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Environmental Analysis

Ray E. Clement* and Paul W. Yang

Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road,Etobicoke, Ontario, Canada M9P 3V6

Carolyn J. Koester

Analytical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94551

ReviewContents

General Trends 2761

Review Articles 2766

Solid-Phase Microextract ion Applicat ions 2766

Characterization of Organic Compounds 2767

Water Analyses 2767

Soi l, Sedi ments, and Por e Water s 2767

Air M onitoring 2767

Inorganic/ Organometall ic Compounds 2767

Air M onitor ing and Analysis Appl icat ions 2767General Comments 2767

Sampling 2768

Volatile Organic Compounds 2769

Semi volati le Or gani c Compounds 2769

Inorganic Compounds 2771

Chemometrics and Real-Time Monitoring 2772

Automated Analysis 2772

Deposition and Atmospheric Transport 2773

Incineration and M iscellaneous 2773

Water Analysis Applications 2774

Sample Collection 2774

Extr acti on and Sampl e Pr epar ati on 2774

I nt egr at ed Ex tr act ion and D et ect ion 2775

Separation and Detection 2775

Analytes of Interest 2777

Solid Sample Types Analysis Applicat ions 2777

Soils and Sediments: M etals 2777

Soils and Sediments: Or ganics 2779

Sewage Sludge: Metals 2780

Sewage Sludge: Organics 2780

Organometallic Analytes 2780

Biota Analysis Applications 2780

Radionuclides 2781

Quality Assurance, Reference Materials, and RelatedTopics

2781

Biomonitoring and Biomarkers 2782

Literature Cited 2782

This review covers developments in applied environmental

analytical chemistry from November 1998 to the end of October

2000, as found in the Chemical Abstracts Service CA Selectsfor

gas chromatography, mass spectrometry, inorganic analytical

chemistry, pollution monitoring, and environmental pollution. We

have coordinated our efforts with Susan Richardson, who prepared

the review on Water Analysis for this issue, and therefore have

greatly reduced our coverage in areas she has reviewed in detail.

As in the previous review in this series (A1), we have not

attempted to cover industri al hygiene, greenhouse gases, gui de-

lines and regulations, risk assessment, human levels, modeling,

commercial products, and food. We emphasize the determination

of trace organics, trace metals, and organometallics i n real

environmental samples.

In an ongoing attempt to control the size of this review, we

changed our strategy somewhat thi s year, by focusing on overall

trends in environmental analysis, rather on the number of citations

in a given area. The citations we use are therefore representativeof the current state of the art and should be used by the reader

as a starti ng point for fur ther i nvestigation. However, for readers

who wish much more detail, an extensive annotated list of r eview

articles published by others over the past two years is presented

in Table 1.

In preparing this review, we have noticed that more citations

now appear in published conference proceedings than was the

case for the first review in this series. Also, some of thek ey studies

reported in proceedings may not appear in published journals at

all. We attribute this, at least in part, to our observation that a

proportion of environmental publications are generated from

industrial and government researcherssfor whom journal publica-

tion is often less important than for academic researchers. Wealso note that although the Internet is not yet a significant source

of published papers in the environmental analysis field, it is likely

that more information will be disseminated in this manner in the

near future. Therefore, the authors believe that those who wish

to keep up to date in the environmental analysis field will have to

consider all of t hese sources of information, not just printed

journals. In the previous review in this series ( A1), we included

a table of Internet URLs we believe are of significant value to

envir onmental analytical researchers. Some of these URLs refer

to science societies or conference sites where some of the

conference proceedings cited here may be obtained. The only

addition we wish to make this year is the web site of theInternational Society for Optical Engineering (SPIE). M any

significant advances in chemometri cs, sensor technology, and

remote and automated environmental monitoring are presented

at various SPIE meetings. Published proceedings for many

of these meetings can be found through their web site

(www.spie.org).

GENERAL TRENDSThe first review in this series was published in 1991 ( A2).

Ultratrace methods were considered those that could achieve

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Table 1. Environmental Analysis Review Articles, 1998-2000

review topic/ analyteno. papers cited

or pages published review title and comments ref

1. Conference Proceedingsgener al 240 p p Envir oAnal ysis: Pr oceedings of the T hir d Biennial I nter national

Conference on Monitor ing and Measurement of the EnvironmentA3

general 249 pp Proceedings of the 2nd Euroconference on Environmental Analytical Chemistry A4air monitoring 160 pp Air M onitoring and Detection of Chemical and Biological Agents A5remediation 420 pp Environmental M onitoring and Remediation Technologies A6

2. Matrix-Specific

air many Analysis of organic compounds in air A7air 16 M easur ements of concentr ations of air pollutants; cover s methods,

deployment, site selection, networksA8

air 45 Modern methods of the measurement of atmospheric trace gases A9air 58 X-ray fluorescence analysis of ambient air samples A10air 31 The physicochemical characterization of urban air particulate

matter; diesel exhaust particles and carbon black are emphasizedA11

air 106 Tr ace element deter mi nati on of air bor ne p ar ticl es by neutr on activati on analysi s A12air 57 Trace element analysis of airborne particles by atomic absorption

spectroscopy, and inductively coupled plasma mass spectrometryA13

air 17 Composition of air pollution particles; includes definitions of air borneparti cle types and sources of PM10

A14

air 57 Sampling and analysis of individual par ticles by aerosol mass spectrometr y A15air many Or ganic atmospher ic aer osols: r evi ew and state o f the science; main objecti ve

is to present a basis for defining what data are needed in this areaA16

air 22 Accelerator based ion beam techniques for trace element aerosol analysis A17air 10 Health-r elated monitoring and assessment of airbor ne particulate matter:

an overview of recent IAEA (International At. Energy Agency) programsA18

air 204 Mass spectrometry of aerosols; off-line M S techniques discussed A19air 165 New concepts for sampling, measurement, and analysis of atmospheric

anthropogenic aerosolsA20

air 27 pp Real-time single par ticle mass spectrometry: a h istorical review of aquarter century of the chemical analysis of aerosols

A21

air 26 Correlations of personal exposure to particles with outdoor airmeasurements: a review of of recent studies

A22

air 58 Aerosol time-of-flight mass spectrometry A23automobi le 25 Gas det ecti on for aut omoti ve pol luti on contr ol ; emphasi s on chemi cal sensor s A24air 60 Reactive sorption concentration in air pollution A25solid wastes and leachates 13 Multielemental analysis of solid wastes and leachates; NAA,

XRF, ICP-AES methods are coveredA26

water 672 Water analysis; extensive review of developments in water analysis A27gr oundwater 90 Fi el d methods for site assessment and r emediati on of

contaminated ground watersA28

wastewater 16 Trends in monitor ing of waste water systems; focus on use of sensors A29r iver wat er 21 Use of fl ow i njecti on anal ysi s for conti nuous moni tor ing of r iver water qual ity A30

marine water 27 Introduction - envir onmental analytical chemistry as a tool forstudying chemical processes in marine envir onments A31

3. Metals and Organometallics Speciationmetals 30 The r ole of speciation in analytical chemistry; coverage i ncludes

use of sequential extractionA32

metal s 47 Speci ation i n the envi ronmental fi eld. Tr ends in anal yti cal chemi str y;special attention to need for speciation analysis in biota

A33

super critical fluid extr action 25 Supercritical fluid extraction in speciation studies A34l iqui d chr omatogr aphy 141 Liqui d chr omatogr aphy: a t ool for the analysi s of metal speci es A35stripping voltammetry 117 Stripping voltammetry for the determination of trace metal speciation and

in-situ measurements of trace metal di stributions in marine watersA36

HPLC-I CPM S 11 H igh-per for mance l iqui d chr omatogr aphy-i sotope di luti on i nduct ivel ycoupled plasma mass spectrometry for speciation studies: an overview

A37

atomic spectroscopy many Speciation studies by atomic spectroscopy A38capil lar y electr ophor esis 179 El ement speciati on anal ysi s by capill ar y el ectr ophor esi s A39ICPM S 118 New approaches for elemental speciation using plasma

mass spectrometryA40

SPM E 40 Metal speciation by SPME-CGC-

ICPM S A41metals 199 Chemical speciation of trace metals A42microwave-inducedplasmas

131 Microwave-induced plasma-optical emission spectrometry-fundamental aspects and applications in metal speciation analysis

A43

phosphorus 93 Phosphorus speciation in water and sediments A44or ganometal li cs 17 I mpr ovi ng th e r el iabi li ty of speci ati on anal ysi s of

organometallic compoundsA45

Hg 80 Analytical methods for mercury speciation in environmental andbiological samples - an overview

A46

Hg 322 The determination of mercury species in environmental andbiological samples

A47

Hg 80 The speciation of mercury and organomercury compounds by usinghigh-performance liquid chromatography

A48

H g, As, Se 34 Speci ati on and anal ysi s of mer cur y, ar seni c, and sel eni um by at omi cfluorescence spectrometry

A49

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Table 1. (Continued)

review topic/ analyteno. papers cited

or pages published review title and comments ref

3. Metals and Organometallics SpeciationAs, Se 152 Speciat ion of arsenic and selenium compounds by HPLC hyphenated to specific detectors:

a review of the main separation techniques; covers papers published since 1980A50

Sn 129 Determination of tin species in environmental samples A51Cr 224 Chromium occurrence in the environment and methods of its speciation A52

