaiil and the keywords
"air monitoring" provided a large number of
links, many of them interesting, and perhaps 5%
of them yielding some information relevant to
this task. The general impression from study of
the material from this search was that analytical
instruments are changing fast, and peer-
reviewed journals are not keeping up. The trend
is toward portable instruments that are more
suited for process control and hazardous waste
remediation than scientific research directed at
exposure assessment, so the use of these
instruments is less likely to be reported in peer-
reviewed journals. Some examples include
3-2
-------
portable GC-MSs, GCs (some handheld) with
various detectors including TCD, PID, BCD,
surface acoustic wave , photoacoustic IR, etc.
An important aspect of some of these systems is
their ability to be operated remotely. Not all of
these instruments are appropriate for personal
exposure monitoring, but they are interesting as
examples of technological improvements that
will ultimately lead to more sensitive/selective
and more portable analytical devices. A website
[http: //fate. clu -in .orgl, run by EPA, was also
found that provides an online encyclopedia
containing information about technologies that
can be used in the field to characterize
contaminants in soil and ground water, and to
monitor the progress of remedial efforts, and in
some cases, to confirm by analysis that the site
is ready for close out. The website also provides
information here on new instruments that have
been field tested. It appears that technological
advances over the past decade have created
specifically designed tools to improve site clean-
up and long-term monitoring.
A solicitation from DOE/PNWL to
companies interested in obtaining license rights
to commercialize, manufacture and market a
prototype exposure-to-risk monitor (E2RM) was
also recently encountered on the web
[technologyigipnl.gov]. The E2RM developed at
DOE/PNWL is intended to monitor exposure of
workers who work with or around hazardous
chemicals (notably VOCs) by determining the
amounts of chemicals in the worker's breath.
The system combines a breath inlet device with
an ion trap mass spectrometer that is controlled
by a PC with appropriate software. A
physiologically-based pharmacokinetic model
(PB-PK) is then used to relate exposure
concentrations to the amount of internal dose
received and thus, the resulting health risk,
immediately following the worker's exposure.
VOCs studied include trichloroethylene, carbon
tetrachloride, benzene, toluene, and others. This
interesting approach to personal exposure
monitoring/assessment might be useful in a non-
occupational setting as well. However, this
approach is subject to all the uncertainties
normally associated with the use of animal-
based PB-PK models when extrapolated to
humans. Although this is an attractive and
promising technology, special care will need to
be exercised in using and interpreting the
data/results obtained from the use of such
monitors.
3.2 SOME CURRENT METHODS AND
TECHNOLOGIES
Although many papers were found
which appeared to be of sufficient interest to
warrant review, only a small percent of the
overall search material obtained had a direct
bearing on the goals of this project. References
(grouped according to sample matrix/type) for
some of the more relevant and important
scientific publications in the recent literature
identified from the above search efforts are
shown in the Reference Section. References in
the general category are of general
interest/reviews and/or more research and
development in nature. Hard copies of most of
these articles have been obtained. A number of
the recently published papers emphasizing both
organic and inorganic analytes in different
media (with an emphasis on air) using current
and/or emerging methods and approaches have
been reviewed in more detail to identify
performance characteristics for both the
sampling and measurement components of the
method to the extent possible. These papers
have been organized into six groups including:
(1) conventional time-
integrated/continuous/real-time
methods
(2) recent developments and
applications of SPMDs,
(3) new high-speed/portable/sensor
based approaches to
ambient/personal monitoring of
VOCs in indoor air and breath,
(4) recent developments and
applications of molecular
imprinted polymer based
sensors for various organics in
water environments,
3-3
-------
(5) recent developments and
applications of sensors for
various inorganics (metals,
oxyanions, halides, etc),
(6) recent developments and
applications of the electronic
nose and tongue.
A summary table of the groups by
matrix, type, chemicals and timeframe is
provided in Table 3-2 emphasizing air and water
as sample matrix, and showing a range of old,
new and improved method types, range of
chemicals/classes of target analytes, and various
monitoring timeframes. This is followed (p 3-
21) by more detailed descriptive material for
each method within each group to the extent it
was possible to extract it from the reference. In
some cases, review or more general interest
papers are included which are useful in
understanding emerging technologies and
potential applications. In moving from Group 1
to Group 6, the methods/technologies tend to
proceed from currently in use, to will be ready
in 2-3 years, to promising technologies that are
well into the future (more than five years out).
Group 1 includes some attractive, amply
validated methods for long-term sampling (4 to
12 weeks) of ambient indoor air for a range of
VOCs. For example, the sampling tube method
described by Uchiyama and Hasegawa is ready
to use, and a hand-packed tube of
carbotrap/carboxen material with a drying tube
placed in front is used to collect the sample by
pumping and the tubes are thermally desorbed
directly onto GC-MS. A passive (diffusive)
sampler method described by Mabilia et al,
based on activated charcoal with solvent
extraction and GC analysis would appear to be
ideal for long-term indoor air use. The method
might have potential for application to a wide
range of VOCs for even longer time periods (up
to 8 months). Other papers are included from
the same group headed by Bertoni. A
conventional PUF air sampling method
described by Carlsson et al., for organphosphate
ester flame retardants in indoor air is also
included with reported mean levels in schools,
daycare and office buildings. The paper does
not mention organophosphate pesticides, which
are presumably amenable to this method.
Group 2 includes papers describing
some new developments for the application of
SPMDs as time-integrated passive samplers. Of
particular interest are two papers describing their
use for very long-term (2 years) sampling of
outdoor air for PCBs which are considered
prototypes for nonpolar analytes. One paper
presents data showing good agreement between
SPMD and HiVol PUF samplers at two sites
with widely different mean ambient
temperatures. The primary advantage of this
approach is that it allows for long-term (2-24
months), unattended, time-integrated sampling,
and low limits of detection. Also new
developments on the use of low density
polyethylene (LDPE) lay-flat tubing instead of
lipid-filled SPMDs are described that show
much potential, but the testing presented does
not appear to be rigorous enough to support
deployment at this time. Novel integrative
passive samplers of this type for long-term
monitoring of SVOCs in air have been described
in the very recent literature (see reference 47).
They consist of poly(dimethylsiloxane)
(PDMS)-coated stir bars or silcone tubing,
acting as a solid receiving medium, enclosed in a
heat-sealed LDPE membrane. In addition,
accumulated analytes are analyzed by thermo-
desorption GC-MS to avoid the use of solvents
and costly sample preparation and clean-up
steps.
Group 3 includes three recent papers
from one of the more active industrial hygiene
based groups (ET Zellers et al.) working on
acoustic wave sensing systems for indoor air
applications to VOCs and SVOCs. One paper
describes a promising approach to indoor air
measurements using a high-speed analysis of
complex indoor VOC mixtures by vacuum-
outlet GC with air carrier gas and programmable
retention. This would appear to be useful for a
broad range of VOCs and SVOCs using a
portable, in-home instrument with no gas supply
3-4
-------
tanks. However, there is apparently not a
prototype ready for deployment at this time.
Group 4 includes several recent papers
on promising developments and applications of
molecular imprinted polymer (MIP) sensors for
a range of different analytes, viz., pesticides,
herbicides, nerve gases, organophosphate flame
retardants, and metal ions. MIPs are a very
promising technology, but routine field use will
probably have to wait until an instrument
manufacturer starts producing the sensors.
However, the potential for designing MIPs for
detecting families of similar chemicals such as
organophosphate pesticides and triazene
herbicides is already evident. Similarly, group 5
includes several sensor/multisensor-based
approaches for determination of inorganic
analytes (metals, oxyanions, halides, etc) in
aqueous environments, including soil pore
water. Although such methods are attractive for
possible field work, most, if not all, suffer from
serious matrix effects that will require sample
pretreatment. Group 6 includes several recent
papers on developments and applications of
electronic nose/tongue sensors to air, water and
food samples with some attention given to
VOCs and sensorial odor perception. However,
the use of such devices for exposure monitoring
could be limited by their inability to identify
individual contaminants at low concentrations in
complex matrices.
Groups 1-3 include methods that could
possibly be adapted for quantitative, time-
integrated studies of some target chemicals in
indoor environments. Methods described in
Groups 4-6 are generally not currently suitable
for such indoor studies but might be useful in
pilot studies aimed at screening and
preclassifying samples for further study using
other methods and approaches.
3.3
3.3.1
EMERGING TECHNOLOGY
INCLUDING APPLICATIONS FROM
OTHER FIELDS
SPMDs as Passive Samplers
Membrane-based passive samplers such
as the semi-permeable membrane devices
(SPMDs) seem to be a promising tool for time-
integrated monitoring of hydrophobic pollutants
in both water and air media. Despite earlier
promising results and the numerous attractive
qualities, i.e., their long-term stability, low cost,
and ease of deployment, there are only limited
published data pertaining to their use as passive
sampling tools in air monitoring. It is
recommended that the low density polyethylene
usually used as membrane material be
preextracted prior to use to remove impurities
(shown to contain many PAHs). Recent studies
present results from side-by-side comparison of
SPMDs and conventional HiVol systems in the
field. Excellent agreement was found between
air concentrations (of PCBs as prototype
persistent organic pollutants/POPs) calculated
from the SPMDs and the active samplers
suggesting the potential of these devices for
time-integrated passive atmospheric sampling of
gas-phase POPs. Furthermore, the use of
SPMDs in indoor environments might be useful
for shedding considerable light on the dynamics
of POPs at the air-water interface. There are
also recent studies (see for example reference
77) suggesting that there are no technical
barriers to the use of performance reference
compound (PRC) data to estimate site-specific
sampling rates of POPs and improve the
accuracy of sample concentration estimates
while reducing the amount of calibration data
required for the use of SPMDs and passive
sampling devices (PSDs). However, SPMDs
require rather labor-intensive extraction and
clean-up procedures to prepare samples for
analysis by conventional methods.
3.3.2 Sensors as Real-time Devices
A means to produce sensors for any
specific chemical or chemical class that requires
quantitation would be ideal. Chemical sensors
must fulfill two goals: 1) the development of a
specific chemical recognition element that
allows a molecule, or class of molecules, to be
identified, and 2) a means of signal transduction
in which the presence of the molecule causes a
measurable change in a physical property of the
material. Recent promising developments in the
3-5
-------
area of chemical (both organic and inorganic)
sensor research are using the technique of
molecular imprinting to provide the desired
chemical recognition element required, and
chemical sensing using optical fibers and
luminescence spectroscopy or acoustic wave
detection. Their use for monitoring indoor
pollutants remains a goal for the future, and the
current view is that such sensor-based
approaches generally can not yet replace
laboratory analysis but are very useful to guide
the sampling process, to delineate contaminated
areas, or to preclassify samples. Although
chemical sensor research has been more directed
toward specific target analytes (such as might be
needed in an occupational setting), recent
development using double/multiple imprinting
and the principles of supramolecular host-guest
chemistry are permitting more flexibility in the
design and fine tuning of layers sensitive to
specific chemicals used for molecular
recognition. For example, it seems reasonable
that one could design a chemical sensor that is
the equivalent of the biological receptor for
dioxin in terms of its ability to screen for the
presence of the broad class of dioxin-like
compounds. Progress is also being made in
linking sensor arrays to portable instruments
such as the system under development by
Zellers, et al. (reference 14) for high-speed
analysis of complex indoor VOC mixtures by
vacuum-outlet GC with air carrier gas and a
dual-preconcentrator, a separation-column
ensemble with tunable and programmable
retention.
3.3.3 Electronic Nose/Tongue as Biomimetic
Sample Quality Sensors
Gas sensor arrays, i.e., electronic noses
or odor/smell sensors, have received far more
study than their wet chemical counterparts, i.e.,
electronic tongues or taste sensors. Behind these
somewhat misleading terms, one finds an array
of bio-or chemical-sensors, the response pattern
of which are analyzed with pattern recognition
routines and/or chemometrical methods. These
sensor combinations behave in a biomimetic
way when they are used, e.g., for quality control
and/or classification of water, food, air, clinical
samples, etc. The sensor array in these systems
produces signals which are not necessarily
specific for any particular species in the
environment, in the water, etc., but are
components of a signal pattern which can be
related to certain features or qualities of the
sample. These qualities can be determined by a
computer trained to recognize the class of
response patterns related to the sample
environment under study. This is similar
(biomimetic) to the way the human sense organs
produce signal patterns to be qualitatively
interpreted by the brain. Electronic nose and
tongue techniques are normally used to give
some qualitative answers about the sample under
study and only in special cases are they used to
estimate concentration of individual species in
the sample. So in terms of drinking water, the
electronic system provides a way to classify the
water but not generally to determine if it is
drinkable or undrinkable. These systems will
most likely find applications in environmental
monitoring. Several of the technologies and
applications are not yet fully developed. Sensor
drift, for example, is a problem that has to be
solved if sensor arrays are to be implemented for
routine monitoring purposes. It is anticipated
that combinations of sensors based on different
technologies may give even more useful
information. Attention is also being given to
metallo-porphyrins as a class of molecules for
use as sensitive layers in these sensors. The
important point to remember is that these
systems often predict a quality of a sample but
do not provide hard data in terms of composition
and concentration.
3.3.4 Portable/Field-Readv Instruments from
the Gray Literature
As indicated previously, the trend in
instrumentation development in the gray
literature is toward very portable instruments
that are more suited for process control and site
remediation than for scientific research. It
appears that technological advances over the
past decade have created a whole new set of
tools to assess site clean-up and long-term
monitoring following clean-up. Descriptions of
3-6
-------
some of the better GC and MS portables found
in the gray literature are included here and
summarized in Table 2-3 (p 2-61). The portable
GC manufactured by Photovac, Inc. uses a
photoionization (PID) or electron capture
detector (BCD), making it much more sensitive
(and more suitable for environmental use) than
instruments using thermal conductivity detectors
(TCD) or standing acoustic wave (SAW)
detectors. A new field portable, high speed
GC/time-of-flight-MS (described on the web) is
manufactured by Syagen Technology, Inc.
[wjvw.svggglLCom]. A new gas chromatography
system based on the use of a water electrolyzer
as its only source of gases has also been
developed (not shown in the descriptive tables,
but see reference 117 for details). Other systems
appropriate for organic analytes were not
considered further since they had various
problems associated with their use, i.e., the
hand-held PID was mostly for non-specific gas
detection, the photoacoustic IR had poor LOD,
the FTIR generally required a long pathlength to
achieve low LOD, odor meters have
selectivity/analyte identification problems, and
so on. Also references 118 and 119 are recent
reviews describing new developments in gas
chromatography and miniature mass analyzers
including portable systems.
