Chromatography GCMS_Overview__1719054462.pdf

Gcms

1. GasChromatography/Mass
SpectrometryAnalysis
(GC/MS)
FundamentalsandSpecialTopics

2. GasChromatography/Mass
Spectrometry
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GC/MSOverview
thenutsandboltsofhowGC/MSworks
GC/MSAnalysisSpecialTopics
Chromatograms&PeakIntegration
TICs&MSLibraries,Interferences
DioxinsandPCBAnalyses
GC/HighResolutionMassSpectrometry

3. GasChromatography/MassSpectrometry
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Introduction
OrganicAnalysisOverview
History
ThewideworldofMassSpectrometry
Howitallworks
Tuning/Calibration
Break
GasChromatography/MassSpectrometry(GC/MS)
FromChromatogramstofinalreport
MassSpectrometryLibrariesandCompoundIdentification(TICs)
ProperandImproperPeakIntegrations-ManipulatingResults
DealingwithInterferences
Break
-DioxinandPCBAnalysesUsingGC/HighResolutionMassSpectrometry
ReviewofEPAMethods
WhyHighResolutionMassSpectrometry
HighResolutionMassSpectrometryFundamentals
DioxinandPCBAnalysisMethodsHighlights
ComparingPCBMethods1668Ato8082-AroclorsorCongeners.

4. GasChromatography/Mass
Spectrometry
(GC/MS)
Gas
Chromatography
Mass
Spectrometry
GasChromatography-
MassSpectrometry =
Identifies(detects)pollutantmolecules
basedontheirmolecularweightormass
AChemicalAnalysisTechnique
combiningtwoinstrumentstoprovide
forpowerfulseparationand
identificationcapabilities
Separatesmixtureofpollutants
soeachcanbeidentifiedindividually

5. GasChromatography/MassSpectrometry
WHATTHEMASSSPECTROMETRISTSAYS WHATTHEAVERAGEPERSONHEARS
Themassspectrometryresultsata
resolvingpowerof10,000indicatethat
isobaricinterferencesexistthatmakethe
chlorineionintensitiesinconsistentwith
theirnaturalisotopicabundanceatthe
molecularion.
Themassspectrometryresultsblah,
blah,blah,blah,blah,blah,blah,blah,
blah,blah,blah,blahthatmakethe
chlorineblah,blah,blah,blah,blah,
blah,blah,blah,blah,blah,blah,blah,
blah,blah,blah,blah.

6. HistoricalTimelineofGC/MS
1900 2000
1942
FirstCommercial
MassSpectrometer
1971
USEPAPurchases6
FinniganGC/MassSpecs
1906
SirJ.J.Thompson
NobelPrizefor
discoveryofelectron
1952
MartinandSynge
NobelPrize
Chromatography
1979
USEPAPublishes
WastewaterMethods
UnderCleanWaterAct
GC/MS
LC/MS
ICP/MS

EPABorn

7. DatesofHistoricalNote
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1906-SirJ.J.Thomson(Cambridge)getsNobelPrizeforthediscoveryof
theelectron.
1930-AstonusesMStostudyisotopes
1942-firstcommercialmagneticmassspectometer
1952-MartinandSyngewinNobelPrizeforChromatography
1959-GasChromatographyinterfacedtoMassSpectrometer
1968-FinniganCorp.deliversfirstQuadrupoleGC/MS
1969-FinniganCorp.deliversfirstQuadrupoleGC/MSwithcomputer
1970-USEPAisborn
1971-USEPApurchases6FinniganGC/MSsystems
1972-FederalWaterPollutionControlAct(CWA)ispassed
1976-HewlettPackardintroducesfullycomputerizedGC/MSsystem
1976-RCRAEnacted
1979-USEPApublisheswastewatermethodsunderCWA
1983-DevelopmentofLC/MSinterfacebyVestalet.al.