4. Organic AnalytesPOPs many Persistent Organic Pollutants (POPs): state of the science A53endocrine disruptors 14 M onitoring endocrine-disrupting chemicals A54endocrine disruptors 21 Endocrine-disrupting chemicals in a source water; drinking water source reservoirs A55endocr ine disr upt or s 12 pp I dent ifying endocr ine disr upt or s by high-r esolut ion mass spect romet ry A56endocrine d isruptors many Endocrine disruptine chemicals in the aquatic environment A57estr ogens 7 p p M ass spectr ometr y appli ed to the analysi s of estr ogens i n the envi ronment A58toxaphene 257 Toxaphene. Analysis and environmental fate of congeners A59PCBs 302 M eth ods for t he d eter mi nati on and eval uat ion of chl or inated bi phenyl s i n

environmental matricesA60

pharmaceuticals 154 Pharmaceuticals and personal care products in the environment: agents of subtle change? A61PAH many The analysis of polycyclic aromatic hydrocarbons in marine samples A62PAH 11 Appl icat ion of st ablec ar bon isot opic analysis t o sour ce polycycl ic ar omat ic hydr ocar bons

in t he environmentA63

nitro-PAH 9 pp Chromatographic methods for carcinogenic/ mutagenic nitropolycyclic aromatichydrocarbons

A64

VOCs 157 Ant hr opogenic volat ileorganic compounds in ambient air and nat ur al wat er s: ar eview onrecent developments of analytical methodology, performance and interpretation offield measurements

A65

drinking water 67 Analysis of organic micropollutants in drinking water A66herbicides 50 Determination of herbicides in water using HPLC-M Stechniques A67phenols 108 Liquid chromat ogr aphic and bior ecognition t echniques for t he det er minat ion of

phenols and their substituted derivatives in water samplesA68

aldehydes 16 pp A users guideto aldehyde analysis using PFBHA derivat izat ion and GC/ ECDdetection: avoiding the pitfalls

A69

isocyanates 138 Determination of isocyanates in air A70petroleum hydrocarbons 61 Environmental monitoring of petroleum products A71petroleum hydrocarbons 82 Oil and greases and petroleum hydrocarbon analysis A72algal analysis 89 Algal analysis-organisms and toxins A73microorganisms 107 Bacteriological analysis A74

5. Inor ganic Analytesheavy metals in water 57 Heavy Metals; review covers the biosensor monitoring of heavy metals in water A75met als many M et als and air pol lut ion par ticles; includes discussion of lung injur y fr om ex posur e A76trace elements 90 Plasmasource isotope dilut ion mass spectrometry: an optimum combination for

high-precision analysis of trace elementsA77

Hg 52 Sampling and determination of particulate mercury in ambient air: a review A78

Hg 85 Sample pr eparation procedures for total mercury deter mination inmaterials of natural origin

A79

Sb 117 M ethodol ogi es for deter mination of antimony i n ter restr ial envir onmental sampl es A80t ribut yl tin 24 Col labor at ive evaluat ion of met hods for t ribut yl tin det er minat ions

in sediment and mussel tissueA81

organometall ics 69 Separat ion of metal chelates and organometall ic compounds by SFC and SFE/ GC A82phosphat e 29 Phosphat e; r eview cover s multi -enzyme-based biosensor s for phosphat ein wat er A83lanthanides 484 Trace determination of;anthanides in metallurgical, environmental,

and geological samples; covers l iterature since 1980A84

sulfide 125 Analytical strategies for the detection of sulfide: a review A85As many Arsenic compounds in terrestrial biota A86marine waters many Automated techniques for real-t imeshipboard determination

of dissolved trace metals in marine surface watersA87

mar ine biological samples 99 Tr ace m etal status in marine biological samples: a r eview A88seawater 60 Fl ow i njecti on wi th chemi lumi nescence d etecti on for the shi pboar d

monitoring of tr ace metalsA89

marine waters 27 Electrochemical monitor for near real-t imedetermination of dissolvedtrace metals i n marine waters

A90

6. Radionuclides

r adi ochemi str y many Envi ronmental r adi ochemi str y and r adi oacti vi ty. A cur rent bi bl iogr aphy A91r adi ochemi str y many Radi ochemi str y and r adi ochemi cal separ ati ons. A cur rent bi bl iogr aphy A92NAA many Analysis by nuclear reactions and activation. A current bibliography A93radionuclides 181 Determination of radionuclides in environmental samples A94long-l ived r adi oisotopes 27 Ul tr atr ace d eter mination of l ong-li ved r adioactive i sotopes A95radiochemistry many Radiochemistry: inconvenient but indispensable A96radiochemistry 7 Chemical yield tracers for radiochemical analysis A97proficiency testing 32 ISO recommended reference radiations for the calibration and proficiency testing of

dosimeters and dose rate meters used in r adiation pr otectionA98

accelerator MS many Accelerator mass spectrometry analyses of environmental radionuclides: sensitivity,precision and standardization

A99

Ra 132 Radon in the environment: a current bibliography A100

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Table 1. (Continued)

review topic/ analyteno. papers cited

or pages published review title and comments ref

6. RadionuclidesU many Analyti cal methods for the d eter mi nation of ur ani um i n geological and

environmental materialsA101

Pu 8 D eter mi nat ion of Pu i sotopes at t race l evel s i n envi ronmental sampl es: r adi oi sotopesand stable elements evolution during the radiochemical method. Comparison ofthree radiochemical protocols.

A102

actinides 10 Separat ion of mono-, di-, t ri-, tetravalent and act inide cations on a cation exchangechromatography column wit h I CPM S detection

A103

7. Atomi c Spectroscopy

general review 84 Analyt ical atomic spectroscopy going into the next mil lennium: photons or ions,atoms or molecules?

A104

general environmental 859 Environmental analysis; extensive review of field A105general review 319 Atomic mass spectrometry A106monitoring 54 Atomic spectroscopy in environmental monitoring and process control A107ICPM S 101 Environmental applications of plasma spectrometry A108flow injection 255 Applications in environmental analysis A109general review 676 Advances in atomic emission, absorption and fluorescence spectrometry, and

related techniquesA110

XRF many X-ray fluorescence spectrometry A111r emot esensing 32 N ew spect roscopic met hods for environment al measur ement and monitor ing A112acid interferences 161 Acid interferences in atomic spectrometry: analyte signal effects and

subsequent reductionA113

8. Mass Spectrometry and Chromatographyportable MS 22 Advances in field-portable GC/ M S instrumentation A114

portable MS 22 Advances in field-portable GC/ M S instrumentation A114membrane MS 37 pp Membraneintroduction mass spectrometry; review of MIMStechniques and

applications, including environmentalA115

environmental MS 532 Environmental Mass Spectrometry; comprehensive coverage of mass spectrometryas applied to environmental analysis, covers 1998-1999

A116

LC/ M S 241 LC/ M S int er facing syst ems in environment al analysis: appl icat ion t o polar pest icides A117LC/ MS 159 Applications of liquid chromatography-mass spectrometry in environmental chemistry:

characterization and determination of surfactants and their metabolites i nwater samples by modern mass spectrometric techniques

A118

LC/ ICPMS 21 Speciat ion of metal-containing compounds found in the environment by micellar l iquidchromatography interfaced to inductively coupled plasma mass spectrometry

A119

INAA and ICPMS 8 pp Comparative use of INAA and ICP-MS methods for environmental studies; reviewincludes an element-by-element assessment

A120

GC-AED 59 Envir onmental appl icati ons of gas chr omatogr aphy-atomic emission detection A121IC 211 Advances in the determination of inorganic anions by ion chromatography A122IC 131 Ion chromatography in elemental analysis of airborne particles A123IC and CE 119 Developments in samplepreparat ion and separat ion techniques for the determination

of inorganic ions by ion chr omatography and capillary electrophoresisA124

CE 43 Recent developments in the separ ati on of inor gani c and small or gani cions bycapillary electrophoresis

A125

9. Sensors and Electrochemicalbiosensors 421 pp Biosensors for environmental monitoring A126sensors 393 pp Pr oceedings of the seventh inter national meeting on chemical sensors A127sensor s 30 Chemical and biological sensor s: meet ing t he chal lenges of environment al monitor ing A128sensor s 76 Ot her t ypes of sensor s for or ganic pol lut ant s; focus on immunosensor s for

organics in waterA129

biosensors 32 Update on environmental biosensors A130biosensors 76 Other organic pollutants: enzymatic biosensors A131biosensors 5 pp Enzyme sensors for environmental analysis A132sensors 71 Fiber optic sensors in environmental monitoring A133elect rodes many Elect rodes; ex tensive r eview on signal t ransduct ion by elect rochemical techniques A134biosensors 122 Gas-phase enzyme electrodes A135sensor s 20 I n si tu el ectr ochemi cal moni tor ing: fr om r emote sensor s to submer si bl e

microlaboratoriesA136

sensors 48 Affinity sensor systems A137sensors 95 M icroelectrode sensors for biomedical and envir onmental applications A138microelectrode arrays 53 Microfabricated ultramicroelectrode arrays: developments, advances, and

applications in environmental analysisA139

sensor s 171 Advances i n the m icr ofabr ication of el ectr ochemi cal sensor s and systems A140biosensor s 205 M olecular pr obes and biosensor s in bi or emedi ation and site assessment A141gas sensors 15 Next-generat ion diode laser gas sensors for environmental and industrial monitoring A142microbial sensors 36 Biochemical oxygen demand A143sensor arrays 10 pp Electronic tongues for environmental monitoring based on sensor arrays and

pattern recognition: a reviewA144

stripping voltammetry 230 Stripping voltammetr y in environmental and food analysis A145electrochemical detection 110 Metalloporphyrin, metallophthalocyanine and related macrocycle complex-based

film modified electrodes: review of selected significant designs andapplications to the electrochemical detection of pollutants