Unfortunately, none of these
systems/methods clearly meet the objectives of
this project for identifying methods/equipment
that are either currently in use or will be
validated and field-ready in 2 - 3 years nor do
they meet the criteria that the collection and
analytical methods be integrated or combined
into a single method and which can be used with
a minimum of evaluation for assessing time-
integrated indoor exposures. As indicated
earlier, these systems/methods are generally not
designed for such purposes and would need to
be adapted. However, some of the very portable
instruments described in the gray literature have
considerable promise for continuous, periodic
(and possibly long -term) monitoring of indoor
environments. Such real time, autonomous
monitoring has some distinct advantages over
conventional grab-sampling techniques.
However, field validation of such autonomous
systems appears to be generally lacking. The
portable MS system produced by Intelligent Ion,
Inc. was clearly the most advanced, well
documented, and best marketed portable
instrument. Numerous publications about this
portable MS system are available on the web
site.
In addition to conventional literature
searches, an attempt was made to go through the
2002 Pittcon vendors list to find methods that
could be used (currently or in the near future)
for the time-integrated determination of metals
in air, dust, food, and water. The biggest
obstacle to such trace-element determinations is
the preparation required to put samples in a form
amenable to analysis. Sample preparation,
invariably the bottleneck for most trace metal
determinations, would be difficult to complete in
the field. This would make real-time on-site
exposure measurements for these analytes and
samples more difficult. Sample preparation
would be especially critical for many of the
analytical techniques described in the other
papers reviewed. For example, electrochemical
methods are vulnerable to matrix interferences
which is a restriction on the utility of these
measurements.
With this is mind, attention was given to
gray-literature searches for techniques that
would require minimal sample preparation and
could readily make field measurements of the
chemical classes of interest. One potentially
useful technique is X-Ray Fluorescence (XRF).
Several instrument manufacturers have portable
systems that are available for immediate
purchase and use. Niton is marketing a hand-
held product for the determination of Pb in air
filter samples [w^wjiitQjLCQrn/airfilLhtml]. An
application note for this product can be found at:
http://www.niton.com/7702.pdf Dust wipe
samples could be analyzed using a similar
approach. Other manufacturers (Spectro,
Cianflone, etc.) offer similar portable products
that could probably be adapted to such an
application. A description of Spectra's smallest
XRF instrument can be found at [www.spectro-
ai.com/pages/e/pO 10501 .htmll while Cianflone's
3-7
-------
can be found at
[www^cianflono.coniATiodcl^jOlbt.htail].
Detection limits for XRF instruments are
generally higher than those for other trace-
element techniques (ICP-MS, GFAAS, etc.).
Since the technique is non-destructive, samples
could be screened/analyzed in the field and then
sent to a laboratory for further study.
Instruments are also currently available
for time-integrated mercury vapor measurements
in air. A description of a Tekran, Inc. mercury
vapor analyzer is available at:
4. i63/2537/2537A^df|. This
system does require a preconcentration step, the
length of which varies with the level of Hg in air
that you wish to measure. If airborne elemental
Hg is of interest, this approach may be suitable.
3-8
-------
TABLE 3-1. PARAMETERS FOR MAJOR SEARCHES
Keywords (* indicates truncation)
Databases
Language
Time
Period
(organic chemicals/analysis or inorganic
chemicals/analysis or environmental pollutants, noxae,
and pesticides/analysis) and (time integrated or
continuous sampling or continuous monitor* or time
factor* or biosensing techniques) or (sensor* or
biosensor* or microsensor* and air or soil or water or
surface not blood or urine or biomarker* or biological
marker*)
time integrated or continuous sampling or continuous
monitor* or sensor* or biosensor* or microsensor*
electronic nose or electronic tongue
(real-time monitoring or realtime monitoring or spmd*
or semipermeable membrane device*) and (indoor or
sampling or analy* or measurement* or collection or
determination or detection or identification) and
(method* or technique*) and (air or water or soil or
surface*) or (spmd or semipermeable membrane
device*) and (continuous monitoring or time
integrated)
(time integrated or attic dust or window* of exposure
or badge*) and (monitoring or sampling or analy* or
measurement or collection) or (automated monitoring
or repetitive monitoring or long term monitoring or
passive monitoring) and (time integrated or indoor or
environmental or review* or technique* or pollutant*
or device* or gated)
(long term monitoring or continuous monitoring or
continuous sampling or repetitive sampling) or indoor
and (sampling or collection or analy* or
measurement*) and (air or water or soil* or surface*)
or time integrated
MEDLINE
ScienceDirect (chemistry,
engineering, and
environmental sections),
USPTO Patent Database
MEDLINE, NLM
LOCATORplus, NTIS,
ScienceDirect, LC MARC
MEDLINE, Environmental
Bibliography, Enviroline,
Water Resources Abstracts,
Biosis, Food Science and
Technology Abstracts,
Pollution Abstracts, Aquatic
Sciences and Fisheries
Abstracts, Abstracts in New
Technologies and
Engineering, Conference
Papers Index, Ei
Compendex, NTIS
MEDLINE, Environmental
Bibliography, Enviroline,
Water Resources Abstracts,
Biosis, Food Science and
Technology Abstracts,
Pollution Abstracts, Aquatic
Sciences and Fisheries
Abstracts, Abstracts in New
Technologies and
Engineering, Conference
Papers Index, Ei
Compendex, NTIS, EPA
Catalog, LC MARC
Analytical Abstracts,
Chemical Abstracts
no restriction
1966-
present
no restriction
no restriction
no restriction
1980's-
present
1980's-
present
1960's-
present
no restriction
1960's-
present
no restriction
1960's-
present
3-9
(continued)
-------
Keywords (* indicates truncation)
Databases
Language
Time
Period
flame retardant* and indoor
lab-on-a-chip
time integrated or continuous monitoring or continuous
sampling or long term monitoring
real time and PAH or PAHs or polycyclic aromatic
hydrocarbon* or polynuclear aromatic hydrocarbons)
time integrated or continuous monitoring or continuous
sampling or long term monitoring
(time integrated or real time or realtime or continuous)
and monitoring or (long term monitoring and indoor or
passive or active or sensor* or biosensor* or spmd* or
semipermeable membrane*)
3M organic vapor monitor*
MEDLINE, NTIS, Toxline, no restriction 1960's-
ScienceDirect, present
Environmental Sciences and
Pollution Database,
SciSearch
Google, ScienceDirect, Ei no restriction 1990's-
Compendex, Environmental present
Sciences and Pollution
Database, SciSearch, NTIS,
Academic Search Elite,
MasterFILE Premier
1980's-
present
1990's-
present
1970's-
present
1970's-
present
Dissertation Abstracts no restriction
Google, SciSearch, no restriction
Environmental Sciences and
Pollution Database
GrayLIT Network no restriction
Occupational Safety and no restriction
Health, Aerospace Database,
Agricola, Current
Biotechnology Abstracts,
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Materials Database,
Geobase, INSPEC,
International Pharmaceutical
Abstracts
Google, ScienceDirect, no restriction 1990's-
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Sciences and Pollution
Database
3-10
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TABLE 3-2. SUMMARY TABLE OF SOME METHOD PAPERS BY GROUP
Group 1. Conventional Time-integrated/Continuous/Real-time Methods
Matrix
Air
Air
Air
Air
Air
Air
Air
Air
Water
Water
Matrix
Air
Air
Water
Water
Water
Water
Type
Air Sampling (pump),
carbotrap/carboxen
Passive sampler/diffusive device
charcoal
Passive(diffusive) sampler/charcoal
Passive(diffusive) sampler/carbopack
Passive(diffusive) sampler/Tenax
Passive (diffusive) membrane/charcoal
Wet effluent diffusive
Conventional PUF air sampler
On-line membrane extraction
Diffusive sampling based photo-
acoustic cell
Group 2. Recent Developments
Type
Passive/SPMD
SPMD/HiVol PUF comparison
SPMD
SPMD
SPMD
SPMD
Chemicals
VOCs
Benzene/alkyl benzene
Benzene/Xylenes
PAHs
Acetone,benzene, alkyl
benzene, alkanes
Alkyl benzene, chloro-
alkanes
Alcohols/Acetone
Flame retardant/alkyl
phosphate
Semivolatiles
Benzene/toluene
and Applications of SPMDs
Chemicals
PCBs
PCBs
Chrysene/DDT/SVOC
PAHs
Pesticides/PCBs
Hydrophobic
Time Frame
Up to 4 weeks
Continuous
4-12 weeks
Up to 8 months
2 months
1-14 days
8 hours
Continuous up to
24 hours plus
Approximately
12 hours
Real time/HPLC
Continuous
Time Frame
2-24 months
2-24 months
2-24 months
14days
Various
Various
3-11
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Air
Group 3. High-speed/Portable/Sensor Based Approaches to Ambient/Personal
Monitoring of VOCs
Matrix
Air
Air and
breath
Type
Portable GC instrument/air carrier gas
Portable/preconcentrator/pump/
SAW detector
Chemicals
VOCs/SVOCs
VOCs
Time Frame
Periodic/few days
Continuous/5 min
cycle/long-term
Personal monitor/sorbent
preconcentrator pump/SAW detector
VOCs
potential
Periodic/few days
Group 4. Molecularly Imprinted Polymer (MIP) Based Sensors for Organics in Water
Matrix
Water
Water
Water
Water
Water
Hexane
Type
MIP based sensor
MIP based sensor
MIP based sensor
MIP based sensor/general interest
MIP based sensor/preconcentration
MIP based extraction/preconcentration
Chemicals
Pesticides/OPs
Herbicides/atrazine
family
Nerve gases/related to
OPs
cAMP/related to OPs
Divalent lead
OP flame retardant
Time Frame
Real-time with
cycle
Periodic/10 min
cycle
Periodic/10 min
cycle
Periodic/cyclic
Periodic/ISE
analysis
3-12
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Group 5. Sensors for Various Inorganics in Water
Matrix
Water
Water
Water
Water
Water
Water
Soil
Columns
Type
Multisensor array /artificial neural
network
Multisensor/thin film sensors
Sensor head/laser excitation with
fluorescence emission
Various methods for real-time
determination of trace metals/marine
surface water
Membrane potentiometric sensor based
on crown ether
Synchronous fluorescence/sensor
Tracer compound in soil column
Chemicals
Various ions, cation and
anions
Metal ions/Divalent lead,
cadmium, zinc, and Iron
Heavy metals
Trace metals
Lead
Hexavalent chromium
Nitrate as tracer
Time Frame
Real-time
aqueous monitor
Real-time
aqueous monitor
Real-time
approximately 30
minute cycle
Various real-time
Periodic/ 40
second cycle
Instrument
development/
emerging work
Near real-time
potential
Group 6. Recent Developments and Applications of Electronic Nose and Tongue (EN/ET)
Matrix
Air
Water
Water
Water
Water
Urine
Milk
Type
Electronic nose/porphyrin based
Electronic tongue/sensor array
Electronic nose
Electronic nose
Electronic nose/multiple sensor
Electronic nose/tongue/based on
metalloporphyrins
Chemicals
Volatile compounds
Review/general
Pesticides/pyrethroids
VOCs/wastewater
Cyanobacteria
Headspace Volatile s
Time Frame
Real-time
Real-time
Periodic/real time
potential
Continuous
monitoring
potential
Potential for
long-term
continuous
monitoring
Real-time
3-13
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Group 1
Authors
Shigehisa Uchiyama and Shuji Hasegawa
Title
Citation
Matrix
Method Type
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
26 VOCs:
Other Chemicals:
Participant Burden
Field Burden
Analytical Costs
Comments
Investigation of a long-term sampling period for monitoring volatile organic
compounds in ambient air
Environ. Sci. Technol. 34:4656-4661 (2000)
air
air sampling tube
Sampling tube (150x4 mm) packed with Carbotrap C (250 mg), Carbotrap B
(120 mg), and Carboxen 1000 (200 mg). Magnesium perchlorate (2 g) drying
tube used in front of sampling tube. Pump flow was 0.5 mL/min for 4-week
period. Tubes were thermally desorbed onto GC-MS. 24 hour samples collected
for comparison. Paper gives data to show good agreement between mean 24
hour samples and 4-week samples. Sampling pump and flow controller are off-
the-shelf components. Styrene was low in 4-week samples because of
ozonolysis.
Integrating, up to 4-week
Precision: 1 to 5% for 21 of 26 VOCs. All < 9%.
Bias: given with respect to 24 hour samples, < 9%.
Method QL
Personal
not applicable
Microenvironmental
or ambient
0.01 to 0.04 |jg/m3
Level of Validation
single laboratory
most VOCs with -29°C < bp < +174°C
not applicable (mass flow controller + pump required)
pumps could be left unattended in field
$100 to $3 00 (GC-MS)
***** Highly recommended. This method is ready to use with a sampling
period of 4 weeks. This paper gives ample validation data. Tubes must be
packed by hand, but all other components are readily available.
Other References
None
3-14
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Authors
Title
Citation
Matrix
Method Type
R. Mabilia, G. Bertoni, R. Tappa,
A. Cecinato
Long-term assessment of benzene concentration in air by passive sampling: a
suitable approach to evaluate the risk to human health
Analytical Letters. 34(6): 903-912
(2001)
air
passive sampler
Method Description
Sample Collection
Sample Preparation
Analysis
Sampler is a glass tube with a diffusion device and activated charcoal. Sampler
is placed in field and retrieved 4 to 12 weeks later. Charcoal is then extracted
with solvent, and the solvent analyzed by GC. Data is presented showing
agreement (± 6%) with BTX monitors (field-based GC system) for benzene,
toluene, ethylbenzene, and xylenes for a 4 week exposure. Additional data
indicates agreement for benzene over a 12 week exposure.
Monitoring Time Frame
continuous, 4 to 12 weeks
Method Performance
Precision
Bias
Comments
precision: ~ 5%
bias: ± 6% compared with field-based GC system.
Applicable Chemicals
Target Chemicals:
Other Chemicals:
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
not tested
Microenvironmental
or ambient
not stated
Level of Validation
probably useful for VOCs with bp > benzene
unknown
low (deploy and retrieve passive device)
$100 to $300 (GC-FID or GC-MS)
Paper does not give a good description or diagram of sampling device. This
sampling method might be applicable to a wide range of VOCs. If so, this
would be ideal for long-term IAQ use. Authors have applied for a patent for
sampling device.
Other References
Assessment of a new passive device for the monitoring of benzene and other
volatile aromatic compounds in the atmosphere. Bertoni, G., Tappa, R.,
Allegrini, I.,Annali di Chimica. 90:249-263
3-15
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Authors
Title
Citation
Matrix
Method Type
G. Bertoni, R. Tappa, A. Cecinato
The Internal Consistency of the 'Analyst' Diffusive
Field Test
Sampler - A Long-Term
Chromatographia 54, 653 - 657 (2001)
air
passive (diffusive) sampler
Method Description
Sample Collection
Sample Preparation
Analysis
Sampler consists of a tube or vial, closed at one end. Charcoal sorbent is
packed in a layer against the closed end, and held in place with a screen.