8. VariousFormsofMass
Spectrometry
•Awholerangeofpossibilities/permutations
SampleIntroduction Ionization MassSeparator Detector
Gas Chromatography EI (electron impact) Quadrupole
channeltron
GasChromatography EI(electronimpact) Quadrupole
channeltron
LiquidChromatography CI(chemicalionization) IonTrapdiscrete
dynode
Electrospray NCInegativeCI Time-of-Flight(TOF) photo-
optical
FAB(fastatombombardment) Sector(BE,EB,EBE)image
current
API(atmosphericpressure)FTMS(MS
n
)
LIMS(laserionization) IonMobility
FI/FD(fielddesorption) TripleStageQuadrupoles(MS/MS)
MALDI(matrixassistedlaserHybridCombinations(Q-TOF,BEQ)
desorptionionization)
ParticleBeam(PB/LC/MSInterface)
Thermospray(TSP/LC/MSInterface)
AtmosphericPressureIonization(API/LC/MS)
ETC.

9. GC/MS
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GreatFortheAnalysisofOrganics
GasChromatographyAnalysisRequirement
OrganicstobeanalyzedmustbeVOLATILEorat
leastPartiallyVOLATILE.
First30yearsofEPAhaveconcentratedonrelativelyvolatile
organics
Next30years? PolarandNon-Volatiles?
LC/MS?

10. BroadRangeofOrganicCompounds
(Howmanyarethere?)
ChemicalAbstractsService16,000,000
(basedonCAS#’sasof1998)
NISTOrganicMSDatabase approx.
150,000
FederalPollutantDatabase approx700
e.g.
MostOrganicAnalyses:
approx.10to80compoundsinone
analysis

11. ClassificationofOrganic
Compounds
BoilingPoint Polarity* Technique
Ionic high high HPLC,HPLC/MS
NonVolatiles high high HPLC,HPLC/MS
SemiVolatiles medium low-medium GC;GC/MS;HPLC
Volatiles low low-medium GC;GC/MS
*Increasingpolarity=Increasingsolubilityinwater

12. SurveyofGC/MSMethods
(byProgram)
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SDWA
EPA500series e.g.524.2,525
CleanWaterAct
EPA600and1600series e.g.624,625,1624,
1625,1666
RCRA(SolidandHazardousWaste)
EPA8000series e.g.8260,
8270
CERCLA(Superfund)
OLMOcontracts
CleanAirAct
TO(ToxicOrganics)series e.g.TO-14,
TO-15, TO-17
(SomeASTMandStandardMethodsarealsoEPAapproved)

13. PrinciplesofGasChromatography–MassSpectrometry
Advantages
-highsensitivity
excellentdetectionlimits.Typicallylowppbtohigh
ppt
-highselectivity
identificationisbasedontwoparametersnotone
(retentiontimeandmassspectrummustmatch
standard)
selectsanalyteofinterestwithveryhighconfidence
-Speed
typicalanalysistakesfrom1/2hourtoapprox.1hour
analysiscancontainupwardsof80andmore
pollutants
Disadvantages
-highercapitalcost(approx.$>85Kvs.$15KforGC)
-highermaintenance(time,expertiseandmoney)
-foroptimumresultsrequiresanalystknowledgeablein
both
chromatographyandmassspectrometry

14. TheAnalyticalProcess-GC/MSisLast
Step
SampleSite
ContaminatedSite
MonitoringWell
PermitteeEffluent
DrinkingWaterFacility
DataReceivedby
DEP
5.6ppb
Benzene
LaboratorySide
Sample
Preparation
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DeterminativeStep
GasChromatography(GC)
GasChromatography/MassSpectrometry
(GC/MS)
HighPressureLiquidChromatography
(HPLC)
Sample
Clean-Up
(optional)
SampleAnalysis

15. TheAnalyticalProcess
(ItallstartswithSamplePreparation)
Sample
Preparation
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DeterminitiveStep
GasChromatography(GC)
GasChromatography/MassSpectrometry
(GC/MS)
HighPressureLiquidChromatography
(HPLC)
SampleAnalysis
PurgeandTrap
Liquid-LiquidExtraction
Sonication
SolidPhaseExtraction(SPE)
SoxhletExtraction
(notanexhaustivelisting)
Sample
Clean-Up
(optional)

16. SamplePreparationTechniques
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Preparation-v.v.importantfirststep
1)usedtoseparateorganiccontaminants
from
theirenvironmentalmatrix(e.g.
groundwater
orsoil)
2)usedtoconcentratethecontaminants
TypicalPreparationTechniquesinclude:
PurgeandTrap,LLE,Soxhlet,LSE(SepPaks,
Cartridges)

17. PurgeandTrap
(AqueousandSoils/VolatilesPreparation)
CourtesyofEnvironmentalConservationLaboratories,Inc.

18. Liquid/LiquidExtraction
(SeparatoryFunnel)
(AqueousSamples/SemivolatilesAnalysis)
CourtesyofEnvironmentalConservationLaboratories,Inc.