A146

SPM E 44 New developments in SPM E A147

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Table 1. (Continued)

review topic/ analyteno. papers cited

or pages published review title and comments ref

10. SPE, SPME, and Sample Extr actionSPM E 40 Analysis of industrial pollutants in environmental samples A148SPM E 12 p p Sol id-phase m icr oextr action: a pr omi sing technique f or sample p repar ation i n

environmental analysisA149

SPM E 40 M etal speciation by SPM E-CGC-ICPM S A150SPM E 16 Or ganometall ic speci ation by combi ni ng aqueous phase d er ivatizati on with

SPM E-GC-FPD-MSA151

SPM E 41 The application of SPM E-LC-M S to the determination of contaminantsin complex environmental matrices

A152

SPE 9 pp Advances in solid-phase extraction disks for environmental chemistry A153SFE 29 On-line detection for supercritical-fluid extraction A154

11. Sample Handling and Extractionsampleprepar at ion 36 pp Sampleprepar at ion for environment al analysis; st at e-of-t he-ar t r eview A155microwave extraction 73 M icrowave assisted extraction of organic compounds A156microwave extraction 33 Application of microwave t echniques in analytical chemistry A157mi cr owave extr acti on 61 M icr owave-assi sted sol vent extr acti on of envi ronmental sampl es A158pressurized l iquid

extraction40 Pressurized liquid extraction of persistent organic pollutants in

environmental analysisA159

membrane extraction 24 Liquid membrane extraction in analytical sample preparation A160membr ane and SPE ex tr act ion 43 I on separ at ion in membr ane and sol id-phase ex tr act ion syst ems A161cellul ose sorbent

preconcentration42 Functionalized cellulose sorbents for preconcentration of trace

metals in environmental analysisA162

organic analytes in water 167 Chemical analysis: sample handling and analysis of organic pollutantsin water matrices

A163

water removal from samples 55 Water vapour removal from gaseous samples used for analytical purposes A164SFE 14 p p Pr oper ties of super cr itical fluids r el evant to extr acti on and chr omatogr aphy A165POPs 174 Separ ation, clean-up and r ecover ies of per si stent tr ace o rganic

contaminants from soils, sediment and biological matricesA166

12. Sampling, QA and QC, Chemometrics

sample handling 1138 pp Sample handling and trace analysis of pollutants: techniques, applicationsand quality assurance

A167

water sampling 20 pp Sampling methods in surface waters A168sediment sampling many Sediment trap sampling in surface waters A169soil water sampling 33 Collection of soil solution A170vocs in air 190 Sorbent trapping of volatile organic compounds A171passive dosimet ry 14 pp Passive sampl ing for long-t er m monitor ing of or ganic pol lut ant s in wat er A172monitor ing pr ogr ams 10 D esigning monitor ing pr ogr ams t o evaluat et he per for mance

of natural attenuationA173

diffusive sampl ing 147 M onitor ing t he ambient environment with di ffusive sampler s: t heor yand practical considerations

A174

quality assurance many Quality assurance in environmental monitoring A175

long-term monitoring 69 Ensuring quality in long-term environmental monitoring for chemical speciation A176airborne particles 10 Quality assurance, quality control, and datavalidat ion in environmentalanalysis of airborne parti cles

A177

airbor ne par ticles 38 Qual it y assur ance and qual it y cont rol in t he element al analysis of airborne particles

A178

QA and QC 34 Quality of residue data A179reference materials 54 Certified reference materials for quality control of measurements in

envir onmental monitori ngA180

r efer ence mat er ials 56 St andar d r efer ence mat er ials for t he det er minat ion of t race or ganicconstituents in environmental samples

A181

r efer ence mater ial s 16 Pr oper use o f r efer ence mater ial s for el emental speci ati on studi es A182uncer tai nty 75 Sour ces of uncer tai nty i n gas chr omatogr aphy and hi gh-per for mance

liquid chromatographyA183

uncertainty 15 Evaluating uncertainty in routine analysis A184statistics 95 Some applications of statistics in analytical chemistry A185chemometrics 142 pp Pattern recognit ion, chemometrics, and imaging foroptical environmental

monitoringA186

chemometrics 60 Spectral pattern recognition: the methodology A187

TM S der ivat izat ion 65 Ar ti fact s in t rimet hylsi lyl der ivat izat ion r eact ions and ways t o avoid t hem A188blank optimization 25 Blank optimization for elemental analysis of laboratory water down to ppt levels A189analyte stability 86 Stability of chemical species in environmental matrices A190

13. Biomonitoring and Biomarkersfr eshwater bi omonitor ing 43 Bi omonitor ing for the 21st century A191fish as biomonitors 144 Biomonitoring and ecotoxicology: f ish as indicators of pollution-induced

stress in aquatic systemsA192

vegetation as biomonitors 154 Biomonitoring using aquatic vegetation A193mar ine biot est s 84 Choice of biot est s and bioindicat or s for evaluat ion of t he qual it y of t he mar ine

environmentA194

great lakes f ish 64 Neoplast ic and inf lammatory l iver diseases of whitesuckers as environmentalquality indicators

A195

mussel biomonitors many The mussel watch approach and its applicability to global chemicalcontamination monitori ng progr ams

A196

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parts-per-trilli on (ppt) detection limits, and methods achieving

these levels were mostly based on high-resolution mass spec-

trometers (HRMS). Capillary columns for trace organics deter-

mination were commonplace, but many packed column methods

were still used. Many citations to methods for the chlorinated

dibenzo-p-dioxins, dibenzofurans, and PCBs were found. Speciation

methods for organometallics were beginning to achieve impressive

results, with detection based mostly on atomic absorption (AA)

techniques. Supercriti cal fluids for extractions and microwave

ovens looked like huge new developments, and the promise of

immunoassays for rapid screening appeared promising.Ten years later, the environmental analysis field has changed

significantly. Few references to improved methods for dioxins/

furans/ PCBs were found, as HRMS methods for these analytes

have now matured. Impressive improvements in detection limits

for such analytes are such that ppt detection is routine for many

organic analytes, even by using benchtop quadrupole and ion trap

mass spectrometers. Parts-per-quadri lli on (ppq) detection is now

becoming routine, and detection of a few hundred femtograms of

some analytes is now possible, although such detection levels

cannot yet be considered routine. Relatively new organic groups

such asthe nonylphenol ethoxylates, pharmaceuticals and steroids

asenvironmental contaminants, and higher molecular weight polar

compounds are being studied. Many seemingly different chemicals

are now listed under the label ofendocrin e disruptors, the study

of which will be an exceedingly difficult analytical challenge

because of the low detection limits required and widely varying

analytical properties of the many chemicals in this group. Such

investigations have greatly expanded over the past few years

because of the maturing field of liquid chromatography/ mass

spectrometry ( LC/ MS). Benchtop LC/ M S models are now avail-

able for this work that make such studies available to a much

greater range of researchers, much as the benchtop GC/ M S did

in the earl y 1980s. For metals and organometalli cs determination,

the field is rapidly becoming dominated by the inductively coupled

plasma mass spectrometry ( ICPMS) technology. Although AA i s

still widely used, most significant new developments in the

environmental analysis field are ICPMS based. Other technologies

that have been significantly advanced in the past two years are

GC/ time-of-flight mass spectrometry (GC/ TOFMS), membrane

introduction M S, pressurized liquid extraction, and real-time

emissions monitoring. Mi crowave ovens for sample extraction are

still being developed, but have not yet achieved the widespread

use that seemed inevitable a few years ago, and supercri tical fluid

extraction (SFE) now seems to be a terrific technique for selectedapplicationssbut it now appears SFE will not reach the status of

an essential, widely applicable technology. One relatively recent

development that has exploded in the past two years is soli d-phase

microextraction (SPME). So many references to environmental

analysis applications by using SPM E were published, that we

decided to highlight this technique in a special section im-

mediately following the summary of review articles.

REVIEW ARTICLESThis section is the only one of this review where our intention

was to be inclusive rather than exclusive. By summarizing other

published review articles relating directly to environmental

analysis, the authors hope to provide readers with a source of

more detailed follow-up information. We have done this because

it is impractical for a single article to be comprehensive in

coverage for such an active and broad field as environmental

analysis. These citations are presented in Table 1.