Another screen covers the open end of the tube to control eddy currents. The
sampler is placed on location in the field, then retrieved up to 8 months later.
The charcoal is extracted with 1.5 mL benzyl alcohol. The extract is then
analyzed by GC-FID.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
benzene
xylenes
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
up to 8 months
duplicates within +/- 10%
accuracy not tested
Method QL
Microenvironmental
Personal or ambient Level of Validation
0.3 |ig/sampler not given
0.03 ng/sampler not given
not applicable to personal monitoring
low - no pumps needed
$50 -- $200 (quick extraction, then GC-FID)
presumably, a modification of this method would be applicable to a wider range
of VOCs. This seems like the kind of cost-effective long-term sampling
technique that this Task calls for.
Bertoni, G.; Tappa, R; Allegrini, I; Annali de Chimica 2000, 90, 249
3-16
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Authors
Title
Citation
Matrix
Method Type
G. Bertoni, R. Tappa, A. Cecinato
Environmental Monitoring of Semi -Volatile Polycyclic Aromatic
Hydrocarbons by Means of Diffusive Sampling Devices
and GC-MS Analysis
Chromatographia 53, Suppl, S-312-S-316 (2001)
air
passive (diffusion) sampler
Method Description
Sample Collection
Sample Preparation
Analysis
Sampler consists of a glass tube, open on both ends, with a sorbent disk held in
place in the middle of the tube between two screens. Sorbent was 400 mg
Carbopack C. Samplers are exposed for 2 months, then extracted with 1.5 mL
toluene. Extract is analyzed by GC-MS. Authors calculate an uptake rate for
PAHs of 18.5 mL/min by comparison with co-located active samplers.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
PAHs:
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
2 months
spike recovery: 72 to 100% for naphthalene, phenanthrene, and fluoranthene;
chrysene 59% (?). Accuracy ~ 10%.
Method QL
Personal
not applicable to personal
Microenvironmental
or ambient Level of Validation
~ 5 ng/m3 no data
monitoring
low - no pumps needed
$200 - $300 (quick extraction, then GC-MS)
method needs a little work
Note also that this method
to expand scope to heavier PAHs.
does not measure PAHs bound to particles.
None
3-17
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Authors
Title
Citation
Matrix
Method Type
Nicholas M. Bradshaw and James A. Ballantine
Confirming the Limitations of Diffusive Sampling Using Tenax TA
Long Term Monitoring of the Environment
During
Environmental Technology, Vol. 16. pp 433-444 (1995)
Air
High sensitivity/cost/burden method
Method Description
Sample Collection
Sample Preparation
Analysis
Target analytes diffuse at a known rate and are adsorbed onto Tenax TA.
None.
Analytes are thermally desorbed onto a GC column where they are separated by
gas-liquid chromatography and detected using FID.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Target Chemicals:
Acetone
Hexane
Benzene
Toluene
m/p-Xylene
Nonane
Decane
Undecane
Other Chemical:
Participant Burden
Field Burden
Analytical Costs
1 to 14 day intervals
Not determined
Not determined
Method QL
Personal
Microenvironmental
or ambient
Approx. 1 ng each on-
cartridge (FID) !
Level of Validation
F
Low
Low
Approx. $300.00 per sample for mass spectrometry confirmation
Comments
Approach should be considered for the determination of volatile organic
compounds in ambient air over long sampling periods.
1 Method quantitation limits will be based on diffusion rates of individual
compounds and exposure times.
Other References
None
3-18
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Authors
Title
Citation
Matrix
Method Type
Mannino, D.M., J. Schreiber, K. Aldous, D. Ashley, R. Moolenaar,
D. Almaguer
Human exposure to volatile organic compounds: a comparison of organic vapor
monitoring badge levels with blood levels
Int Arch Occup Environ Health (1995) 67:59-64
Air
High sensitivity/cost/burden method
Method Description
Sample Collection
Sample Preparation
Analysis
Target analytes diffuse through a permeable membrane at a known rate and are
adsorbed onto a charcoal pad.
Analytes are extracted form the charcoal pad with carbon disulfide.
Extraction solvent is analyzed by GC/FID or GC/ECD
Monitoring Time Frame
8 hours
Method Performance
Precision
Bias
Not addressed in this study. However, organic vapor monitors are used
routinely to determine workplace exposures. Precision data is available in the
literature.
Not determined by direct comparison to known reference standards. There was
a high correlation between air concentrations of gasoline components
determined by the organic vapor monitor and levels found in blood assays.
Applicable Chemicals
Target Chemicals:
Toluene
Ethyl benzene
m/p-Xylene
1,1,1 -Trichloroethane
Tetrachloroethane
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Method QL
Personal
8 j-ig/m3
8 lig/m3
8 j-ig/m3
2 [ig/m3
2 [ig/m3
Microenvironmental
or ambient
Level of Validation1
F
F
F
F
F
Low
Low
Approx. $100.00 per sample
The use of organic vapor monitors is not a novel approach. These devices have
been used extensively to determine personal exposures.
1 Not validated in this particular study. Other validations have been performed.
None
Authors
Jana Peskova, Petr Parizek, Zbynek Vecera
3-19
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Title
Citation
Matrix
Method Type
Wet effluent diffusion denuder technique and determination of volatile
compounds in air
organic
Journal of Chromatography A, 2001; 918: 153-158
air
sampler/concentrator device
Method Description
Sample Collection
Sample Preparation
Analysis
A thin film of water traverses the inside of a glass tube (40 x 1.1 cm) at a flow
rate of 0.5 mL/min. The air being sampled is pulled through the tube at a
constant flow rate. Alcohols and ketones are thereby stripped from the air and
concentrated in the water stream. The analyst collects 5 \^L of water from the
tube exit, and analyzes by GC-FID. The tube operates continuously. This setup
could easily be automated. The method is limited to analytes with high water
solubility.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
probably up to 24 hours or more; continuous sampling
collection efficiencies reported: methanol 98%, ethanol 83%, 2-propanol 73%, ...
, acetone 31%, MEK 30% @ 20 °C
Method QL
Personal
Microenvironmental
or ambient
0.24 \i (GC-FID)
1 ng/L (GC-MS)
Level of Validation
needs work
not given
method could apply to alcohols and other water soluble analytes
see comments
see comments
sampling- $10/day; GCMS analysis- $100 to $200/sample
Comments This method was intended for industrial hygiene use, and requires operator
intervention in order to take a sample. Although this method could be
automated, the device lacks ruggedness, and the method is only applicable for
alcohols and ketones.
Other References
None
3-20
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Authors
Title
Citation
Matrix
Method Type
Hakan Carlsson, Ulrika Nilsson, Gerhard Becker, and Conny Ostman
Organophosphate ester flame retardants and plasticzers in the indoor
environment: analytical methodology and occurrence
Environ. Sci. Technol 31:2931-2936 (1997)
Air
conventional PUF air sampler/GC-NPD, GC-AED or GC-MS
Method Description
Sample Collection
Sample Preparation
Analysis
Indoor air is sampled at 3 and 17 L/min for 700 minutes using sampling tubes
consisting of borosilicate fiber filters with cellulose backing pads and PUF
plugs. Battery-powered pumps used. Filters and PUF extracted with
dichloromethane by sonication, concentrated and analyzed by GC-NPD, GC-
AED (atomic emission) and GC-MS. Authors report mean levels of alkyl
phosphates in schools, daycare, and office building as 1 to 250 ng/m3
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tri(2-chloroethyl)phosphate
other alkyl phosphates
Participant Burden
Field Burden
Analytical Costs
700 minutes (~12 hours)
precision ~ 10% (when comparing co-located samplers)
recoveries from spiked filters/PUF: >95%
accuracy not reported
Method QL
Personal
not given
not given
Microenvironmental
or ambient
0.5 ng/m3
0.5 ng/m3
Level of Validation
field study
field study
moderate (loud pump in home, two visits in the same day)
moderate (12 hour sample
requires field staff to be diligent)
$200 to $400 (GC-AED or GC-MS)
Comments Conventional sampling and analysis techniques used. This is an excellent
paper, both for the detailed description of the analysis, and for important data
on this class of compounds. Paper does not mention phosphate pesticides,
which are presumably amenable to this method.
Other References
Plastics Additives, Stabilizers, Processing Aids, Plasticizers, Fillers,
Reinforcements, Colorants for Thermoplastics, 4th ed., Gachter, R. Miiller, H.,
Eds.; Hanser/Gardner Publications, Inc., Cincinnati, OH, 1993.
3-21
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Authors
Title
Citation
Matrix
Method Type
Guo, X. and S. Mitra
On-line Membrane Extraction
Volatile Organics in Aqueous
Liquid Chromatography for Monintoring
Matrices
Semi-
Journal of Chromatography A
Water
High sensitivity/cost/burden
Method Description
Sample Collection
Sample Preparation
Analysis
Not addressed. Semi-volatile organic compounds (SVOCs) are extracted from
water on-line. Parameters associated with the collection of water samples for
exposure monitoring that may affect extraction efficiency such as pH and
temperature have not been studied.
Extraction method is optimized for removal efficiencies. Parameters studied
include flow rate, flow direction and extraction solvent.
Extraction solvent flow is sampled periodically using a six-port liquid sample
valve. Aliquots are analyzed by HPLC.
Monitoring Time Frame
Real-time
Method Performance
Precision
Bias
Comments
RSD less than 1 percent at nominal stream concentration of 1 ppm.
Not determined. Linear relationship between SVOC concentration in water and
detector response was assessed.
Applicable Chemicals
SVOCs
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental
or ambient
Nominal 10 i-ig/L
Level of Validation
None
High (if sample analysis is performed in the field)
High
Not determined.
Applicability of method to concentration of SVOCs found in typical drinking
water is questionable.
Other References
None
3-22
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Authors
Title
Citation
Matrix
Method Type
A. Mohacsi, Z. Bozoki, R. Niessner
Direct diffusion sampling-based photo acoustic cell for in situ and
monitoring of benzene and toluene concentrations in water
on-line
Sensors and Actuators B 79: 127-13 1 (2001)
water
sensor, photoacoustic
Method Description
Sample Collection
Sample Preparation
Analysis
R&D of photoacoustic (PA) cell intended for remote monitoring benzene,
toluene and xylene in ground water. Benzene in water diffuses across PTFE
membrane into air-filled PA cell. Diode laser (1 mW, 1668 nm) pulsed at 3300
Hz. Note: water vapor in PA cell also absorbs near 1668 nm, causing high
background and poor sensitivity. Cell tested at 1 - 5 mg/L concentration level in
lab. Sensitivity must be improved by a factor of > 1000 before it is suitable for
the stated purpose.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
benzene
toluene
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
continuous
not given
Method QL
Personal
not applicable
not applicable
not applicable
Microenvironmental
or ambient
1.5 mg/L
1.5 mg/L
Level of Validation
none
none
requires installation
unknown. Sensor probably $5k to 20k; $0 marginal cost per sample.
It is unlikely that this cell design will ever meet the desired sensitivity (< 1
Hg/L for potable water).
None
3-23
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Group 2
Authors
Title
Citation
Matrix
Method Type
Wendy A. Ockenden, Harry F. Prest, Gareth O
J. Sweetman, and Kevin C. Jones
Thomas, Andrew
Passive air sampling of PCBs: field calculation of atmospheric sampling rates
by triolene-containing semipermeable membrane devices
Environ. Sci Technol. 1998, 32: 1538-1543
Air
SPMD passive sampler / GC-MS
Method Description
Sample Collection
Sample Preparation
Analysis
Passive sampler (SPMD) deployed 2-4 months
Extract with hexane, cleanup on silica gel, followed by GPC, followed by
second silica gel fractionation. GC-MS determination.
This paper gives sampling rates (diffusion of PCBs -> SPMD) for 43 PCB
congeners at two temperature ranges, and shows that air concentrations
calculated from SPMDs closely matches concentrations measured by
conventional PUF Hi-Vol samplers.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes:
Potential Analytes:
Participant Burden
Field Burden
Analytical Costs
2-24 months, time-integrating, unattended.
Accuracy: ~ ±50% agreement with PUF sampler
Precision: ~ 20% from duplicate SPMDs
Method QL
Personal
nonpolar SVOCs
Microenvironmental
or ambient
PCBs (43 congeners)
<0.1pg/m3
Level of Validation
single field test
none
not applicable
not applicable
probably ~ $300 - 600
Comments The primary advantage to this method is that it allows for long-term (2-24 mo.)
unattended time-integrated sampling, and low limits of detection. This method
is ready to use (PCBs only). Cleanup of SPMD extracts is labor-intensive.
Interesting note:
in air, SPMD sampling rate increases with decreasing temp
in water, SPMD sampling rate decreases with decreasing temp
Other References
None
3-24
-------
Authors
Title
Citation
Matrix
Method Type
Wendy A. Ockenden, Andrew J. Sweetman, Harry F. Prest, Eiliv Steinnes, and Kevin
C. Jones
Toward an understanding of the global atmospheric distribution of persistent organic
pollutants: the use of semipermeable membrane devices as time-integrated passive
samplers
Environ. Sci. Technol, 1998, 32: 2795-2803
Air
SPME (time-integrated passive samplers)
Method Description
Sample Collection
Sample Preparation
Analysis
SPMD (semipermeable membrane device) is hung in screened box outdoors for > 2
mo. then analyzed by soaking in hexane 2 x 24 hr. Extracts concentrated and analyzed
by GC/MS and GC/ECD.
USGS SPMDs were deployed for 2 years at 11 locations in western Europe at varying
latitudes from north Norway to south UK. SPMDs were then analyzed for PCBs. Air
concentrations were calculated from diffusion rates previously reported by this group
(see ref. at bottom of this review sheet). Authors provide data indicating that these rates
are applicable to a wide range of climate (temperature). Data is presented showing
good agreement between SPMD and HiVol PUF samplers at 2 sites with widely
different mean temperatures.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
2-24 months; time-integrated passive sampler
precision ~ 25% (duplicate SPMEs)
accuracy ~ 25% (compared with HiVol PUF)
Method QL
Personal
nonpolar SVOCs
Microenvironmental
PCBs (43 congeners)
QL < 1 pg/m3
Level of Validation
field tested
not tested
not applicable
low
about $300 to $600 per sample
Comments This is a good method for PCBs in outdoor air when a low QL is needed, and a very
long sampling time (2 years) can be tolerated.
SPMDs can probably by used for a wide range on non-polar analytes, although the
diffusion rates must first be determined for each analyte. Reference given below
describes how rates were determined for PCBs.
Other References
Major ref.: Ockenden, W. A.; Prest, H. F.; Thomas, G.O.; Sweetman, A.; Jones, K. C.