19. Sonication
(Soils,Solids/Semivolatiles)
CourtesyofEnvironmentalConservationLaboratories,Inc.

20. SolidPhaseExtraction
(Aqueous/Semivolatiles)
CourtesyofStanford
Laboratory
Cartridge
Sample

21. SoxhletExtraction
(Soils,Solids/Semivolatiles)
CourtesyofEnvironmentalConservationLaboratories,Inc.

22. SampleClean-UpTechniques
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Clean-Ups-usedifinterferencesareaproblem
standalonemethodsareavailable
alsoprocedureswrittenintosomemethods
theseareoftenoptionalandchoicesoftenrestwith
analystandisdependentonthesample
Examplesoftypicalclean-upprocedures
include:
Alumina,Silica,Flourisil,GelPermeation
Chromatography,AcidWashetc.

23. SampleClean-UpTechniquesfromSW-846
(standalonemethodsstrictlyforcleanups)
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AnalytesofInterest Methods
Aniline&anilinederivatives 3620
Phenols 3630,3640,8041a
Phthalateesters 3610,3620,3640
Nitrosamines 3610,3620,3640
Organochlorinepesticides&PCBs 3610,3620,3630,3660,3665
Nitroaromaticsandcyclicketones 3620,3640
Polynucleararomatichydrocarbons 3611,3630,3640
Haloethers 3620,3640
Chlorinatedhydrocarbons 3620,3640
Organophosphoruspesticides 3620
Petroleumwaste 3611,3650
Allbase,neutral,andacid 3640
prioritypollutants

24. GasChromatography–MassSpectrometry
(OperationalDescription)
IntroductionSystem-GasChromatography
Ionization
MassSeparation
MassDetection
DataSystem
MassSpectrometer
Ionization
Source
Mass
Analyzer
Particle
Detector
Gas
Chromatograph
y
Dedicated
DataSystem
VacuumSystem-approx.10
-6
torr

25. GasChromatography
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PowerfulAnalyticalChemistry
techniqueusedtoseparateandidentify
organiccompoundsfrommixtures.
Onerequirement:
organicsmustbevolatileorsemivolatile
anyverypolar,nonvolatileorioniccompoundsinsample
willnotbedetected

26. GasChromatography

27. Columns
•Packed
•Capillary
Crosssection

28. THE CHROMATOGRAPHIC PROCESS - PARTITIONINGTHECHROMATOGRAPHICPROCESS-PARTITIONING
(gasorliquid)
MOBILE PHASEMOBILEPHASE
STATIONARY
PHASE
STATIONARY
PHASE
Sample
out
Sample
in
(solidorheavyliquidcoatedontoasolidorsupport
system)

29. TemperatureControl
Isothermal
Gradient
0
40
80
120
160
200
240
0 102030405060
Time(min)
Temp(degC)
ParametersAffectingSeparation
ColumnType(Phase)
Polar(DB-1701
NonPolar(DB-1)
PhaseThickness
ColumnDimensions

30. Phases

31. Chromatograms-551.1
SameOrganicMixture–DifferentCapillaryColumns

32. Instrumentation-Detectors
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Destructive
MassSpectral(CI/EI)[625]
FlameIonization(FID)[604]
Nitrogen-Phosphorus(NPD)[8141A]
FlamePhotometric(FPD)[8141A]
ElectrolyticConductivity(Hall/ELCD)[502.2]
Non-Destructive
ThermalConductivity(TCD)
ElectronCapture(ECD)[551.1]
PhotoIonization(PID)[502.2]

33. HowMassSpectrometryDetectorsWorks
All“OrganicMolecules”aremadeupofcombinationsof
atomscontainingCarbonandHydrogen
InadditiontoCarbonandHydrogen,otherelementsarefrequentlya
partofamoleculetoprovideavarietyofchemicalandphysical
properties(e.g.Oxygen,Nitrogen,Chlorine,Fluorine,etc.)
Molecularweightscanbecalculatedknowingtheelemental
compositionofamolecule.
MassSpectrometryanalyzes(identifies)organic
moleculesaccordingtotheirmolecularand
fragmentweights.