SOLID-PHASE MICROEXTRACTION APPLICATIONSThe use of SPME, in which a small, polymer-coated fiber is

used to extract analytes from aqueous samplesor air, hasexploded

since our last review. The first SPME device was described in

1990 (B1) and represented an innovative approach to sample

Table 1. (Continued)

review topic/ analyteno. papers cited

or pages published review title and comments ref

13. Biomonitoring and BiomarkersEROD induction 60 EROD induction in fish: a t ool to measure envir onmental exposure A197dendr oanal ysis 22 Dendr oanal ysi s: a t ool for biomonitor ing envi ronmental poll uti on? A198t ree monitor ing 172 A decade of for est t ree monitor ing in Canada: evidence of air pol lut ion effect s A199bivalve markers many Appraisal of prospective bivalve immunomarkers A200biomarkers many Biomarkers of exposure A201bioremediation efficiency 28 Biomarkers for monitoring efficacy of bioremediation by microbial inoculants A202

14. Toxici tyWatertox bioassays 98 pp Watertox Bioassays; comprehensive discussion of A203toxicity testing guideline many Assessment of the U. S. EPA methods for identification of hazards

to developing organisms: the developmental toxicity t esting guidelineA204

mar ine t ox ici ty many Char act er izing and ident ifying t ox icant s in mar ine wat er s: ar eview of marine toxicity identifi cation evaluations

A205

endocrine disruptors many Assays for endocrine-disrupting chemicals: beyond environmental estrogens A206aquatic plants many Aquatic plants for toxicity assessment A207wholeeffluent t est ing many Field assessment s in conjunct ion with wholeeffluent t ox ici ty t est ing A208whole effluent testing many Whole effluent toxicity testing: usefulness, level of protection,

and r isk assessmentA209

15. Miscellaneous Review Topicsmonitoring trends 260 Trends in environmental analytics and monitoring A210asthma agents monitoring 73 Environmental monitoring of chemical agents A211management 11 The p roper pl ace of anal yti cal chemi str y i n envi ronmental management A212humics 80 Humic substances in water A213dendrochemical

monitoring

many Monitoring historical changes in soil and atmospheric trace

metal levels by dendrochemical analysis

A214

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preparation. Analyte collection and concentration, from an aqueous

sample, were accomplished simultaneously. Because t hermal

desorption was used to transfer the analytes from the SPM E fiber

to t he GC/ ECD, no harmful organic solvents were r equired for

sample intr oduction into the detection system. Continued interest

in SPME has been fueled by its commercialization by Supelco

(Bellefonte, PA) in 1993 and by the choice of almost a dozen

different fiber coatings, which allow the analyst to optimize the

extraction of various compound classes. SPME can be considered

a universal extraction method, as it can be used on gases, liqui ds,and solids (the headspace above the solid is typically sampled).

SPM E can be coupled easily with both GC and LC. BecauseSPM E

coupled with GC requires no solvent, it is an excellent sample

preparation technique for field analyses and is particularly well

suited to rapid response applications. Despite the fact that there

have been many publications about this technique, some aspects

of SPME, including the fundamentals of how analytes interact with

the fiber coatings and the stabilities of analytes collected on a

fiber, remain to be addressed. In addition, obtaining accurate

quantitation wit h SPM E can be challengingsfactors such as

matrix composition, temperature, pH, and extraction times must

be strictly controlled. The theory and application of SPME were

summarized recently in several books (B2-B4). Because a

comprehensive review of SPME is outside the scope of this paper,

we will highlight articles that i llustrate trends and r ecent SPM E

applications.

Characterization of Organic Compounds. The largest use

of SPME is for the characterization and quantitation of organic

compounds. SPM E/ GC/ M S was used to characterize landfill

leachate; aliphatic and aromatic compounds with alcohol groups

were detected (B5). SPME was used to sample the headspace

above fish tissue extract; approximately 170 organic compounds

were detected by GC/ MS (B6). Automated SPME/ GC/ FID,

which operated in a stop-flow mode, allowed on-line pH adjust-

ment of samples, internal standard addition, and unattended fieldoperation for 1 week, was used to monitor part-per-billion

concentrations of organic compounds in industri al wastewater

(B7). SPME/ GC/ FID and pattern recognition algorithms were

used to characterize different types of jet fuels and to determine

contamination sources ( B8).

Water Analyses.SPME/ GC/ MS was used for the determi-

nation of 55 volatile organic compounds; this technique had

linearity comparable to and detection limits (50 ng/ L for some

analytes) better than purge-and-trap GC/ M S (B9). Precise pH

adjustment is criti cal for the extraction of organic acids and bases;

small changes in pH changethe concentrations of neutral species

in water and, thus, affect their parti tioning between water and the

SPME fiber (B1 0). This can make quantitation challenging.SPME/ GC/ MS has been applied to the analysis of small, polar

molecules, such asvolatile amines (B1 1) and gasoline oxygenates

(B12, B13). SPME/ GC/ MSyielded excellent detection limits,10

ng/ L, for the gasoline oxygenate methyl tert-butyl ether (B12,

B1 3) and 15 g/ L for ethanol (B1 3). SPM E/ GC/ M S, with

derivatization, was used for analyses of haloacetic acids at

concentrations as low as10-500 ng/ L (B1 4) and pharmaceuticals

at concentrations of 0.2 and 50 g/ L (B1 5) in water.

There continues to be interest in coupling SPME with LC/

M S. Li near alkylbenzenesulfonates, at detection l imits of 0.5g/

L, were determined with SPME coupled with electrospray MS

(B1 6). In-tube SPME, which uses a polymer-coated tube instead

of a conventional fiber, coupled with LC/ MS was used to

determine trimethyl- and tr iethyllead, at 10g/ L (B1 7). A home-

built electrospray probe was developed, coupled to a SPM E

graphite fiber, and used to detect 10-9 M Triton-X (B1 8).

Soil, Sediments, and Pore Waters. SPME was used to

concentrate organic compounds in the headspace above sediments

and soils. Polycyclic aromatic hydrocarbons, at an estimated

detection limit of 1g/ kg sample, were detected in sediments bySPME/ GC/ MS(B19). SPME/ GC/ M Swasalso used to determine

polychlorinated biphenyls, at submicrogram per kilogram con-

centrations, in soils (B2 0). In an unusual application (called

matrix SPME) , poly(dimethylsiloxane)-coated glass fibers were

used assamplers of polychlor inated biphenyls (PCB) in sediment

pore water (B2 1). The results of this work might be considered

controversial, as absorption partit ion coefficients are used to

calculate PCB concentrations (B2 2). It has been asserted that

surface adsorptionis more important than absorptionfor controlling

SPME collection of high molecular weight compounds, such as

PCB (B23, B24); thus, PCB concentrations calculated on the basis

ofadsorptionpartition coefficients would not be accurate.

Air Monitoring. Air monitoring is a relatively new application

of SPME. A rapid, SPME-based method, with 1-min sampling and

15-min analysis t imes, was used to determine BTEX compounds

(benzene, toluene, ethylbenzene, and xylenes) in air; when

coupled with GC/ PID, detection limits were 1 ppb and results

were comparable to those produced by a standard method of the

National Institute of Occupational Safety and Health (B2 5).

SPME/ GC/ AED was used to determine organic sulfur compounds

at detection limits of 4-50 parts-per-tri lli on; however, low storage

stabili ty of the analytes, artifact formation, and the adverse effect

of humidity on extraction efficiency limit SPMEs utility for

quantitative, on-site analyses (B2 6). Bartelt and Zilkowski refined

their model of the relationship between airflow rates and theabsorption of analytes on aSPME fiber (the importanceof sample

temperature was also considered). Using their new model, they

could measure a broad rangeof analytes, collected under different

conditions, without prior calibration of the SPME fiber, and

regardless of whether equilibr ium conditions were established

(B2 7). Temperature and humidity influence the partitioning of

analytes between the air and SPME fiber, thus affecting method

calibration and increasing the complexity of analyte quantitation

(B2 8). While the previous studies focused on the determination

of volatile organic compounds in the gas phase, the feasibility of

using SPME (and also a needle trap device inspired by SPME)

to sample aerosols and airborne particles was demonstrated for

polycyclic aromatic hydrocarbons in diesel exhaust, tri amcinolone

in an asthma drug, and DEET in insect r epellent (B2 9).

Inorganic/Organometallic Compounds. The application of

SPME to analyses of inorganic compounds is increasing. Several

recent applications are described in Table 2. In theseapplications,

headspace sampling of the resulting extr act was most often used

to minimize interferences.

AIR MONITORING AND ANALYSIS APPLICATIONSGeneral Comments. This review emphasizes the develop-

ment of novel sampling and analytical methods and their applica-

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tions in the characterization and analysis of toxic airborne

pollutants. In addition, developments in areas of photochemical

precursors are also included. Articles r elated to nonmetal gases,

acid gases, and cr iteri a gaseous pollut ants are not covered here.

The review is organized by analytes and applications with the

intent to highlight new technologies and/ or methodologies forthe sampling and analysis of different types of toxic airborne

pollutants. These include sampling (design, phase distribution,

sector sampling, and specific sampling devices), volatile organic

compounds (VOCs), semivolatile organic compounds (SVOCs),

inorganic compounds, and spectroscopy/ chemometri cs ( optical

spectroscopy, mass spectrometry, postdata processing, and data

interpretation algorithms). Papers on the subjects of automated

analysis, especially its application to the monitoring of photo-

chemical precursors and emissions from incineration, have been

included. Finally, publications on the subjects of bacterial load,

single aerosol particle analysis using parti cle-induced X-ray emis-

sion (PIXE), and applications of a quartz crystal microbalance

sensor are reviewed.Several new trends were observed in air analysis since the 1999

review. As discussed earlier, SPME methods have been applied

to the sampling and sample preparation of VOCs and SVOCs in

envir onmental sample types such as water, soil, and air . SPME is

a great screening tool but, due to a limited amount of adsorbent

that can be coated on the surface of the SPM E fiber, using SPM E

to achieve accurate quantitative analysis can be challenging. The

development of an impr oved SPME method, the stir bar sorptive

extraction (SBSE) approach where a glass stir bar coated with

poly(dimethylsiloxanes) (PDMS), up to 500 of loading capacity

of atypical SPME fiber, was successfully applied for the sampling

and quantitativeanalysis of airborne VOCs and SVOCs (C10, E20).

SBSE is a relatively new method, and we expect to see more

applications in the future. Airborne polycyclic aromatic hydrocar-

bon (PAH) analysis continues to be a popular subject. In fact, more

than 40%of the SVOC publications are the sampling, analytical

method development, and characterization of air borne PAHs.