Environ. Sci. Technol. 1998, 32, 1538-1543 (we have this).
3-25
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Authors
Title
Citation
Matrix
Method Type
Branislav Vrana, Albrecht Paschke, Peter Popp,
and Gerrit Schuurman
Use of semipermeable membrane devices
Environ Sci. &PollutRes., 2001; 8(1): 27-34
water
integrating, passive sampler
Method Description
Sample Collection
Sample Preparation
Analysis
SPMD consists of a flat polyethylene tube containing 1 mL of triolene
(C57H10406). PE tube is 2.54 x 91.4 cm, 75-90 urn wall thickness. Tube was
placed horizontally in water, tethered to stream bed for 43 days. Tube is
analyzed by soaking in hexane 24 hr x 3. Extracts are combined and
concentrated. A portion is blown to dryness and reconstituted in acetonitrile for
HPLC-Flourescence. The other portion is concentrated to 1 mL and analyzed
by GC-ECD. Results are reported as ng/SPMD. A method is cited and used to
converting/SPMD to ng/L (aq), although the accuracy of these calculations is
uncertain; for example, there is no term in any of these calculations for
temperature.
Monitoring Time Frame
2 to 24 months, integrating
Method Performance
Precision
Bias
precision (duplicate SPMD): 24%
Bias: unknown (measures "bioavailable" concentration)
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
Method QL
50 ng/SPMD chrysene
3 ng/SPMD DDT
nonpolar SVOCs
0.4 ng/L chrysene
10 pg/L DDT
Level of Validation
needs work
see other papers
not applicable
low
probably ~ $300 - 600
Comments
Very low MQL. Excellent method for integrated time monitoring of a stream,
especially over a long time period (here, 43 days). However, calculating water
concentrations from SPMD results involves several approximations and
assumptions.
Other References
Petty, J. D.; Huckins, J. N.; Zajicek, J. L. Application of semipermeable
membrane devices (SPMD) as passive air samplers. Chemosphere, 1993; 27:
1609-1624
3-26
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Authors
Title
Citation
Matrix
Method Type
Crunkilton, R.L., W.M. DeVita
Determination of Aqueous Concentrations of Poly cyclic
(PAHs) in an Urban Stream
Aromatic Hydrocarbons
Chemosphere, Vol. 35, No. 7, pp. 1447-1463, 1997
Water
High sensitivity /cost/burden
Method Description
Sample Collection
Sample Preparation
Analysis
A lipid filled semipermeable membrane device (SPMD) is exposed to a continuous
water stream. PAHs below a certain molecular size diffuse through a low density
polyethylene tube and concentrate in the neutral lipid triolein.
SPMDs are returned to the lab and cleaned with DI water, acetone, and hexane prior to
dialysis. Sample are then dialyzed for 2 hours with hexane. The dialysates are
concentrated to 1 mL by Kuderna-Danish under nitrogen. The lipid is removed from the
concentrated dialysate by gel permeation chromatography.
Final volumes are analyzed by gas chromatography/ion trap mass spectrometry.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
PAHs (below 1.0 run)
Participant Burden
Field Burden
Analytical Costs
14 days
Replicate measurements were made, but not reported
Estimates of concentrations compare favorably with standard techniques.
Method QL
Personal
Microenvironmental
or ambient
14 day average reported at
nominal 0.01 [ig/L for most
PAHs
Level of Validation
Partial
High
High
Not determined. Expected to be high due to sample recovery and analysis costs (GC/MS)
Comments
Time-integrated average measurement. Based on concentrations of environmental
contaminants expected in exposure monitoring tasks, field deployment could require weeks
of exposure to collect enough sample to satisfy instrumental detection limits.
Other References
None
3-27
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Authors
Chris S. Hofelt and Damian Shea
Title
Accumulation of Organochlorine pesticides and PCBs by semipermeable
membrane devices and Mytilus edulis in New Bedford harbor
Citation
Matrix
Method Type
Environ. Sci. Techno! . 31: (1)
154-159 (reprinted in dissertation as chapter 1)
Water
SPMD passive sampler
Method Description
Sample Collection
Sample Preparation
Analysis
Using SPMDs with greater surface area and thinner LDPE walls, SPMD
reaches equilibrium with the surrounding water in < 30 days for most
compounds. The resulting data show better agreement with concentrations
measured in mussels. This method avoids the problems with traditional SPMD
stemming from the assumption of linear uptake of analytes over the sampling
period.
Standard SPMD:
Thin SPMD (here):
2.54 x 91.4 cm, 75-90 um wall thickness.
5 x 90 cm, 25 um wall thickness
Monitoring Time Frame
time-integrating
Method Performance
Precision
Bias
Correlation with levels found in mussels:
pesticides: r2 = 0.80
PCBs: r2 = 0.90
Applicable Chemicals
Pesticides/PCBs
Potential Analytes:
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
not applicable
not applicable
Microenvironmental
or ambient
0.1 mg/Kg in lipid
Other nonpolar
semivolatile organics
Level of Validation
not given
not applicable
low (place/retrieve SPMD in field)
$300 - $600 (extensive cleanup procedure)
Comments This was reproduced as chapter 2 in Hofelt's dissertation (NCSU 1998)
This is a useful alteration of the standard SPMD method (see reference below).
It makes sense to let the SPMD reach equilibrium with respect to aqueous
concentrations, and thereby eliminate one (of many) source of errors in this
technique.
Other References
J. N. Huckins, M. W. Tubergen, G. K. Manuweera. Semipermeable membrane
devices containing model lipid: a new approach to monitoring the
bioavailability of lipophilic contaminants and estimating their bioconcentration
potential. Chemosphere 20: 533-552 (1990). [original pub. on SPMD]
3-28
-------
Authors
Title
Citation
Matrix
Method Type
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
DDT, DDE...
Potential Analytes:
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Christopher Scott Hofelt
Use of artificial substrates to monitor organic contaminants in the aquatic environment.
Dissertation, North Carolina State University Department of Toxicology, Raleigh 1998
Water
SPMD passive sampler
Chapter 3: Measurement of sampling rates of SPMDs and LDPE strips. They suspend
strips in jars of water with triolene (spiked with analytes) floating on top. Although the
rates they calculate are suspect (two adjustment factors), LDPE strips appear to work as
well as SPMDs.
Chapter 4. Field test of LDPE strips in streams, alongside SPMDs. They report levels
found in LDPE strips against levels found in fish and sediment, but not in SPMDs.
Calculations are fuzzy, and hard data is thin in this work, but LDPE strips (without
lipids) are worth looking into.
time-integrating
Precision: factor of 2 at best
Bias: yes, probably greater than factor of 2.
Method QL Level of Validation
QL (LDPE) ~= QL (SPMD) = 0.01 ng/L in water
hydrophobic molecules not much larger than pyrene
not applicable
low (deploy and retrieve)
~ $ 200 - 400 (GC-ECD). LDPE cheaper than SPMD - less effort in cleanup
The use of strips of LDPE lay-flat tubing instead of lipid-filed SPMDs has much
potential, but the testing presented here is not rigorous enough to support deployment.
In this work, the LDPE strips are presumed to have reached equilibrium with the water.
With SPMDs, the opposite is presumed. LDPE is presented here as a screening method,
and as a substitute for catching a fish for analysis.
J. N. Huckins, M. W. Tubergen, G. K. Manuweera. Semipermeable membrane devices
containing model lipid: a new approach to monitoring the bioavailability of lipophilic
contaminants and estimating their bioconcentration potential. Chemosphere 20: 533-
552 (1990). [original pub. on SPMD]
3-29
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Group 3
Authors
Title
Citation
Matrix
Method Type
Andrew J. Grail, Edward T. Zellers, and Richard D. Sacks
High-speed analysis of complex indoor VOC mixtures by vacuum-outlet
with air carrier gas and programable retention
GC
Environ. Sci. Technol., 2001; 35: 163-169
air/VOCs
portable instrument
Method Description
Sample Collection
Sample Preparation
Analysis
Paper describes on-going development towards a portable (field) GC system for
determination of 42 VOCs and SVOCs in air at indoor air concentrations.
System consists of two short GC columns (4.5 m DB-1, and 7.5 m
trifluoropropyl methyl) joined with a variable pressure junction. Inlet is at
atmospheric pressure. Detector end of column is connected to vacuum pump.
SAW array detector is promised for eventual field use, but is not discussed in
this paper. Sample is collected on sorbent beds, then thermally-desorbed onto
column. Bulk of paper discusses optimization of separations through pressure
programming of the column junction. No working prototype is discussed.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
periodic, 30% duty cycle, could perhaps operate for a few days
Not Tested
Method QL
Microenvironmental
Personal or ambient Level of Validation
not given none
Potential for use for a broad range of VOCs and SVOCs
instrument in home
portable instrument - no tanks
about $20/24 hour sample
Comments This is promising for indoor air VOCs. However, the authors do not have a
prototype as of this paper.
Look for more recently published reports from this group
Other References
Refer to papers on SAW:
Park, J.; Groves, W. A.; Zellers, E. T. Anal Chem 71, 3877
3-30
-------
Authors
Title
Citation
Matrix
Method Type
William A. Groves and
Edward T. Zellers
Analysis of solvent vapors in breath and ambient air with a surface acoustic
wave sensor array
Ann Occup Hyg. , 200 1 ;
45(8): 609-623
air, breath
portable monitor, 0.6 to
37mg/m3forVOCs
Method Description
Sample Collection
Sample Preparation
Analysis
Prototype monitor evaluated. Uses internal thermally-desorbed preconcentrator,
pump, and four acoustic wave sensors. Sensor frequency output must be
acquired in real time by external computer.
Unit distinguishes between 16 VOCs and simple mixtures by the relative
response of the four sensors using principal components regression or neural
network software.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes:
Potential analytes
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
potentially long term (months?); continuous (5 min cycle)
precision ~ 10%
bias - not given
Method QL
Microenvironmental
Personal or ambient Level of Validation
16 VOCs 16 VOCs none
~ 0.6 to 37 mg/m3 ~ 0.6 to 37 mg/m3
Potentially applicable to all VOCs
not applicable
not applicable
probably $20 for 24 hour sample
This prototype is not ready for deployment see later papers from this group
None
3-31
-------
Authors
Title
Citation
Matrix
Method Type
Jeongim Park, Guo-Zhen Zhang, Edward T. Zellers
Personal monitoring instrument for the selective measurement
organic vapors
of multiple
AIHAJ, 2000; 61: 192-204
Air
Personal Monitor
Method Description
Sample Collection
Sample Preparation
Analysis
Development and testing of a small, personal monitor for occupational
exposure to 16 VOCs. Monitor uses polymer sorbent preconcentrator, pump,
and surface-acoustic-wave (SAW) detector. Monitor operates on a 5.5 minute
cycle: sampling, thermal desorption/analysis, then recycling. Monitor stores
raw data which is later uploaded to computer for analysis. Authors present
results of lab testing of six SAW chips, each coated with a different polymer.
By analyzing desorption curves and varying response of solvents on different
chips, authors are able to distinguish among 16 individual VOCs, and several
binary and ternary mixtures. LODs are mostly ~ 0.1 x TLV or higher.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes:
Potential analytes;
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
periodic, 30% duty cycle, could perhaps operate for a
few days
data given for recognition rate and precision at ~ 10 to 300 ppm
selectivity given as recognition matrix
Method QL
Personal
16 VOCs- 10 ppm
Microenvironmental
or ambient
Level of Validation
preliminary
Potentially applicable to all VOCs
low
low
about $20/24 hour sample
Monitor not useful at concentrations below 0. 1 x TLV
Paper gives good discussion of SAW calibration
None
3-32
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Group 4
Authors
Title
Citation
Matrix
Method Type
Jenkins, A.L., R. Yin, and J.L. Jenson
Molecularly Imprinted Polymer Sensors for Pesticide and Insecticide
in Water
Detection
Analyst. The Royal Society of Chemistry 200 1 .
Water
High sensitivity/cost/burden
Method Description
Sample Collection
Sample Preparation
Analysis
Sample collection not addressed. For exposure monitoring, it is assumed that
water could be collected directly from the tap and shipped to the laboratory for
analysis.
Preparation of real-world samples not addressed. Water samples generated in
the laboratory were adjusted to pH = 10.5 with sodium hydroxide and analyzed.
A fiber optic probe coated with a 200 ^m film of molecularly imprinted
polymer (MIP) is exposed to the water sample for 12 to 15 minutes. The MIP is
excited to a wavelength of 465.8 nm with an argon ion laser for detection.
Monitoring Time Frame
Snap-shot
Method Performance
Precision
Bias
Comments
Not determined.
Not determined. Linear relationship between pesticide concentration in water
(nominal 5 ppt to 100 ppm) and detector response was assessed.
Applicable Chemicals
Pesticide
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental
or ambient
Nominal 5 ppt
Level of Validation
None
Low
Low
Not determined.
Method is in early stages of development. No method validation performed.
Future work to involve miniaturization of detector, which may lead to a
portable monitor for field use.
Other References
None
3-33
-------
Authors
Title
Citation
Matrix
Method Type
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
T. A. Sergeyeva, S. A. Piletsky, A. A. Brovko, E. A. Slinchenko, L. M.
Sergeeva, A. V. El'skaya
Selective recognition of atrazine by molecularly imprinted polymer
membranes. Development of conductometric sensor for herbicides detection
AnalyticaChemicaActa. 1999,392: 105-111
water
electrochemical sensor / MIP
Grab sample, adjust pH to 7.5, dip sensor in sample, read in 6-10 minutes.
Could possibly be used as a continuous monitor if water stream is pH > 6.
Molecular imprinted polymer (MIP) membrane must be prepared in lab by
skilled personnel. This paper gives sufficient information for MIP production.
Low-frequency waveform generator applies 60 mV across membrane;
conductivity is measured with nanovolt meter across a resistor connected from
one electrode to ground. This equipment could be miniaturized, but at
substantial cost.
periodic (10 min) / possibly continuous
Accuracy: not tested
Precision: not tested
Selectivity: > 7x compared with simazine, triazine, prometryn
Method QL Level of Validation
atrazine: 5 nM ~ 1 ng/mL laboratory calibration
extensive development required to make applicable to other analytes
not applicable
low (grab sample) / possible use as a portable instrument
unknown (cost of membrane production/no, of samples over lifetime)
If commercialized could be $5/sample.
MIPs are a very promising technology. However, routine field use will
probably have to wait until an instrument manufacturer starts producing the
sensors. A sensor like this is ideally suited to agricultural applications where
the analyst already knows that atrazine is in use. The use of a MIP in a
conductivity cell could probably be extended to other polar pesticides such as
2,4-D orglyphosate.
This paper gives an excellent treatment of MIP production and "tuning."
Discusses use of oligourethane acrylate to make MIP flexible.