34. HowMassSpectrometry(MassAnalysis)Works
(UseTabletoCalculateMolecularWeights)
Isotopes

35. CalculatingMolecularWeight(Mass)
Benzene
(C
6
H
6
)
Pyridine
(C
5
H
5
N)
6x12=72
6x1=6
MW=78amu
5x12=60
5x1=5
1x15=15
MW=79amu
Element atomicmass(amu)
Carbon(C) 12
Hydrogen(H) 1
Chlorine(Cl) 35
Fluorine(F) 19
Oxygen(O) 16
Nitrogen(N) 14
amu-atomicmassunits

36. GasChromatography–MassSpectrometry
(OperationalDescription)
IntroductionSystem-GasChromatography
Ionization
MassSeparation
MassDetection
DataSystem
MassSpectrometer
Ionization
Source
Mass
Analyzer
Particle
Detector
Gas
Chromatograph
y
Dedicated
DataSystem
VacuumSystem-approx.10
-6
torr

37. Molecular
‘Ion’
TheIonizationProcess
(ElectronImpact)
NeutralmoleculesareconvertedintoIons(chargedparticles)
e
-
+ +2e
-
(70ElectronVolts)
NeutralMolecule
FragmentIon1
FragmentIon2,etc.
e
-
+
+
.
*MassAnalysiscanonlyworkforchargedspecies-notforneutrals.
+2e
-
+
.

38. GC/MS-MassAnalysis
Ions
MassSeparation
(quadrupole)
WavelengthSeparation

ContinuousLight
m 4V
z qr
2

2=

39. PrinciplesofGasChromatography/MassSpectrometry
(NISTLibraryMassSpectraforBenzene)
Abundance(Signal)
mass/charge(m/z)------>
Benzen
e
m/z
78
78amu

40. PrinciplesofGasChromatography/MassSpectrometry
(NISTLibraryMassSpectraforPyridine)
Abundance(Signal)
mass/charge(m/z)------>
Pyridine
m/z
79
79amu

41. OneMoreExampleforo-Xylene
(FragmentIonscontainUsefulInformation)
Xylene
(C
8
H
10
)
8x12=96
10x1=10
MW=106
Element mass
Carbon(C)12
Hydrogen(H) 1
Chlorine(Cl) 35
Fluorine(F) 19
Oxygen(O)16
Nitrogen(N) 14
+
.
+
.
+
.
MolecularIonscanbreakdownintosmallerfragments
m/z106 m/z91 m/z77

42. o-Xylene
(C
8
H
10
)
8x12=96
10x1=10
MW=106
Element mass
Carbon(C)12
Hydrogen(H) 1
Chlorine(Cl) 35
Fluorine(F) 19
Oxygen(O)16
Nitrogen(N) 14
PrinciplesofGasChromatography/MassSpectrometry
(NISTLibraryMassSpectraforXylene)
Abundance(Signal)
mass/charge(m/z)------>

43. WhatDoesGC/MSDataLookLike?
GC/MSChromatogramofa4ComponentMixture
RetentionTime------>
Abundance(Signal)

44. WhatDoesGC/MSDataLookLike?
GC/MSChromatogramofa4ComponentMixture
RetentionTime------>
Abundance(Signal)

45. WhatDoesGC/MSDataLookLike?
GC/MSChromatogramFromEPAMethod524.2Analysis
RetentionTime------>
Abundance(Signal)
*
CourtesyoftheNJDHSSLaboratory

46. WhatDoesGC/MSDataLookLike?
ReviewingofMassSpectra
*
m/z
78
Abundance(Signal)
RetentionTime------>
mass/charge------>
6.99min.