Similar to PAHs are the endocrine disruptors that may be released

from many sources but have yet to be characterized in a

systematic manner. We expect to see more PAH and endocrine

disruptor-related publications in the future. In the area of inorganic

applications, we noted an increasing number of publications

related to the use of chromatographic separation followed by

various detection techniques for the analysis and speciation of

metals and organometallics. The instrumentation typically consists

of GC/ MS, ion chromatography (I C), LC/ ICPM S, and LC-atomic

emission spectroscopy (LC-AES). We expect to see more publica-

tions related to separation-enhanced speciation of inorganic

compounds.Sampling. The collection of r epresentative air samples for

laboratory analysis remains the most challenging part in environ-

mental air monitori ng and analysis. Proper sampling and sample

storage procedures are essential to ensure that laboratory data

are representative of the sampling site and comply with applicable

technologies and regulations. Romano described a method to

determine and optimize the number of monitoring stations

required in an air pollution network ( C1). Using clean quartz and

tobacco smoke particles as a model for mineral surface and aerosol

organic matter, Pankow studied two mechanisms by which gas/

particle partitioning of SVOCs such as PAHs, PCBs, and organo-

chlorines (OCs) can occur via adsorption to particle surface or

organic aerosols (C2). Gas/ particle phase distribution of PAHs,PCBs, and OCs was also studied by Bidleman using a high-volume

air sampler which employs a filter and a sorbent trap to retain

particulate and gaseous compounds ( C3). Using a similar experi-

mental setup, Sanusi studied the characteristics of gas/ particle

distri bution of OCs and carbamate pesticides in urban, rur al, and

remote sites (C4). A study on the effect of meteorological

parameters on the size distribution of particle-adsorbed PAHs was

carr ied out by Schnelle-Kreis. Depending on wind direction,

maximum PAH concentrations varied on particles depending on

their geometric mean diameters, which vari ed from 75 to 920 nm

(C5). The capability of a porous plastic foam and an air-to-liquid

membrane for particle size-selective sampling and/ or direct

airborne part icle sampling, respectively, was also evaluated ( C6,

C7).

The use of a multisorbent-based cartridge for VOC sampling

followed by thermal desorption-GC/ M S(TD -GC/ MS) analysis has

been popular since the intr oduction of the USEPA method TO-17

in 1996. A study was carried out to evaluate the performance of

Tenax GR and Carbosieve SII I as VOC sampling media followed

by a short-path thermal desorption analysis of 77 VOCs (C8). The

performance of a Carbograph 2 and Carbograph 5 multisorbent

cartr idge was also evaluated at various sample loadings and sample

volumes ranging from 0.1 to 1000 mg/ m3 (C9). Contrary to the

Table 2. SPME Applications to Environmental Analysisa

analyte method matrix D.L (ng/ L) ref

Hg, methyl- water extraction, NaBEt4derivatization, SPME/ GC/ MS spiked soil B30Hg, methyl- SPME/ thermal desorption/ ICP/ M S water, reference tissue 200 B31Pb, tetraethyl- NaBEt4derivatization, SPM E/ GC/ M S water 400 B32Pb, al kyl- NaBEt4derivatization, SPM E/ GC/ M S water 100 B33Se der ivati zati on wi th 4,5-di chl or -1,2-phenyl di ami ne, SPM E/ GC/ M S tap and r iver water 6 B34Sn, H g, Pb N aB Et4 der ivat izati on, SPM E/ GC/ I CP/ M S sur face w ater and sedi ment 0.1-4 B35Sn, butyl- and

phenyl-NaBEt4der ivat izat ion, SPM E/ GC/ FPD wat er , sedi ment, sewage sl udge 0.006-0.6 B36

Sn, butyl - N aBEt4derivatization, SPM E/ GC/ FID water, reference sediments 30 B37Sn, triphenyl- TMAH or KOH-EtOH extraction, N aBEt4 derivatization,SPME/ GC/ ICP/ MS

water, potatoes, mussels 0.1 B38

a Abbreviations: AAS, atomic absorption spectroscopy; DL, detection limit; EtOH, ethanol; FID, flameionization detector; FPD, flamephotometricdetector; GC, gas chromatography; ICP, inductively coupled plasma; NaBEt4, sodium tetr aethyl borate; MS, mass spectrometr y; SPME, solid-phasemicroextraction; TMAH, tetramethylammonium hydroxide.

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multisorbent-based VOC sampling is the SBSE-based approach,

where equilibrium sorptive enrichment on PDMS instead of an

adsorption process was used to concentrate VOCs in the air

sample prior to analysis. This allows the use of a high-inertness

sorpti on material such as PDMS and provides an analytical blank

freefr om interference (C10). The use of new sampling media such

as mesoporous carbons for airborne polar VOC sampling (C11)

and a reversed-phase packing material (C18-Sili ca) for airborne

VOC sampling (C12) foll owed by off-line extraction or elution and

GC-flame ionization detector (GC-FID) or GC/ MS analysis wasevaluated against criteria such as compatibili ty with Tenax,

reusabili ty, and backgr ound interference in the GC analysis. The

use of fullerene-extracted soot (a byproduct of fullerene produc-

tion) in place of the Tenax GR (C13) was also evaluated using 17

VOCs.

The applicability of two different types of Nafion membrane

dryers and a poly(phenylenesulfide) wool-based O3 scrubber was

evaluated for the adsorptive sampling of selected volatile organo-

sulfur compounds and was demonstrated to provide an artifact-

free analytical results (C14). Due to the potential health effect

induced by the long-term exposure to ambient VOCs, continuous

sampling periods of 4 weeks, 7 days, and 24 h were evaluated at

0.5, 2.0, and 14 mL/ min sampling rates via a multisorbent

sampling tube followed by GC/ MS analysis (C15). It was found

that, except for vinyl group-bearing compounds, concentrations

of other TO-14 target compounds estimated by 4-week and 7-day

sampling methods were approximately equal to the 24-h mean

concentration.

The feasibility of using Carbopack B 60/ 80 for diffusive

sampling of VOCs was evaluated and found to have a superior

uptake rate to Tenax TA 60/ 80 for the majority of VOCs analyzed

(C16). The Carbopack 60/ 80 showed a stabili ty of up to 28 days.

Similarly, the performance of the 3M 3520 organic vapor monitor

as a passive VOC sampler was evaluated for 24-h periods under

various humidity and temperature conditions. It was found that,except for 1,3-butadiene, styrene, and methylene chloride, the 3520

device can be effectively used over the range of concentrations

and conditions tested with a 24-h sampling period with an error

of( 25%(C17). In the bioaerosol sampling area, glycerol was

tested as a collection substrate for passive sampling from three

fungal species with results compared with a closed-face polycar-

bonate fi lter sampling method (C18). The glycerol was demon-

strated to have good correlation with the closed-face sampler and

to have a sample storage time of up to 7 days.

Indoor air sampling methods for the assessment of environ-

mental contamination were also investigated. A field comparison

of the standard dust wipes method and the Lioy-Wainman-

Weisel (LLW) sampler was carried out to evaluate comparabilityof these two methods of indoor dust lead analysis. Correlation

results withi n paired samples indicated that the LLW sampler has

a significantly hi gher internal reproducibilit y for Pb loading than

the dust wipe method (C19). Tedlar air sampling bags were used

extensively for both i ndoor, ambient and abatement, sampling

purposes. A study examining the adsorption and desorption

behavior of six different organic compounds was carried out to

evaluate the reusabili ty of Tedlar air bags for air sample collection

(C20). It was demonstrated that one should consider carefully

before the start of any sampling program using Tedlar air bags.

On the other hand, it was also demonstrated that Tedlar air bags

can be an effective and a convenient sampling tool collecting

volatile metalloid compounds in ambient air (C21). The ability of

Tenax or XAD or activated carbon-embedded solid-phase extrac-

tion (SPE) disks for SVOC sampling in diesel exhaust was

validated and compared with a conventional polyurethane foam

(PUF) sampling method (C22). The capability of a personal air

sampler for 24-h collection of fi ne parti cles and SVOCs, especially

PAHs, was cri tically evaluated ( C23) for use in human exposure

and biomarker studies. The suitabili ty of using diffusive samplersfor indoor air benzene, toluene, xylenes, and ethylbenzene

sampling was evaluated using headspace SPM E and GC-FID

analysis (C24). Finally, a new personal aldehyde and ketone

sampler was developed and validated using dansylhydr azine

derivatization on solid sorbent with part-per-billion sensitivity

(C25).

VolatileOrganic Compounds. VOC analysis requires the use

and preparation of l ow-concentration standard gas mix tures with

good consistency and high accuracy. This i s usually prepared by

using either a static dil ution system or a dynamic dilution system

with primary standards that can be tr aced back to a certifi ed

reference material (CRM ). Combining a diffusion device with a

dynamic dilution system, a new VOC standard pr eparation system

was developed and validated at the part-per-trillion, v/ v (pptv) to

part-per-billion, v/ v (ppbv) levels for various VOCs over 21 months.

The system was demonstrated to be suitable for compounds with

a wide range of boiling points from 305 (32 C) to 418 K ( 145 C)

and a linear dynamic range of104 (D 1).

A procedure using an active charcoal packed porous poly-

(tetrafluoroethylene) (PTFE)-based tube passive sampler followed

by toluene extraction and GC-electron capture detection (GC-

ECD) analysis of 18 indoor and ambient airborne organohalogen

VOCswasdeveloped and validated using r eal world samples (D 2).