None
3-34
-------
Authors
Title
Citation
Matrix
Method Type
Bradley A. Arnold, Alex C. Euler, Amanda L. Jenkins, O. Manuel Uy,
George M. Murray
and
Progress in the development of molecularly imprinted polymer sensors
Johns Hopkins APL Technical Digest, 1999,20(2): 190-197
Water
MIP/Fiber Optic Luminescence
Method Description
Sample Collection
Sample Preparation
Analysis
Other References
Nerve agent (soman) sensor described, but may be applicable to phosphate
pesticides. MIP is created by complexing Eu3+ with phosphate analyte, then
deposited on end of optical fiber in divinyl benzene / styrene copolymer. Argon
laser/monochromator-CCD detector used to stimulate and detect luminescence.
At 1000 ppm level, phosphate pesticides are spectrally resolved from nerve
agent. This method should be optimized for pesticides before deployment.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes:
Potential analytes:
Participant Burden
Field Burden
Analytical Costs
grab sample; dip sensor, read in 6 minutes
Accuracy not given.
Bias stated in terms of selectivity for nerve agent.
Method QL
Personal
possibly OP pesticides
Microenvironmental
or ambient Level of Validation
soman: 0.7 ppb not given
not applicable
low if modified for portability, high if table-top laser used
probably < $5/sample if optimized for field use
Comments Like all MIP methods, this would require the fabrication and testing of specific
MIPs for our analytes. However, this method, using Eu3+ as a chromaphor that
complexes with the phosphonate ion, is already geared towards phosphate
pesticides. Ar laser could be replaced with a blue LED for better portability.
Paper mentions previous work in which authors developed a MIP method for
lead in water. See reference below.
Murray, G. M., Jenkins, A. L., Bzhelyansky, A., and Uy, O. M., "Molecularly
imprinted polymers for the selective sequestering and sensing of ions, Johns
Hopkins APL Tech. Dig., 1997, 18(4): 464-472.
3-35
-------
Authors
Petra Turkewitsch, Barbara Wandelt, Graham D. Darling, and William S.
Powell
Title
Fluorescent functional recognition sites through molecular imprinting. A
polymer-based fluorescent chemosensor for aqueous cAMP
Citation
Anal. Chem. 1998, 70: 2025-2030
Matrix
water
Method Type
unfinished; MIP
Method Description
Sample Collection
Sample Preparation
Analysis
Paper reports fabrication of a molecular imprinted polymer (MIP) for cyclic
adenosine monophosphate (cAMP). A dye molecule (with an olefin chain) is
incorporated into the polymer while bound to cAMP. After polymerization and
rinsing, the MIP contains 'imprinted' sites containing the dye as a functional
unit. 150 mg of the finished granular MIP is incubated with an aqueous
solution of cAMP. The MIP granules are analyzed by fluorescence as an
aqueous suspension in a quartz cell. As it turns out, cAMP quenches the
fluorescence of the dye rather than shifting or enhancing the band as the
authors expected. By measuring the degree of quenching. [cAMP] can be
determined in the range 10-100 nM.
Interesting work, but useful to us only as a starting point for designing MIPs.
Monitoring Time Frame
grab sample
Method Performance
Precision
Bias
not applicable (method development not complete)
Applicable Chemicals
Tested analytes:
Potential analytes:
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental
or ambient
cAMPO.l nM
Level of Validation
incomplete
requires extensive development to extend to other analytes
not applicable
not applicable
not known
Comments
General interest paper only.
"Until recently, organic solvents have been used exclusively as the media for
studies on the binding of ligands to MIPs." ... "substitution of water for organic
solvents dramatically alters the relative importance of polar and hydrophobic
interactions"
Other References
None
3-36
-------
Authors
Title
Citation
Matrix
Method Type
G.M. Murray, et al.
Molecularly Imprinted Polymers for the Selective Sequestering
and Sensing of Ions
Johns Hopkins Apl. Technical Digest, 1997, 18(4), 464-472
Various: seawater, organic solvents.
Lower sensitivity; Potential for analysis in field.
Method Description
Sample Collection
Sample Preparation
Analysis
Several ion exchange materials were used to preconcentrate Pb in seawater prior to analysis
with fabricated ion selective electrode (ISE). Calibration standards for determination of Pb
with fabricated optical sensor prepared in hexane.
Paper described potential uses of imprinted polymers. For example, an ISE based on
vinylbenzoic acid for Pb2+ determination in seawater, an imprinted optical sensor for Pb2+
determination in hexane standards, and an imprinted polymer detector for the hydrolysis
byproducts of nerve agents.
Monitoring Time Frame Single "grab" for ISE, optical sensor work.
Method Performance
Precision
Bias
ForPb2+ ISE, linear range 100 ng/L to 2,000 ng/L in aqueous solutions. Preconcentration would
lower detection limit. No precision/bias data presented. Results for analyzed sample confirmed
with ICP-AES.
For Pb2+ optical sensor, linear range 70 \igfL to 70,000 ng/L in hexane.
Applicable Chemicals
Pb2+ in seawater (ISE)
Pb2+ in hexane (optical)
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental
or ambient
< 100 ng/L
50 ng/L (in hexane)
Level of Validation
P
P
Very low (water collection).
Low (water sample collection).
Fabrication/imprintingprocedures labor intensive. Once completed (i.e. foraPb2+ ISE) analyses
appear to be simple and inexpensive..
Comments
Authors describe fabrication of several polymers imprinted with desired analyte. A
vinylbenzoic acid resin imprinted with Pb2+ was used to selectively measure this ion in
seawater. Imprinted polymers were also employed to develop an optical sensor for Pb2+,
an ISE for the uranyl ion, and a detector for the hydrolysis products of nerve agents.
2. Resins may be vulnerable to acidic pH's, limiting potential utility.
3. Small linear range for Pb ISE results from low exchange capacity of imprinted resins
(many exchange sites not accessible to ions).
4. Imprinting intended to make polymers analyte specific. Other cations common in
environmental samples may present interferences.
5. Optical sensor based on imprinted polymer not readily adapted for field studies.
Laboratory use only. Calibration curve in hexane reported.
Other References
None
3-37
-------
Authors
Title
Citation
Matrix
Method Type
K. Moller, U. Nilsson, C. Crescenzi
Synthesis and evaluation of molecularly imprinted polymers for extracting
hydrolysis products of organophosphate flame retardants
Journal of Chromatography A, 938:121-130 (2001)
none (R&D)
cleanup of biological fluids
Method Description
Sample Collection
Sample Preparation
Analysis
R&D towards a cleanup method for determination of diphenyl phosphate and
other metabolites of flame retardants in urine. Authors synthesize and test MIP
stationary phase for use in SPE (solid phase extraction) columns. Work not
complete.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Target Chemicals:
Other Chemicals:
Participant Burden
Field Burden
Analytical Costs
not applicable
not applicable
Method QL
Personal
not applicable
not applicable
not applicable
Microenvironmental
or ambient
not applicable
not applicable
Level of Validation
not applicable
not available (probably prohibitive)
Comments Work is geared towards the analysis of urine.
If commercially produced columns become available in the future, this
technology could greatly simplify sample cleanup. I suspect that these will be
available in 10 years or so, but probably only for analytes with a strong
commercial demand, i.e. drug metabolites.
Other References
None
Group 5
3-38
-------
Authors
Title
Citation
Matrix
Method Type
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Method Performance
Precision
Bias
A. Rudnitskaya, et al.
Multisensor System on the Basis of an Array of Non- Specific Chemical
Sensors and Artificial Neural Networks for Determination of Inorganic
Pollutants in a Model Groundwater
Talanta, 2001,55, 425-431
Synthetic aqueous solutions.
Lower sensitivity, potential for analysis in field.
Not applicable (synthetic aqueous solutions).
None.
Use of sensor array for simultaneous determination of several ion species: Cu2+,
Mg2+, Na+, C1-, Mn (II), Fe(III), Ca2+, Zn2+, SO42- in model water solutions.
Artificial neural network used to process complex analytical signals from non-
specific electrode detectors. Two sets of synthetic aqueous solutions prepared
to test array.
Potential use for single "grab" or real-time aqueous sample monitoring.
For samples with same background ion content as calibration standards: accuracy
within « 1% for Cl", Cu2+, Fe(III), Ca2+, SO42- «5% for Na+, Mg2+, Zn2+; « 17% for
Mn (II).
For samples with ion background different than calibration standards:
accuracy within «5% for Cu2+; « 10% for Ca2+, Mg2+, SO42-, Cl", Na+; « 60% for
Zn2+; «25%forMn(II).
%RSD generally < 1 0% for Cu2+ Zn2+ Mn (II) Fe(III) regardless of background ion
content; % RSD generally < 10% for Cl", Ca2+, SO42-, Na+, Mg2+ when background
matches calibration standards, < 25% when background is variable.
3-39
(continued)
-------
Group 5 (continued)
Applicable Chemicals
Cu2+
Mg2+
Na+
cr
Mn (II)
Fe(III)
Ca2+
Zn2+
S042
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental or ambient
0.003 |ig/mL (low cal. standard)
1.2 ng/mL (low cal. standard)
4.6 |ig/mL (low cal. standard)
10.6 ng/mL (low cal. standard)
0.055 |ig/mL (low cal. standard)
0.280 ng/mL (low cal. standard)
4 |ig/mL (low cal. standard)
0.007 ng/mL (low cal. standard)
9.6 |ig/mL (low cal. standard)
Level of Validation
P
P
P
P
P
P
P
P
P
Very low (potential water collection).
Sample collection/preparation inexpensive. Electrode component and data
processing equipment are commercially available.
Potentially expensive to assemble array and "train" electrodes, inexpensive
sample collection, preparation, and in-field monitoring.
Comments
1. Authors describe development of array of non-specific detectors (both solid-
state and PVC) for simultaneous determination of metal ions in aqueous
samples.
2. Best results for majority of ions obtained when using entire array (not just
solid state or PVC electrodes).
3. Reported accuracy for ion species often varied significantly when array
challenged with variable "background" ion content from other species. For
example, zinc accuracy in test solution was within ~ 5% while accuracy in test
solutions with different background was within »60%.
4. Potential application: "real-time" water monitoring.
Other References
None
3-40
-------
Authors
Title
Citation
Matrix
Method Type
Y. G. Mourzina, et al.
Development of Multisensor Systems Based on Chalcogenide Thin Film
Sensors for the Simultaneous Multicomponent Analysis of Metal Ions in
Solutions
Chemical
Complex
Electrochimica Acta, 2001, 47, 251-258
Synthetic aqueous solutions.
Lower sensitivity, potential for analysis in field.
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Not applicable (synthetic aqueous solutions)
None.
Use of laboratory fabricated microsensor array for simultaneous determination of heavy
metal ion species (Pb2+, Cd2+, Zn2+, and Fe3+). Only solid state sensors (n = 7) were
used to construct array. The multidimensional sensor array response is processed by
means of an artificial neural network
Potential use for single "grab" or real-time aqueous sample monitoring.
Method Performance
Precision
Bias
For replicate analyses of metal ions present at ng/mL levels in synthetic aqueous
solutions, RSD for Pb2+ranged from 12 - 21%, Cd2+ from 14 - 23%, Zn2+ from 15 - 26%,
Fe3+ from 15-31%. Reported average accuracy within ± 15 - 30% when array of seven
solid state sensors was used to determine Pb2+, Zn2+, and Cd2+. Error exceeded 30% for
Zn2+, Fe3+ for system when additional macrosensors added to array. Authors suspect
presence of iron in mixtures adversely impacting accuracy.
Applicable Chemicals
Pb2+
Cd2+
Zn2+
Fe3+
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental or ambient
4.14 ng/mL (lowest sample cone, measured)
3.36 ng/mL (lowest sample cone, measured)
0.655 ng/mL (lowest sample cone, measured)
2.79 ng/mL (lowest sample cone, measured)
Level of
Validation
P
P
P
P
Very low (potential water collection).
Low (sample collection). Moderate if analysis done in field.
Potentially expensive to assemble array and "train" electrodes, inexpensive sample
collection, preparation, and in-field monitoring.
Comments 1. Authors describe multidimensional array comprised of novel thin film solid state
sensors (n = 7) for simultaneous determination of metal ions in aqueous matrix. It
was necessary to add additional "macrosensors" to the array to determine Fe3+.
Response processed by means of an artificial neural network.
Much of the article deals with the analytical performance of individual solid state
sensors in single-ion solutions as a means of selecting the best candidate sensors
for the array. Eventually films with Cu, Pb, Cd, and Tl primary ions were selected
for incorporation into the array.
Other References
None
3-41
-------
Authors
Title
Citation
Matrix
Method Type
H. Prestel, et al.
Detection of Heavy Metals in Water by Fluorescence Spectroscopy : On the Way to a
Suitable Sensor System
FreseniusJ. Anal. Chem., 2000, 368, 182-191
Water (ground, surface).
Lower sensitivity; adaptable for field measurements.
Method Description
Sample Collection
Sample Preparation
Analysis
Monitoring Time Frame
Not applicable. Sensor head is lowered directly into water to be tested.
None.
Fiber optic bundle transmits N2 laser excitation energy to sample and the resulting
fluorescence emission radiation back to CCD array detector. Sensor head can be
equipped w/ modules for simultaneous multielement determinations. Several
fluorescing compounds were used to chelate metals.
Approximately 30 minutes required between quantitative measurements.
Method Performance
Precision
Bias
Not described.
Applicable Chemicals
Cd2+
Hg2+
Ni2+
Cu2+
Be2+
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental or ambient
3 ng/L (low cal. standard)
300 ng/L (low cal. standard)
20 ng/L (low cal. standard)
200 ng/L (low cal. standard)
5 ng/L (low cal. standard)
Level of Validation
P
P
P
P
P
Very low (water collection).
High. Described system is designed for larger scale field operations (rivers, lakes,
effluents) not so much for residential applications.
Moderate to high.
Comments 1. Authors describe inert sensor head (consisting of 5 modules) which can be lowered
into water sample for multielement determinations. Sample water is introduced into
module where it is separated from fluorescent complexing agent by a membrane. 2.
When metal complexes form, the fluorescence emission behavior of the complexing
agent changes (wavelength shift, enhancement, or suppression of signal). These
changes can be used to identify different complexes (Ni2+, Cu2+, etc.).
Metal/complexing agent reaction rate is limited by diffusion through membrane.
System requires approximately 30 minutes between quantitative measurements.
Multielement calibration calculations are described for several metals as there are
competing complexation reactions which can alter measurements. Other potential
matrix effects include organic acids and chloride.
Other References
None
3-42
-------
Authors
Title
Citation
Matrix
Method Type
E.P. Achterberg
Automated Techniques for Real-Time Shipboard Determination of Dissolved
in Marine Surface Waters (Review Paper)
Trace Metals
Int. J. Environment and Pollution, 2000, 13(1-6), 249-261
Seawater.