47. WhatDoesGC/MSDataLookLike?
ReviewingofMassSpectra
*
m/z
78
*
Abundance(Signal)
RetentionTime------>
mass/charge------>
6.77min.
1,1-dichloropropene/carbontetrachloride

48. DifficultMassSpectra
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MassSpectrometrydoesnotalwaysprovideaneasily
interpretablecompoundidentification:e.g.MTBE
useofmassspectrallibrariesforIDdetermination
useofmanualinterpretationtechniques
useofalternateMSandothertechniques
usually
MTBEMW=88

49. MassSpectralInterpretationProcedures
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GC/MSInterpretationProcedures
IdentifyMolecularIonifpresent
EvaluateanyIsotopicObservations
UseIsotopestocalculateprobablecarbon#sforMoleculeand/or
fragments
Reviewalllossesobservedtodeterminesubstructures
Reviewmajorfragments
Hypothesizeamolecularstructureconsistentwithabove
observations
MustConfirmHypothesiswithadditionaldata.
TypicallychemicalionizationMS
Highresolutionmassspectrometry
InfraRedSpectroscopy
NuclearMagneticResonanceSpectrometry
Obtainingapurestandardandconfirmingmassspectrawithunknown

50. GC/MSSummary
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PowerfulanalyticaltoolcombiningtheseparationcapabilityofGas
ChromatographyandtheidentificationcapabilityofMass
Spectrometry.
Providesforahigherlevelofconfidenceintheidentificationof
organics(BothretentiontimeANDthemassspectrumareused).
Capableofanalyzingupwardsof80pollutantsinoneanalysis.
TypicalDetectionLimits(Aqueous)areinlowppbandhighppt
range.
Appropriatecalibrationsandcontrolsmustbeperformedbefore
anysamplescanbeanalyzed.

51. GC/MSAnalysis
(SpecialTopics)
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FromRawDataChromatogramstofinalreport
ProperandImproperPeakIntegrations–Data
Processing
DealingwithInterferences
MassSpectrometryLibrariesandTentatively
IdentifiedCompounds(TICs)

52. GC/MSDataProcessing
ImportanttoReviewPeakIntegration
Chromatogra
m
(maximum
information
content)
FinalReport
GC/MS

53. •Calibrationsandquantitationoforganicsall
relyoncorrectchromatographicpeak
integrations
GC/MSDataProcessing
ImportanttoReviewPeakIntegration
Standards(A
x
/A
is
)----->ResponseFactors----->SampleQuantitation
A
is
A
x

54. NJDEP
OQA
OCTOBER2002
ManualIntegration
FORGC/MS

55. Definition
AManualIntegrationis anyeditingof
theareaofintegrationbythechemist.
Manualintegrationisaperfectly
acceptable,scientificallyvalid,
analyticaltechniqueusedtoaccurately
reflecttheareaofapeakwhenauto-
integrationfails.

56. AManualIntegrationisnotaway
tocompensateforanimproperly
maintainedinstrument.Manual
integrationsarenottobeusedin
lieuofestablishingappropriate
integrationeventsusingthe
analyticalsystemsoftware.

57. •
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Manualintegrationmaybedoneinthe
followingcaseswheretheautomatic
integratorhas:
failedtointegrateapeakorpartofapeak
integratedonepeakastwopeaks
integratedthewrongpeakoutoftwosimilarpeaks
notintegratedfrombaselinetobaseline
integratedapeakduetoanelevatedbaseline
integratedanegativepeak
integratedapeakbeyondbaselineresolution(toomucharea)
Anyadditionalsituationsinwhichtheauto-integratorfailsto
performproperlyand/orconsistently

58. ManualintegrationsareNOTtobe
performedforthesolepurposeof
makingacalibrationcurve,ICV,CCV,&/
oraQCchecksample(LCS,MS,
surrogate,etc.)passacceptance
criteria.

59. History
Mostofthesoftwareprogramsusedfor
chromatographyarecapableofquantitating,using
eitherpeakareaorpeakheightandemploy
mathematicalalgorithmsrelatedtotheslopeofthe
responsetodetectthebeginningandendofpeaks.