Two direct sampling ion trap M S (I TMS) systems were evaluated

for monitoring trace levels of halogenated VOCs in air. It wasfound that both dir ect sampling I TM S systems offer comparable

analytical results with a detection limit at 50 ppbv in selection

ion monitoring (SIM) and MS/ MS operation modes ( D 3). The

capability of multisorbent-based sampling followed by GC/ MS

analysis of a wide range of VOCs was investigated and demon-

strated that by changing the sample volume and the amount of

Carbotrap B and Carboxen 1000 in the sampling cartridge, one

could analyzeVOCs from dichlorofluoromethane(CFC12) to 1,2,3-

trichlorobenzene at method detection limit s from 0.02 to 0.4 ppbv

(D 4).

Analysis of odorous and/ or polar VOCs remains a major

challenge for analytical chemists. The capabiliti es of various

sampling methods, sample preparation pr ocedures, in situ or off-line derivatization schemes, and analyti cal systems were evaluated

with the goal to optimize the system performanceto enhancedata

quality. Table 3 summarizes these activities according to the

analytes, sampling methods, derivatizing schemes, and analytical

systems used in the method (D 5-D 14).

Semivolatile Organic Compounds. New procedures for the

sample preparation and analysis of SVOCs including OCs, PAHs,

and pesticides have been reported. These measurements have

stringent quality control and quality assurance (QC and QA,

respectively) protocols to support the usability of analytical data.

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In addition, the use of CRMs and standard reference materials

(SRMs) improve precision and accuracy. For the determination

of PAHs, the National Institute of Science and Technology (NIST)

has recertified PAH urban dust SRM 1649 as SRM 1649a using

normal-phase liquid chr omatography (NPLC) followed by r eversed-

phase liquid chromatogrphy-fluorescence detection (RPLC-FL),

i.e., NPLC/ RPLC-FL for isomeric PAH analysis and GC/ MS

analysis using three different stationary phases (E1). Twelve new

procedures were developed for PAH sample pr eparation and/ or

analysis using optical or M S-based detection methods (E2-E1 4).

These applications are summarized in Table 4.

In addition to PAH analysis, the long-term performance of a

GC/ negative ion chemical ionization M S (GC/ NICI-MS) system

for the continuous measurement of peroxyl acetyl nitrate (PAN)

and its homologues was studied. Sensitivity and linearity of the

GC/ NICI-M system were demonstrated at the pptv level with

significant sensitivity dri ft that can be corrected using an internal

standard (E1 5). A method using GC/ ITM S and GC/ NI CI-M S for

atmospheric s-triazines and their metabolites, at detection limits

from 0.8 to 15 pg/ m3, was developed (E1 6). Identification of

unknowns in multicomponent organic aerosols was demonstrated

by a temperature-programmed thermal desorption particle beam

Table 3. Polar/Odorous VOC Analytical Methods

analytes method/ description/ comments refs

chlorine- and sulfur-containing biogases fr omsewage and landfill

Summa canister foll owed by GC/ MS or GC-atomic emissionspectroscopy (GC-AES) analysis

D5

ambient sulfur-containing odorous VOCs automated Tenax GRtrap preconcentration, liquid N2focusing,followed by GC and flameless sulfur chemiluminescence detection

D6

ambient polar VOCs such as carboxylic acids,alcohols, and phthalates

impinger sampling followed by solid-phase extraction (SPE) andGC/ MS analysis

D7

airbor ne for maldehyde sampl ing with in si tu der ivat izat ion of for maldehyde on3,5-bis(tr ifluor omethyl) phenylhydrazine-coated silica followed byGC-ECD and GC/ M S analysis; results were validated with

NIOSH method 3500 and 2,4-dinitr ophenylhydrazine derivatization

D8

at mospher ic alcohols sampl ing with 200-mL glass bot tlef ol lowed by t he r eact ion with200 ppmv nitrogen dioxide on the glass surface to form alkylnitrites and then by GC-ECD analysis.

D9

particulate matter-associated aromatic amines direct MS identification of vapor-phase and particulate samplescollected in heavy traffic area; five chemical classes of aromaticwere found to exist in the samples.

D10

ambient carbonyls and hydroxy carbonyls impinger sampling and in situ derivatization of carbonylcompounds with o-(2,3,4,5,6-pentafluorobenzyl)hydroxyaminehydrochloride; further reaction of hydroxy carbonyls withbis(tr imethylsilyl )tr ifluor oacetaamine followed by GC/ ITM S analysis

D11

ambient aldehydes and ketones multisorbent cartridge sampling followed by TD-GC using a newPLOT column capable of separating k etones and aldehydesfrom hydrocarbons

D12

ambient formaldehyde and acetaldehyde in situ 2,4-dinitrophenylhydrazine sampling and derivatizationfollowed by HPLC-APCI-MS analysis using stable isotope-labeled standards

D13

ambient formaldehyde and acetaldehyde in situ 2,4-dinitrophenylhydrazine sampling and derivatization

followed by micro-HPLC analysis and fiber-optic-based UV detector

D14

Table 4. Ambient PAH Analytical Methods

analytes method description/ comments refs

PAH sample preparation method for airborne particulate-associated PAHs using focusedmicrowave extraction for GC/ MS analysis with 3-h sample preparation time andsuperior recovery and precision

E2

azaarenes airborne particulate-associated azaarenes analysis using normal-phase semipreparativeLC fractionation foll owed by RP/ LC-FL analysis of nine azaarenes

E3

PAH critical evaluation of LC-UV, GC-FID, and GC/ ITM S for the analysis of 19airbor ne particulate-associated PAHs

E4

PAH, DDT, BHC laser desorption-ITMS screening method of target compounds on a single airborne particle E5B[ a]P diones column chromatographic cleanup of soot aerosols followed by LC/ atmospheric pressure

chemical ionization/ M S (LC/ APCI-M S) analysisE6

B[ a] P isotope dilution B[ a] P analysis using a benchtop GC/ M S E7

PAHs andnitro-PAHs

direct screening of aerosol filter samples using laser desorption-time-of-flight-MS(LD-TOFMS)

E8

PAH s gr ease-coated D enuder sampl ing for the deter mi nati on of phase-di str ibuted PAH s E9nitro-PAHs extraction of particulate-associated nitro-PAHs, reduction of nitro-PAH to amino-PAH,

and deri vatization of t he amino-PAH followed by GC/ ECD analysis at the picogram l evelE10

PAHs method was developed for LC/ APCI-MS analysis of particulate-associated high molecularweight PAHs (M W >300)

E11

PAHs andthiaarenes

workplace air of an aluminum reduction plant was analyzed using GC-AED; runni ngGC-AED in sulfur-selective mode allowed the analysis of thiaarenes without priorseparation of PAH from thiaarenes

E12

PAHs PAHs in gasoline and diesel fuels and emissions from engine exhaust werecharacterized and quantitated at mg/ L andg/ kg levels

E13

NIST 1649PAH SRM

micr oscale sealed vessel ( MSSV) thermal extraction-GC/ MS and MSSV-pyrolysis-GC/ MS methods were evaluated using the SRM and found to be useful for t hecharacterization of PM 10organics.

E14

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mass spectrometer ( E1 7). A novel application using GC/ electron

capture negative ion M S (GC/ ECNI-MS) for the analysis of

airborne toxaphene congeners was investigated (E1 8). Finally,

an SBSE sampling TD-GC/ M S and TD-GC-nitr ogen phosphorus

detector ( TD-GC-NPD) method was developed for the monitoring

of airborne nicotine at the 5-250g/ m3 level (E1 9).

Inorganic Compounds. The sample preparation and analysis

of inorganic compounds including metals, mercury, and volatile

and nonvolatile organometalli cs were reported in several publi ca-

tions. Analytical technologies include I C, inductively coupled

plasma-optical emission spectrometry (ICP-OES), ICPMS, X-ray

fluorescence (XRF), AA, and AES. M ethods were also developed

for the introduction of samples and calibr ation standards to ensure

the precision and accuracy of the analysis. For example, Woskov

demonstrated a microwave-sustained atmospheric plasmaequipped

with an attached source of real-time calibr ation of metal standards

that was capable of providing the highly sensitive and accurate

data required for on-line continuous emission monitoring ( F1).

Using ICP-OES, a method was developed for the elemental

analysis of size-segregated particles ranging from 0.03 to 10 m

(F2). ICPM S instrumentation has had a wide acceptance i n

inorganic analysis, and several methods were developed for tr ace

element analysis of airborne particles using ICPMS-based instru-

mentation, summarized in Table 5 (F3-F7) according to analytes,

analytical methods, and applications. In addition, a method wasdeveloped using laser-induced plasma spectroscopy (LIPS) for the

on-line monitoring of chromium aerosols of an industrial waste

stream (F8). Laser ablation-based ICPMS (LA-ICPM S) methods

were also developed for the direct analysis of airborne particulate

collected on poly(tetrafluoroethylene) membrane fil ters (F9) and

the high-resolution, r apid quantitative chromium analysis at a

detection limit of 0.05 g/ filter (F1 0). Combining instrument

neutron activation analysis and ICPMS, concentrations of metal

collected by PM 10and PM 2.5 filters were quantified for various

metals with comparable results ( F11).