Several techniques for field measurements of seawater reviewed.
Method Description
Sample Collection
Sample Preparation
Analysis (3 modes
reviewed)
Comments
Two major modes of shipboard collection described: 1-Discrete mode, using pump and
weighted hose, and 2-"underway pumping", where hose attached to pump is secured to
torpedo structure and held at fixed distance/depth from the ship. Water continuously
sampled while ship moves.
Varied with the mode of analysis reviewed (voltammetric, chemiluminescence, and
colorimetric methods). Generally involved combination of preconcentation, filtration, and
matrix removal steps.
Colorimetric: Analyte reacts w/ reagent and color change is monitored. Generally low
sensitivity for metals.
Chemiluminescence: Analyte reacts w/ reagent and electromagnetic radiation is monitored.
Higher sensitivity. Requires matrix treatment.
Voltammetric: Analyte collected on electrode, voltammetric scan applied and current
measured. Differential pulse voltammetry (anodic/cathodic striping) using hanging Hg drop
electrode is most popular form. Matrix treatment required, no preconcentration step.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
All modes can be equipped for real-time measurements.
Review paper, specifics not provided.
Method
Personal
Very low (water collection).
QL
Microenvironmental
or ambient Level of Validation
Moderate if laboratory analysis, higher if field analysis.
Inexpensive instrumentation and analysis procedures reviewed.
1. Review paper focusing on modes of shipboard metal determinations. Three modes of
analysis were reviewed: colorimetric, chemiluminescence, and voltammetric. All utilize
small, inexpensive instrumentation adaptable to residential field work (less so for
voltammetric methods using dropping Hg electrodes).
2. All three of the reviewed analysis modes can suffer from serious matrix effects. As a
result, water samples containing potential interferences (dissolved organic material,
interfering ions, etc.) often require sample pretreament. Sample preconcentration may
needed if lower detection limits are desirable for colorimetric and chemiluminescence.
Other References
None
3-43
-------
Authors
Title
Citation
Matrix
Method Type
Method Description
Sample Collection
Sample Preparation
Shamsipur, et al.
Lead-Selective Membrane Potentiometric Sensor Based on an 18-Membered
Thiacrown Derivative
Analytical Sciences, 2001, 17, 935-938
Water
Lower sensitivity; Potential for analysis in field.
Not described.
None.
Analysis
Use of laboratory fabricated Pb selective membrane sensor. Potential use in
field
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Pb2+
Participant Burden
Field Burden
Analytical Costs
Single "grab" described. Stabilization time between samples is 40 s.
For one field water sample measured in quadruplicate, 1.4% RSD.
<5%(atpHof2.0-5.0).
Method QL
Personal
Microenvironmental
or ambient
Approx. 200 |ig/L
Level of Validation
P
Very low (water collection).
Low (sample collection). Moderate if analysis done in field.
Sample collection/preparation inexpensive. Fabrication of Pb selective PVC
membrane labor intensive, not automated.
Comments 1. Authors describe development and optimization of Pb-selective membrane
sensor, with less emphasis on application of sensor.
2. Electrode is Pb2+ selective, but suffers from potential interferences from
other ionic species (mostly Hg2+, other species to lesser extent).
3. Bias expected at alkaline pH. Response appears to be linear from pH range
of 2 - 5, but drops at pH of 6 and above.
4. Field water sample was collected from a lead mine and had measured level
(22.1 ± 0.3 ppm) in agreement with collected AAS data (22.3 ± 0.2 ppm).
Other References
None
3-44
-------
Authors
Title
Citation
Matrix
Method Type
Xiao, et al.
Synchronous Fluorescence and Absorbance Dynamic
Determination at the Femtomole Level
Liquid Drop Sensor for Cr(VI)
Analyst, 2001, 126, 1387-1392
Water
Low or high sensitivity; laboratory analysis required.
Method Description
Sample Collection
Sample Preparation
Analysis
Not described.
Wastewater samples (n=4) were filtered prior to analysis.
Synchronous fluorescence and absorbance detection on dynamic liquid drop. Collected
signals from both measurements are used to determine Cr(VI). Instrumentation would
require laboratory setting.
Monitoring Time Frame
Method Performance
PrecisionBias
Applicable Chemicals
(XVI)
Participant Burden
Field Burden
Analytical Costs
Single "grab".
< 5% at 50 [igfL.
< 10% in absence of potentially interfering species.
Method QL
Personal
Very low (water collection).
Low (batch water collection)
Microenvironmental or
ambient
Approx. 1 [ig/L
Level of Validation
P
analysis in laboratory.
Sample collection and preparation inexpensive. Instrument operation expected to be
labor intensive.
Comments 1. Authors describe dynamic drop system for quantifying [ig/L levels of Cr(VI) in
water samples with minimal pretreatment. System collects both fluorescence and
absorbance data to determine Cr(VI). Article focus is instrumentation development
- not application.
2. Reagent (TMB-d) strong fluorescence emitter at acidic pH. Reaction with Cr(VI)
results in fluorescence quenching and increase in absorbance of reaction product.
3. Other species can react with reagent and cause interferences. Mn(VI) an Fe(III)
are of particular concern.
4. Cr(VI) recoveries for fortified water samples (n=3) range from 98.9% to 99.5%
Cr(VI); concentrations in field water samples (n=4) within ± 3% of data collected
from spectrophotometric analysis of same samples.
Other References
None
Authors
M. Chendorain, et al.
3-45
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Title
Citation
Matrix
Method Type
Real Time Continuous Sampling and Analysis of Solutes in Soil Columns
SoilSci. Soc.Am. J., 1999, 63(May-June), 464-471
Soil columns.
Measurement of tracer compound through soil column (transient signal)
Method Description
Sample Collection
Not applicable (preparation of laboratory soil columns).
Sample Preparation
Analysis
Soil columns (n = 3) of varying composition were packed uniformly and were saturated
with a CaCl2 solution.
Small tube sampler (STS) inserted at various points in soil column and interfaced with
pump. Pore solution pumped to a UV absorbance detector where the concentration of
tracer compound (nitrate) was determined. Measured concentrations were used to
generate breakthrough curves for the tracer as it passed through the columns.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
No metals listed
Participant Burden
Field Burden
Analytical Costs
Potential for near "real-time" integrated measurements (1-2 min. delay).
Not described.
Method QL
Personal
Microenvironmental or ambient
Level of Validation
Moderate (real-time soil monitoring).
High (potential for field measurements).
Highly variable (depends on mode of detection interfaced with STS).
Comments 1. Authors describe sampling device for analysis of pore water during displacement
studies. The small tube sampler (STS) is stainless steel tube with a grid at the
entrance to prevent clogging. The STS is interfaced to pump and pore water is
transported to detector w/1-2 min. delay.
2. Nitrate used as tracer. Mode of detection could be varied depending on analyte list
(electrochemical detection, etc.).
3. Soil must be saturated for this sampling mode to function.
4. Potential utility for sampling real-time effluent flows of desirable compounds?
Other References
None
Group 6
Authors
Corrado Di Natale, D. Salimbeni, R. Paolesse, A. Macagnamo, A. D'Amico
3-46
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Title
Citation
Matrix
Method Type
Porphyrins-based opto-electronic nose for volatile
compounds detetection
Sensors and Actuators B 65 (2000) 220-226
Air
Low sensitivity /cost/burden method
Method Description
Sample Collection
Sample Preparation
Analysis
Not addressed. Assuming instrument can be deployed in the field, air sample would
simply be injected through the inlet port of an 18 mL Plexiglass chamber.
None
Air sample is passed through a Plexiglass chamber coated with various
metalloporphyrins. Each porphyrin layer lies on a different optical path creating an
optical multisensor (opto-electronic nose). UV visible spectrophotometer is used to
detect changes in the optical spectra (blue region) of solid state films of porphyrins in
the presence of volatile analytes.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Target Chemicals:
Hexane
Propanol
Methanol and Ethanol
Acetone
Triethylamine
Other Chemicals:
Acetic acid
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Real-time
Not determined
Not determined
Method QL
Personal
Microenvironmental
or ambient
Not determined
Not determined
Level of Validation
None
None
Low
Low
Unknown
Not practical for ambient air monitoring because of lack of sensitivity.
Concentration ranges studied were between 70 and 4000 ppm.
None
3-47
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Authors
Title
Citation
Matrix
Method Type
Krantz-Rulcker, C., M. Stenburg, F. Winquist, I. Lundstrom
Electronic Tongues for Environmental Monitoring Based on
Pattern Recognition: A Review
Sensor Arrays and
Analytica Chimica Acta, 426 (2000) 217-226
Water
Low sensitivity/cost/burden
Method Description
Sample Collection
Sample Preparation
Analysis
On-line monitoring.
Not addressed.
Electronic tongue based on voltammetry. Water samples from a drinking water
production plant were analyzed with a voltammetric sensor array based on four
electrodes (gold, iridium, platinum, and rhodium). An increasing potential is
applied sequentially across each electrode and measurements are collected in
cycles. Pattern recognition routines are used to distinguish changes in the on-
line stream.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
None
Participant Burden
Field Burden
Analytical Costs
Real-time monitoring
Not addressed.
Not addressed.
Method QL
Personal
Not applicable.
Microenvironmental
or ambient
Not applicable.
Level of Validation
Not applicable.
Low
Low
Unknown
Comments
Paper indicates that technology is not applicable to determining composition of
sample, but rather may be useful in process control or quality control
applications
Other References
None.
3-48
-------
Authors
Title
Citation
Matrix
Method Type
Baby, R.E., M. Cabezas, E.N. Walsoe de Reca
Electronic Noses: A Useful Tool for Monitoring Environmental
Contamination
Sensors and Actuators B 69 (2000) 214-218
Water
Low sensitivity/cost/burden
Method Description
Sample Collection
Sample Preparation
Analysis
Not addressed.
Not addressed.
An electronic nose, MOSES II, equipped with two arrays of eight (tin oxide and quartz
microbalance) sensors is used to detect differences in the concentration of lindane in
water. The tin oxide sensors respond to changes in the resistivity in relation to the
oxidating and reducing properties of the gas in the headspace above the solution.
Differences in the concentration of nitrobenzene in water have also been determined by
this technique. In addition, the electronic nose has been used to distinguish mixtures of
three synthetic pyrethroids in 1) a dry powder mixture, 2) a solution of acetone, and 3)
individual pyrethroids prepared in an inert powder (alumina) and in water at various
concentrations.
Monitoring Time Frame
Snap-shot
Method Performance
Precision
Bias
Not addressed.
Not addressed. Linear relationship between Lindane concentration in water (nominal 1 ppm
to 4 ppm) and detector response was assessed.
Applicable Chemicals
Lindane
Nitrobenzene
Permethrin
Deltamethrin
Cypermethrin
Participant Burden
Field Burden
Analytical Costs
Method QL
Personal
Microenvironmental
or ambient
1 ppm in water
1 ppm in water
Not determined
Not determined
Not determined
Level of Validation
None
None
None
None
None
Low
Low
Not determined.
Comments
Electronic noses are normally used to determine food quality and may have other uses in
process control applications. The use of these devices for exposure monitoring could be
limited by their inability to identify individual contaminants at low concentrations in
complex matrices.
Other References
None
3-49
-------
Authors
Title
Citation
Matrix
Method Type
T. Dewettinck, K. Van Hege, W. Verstraete
The electronic nose as a rapid sensor for volatile
domestic wastewater
compounds in treated
Wat. Res., 2000; 35(10): 2475-2483
Water
grab sample, non-compound-specific.
Method Description
Sample Collection
Sample Preparation
Analysis
Paper describes the use of a commercially available instrument (FOX 3000
electronic nose, Alpha M.O.S., Toulouse, France) to test potable treated
(regenerated) wastewater for unidentified VOCs. Results are given in units of
sensorial odor perception (SOP). No data are given for calibration with respect
to concentrations of VOCs.
2 liter sample collected, transported to lab, and analyzed without sample
preparation.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
grab sample; potential for continuous monitoring (1 day to ? weeks)
none given (instrument not calibrated)
Method QL
Personal
none
Microenvironmental
or ambient Level of Validation
[odor] none
May be applicable to VOCs at the ppm level
not applicable
low (grab sample)
$ 1 0/grab sample ; $ 1 0/day continuous
The commercial instrument described in this paper may be useful for human
exposure studies, however, this paper is of little help. Manufacturer of
instrument claims sensitivity of about 1 ppm.
Kress-Rogers E. (ed.) Handbook of 'Biosensors and Electronic Noses. CRC Press,
Boca Raton, FL. (1997)
3-50
-------
Authors
Title
Citation
Matrix
Method Type
Julian W. Gardner, Hyun Woo Shin, Evor L, Hines,
An electronic nose system for monitoring the quality
Crawford S. Dow
of potable water
Sensors and Actuators B. 2000, 69: 336-341
potable water
gas sensor array
Method Description
Sample Collection
Sample Preparation
Analysis
Grab sample, stick sensor in neck of bottle for 1-2 min, analyze signals on
computer.
Authors use 6 sensor (MOS, metal oxide semiconductor) electronic nose to
identify presence and type of cyanobacteria (blue-green algae) in potable water.
Principal components analysis (PCA) clearly distinguishes between toxic and
non-toxic algae. No information is given that would indicate the usefulness of
MOS detectors for VOCs in indoor air, although one might consider it a
possibility.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Tested analytes
Potential analytes
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
grab; potential for continuous, long term monitoring
No quantitative results given, good selectivity
Method QL
Personal
Microenvironmental
or ambient
not given
Level of Validation
not given
System has undeveloped potential for VOC analysis
not applicable
grab sample, potential for portable field instrument
about $5 per sample
Method is not applicable to personal exposure studies. However, this
technology has potential for VOC analysis. Unlike MIPs, these sensors can be
software-calibrated for multiple analytes. QL is a big question.
Major reference: J. W. Ga
and Applications , Oxford
rdner, P. N. Bartlett, Electronic Noses: Principles
Univ. Press, 1999
3-51
-------
Authors
Title
Citation
Matrix
Method Type
Corrado Di Natale, R. Paolesse, A. Macagnamo, A. Mantini, A. D'Amico, A
Legin, L. Lvova, A Rudnitskaya, Y. Vlasov
Electronic nose and electronic tongue integration for improved classification
clinical and food samples
of
Sensors and Actuators B 64 (2000) 15-21
Urine and milk
Low sensitivity/cost/burden method
Method Description
Sample Collection
Sample Preparation
Analysis
Urine collected from 0 to 13 year old children. Pasturized and ultrahigh
temperature milk obtained from commercial sources.
Whole urine and milk samples were equilibrated in sealed vials for 30 minutes
at 30 C.