Table 5. Inorganic Applications and Methods

analytes methods/ comments refs

ICPMS-Based Methods206Pb,207Pb,208Pb Pb isotope ratio analysis of size-fractionated aerosols for source apportionment applications F3Pt, Pd, Rh method performance for the analysis of airbornePt, Pd, and Rh from vehicles catalytic converters F4235U, 238U using 235U/238U ratio obtained from tr ee bark for the discrimination of nuclear and nonnuclear

emission sourcesF5

NiCl2, NiO, NiCO3 method performance for the analysis soluble and insoluble Ni compounds in airborne particulate matter F6Mn, Fe, Co, Ni, Ag,

Cd, Sn, Sb, Pbdetermination of size-fractionated particles from arctic air for trace metal monitoring F7

Chromatography-Assisted MethodsZn, Co, Fe2+, Fe3+,

Mn, Cd, Pbisocratic ion chromatography separation, postcolumn deri vatization, UV detection at detection l imit s

of 10-60 ppbF12

Zn, Cu, CO, Fe, Cd capillary electrophoresis separation and direct UV detection at detection limits 0.5- 3 ppb F13Be micellar electrokinetic chromatography analysis of Bein airborne part iculateat 1 ppm detect ion l imit F14Ni(CO)4, Fe(CO)5,

Mo(CO)6, W(CO)6cryotrapping-GC/ ICPMS analysis of sewer gas of analytes as a fermentation byproducts F15

Sb(CH3)3, Sn(CH3)4,Sn(CH3)2(C2H5)2,Bi(CH3)3

GC/ ITMS an GC/ ICPMS analysis of volatile organometals in land fill and fermentation gases F16

butylated t rimethyl-,dimethyl-, triethyl-,diethyllead

GC/ ICPMS analysis of organolead compounds using tetraethyl lead as internalstandardwith detection limits of 2-9 fg for a 1-mL injection

F17

arsenic speciation of arsenic in coarse and fine urban aerosols using sequential extraction andLC-atomic fluorescence detection wit h comparable results obtained fr om I NAA analysis

F18

Sb(CH3)3, Sb LC/ ICPM S analysis of analytes in airborne particulate F19

XRF-Based M ethods

Ca, Cu, Fe, Mn, Ni,Pb, V, Zn XRF analysis of aerosol fi lter s of 150-mm diameter wit h comparable quantitativeresults from AA and ICP-OES F20silicon XRF analysis of silicon in airborne-particulate matter with quantitative results validated by LA-ICPMS F21S, Ca, K, Ti, V, Cr, Mn,

Fe, Ni, Cu, Zn, Pbperformance of chemical speciation of analytes in airborne dust by sequential leaching

and XRF was validated by NI ST 1648 CRMF22

lead performance evaluation of portable XRF instrument for analyzing dust wipe sampleswith results validated by AA

F23

S, Ca, Cr, Mn, Fe,Ni, Cu, Zn, Pb

XRF analysis of analytes in particulates of emissions from two disel fuels with different sulfur content F24

As, Ca, Co, Cd, Cr,Fe, Ga, Ni, Pb, Pt,V, Zn

compari son of sample preparation methods using oxygen-plasma ashing on sapphir ecarriers and acid digestion for XRF analysis of analytes

F25

Hg silver-coated filter sampling followed by XRF analysis of mercury in flue gases F26Pb evaluation of portable XRF for the determination of analyte in workplace air F27

Mercury Analysisanalysis of ambient Hg2+ using KCl-coated denuders followed by TD and cold vapor

atomic fl uorescence analysis at detection l imit of

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Applications of various chromatographic techniques for the

analysis of inorganic compounds are summarized i n Table 5

(F12-F1 9). X-ray fluorescence i nstrumentation remains the

method of choice for the determination of t race elements on

aerosols loaded filter or parti culate samples because of its

reliability, operational efficiency, portabili ty, and abili ty to produce

data that can meet different data quality objectives. Table 5

summarizes eight XRF applications for the analysis of metals in

airborne particulates (F2 0-F2 7). Mercury continued to be an

important area of environmental air analysis, and five selectedapplications are documented in Table 5 ( F26, F28-F3 1). Using

ultraviolet spectrometry, a simple, selective, and sensitive method

was developed for the analysis of lead (F3 2). A critical evaluation

of three sampling and analytical methods was carried out for the

determination of airborne hexavalent chromium (F33). Long-term

biomonitoring of Ba, Cu, Fe, Mn, Zn, and Pb in Q uercus ilexleave

and analysis of PM 10 fractions of atmospheric particulate were

performed t o determine the main metal pollutants emitted by

vehicles. Results ruled out Ba and Zn as valid tracers of automobile

traffic and the phase-out of leaded gasoline has resulted in the

decrease of Pb concentration by 20%/ year (F3 4). Hlavay

demonstrated the use of sequential leaching for the distribution

of metals as a function of particle size in aerosol samples (F3 5).

A selective stopped-flow injection method for the spectrophoto-

metric determination of palladium in hydrogenation and automo-

bile exhaust gas converter catalysts was also developed (F3 6).

Chemometrics and Real-Time Monitoring.This section

emphasizesthe development of monitoring methods using optical

instruments such as UV, IR, and laser spectroscopy, mass

spectrometry, and the application of dataprocessing and reduction

methods for the interpretation of monitoring data. Modern

instrumentation, for example, Fourier transform infrared spec-

troscopy (FT-IR) and time-of-flight MS (TOF-MS), is capable of

generating massive amounts of data which can be stored in low-

cost storage devices. The availability of powerful desk top PCsand graphics software has also revitalized interest in mathematic

processes that allow processing analyti cal data in an efficient and

consistent manner. With this massive amount of data and many

data interpretation tools, one can increasenot only the confidence

of unknown identification but also data quality. Optical spectros-

copy remote sensing has been greatly benefited from these

developments.

A paper examining the sampling and analytical requirements

for the observation of statistically significant temporal trends of

concentrations of atmospheric SVOCs was published (G1).

Statistical considerations in determining the health significance

of the constituents of air particulate matter were also reported

(G2). Examples of spectroscopic data needs for atmosphericoptical remote sensing to achieve the ultimate accuracy for the

measurement were discussed (G3). Fundamental studies on the

use of dispersion modeling and a differential optical absorption

spectroscopy (DOAS) monitor for improving pollution prevention

procedures (G4), experimental evaluation of a radial beam

geometry for mapping air pollutants using computer tomography

(G5), and the application of data quality objective process for toxic

emission monitoring around a petroleum refinery using multi-

beam, real-time optical remote sensing (G6) have also been

published.

Optical remote sensing is usually done by FT-IR, DOAS, and

tunable diode laser spectroscopy (TDL). Details of applications

of optical spectroscopy-based r emote sensing methods, including

an intercomparison of optical remote sensing systems such as

FT-IR, TDL, and DOAS (G7) were compared. Quality assurance

procedures were described to ensure data quality (G8). General

applications of open-path FT-IR experiment, including a data

reduction algorithm with atmospheric absorption corrections to

remove atmospheric interference to achieve a good background

(G9) and the application of the shifting method as a technique tocorr ect for the quantitativeanalysis of open-path FT-IR (G10), were

published. The capability of a portable FT-IR gas analyzer for the

measurements of air toxics in pollution prevention applications

(G11) and the detection of air borne chemical reagents by passive

FT-IR remote sensing (emission measurement) and libr ary

searching (G12) were demonstrated.

Frequency modulation and several signal-processing tech-

niques were described for the enhancement of the signal-to-noise

ratio SNR of open-path FT-IR measurement (G13, G14). The

capabili ty of open-path FT-IR t o measure and map air emissions

from volume sources (G15) and emission r ate assessments of

industrial area sources during winter conditions (G16) were also

demonstrated. The capability of difference-frequency-based TDL

spectroscopy for the monitoring of atmospheric formaldehyde was

demonstrated with a detection limit of 7.7 ppbv and precision as

low as 0.24 ppbv (G17). Using a TDL spectrometer and a near-IR

laser, Schiff demonstrated the unique ability of the system in

measuring a number of gases including HCl, C2H2, HCN, and H2S

with low-ppb sensitivity (G18).

Several publications relate to data-processing applications and

real-time measurements using MS equipment. By using a fuzzy

clustering algorithm, a general solution to processing the large

number of mass spectra obtained fr om on-line monitoring of

aerosols using laser desorption TOF-MS, so the chemical com-

position of particle classes, particle distribution, size distribution,and time courses can be r ationalized, was reported (G19). Using

the multi variate patch algorithm for the analysis of LA-ITM S

spectra obtained from individual airborne microparticles, the

capabili ty for real-time detection and classification of samples was

demonstrated (G20). Details of seven M S-based real-time monitor-

ing applications are summarized in Table 6 (G21-G27). Finally,

on-line monitoring of chromium aerosols in industrial exhaust

streams and real-time monitoring of airborne metals were dem-

onstrated by LIPS (G28) and spark-induced breakdown spectros-

copy (G29).

Automated Analysis.Automated analysis of ambient VOCs

and polar VOCs was developed in the early 1990s to meet the

need of Photochemical Assessment Monitoring Stations (PAM S).PAM S was requir ed by the U.S. 1990 Clean Air Act Amendments

(CAAA) for the enhanced monitoring of ozone, oxides of nitrogen

(NOx), and VOCs to obtain more comprehensive and representa-

tive data on ozone air pollution. For VOC analysis, PAMS have

been employing automated gas chromatography in 7 24 mode,

producing hourly monitoring data of 56 VOCs and 3 polar VOCs.

The concept of automated analysis has gained wide acceptance

and been applied to different areas of environmental monitoring

programs using various analytical technologies since the last

review in this series. Eleven publications, including PAMS and

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continuous emission monitoring, are summarized i n Table 7

according to analytes, analytical technologies, and the nature ofthe application (H 1-H 11).

Deposition and Atmospheric Transport.The precision of

precipitation chemistry measurements in the Canadian Air and

Precipitation Monitoring Network was estimated for inorganic ions

such as Na+, Ca2+, M g2+, and K+, to range from 10 to 35%( I 1).

Using a benzylhydroxyloxime-based derivatization scheme, a

method was developed for the determination of R-hydroxylcar-

bonyls and-hydroxylcarbonyls and dicarbonyls in snow and rain

samples by GC-FID and GC/ MS instrumentation (I 2). A new

method developed for the analysis of volatile and extractable

organohalogen compounds using GC-AES and GC/ MS has led

to the discovery of a compound new to environmental investiga-

tion, dichloronitromethane ( I 3). The detection of chlorodifluoro-

acetic acid (CDFA) in precipitation was analyzed using GC/ MS

and confirmed by 19F nuclear magnetic resonance. The possibilit y

that CDFA was a fluorocarbon degradation byproduct was also

speculated (I 4). A new screening method for the speciation of

inorganic lead and alkyllead by GC/ MS in rainwaters was

developed with detection limits of 1-4 ng/ L ( I 5). The tr ansient

isotachophoresis procedure was developed to resolve the problem

of transition metals comigration during electrokinetic injection

of capill ary electrophoresis analysis of trace ions in rainwater (I 6).

A new method was developed for the monitoring of methylmer-

cury in rainwater samples using in situ ethylation followed by GC-

atomic fluorescence spectroscopy (GC-AFS) analysis at adetectionlimit of 0.32 ng/ L (I 7). Using a water surface sampler, concentra-

tions of PAHs were measured for dry deposition and gas exchange

of PAHs at the air-water interface ( I 8).

Incineration and Miscellaneous. (A) Incineration. On-line

emission monitoring of PAHs from stack gas using a mobile

resonance-enhanced laser ionization TOF-MS at detection l imits

of pptv levels was described (J1). Off-line monitoring of PAH

emissions from domestic activities using LC-FL was also carried

out (J2). High cost is usually associated with the measurement

of dioxins/ furans (hence, toxic equivalent quantity, TEQ) in stack

gas emissions from wasteincineration facilities. As chlorobenzenes

(CBs) may be used as a substitute index to the dioxin TEQ, the

efficiency of a sampling train for the collection and analysis of

CBs was critically evaluated (J3). A multidimensional GC (M DGC)

is capable of separating target compounds from complicated

organic mixtures for an unambiguous qualitative and quantitative

analysis. By operating an MDGC/ MS system under sequential

repetitive heart-cutting mode, the capability of the analytical

system for the characterization of unknown, trace amounts of

organic contaminants in a complex sample matrix was demon-

strated (J4). The capability of an argon/ air ICP-OES doing real-

time analysis of metals in stack gas was demonstrated at detection

limits from 0.1 to 20g/ dry m3 (J5).

Table 6. MS Instrumentation-Based Ambient Air Real-Time Monitoring Methods

analytes methods/ comments refs

VOCs r equi rements, desi gn, cal ibr ati on, and use of a sampl ing i nl et/ quadr upol emass spectrometer system for on-line monitoring

G21

par aquat laser desor pt ion/ ionizat ion t andem M S r eal-t ime monitor ing of par aquaton the surface of airborne soil particles

G22

organic aerosols real-time, thermal desorption particle beam MS analysis of organic aerosolswas demonstrated using tridecanoic acid, 1-tetradecene, and ozone

G23

benzene, toluene, xylenes,acetone, methyl methacrylate

low-pressure ionization or atmospheric pressure ionization coupled to anITM S for real-time, continuous monitoring of air borne VOCs

G24

PAH s r eal-t ime, simultaneous multiphot on ionizat ion and laser -induced fluor escence

analysis at a detection li mit of 1 mg/ m3G25

VOCs r eal -ti me, on-l ine VOC moni tor ing usi ng pr ot on-tr ansfer -r eacti on M S atdetection limits of pptv

G26

atmospheric particles single aerosol particle analysis using transportablelaser ionization MSsystem and postdata processing to achieve a time course resolution of 1 h

G27

Table 7. Method Development and Applications of Automated Analysis

analytes methods/ comments refs

C2-C10VOCs in situ VOC measurements above a SierraNevadaponderosa pine plantationat 40-min i nterval over 2 months

H1

carbonyl VOCs solid-phaseextraction of air samples followed by elution/ in situ derivatizationusing 2,4-dinitr ophenylhydrazine and GC/ M S analysis at detection limits of 2-3 pptv

H2

formaldehyde direct measurement of atmospheric formaldehyde using GC-pulsed dischargeionization detection at detection limt of 32 pptv using 0.2-L air sample

H3

C3-C12VOCs multisorbent sampling followed by flash heating desorption to avoid the use ofcyrofocusing prior to GC analysis H4

formaldehyde andacetaldehyde

atmospheric HCHO and CH3CHO sampling using an annular diffusion scrubber,in situ derivatization using 2,4-dinitr ophenylhydrazine, and HPLC-UV analysis

H5

VOCs performance evaluation of an automated GC/ ITMSsystem for f ield VOCmeasurement activities

H6

55 PAMS VOCs PC-based program for the statistical analysis of PAM S data H7limonene and

p-cymeneon-line GC/ M S system for the monitoring of tracers (limonene andp-cymene) of

odor atg/ m3 detection limitH8

C2-C7VOCs, HCHO,CH3CHO

on-line automated TD -GC/ MS analysis of target compounds of biogenic andanthropogenic sources

H9

particulate-boundmetals

energy-dispersive X-ray-based continuous sampling/ analysis of metals in fluegas emissions

H10

Pb conti nuous emi ssi on moni tor ing of Pb usi ng l aser -i nduced br eak down spectr oscopy H 11

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(B) Miscellaneous.With pr oper calibration, aerosol TOF-M S

is a powerful tool capable of providing not only chemical composi-

tion but also the size of single aerosol particles, thus providing

qualitative description of a single particle. A side-by-side study

on the particle detection efficiency of three aerosol TOF-M S

systems was carr ied out and compared to colocated, conventional

referencesamplers (J6). Utilizing muramic acid and concentrations

of three fatty acids (C12:0, C14:0, C16:0), a prototype study on the

ability of a GC/ tandem MS system to measure total and viable

airborne bacterial loadings in two different agricultural environ-mentswas reported. Results from GC/ tandem MS were compared

to conventional culture data and suggested that these two

approaches pr ovided complementary but independent measure-

ment of airborne biopopulation (J7).

Three PIXE methods were developed and applied to the

identification of air pollution sources by single aerosol fingerprints

via a pattern recognition algorithm (J8). The integration of real-

time PIXE and DOAS data and off-line measurement of IC and

ICPM S data was reported to expand the scientific scope of

environmental studies (J9). By combining PIXE and plasma

desorption M S data, the possibility of determining t he chemical

compounds with which elements are associated in aerosol particles

was demonstrated (J10). A quartz crystal microbalance-based

analytical method was developed for the determination of nitro-

aromatics in landfill gas (J11). Finally, the chemical composition

of organic aerosols formed from biogenic hydrocarbon oxidation,

primarily R-pinene ozonolysis, was characterized using atmo-

spheric pressure chemical ionization mass spectrometry (J12).

WATER ANALYSIS APPLICATIONSIn contrast to previous years, this section is organized by order

of steps in the sample analysis process. This organization was

chosen to emphasize the similarity of the techniques used for

analyte determinations in different water matri xes and to facili tate

a discussion of current trends. However, the authors admit thatthe dividing lines between sample collection, extraction, separa-

tion, and detection have become blurred as integrated analytical

systems are developed and used for environmental studies. As in

past r eviews, we emphasize methods that lead to an understanding

of the environmental concentrations, transport, and fate of trace

pollutants. Responding to the request of the editors to write a

concise and critical review, we have chosen to focus on current

trends and new developments in water analysis. Thus, we do not

include applications of well-established techniques such as liquid-

liqui d extraction, gas chromatography coupled with conventional

detectors, liquid chromatography coupled with conventional

detectors, and most r eferences to inductively coupled plasmamass

spectrometry.SampleCollection. Over the past decade, sampling strategies

have evolved from simply placing water in a bottle to collecting,

and, in the process, concentrating, analytes on an appropriatesolid

medium. There are a variety of commercial materials, for example,

graphiti zed carbons and polystyrene-divinylbenzene resins, avail-

able for the collection of both organic and inorganic analytes. The

advantages of collecting contaminants on solid media include the

ease of transporting the sample to the laboratory and, in many

cases, the increased stabili ties of the analytes on the solid medium

compared to an aqueous sample. For example, many insectici des

collected on graphitized carbon black were stable for 2 months

when stored at -20 C (K1). There are increasing uses of passive

samplers and in situ measurements to r eplace sample collection.

Passi ve Samplers.Passive samplers are used to measure time-

averaged concentrations of organic pollutants. Because they are

deployed over long time intervals (days, weeks, or months),

passive samplers more accurately reflect the average conditions

of a water system than grab samples, which mi ght be affected by

short-term fluctuations in analyte concentrations. One type of

passive sampler is a semipermeable membrane device ( SPMD) .A SPMD is a lipid-filled membranestypically a sealed, low-density,

polyethylene tube filled with triolein. SPM Ds mi mic bioconcen-

tration of analytes in fat tissue and allow the detection of low

concentrations of semivolatile organic compounds. SPM Ds were

used to monitor a variety of persistent organic pollutants in r ivers

(K2), and in the study of PAHs in groundwater, PAH concentra-

tions of 0.1-100g/ L were observed (K3). Another type of passive

sampler uses membranes of polysulfone (for the collection of polar

compounds) or polyethylene (for the collection of nonpolar

analytes) to control the accumulation of analytes on aC18 Empore

disk. Diuron and Irgarol 1051 were collected with this sampler

and measured, at detection limits of 5-10g/ L, in natural waters;

measured concentra