Volumes of headspace were injected into 35 mL quartz chambers coated with
eight metalloporphyrins (electronic noses). Electronic tongue measurements
made by immersing seven porphyrin electrodes directly into the sample.
Readings were taken after 15 minutes.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Target Chemicals:
Other Chemicals:
pH
Specific weight
Blood cell content
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Real-time
Not determined
Not determined
Method QL
Personal
Not determined
Microenvironmental
or ambient
Not determined
Level of Validation
None
Low
Low
Unknown
Target parameters (analytes) not applicable to exposure monitoring.
None
3-52
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TABLE 3-3. SUMMARY TABLE OF PORTABLE/FIELD-READY INSTRUMENTS
FROM GRAY LITERATURE
Company
Instrument Type
Matrix
Intelligent Ion, Inc.
Agilent
Varian
Electronic Sensor Technology
Photovac
Monitoring Instruments.com
Moorfield Associates
miniature MS air
portable micro GC air/water
portable GC/TCD air
portable/handheld GC/SAW air
portable GC air
portable MS air
portable MS/TDS air
3-53
-------
Authors
Title
Citation
Matrix
Method Type
Monitoring Time Frame
Working Principle
Mass Range
Resolution
Ionizer
Detector
Duty cycle
Read-out speed
Sensitivity
Trace analysis
Linearity
Long term stability
Front-end
Total Weight
Footprint
GC interface
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Intelligent Ion, Inc.
2815 Eastlake Avenue E Suite 300
Seattle, WA 98 102
tel 206.336.5608 fax 206.336.5558
Miniature Mass Spectrometry Breakthrough
W^lW^^sM£MMM)ILCom
air
portable mass spectrometer
continuous, long term (~ several months unattended?)
Mattauch-Herzog design with permanent magnets and micro-channel plate based
position sensitive ion detector
1-300 amu standard, optional 200-2000 range for medical, genomic and biotech
applications, 1-100 amu lower cost model retaining high
sensitivity and other attributes
1 amu standard, 2 amu over extended mass range
Electron impact, closed, thermionic source
Position sensitive micro-channel based electro optical ion detector
100%, non-scanning instrument
0.02 sec or less
Prototype 10-ppb benzene demonstrated in alpha prototype, expected sensitivity is 5
ppb with new designed (closed) ionizer and dual MCP layout
Part per trillion with enrichment peripheral
3 orders of magnitude demonstrated, 4-5 orders of magnitude expected
Superb long-term stability demonstrated with the existing prototypes This long-term
stability results from the use of DC voltages and permanent magnets
Modular and easily adapted to customer need. Default (a) direct coupled GC, or high-
speed GC, including by-pass valve for direct gas inlet via flow restriction, or (b)
continuously open and heated quartz capillary
35 Ibs (159 kg)
8.5" x20"x 11" (21.6 x 50.8 x 28 cm)
Uniquely suited for direct-coupled, modern high-speed GC interface due to high read-
out speed and 100% duty cycle
VOCs/SVOCs
small, quiet instrument, operated remotely
low (?)
capital cost (?)
This is clearly the most advanced, well documented, and best marketed portable
instrument out there. Numerous publications available on web site.
Resolving power enhancement of a discrete detector (array)
by single event detection, .P. Sinha , D.P. Langstaff , DJ. Narayan , K. Birkinshawb,
International Journal of Mass Spectrometry 176 (1998) 99-102
3-54
-------
Authors
Title
Citation
Matrix
Method Type
Agilent
the power is in your hands. Agilent
wwwjieilcntxom/cta
3000 Micro GC
air/water
portable micro GC
Method Description
Sample Collection
Sample Preparation
Analysis
Agilent is presently selling a line of portable micro instruments that house two
or four micro-machined GC modules. Each module is about 2x4x5" and
contains injector, column, GC oven, and detector. Modules can operate
simultaneously and under different conditions. The two module instrument is
about 4x9x12". Agilent claims that it can be operated continuously, and
controlled remotely. Detector is not described. Carrier gas source not described,
but it does not use external tanks. Injector system not described. Custom
configurations are available.
Monitoring Time Frame
Method Performance
Precision
Bias
Applicable Chemicals
Target Chemicals:
Other Chemicals:
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
continuous/periodic, remote control
no performance data on web site
Method QL
Personal
n/a
n/a
low?
Microenvironmental or
ambient
Level of Validation
portable instrument
capital cost: probably > $10k per instrument
need to find out what detectors are available
None
3-55
-------
Authors
Title
Citation
Matrix
Method Type
Monitoring Time Frame
Varian
Varian CP-4900 Micro-GC
!!iM/6vw\OiMiM!incjM!^
Air
portable GC/TCD
up to 20 days (?) until carrier gas runs out
Manufacturer's Specifications:
Injector
Injection volume:
Optional heated injector:
Column Oven
Detector
Detection Limits
Operating Range
Carrier Gas
Dimensions and Weight
Gas containers:
Rechargeable battery packs:
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Micro-machined injector with moving parts
1 I^L to 10 |iL, software selectable
30 °C - 1 10 °C, including heated transfer line
Temperature range: 30 °C to 180 °C, isothermal Optional backflush capability
Micro-machined Thermal Conductivity Detector (TCD)
WCOT columns: 1 ppm; micro-packed columns: 10 ppm
Linear dynamic range: 106
He, H2, N2 or Ar: 550 ± 10 kPa (80 ± 1.5 psig) input
Two-channel system: 28 cm (h) x 15 cm (w) x 30 cm (d)
Four-channel system: 28 cm (h) x 15 cm (w) x 55 cm (d)
Weight: minimum of 5.2 kg
one or two 300 mL gas containers with maximum pressure of 12,000 kPa (1740
psig)
two
all VOCs, some SVOCs
portable GC with internal gas tanks (small, quiet)
internal gas tanks - restrict duration of sampling
capital costs (?)
TCD has poor LOD. SAW would be better for environmental work.
Carrier gas should last:
300mL*(1740psi/15psi)/(lml/min) = 34,800 min = 24 days
web site.
3-56
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Authors
Electronic Sensor Technology
1077 Business Center Circle
Newbury Park CA 91320
Ph. (805) 480-1994 Fax (805) 480-1984
Title
4100 Portable Handheld Gas Chromatograph
Citation
wwJj;gx^^
Matrix
Air
Method Type
portable GC/SAW
Manufacturer's Specifications:
Size:
Weight:
Power:
Detector:
Detector Temperature:
System Controller:
Communications:
Sampling:
Sample Introduction:
Inlet Connection:
Inlet temperature:
Carrier Gas:
Column Limits:
Column Ramping:
Compound Identification:
Analysis Time:
Recycle Time:
Precision:
Accuracy:
Sensitivity:
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
20" W x 14" D x 10" H
351bs
120-240 VAC at 250 watts MAX, 50 watts typical
Surface Acoustic Wave quartz microbalance
Dynamic Range - 2x105
0°C to 125°C, programmable
Intel Pentium or higher processor
Minimum 16MB RAM - 1GB Hard Drive
Windows 95 or 98
Software Included: MS Office Standard, Winzip,
PCAnywhere and EST System Software
RS-232 between controller and 4100
30-40 cc/m sampling flow from internal pump
Time programmable from 1-60 seconds
Internal Tenax trap
Stainless Steel LUER inlet port
50°C to 200°C
Helium, HP - 12-24 hours depending on usage
35°Cto200°C
Isothermal or ramped from l-18°C/second
Automatic with user calibration
10-60 seconds
30 seconds minimum
5% RSD
10%
Low ppb level for most compounds
All VOCs
carrier gas must be replenished every 24 hours .
(above) Instrument can be operated remotely
capital cost (?)
Specs look good. A portable GC with an internal hydrogen generator for carrier gas
would enhance its utility.
None
3-57
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Authors
Title
Citation
Matrix
Method Type
Photovac, Inc. 176 Second Avenue, Waltham, MA 02451 USA
Phone: 781-290-0777
Voyager Portable Gas Chromatograph
ttllL^ZffiVWJ[to
air
portable GC
Manufacturer's Specifications
Size
Weight
Keypad
Display
Battery Capacity
Serial Output
Detectors
Concentration Range Monitored.
Power
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
15.4" ( 39 cm ) long, 10.6" ( 27 cm ) wide, 5.9" ( 15 cm ) high
15 Ib. ( 6.8 kg ) with battery installed
4 fixed function keys and 4 menu keys
128 x 64 element graphical LCD with backlighting
NiCd replaceable packs, extended life battery to power Voyager for up to 8 hours
depending on ambient and column temperature
RS-232, 9600 baud for connection to Windows based PC and
Voyager SiteChart software
communication to
Photoionization detector with quick-change electrodeless discharge UV lamp, 10.6 eV
(standard)
Electron Capture Detector (optional)
Typical low detection limits are 5 ppb to 50 ppb.
10-18 VDC, 115 or 240 VAC, adapter provided
VOCs and SVOCs
gas cylinders last only 8 hours
?
This instrument uses photoionization detector (PID) or electron capture detector
(BCD), making it much more sensitive (and more suitable for environmental
use) than instruments using TCD or SAW.
None
3-58
-------
Authors
Title
Citation
Matrix
Method Type
http://www.moni torinstrumcnts.com/productsl.htm
MG2100 Portable Mass Spectrometer
http://www.monitorinstruments.com/productsl.htm
Air
Portable mass spectrometer
Manufacturer's Specifications:
Mass Analyzer:
Ion Source:
Vacuum System:
Gas Inlets:
Stream Selection:
Gas Inlet Flow Rates:
Sensitivity:
Min det partial pressure:
Min det partial pressure ratio:
Signal to Noise Ratio:
Communications :
Response Time:
Power Input:
Dimensions:
Weight:
Enclosure:
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Cycloidal Mass Range: 2-100 amu standard;2-200 amu expandable
Electron impact (El); Adjustable eV
Ion getter pump (triode); turbomolecular pump,optional
Flow-By system, capillary, batch inlet, optional temperature & pressure control, corrosive
gas flow-by
Optional discrete solenoid type; dead end or continuous flow, added in blocks of 8 streams,
rotary multiposition
0.125 atmcc/s (flow-by), 0.08 p,Ls (capillary)
5 x 10-4 A/mbar (faraday cup)
1 x 10-12 mbar (faraday cup)
100 ppb (faraday cup) = 3 cts.
150 db
RS-232. RS-485, Modem, Fiber Optics
>=20 msec, depending upon application
80-250 VAC; 12/24 VDC
9" x 13" x 23" (230 mm x 330 mm x 585 mm)
40 Ibs. (20 Kg.)
Portable enclosure and airship container standard
VOCs/SVOCs (m/z of fragment ions < 200)
This is a small instrument (see specs) and probably makes little noise
can probably be operated remotely
capital cost - unknown
portable MS !
None
3-59
-------
Authors
Title
Citation
Matrix
Method Type
Monitoring Time Frame
Dimensions:
Power Sources:
Standard I/O:
Detection Limits:
Response Time:
Operating Modes:
PC Requirements:
Applicable Chemicals
Participant Burden
Field Burden
Analytical Costs
Comments
Other References
Moorfield Associates
Tel: +44 (0) 1565 722609 ... Fax: +44 (0) 1565 722758
Quadrupole Mass spectrometer Products
ttJBL^ZffiQMiiMH^
air
portable mass spectrometer with thermal desorber (TDS)
continuous, long term (?)
530(w) X 450 (h) X 230(d)mm
Weight 26 KG
240V AC or 1 10V AC at 170W
12VDC Via Vehicle Adaptor Kit
12VDC Via Battery Pack
4 analogue Outputs
2 analogue Inputs
2 digital outputs
2 digital inputs
VOC's: <2 ppb (std) or < 2 ppt ( with TDS)
Halogens:
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SECTION 4.0
REFERENCES
4.1 AIR RELATED
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2. Mitra, S. et al. Continuous monitoring of volatile organic compounds in air emissions using an on-line
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3. Patrash, S., et al. Characteristics of Polymeric Surface Acoustic Wave Sensor Coatings and
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4. Saltzman, B., et al. Continuous Monitoring Instrument for Reactive Hydrocarbons in Ambient Air,
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5. Cohen, B., et al. Bias in Air Sampling Techniques Used to Measure Inhalation Exposure, Am. Ind. Hyg.
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6. Nsibande, M. et al., Radon levels inside residences in Swaziland, The Science of the Total Environment,
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7. Grail, A., et al., High-Speed Analysis of Complex Indoor VOC Mixtures by Vacuum-Outlet GC with Air
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9. Groves, W.A., et al. Analysis of solvent vapors in breath and ambient air with a surface acoustic wave
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10. Cai, Q., et al. Vapor recognition with an integrated array of polymer-coated flexural plate wave sensors,
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11. Wang, C., et al. Cyclodextrin derivative-coated quartz crystal microbalances for alcohol sensing and
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13. Whiting, J., et al. A Portable, High Speed, Vacuum-Outlet GC Vapor Analyzer Employing Air as
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15. Friedfeld, S. and Fraser, M. Field intercomparison of a novel optical sensor for formaldehyde
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16. Kelly, T.J., et al., Testing of household products and materials for emission of toluene diisocyanate,
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17. Mannino, D., et al., Human exposure to volatile organic compounds: a comparison of organic vapor
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Environ, 1997,6: 331-336.
19. Fryer, M., et al. Real Time Air Quality Monitoring, Instrumentation Aerospace Industry, Proc. Interntl.
Symp. ISA, RTF, NC, 1998, 44: 642-651.
20. Ockenden, W. et al. Passive air sampling of PCBs: Field calculation of atmospheric sampling rates by
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21. Ockenden, W. et al. Toward an understanding of the global atmospheric distribution of persistent
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22. Koziel, J., et al. Field sampling and determination of formaldehyde in indoor air with solid-phase
microextraction and on-fiber derivatization, Environmental Science and Technology, 2001, 35(7): 1481-
1486.
23. Mabilia, R., et al. Long-term assessment of benzene concentration in air by passive sampling: A
suitable approach to evaluate the risk to human health, Analytical Letters, 2001, Vol 34 No. 6: 903-912.
24. Dobos, R. Field investigation comparing diffusion badge and charcoal tube monitoring for styrene,
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25. Kring, E., et al. Laboratory validation and field verification of a new passive air monitoring badge for
sampling ethylene oxide in air, Am. Ind. Hyg. Assoc. J., 1984, 45(10): 697-707.
26. Scheide, E., et al. A piezoelectric crystal "Film Badge" for monitoring mercury in air, Presented before
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27. Lafreniere, M. et al., Automated monitoring system for indoor air quality control, 1st NSF International
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28 . Carlsson, H., et al. Organophosphate ester flame retardants and plasticizers in the indoor environment:
Analytical methodology and occurrence, Environ Sci Technol, 1997, 31: 2931-2936.
29. Moller K., et al. Synthesis and evaluation of molecularly imprinted polymers for extracting hydrolysis
products of organophosphate flame retardants, J Chromatog, A, 2001, 938: 121-130.
30. Guilbault, G., et al. A coated piezoelectric crystal to detect organophosphate compounds and pesticides,
Sensors and Actuators, 1981, 2: 43-57.
31. Uchiyama, S., et al. Investigation of long-term sampling period for monitoring volatile organic
compounds in ambient air, Environ Sci Technol, 2000, 34: 4656-4661.
32. Zhu, L., et al. Highly sensitive automatic analysis of polycyclic aromatic hydrocarbons in indoor and
outdoor air, Talanta, 1997,45: 113-118.
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33. Dickert, F.L., et al. Supramolecular detection of solvent vapours with QMB and SAW devices, Sensors
and Actuators B, 1993, 13-14: 297-301.
34. Bertoni, G., et al.Environmental monitoring of semi-volatile polycyclic aromatic hydrocarbons by means
of diffusive sampling devices and GC-MS analysis, Chromatographia suppl, 2001, 53: S312-316.
35. Bertoni, G., et al. The internal consistency of the 'Analyst' diffusive sampler-a long-term field test,
Chromatographia, 2001, 54 (9/10): 653-657.
36. Elke, K., et al. Determination of selected microbial volatile organic compounds by diffusive sampling
and dual-column capillary GC-FID-A new feasible approach for the detection of an exposure to indoor
mould fungi? J Environ. Monitor., 1999, 1: 445-452.
37. Vainiotalo, S., et al. Passive monitoring for 3-ethenylpyridine: A marker for environmental tobacco
smoke, Environ. Sci. Technol, 2001, 35/9: 1818-1822.
38. Chen, C-Y, et al. Field evaluation of a passive sampler for the exposure assessment of 2-
methoxyethanol, Int. Arch. Occup. Environ. Health, 2000, 73: 98-104.
39. Charron, K.A., et al. Field validation of passive monitors for the determination of employee exposures
to methylene chloride in pharmaceutical production facilities, Am Ind. Hyg. Assoc. J., 1998, 59: 353-
358.
40. Chung, C.-W., et al. Evaluation of passive sampler for volatile organic compounds at ppb
concentrations, varying temperatures and humidities with 24-h exposures. 1. Description and
characterization of exposure chamber system, Environ. Sci. Technol., 1999, 33(20): 3661-3665.
41. Chung, C.-W., etal. Evaluation of passive sampler for volatile organic compounds at ppb
concentrations, varying temperatures, humidities, with 24-h exposures. 2. Sampler performance,
Environ. Sci. Technol., 1999, 33(20): 3666-3671.
42. Begerow, J.E. et al. Passive sampling for volatile organic compounds (VOCs) in air at environmentally
relevant concentration levels, Fresenius' J Anal. Chem., 1995, 351: 549-554.
43. Otson, R., et al. VOCs in representative Canadian residences, Atmospheric Environment, 1994, 28(22):
3563-3569.
44. Fellin, P., et al. Assessment of the influence of climatic factors on concentration levels of volatile
organic compounds (VOCs) in Canadian homes, Atmospheric Environment, 1994, 28(22): 3581-358.
45. Peskova, J., et al. Wet effluent denuder technique and determination of volatile organic compounds in air
I. Oxo compounds (alcohols and ketones), J Chromatog. A, 2001: 918: 153-158.
46. Dubowsky, S.D., et al. The contribution of traffic to indoor concentrations of polycyclic aromatic
hydrocarbons, J Exposure Analysis and Environ. Epidemiol., 1999, 9 (4): 312-321.
47. Wennrich, L., et al. Novel integrative passive samplers for the long-term monitoring of semivolatile
organic air pollutants, J Environ Monit, 2002, 4(3): 371-376.
4.2 WATER RELATED
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48. Takahata, N., et al. Continuous monitoring of dissolved gas concentrations in groundwater using a
quadrupole mass spectrometer, Applied Geochemistry, 1997; 12: 377-382.
49. Vrana, B., et al. Use of Semipermeable Membrane Devices (SPMDs) - Determination of Bioavailable,
Organic, Waterborne Contaminants in the Industrial Region of Bitterfeld, Saxony-Anhalt, Germany,
Environ Sci & Pollut Res, 2001; 8(1): 27-34.
50. Shamsipur, M., et al. Lead-Selective Membrane Potentiometric Sensor Based on an 18-Membered
Thiacrown Derivative, Analytical Sciences, 2001; 17: 935-938.
51. Dewettinck, T. et al. The electronic nose as a rapid sensor for volatile compounds in treated domestic
wastewater, Wat. Res. 2001; 35(10): 2475-2483.
52. Guo, X et al. On-line membrane extraction liquid chromatography for monitoring semi-volatile organics
in aqueous matrices, Journal of Chromatography A, 2001; 904: 189-196.
53. Jenkins, A.L., et al. Molecularly imprinted polymers sensors for pesticides and insecticide detection in
water, Analyst, 2001: 126: 798-802.
54. Xiao, D., et al. Synchronous fluorescence and absorbance dynamic liquid drop sensor for Cr(vi)
determination at the femtomole level; Analyst, 2001; 126: 1387-1392.
55. Folsvik, N., et al. Monitoring of organotin compounds in seawater using semipermeable membrane
devices (SPMDs) - tentative results, J. Environ. Monitor., 2000; 2: 281-284
56. Cnobloch, H., et al. Continuous momitoring of heavy metals in industrial waste waters, Analytica
ChimicaActa, 1980; 114: 303-310.
57. Jenkins, A. et al., Polymer-based lanthanide luminescent sensor for detection of the hydrolysis product
of the nerve agent soman in Water, Anal. Chem., 1999, 71: 373-378.
58. Kot, A., et al. Passive sampling for long-term monitoring of organic pollutants in water, Trends in
Analytical Chemistry, 2000, Vol 19 No. 7: 446-459.
59. Sabaliunas, D., et al. Semipermeable membrane devices for monitoring pollutants and their effects in
aquatic ecosystems of Lithuania, Critical Reviews in Analytical Chemistry, 1998, 28(2):[SI]50.
60. Murray, G., et al. Molecularly imprinted polymers for the selective sequestering and sensing of ions,
1997, Johns Hopkins Apl Technical Digest, Vol 18 No. 4: 464-472.
61. Achterberg, E., et al. Automated techniques for real-time shipboard determination of dissolved trace
metals in marine surface waters, Int. J. Environment and Pollution, 2000, Vol 13 Nos. 1-6: 249-261.
62. Minunni, M., et al. Detection of pesticide in drinking water using real-time biospecific interaction
analysis (BIA), Analytical Letters, 1993, 26(7): 1441-1460.
63. Crunkilton, R., et al. Determination of aqueous concentrations of poly cyclic aromatic hydrocarbons
(PAHs) in an urban system, Chemosphere, 1997, Vol 35 No. 7: 1447-1463.
64. Hofstraat, J., et al. Fluidized-bed solid-phase extraction: A novel approach to time-integrated sampling
of trace metals in surface water, Environ. Sci. Technol., 1991, 25: 1722-1727.
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65. Sergeyeva, T., et al. Selective recognition of atrazine by molecularly imprinted polymer membranes.
Development of conductometric sensor for herbicides detection, Analytica Chimica Acta, 1999, 392:
105-111.
66. Turkewitsch, P., et al. Fluorescent functional recognition sites through molecular imprinting. A
polymer-based fluorescent chemosensor for aqueous cAMP, Anal. Chem. 1998,70: 2025-2030.
67. Gardner, J., et al. An electronic nose system for monitoring the quality of potable water, Sensors and
Actuators, 2000, B 69: 336-341.
68. Hofelt, C. Use of artificial substrates to monitor organic contaminants in the aquatic environment, PhD
Thesis, 1998, 89pp.
69. Rudnitskaya, A., et al. Multisensor system on the basis of an array of non-specific chemical sensors and
artificial neural networks for determination of inorganic pollutants in a model groundwater, Talanta,
2001,55: 425-431.
70. Mourzina, Y., et al. Development of multisensor systems based on chalcogenide thin film chemical
sensors for the simultaneous multicomponent analysis of metal ions in complex solutions, Electrochmica
Acta, 2001,47:251-258.
71. Vlasov, Y., etal. Cross-sensitivity of chemical sensors for electronic tongue: determination of heavy
metal ions, Sensors and Actuators B, 1997, 44: 532-537.
72. Natale, C., et al. Multicomponent analysis on polluted waters by means of an electronic tongue, Sensors
and Actuators B, 1997, 44: 423-428.
73. Prestel, H., et al. Detection of heavy metals in water by fluorescence spectroscopy: On the way to a
suitable sensor system, Fresenius J Anal Chem, 2000, 368: 182-191.
74. Dickert, F.L, et al. Double molecular imprinting-a new sensor concept for improving selectivity in the
detection of polycyclic aromatic hydrocarbons (PAHs) in water, Fresenius J Anal Chem, 2001, 371: 11-
15.
75. Mohacsi, A., et al. Direct diffusion sampling-based photoacoustic cell for in situ and on-line monitoring
of benzene and toluene concentrations in water, Sensors and Actuators B, 79: 127-131.
76. Hofelt, C..S.., et al. Accumulation of organochlorine pesticides and PCBs by semipermeable membrane
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77. Booij, K., etal. Spiking of performance reference compounds in low density polyethylene and silicone
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4.3 SOIL AND DUST RELATED
78. Chendorain, M et al, Real time continuous sampling and analysis of solutes in soil columns, Soil Sci.
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79. Gressel, M., et al. Real-time, integrated, and ergonomic analysis of dust exposure during manual
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80. Reed, G., Real-time on-site analysis of contaminated soils, Ind. Environ. Manage., 1995, Vol 5 No. 12:
25. (Was unable to locate this journal - foreign publication).
81. Ingerowski, G., et al. Chlorinated ethyl and isopropyl phosphoric acid triesters in the indoor
environment-an inter-laboratory exposure study, Indoor Air, 2001, 11: 145-149.
4.4 FOOD RELATED
82. Rouseff, R et al, Headspace techniques in foods, fragrances and flavors, Headspace Analysis of Food
and Flavors: Theory and Practice (edited by Rouseff and Cadwallader), 2001: 1-8.
4.5 GENERAL
83. Lindgren, KN et al., Relation of cumulative exposure to inorganic lead and neuropsychological test
performance, Occupational and Environmental Medicine 1996; 53: 472-477.
84. Mitra, S. et al., Characteristics of microtrap-based injection systems for continuous monitoring of
volatile organic compounds by gas chromatography, Journal of Chromatography A, 1996; 727: 111-
118.
85. Mitra, S. Continuous Monitoring of Organic Pollutants, Environmental International, 1996; 22 No. 4:
III-XVII.
86. Corley, R., et al., Technical Note: A Device for Obtaining Time-Integrated Samples of Ruminal Fluid, J.
Anim. Sci., 1999; 77: 2540-2544.
87. Groves, W., et al. Analyzing organic vapors in exhaled breath using a surface acoustic wave sensor
array with preconcentration: Selection and characterization of the preconcentrator adsorbent, Analytica
ChimicaActa, 1998; 371: 131-143.
88. Groves, W., et al. Prototype Instrument Employing a Microsensor Array for the Analysis of Organic
Vapors in Exhaled Breath, American Industrial Hygiene Association Journal, 1996; 57: 1103-1108.
89. Ruzicka, J., Flow injection analysis-A survey of its potential for continuous monitoring of industrial
processes, Analytica Chimica Acta, 1986; 190: 155-163.
90. Arnold, B., etal. Progress in the development of molecularly imprinted polymer sensors, Johns
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91. Pristas, R. Passive badges for compliance monitoring internationally, Am. Ind. Hyg. Assoc. J, 1994,
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92. Kishkovich, O., et al, Real-Time monitoring for low-level pollution, Ashrae Journal, Nov 1997, 46-51.
93. Huckins, J., et al. Semipermeable membrane devices containing model lipid: A new approach to
monitoring the bioavailability of lipophilic contaminants and estimating their bioconcentration potential,
Chemosphere, 1990, Vol. 20 No. 5, 553-552.
94. Hori, M., Measurement of indoor air quality, an explanation of recent issues and problems, Zairyo to
Kankyo, 2001,50(10): 432-438.
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Organic Indoor Pollutants, 1999: 3-14.
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96. Namiesnik, J., et al. Some aspects of indoor air pollution and analysis, Pol. J. Environ. Stud., 1994, 3(4):
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97. van de Wiel, et al. Sampling strategies for indoor air analyses, IARC Sci. Publ., 1993, 109
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101. Bradshaw, N., et al. Confirming the limitations of diffusive sampling using Tenax TA during long term
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102. Anderson-Sprecher, A., et al. Environmental Sampling: A brief review, Journal of Exposure Analysis
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103. Di Natale, C., et al. Characterization and design of porphyrins-based broad selectivity chemical sensors
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104. Harper, W. The strengths and weaknesses of the electronic nose, Headspace Analysis of Food and
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105. Baby, R., et al. Electronic nose: a useful tool for monitoring environmental contamination, Sensors and
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106. Mantini, A. et al. Biomedical application of an electronic nose, Critical Reviews in Biomedical
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107. Krantz-Rulcker, C., et al. Electronic tongues for environmental monitoring based on sensor arrays and
pattern recognition: a review, Analytica Chimica Acta , 2001, 426: 217-226.
108. Di Natale, C., et al. Electronic nose and electronic tongue integration for improved classification of
clinical and food samples, Sensors and Actuators B, 2000, 64: 15-21.
109. Di Natale, C., et al. Porphyrins-based opto-electronic nose for volatile compounds detection, Sensors
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110. Steinberg, S.M., et al. A review of applications of luminescence to monitoring of chemical contaminants
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111. D'Amico, A. ,et al. Metalloporphyrins as basic material for volatile sensitivesensors, Sensors and
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112. Huckins, J.N., et al. Development of the permeability/performance reference compound approach for in
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113. Sequeira, M. et al. Towards autonomous environmental monitoring systems, Talanta, 2002, 56: 355-
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118. Eiceman, G.A., et al. Gas chromatogrpahy, Anal. Chem., 2002, 74: 2771-2780.
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121. Hyotylainen, T. et al. Determination of brominated flame retardants in environmental samples, Trends
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122. Khaled, A. et al. Time-weighted average sampling of volatile and semi-volatile airborne organic
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123. Burns, Mark A. Everyone's a (Future) Chemist, Science, 2002, 296: 1818-1819.
124. Reyes, D. R. et al. Micro total analysis systems. 1. Introduction, theory, and technology, Anal. Chem.,
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125. Verpoorte, E. Microfluidic chips for clinical and forensic analysis, Electrophoresis, 2002, 23: 677-712.
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