60. History
Duetothecomplexnatureofsomesample
matrices,theabilitytomanuallyadjustanincorrect
integrationbecamenecessary.Thisflexibilityis
necessaryintheproductionofqualitydata.
Muchofthisprocessisbasedonanalystjudgment.
Eachpeakmustbeevaluatedandadjustedwhen
necessary.However,thisflexibilityhasledto
severalinstancesofimproperlaboratoryactivities.

61. IMPROPERINTEGRATIONS
AccordingtotheEPARegion5’sSOPon
manualintegrations,inappropriateintegration
isanyintegration,eitherautomatedormanual
,whichexcludesareaassociatedwiththe
targetpeakorincludesareanotreasonably
attributabletothetargetpeak,suchasarea
duetoasecondpeakorexcessivepeak
tailingduetoanoisybaseline.

62. CORRECTINTEGRATIONS
Thisisanexampleofproperintegrationswhenseveral
peaksarenotcompletelyresolved(i.e.,theresponse
doesnotreturntothebaselinebetweenpeaks).The
lowestpointbetweentwopoints,thevalley,isselected
astheappropriatestartandstoppoints.

63. •
•
CORRECTINTEGRATIONS
Peakswithslightinterferenceseitherjustpriorto
orimmediatelyafterthetargetpeak.
Inthesecases,partoftheautomaticintegration
may includetheinterferinganalyte.The
following integrationtechniquesmaybe
employed:

64. TYPESOFIMPROPERINTEGRATIONS
Peakshavingisthecommontermfor
unjustifiably excludingareawhen
integratingachromatographic peak.
Almostallofuswouldagreethatcuttingapeak
inhalfhorizontallyorverticallyisunjustified.But
whattodoabouttheinbetweencases?Howcan
judgmentbeappliedcorrectlywhenintegrating
peaks?

65. •
TYPESOFIMPROPERINTEGRATIONS
Baselineadditionorsubtraction
Donotaddorsubtractfromthebaseline.Another
exampleofanincorrectmanualintegration

66. TYPESOFIMPROPERINTEGRATIONS
Poorsensitivity.Signalisnot3timesthe
background.

67. •
•
•
WHYISTHISHAPPENING?
Costfactors
LevelofExpertisefactors
UnethicalBehavior

68. •
•
•
CostFactors
Thepricepaidisoftennotsufficient
tocoverthecostsofproducingthe
product.
Theclientshouldnotacceptlowbids
withoutconsideringthequality
factor.
Thisisafreemarketeconomy-‘Let
thebuyerbeware’or‘Yougetwhatyoupay
for’.

69. •
•
•
LevelofExpertiseFactors
Somelaboratorieshavelettheirmost
experiencedstaffgo.
Lackofunderstandingregardingthe
fundamentalsofanalytical
chemistryat boththelaboratoryand
datauserlevels.
Thinkingthatthecomputerwill
always giveyouthecorrectanswer.

70. •
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•
•
WhyUnethicalBehaviorOccurs
Realorperceivedpressures
Lackofethicseducationandawareness
Lackofmanagementoversiteandreview
Lackofknowledgeorconfidencein
appropriatewaystosolveproblems

71. Prevention
Effortsshouldbemadeduringmethod
developmenttoincludethebestinstrument
parametersthatallowforautomatic
integrationbythedatasysteminmost
cases.
However,regardlessofthesophisticationof
thesoftware,instancesoccurwhenthe
automatedsoftwaredoesnotintegratea
peakcorrectly.

72. Prevention
Thefailureofthesoftwaretoappropriately
integrateapeakisusuallyobviousfromvisual
inspectionofthechromatogram(atan
appropriatescale).Electronicreviewof
analyticalrawdataisessentialindetecting
improperactivities.
Theuseofproperdocumentationprotocols
shouldbeestablishedtoallowmanual
integrationstobereviewedduringdata
validation.

73. DOCUMENTATION

74. Alldatamustbeintegratedconsistentlyin
standards,samplesandQCsamples.
Integrationparameters,bothautomatedand
manual,mustadheretovalidscientific
chromatographicprinciples.Manual
integrationisemployedtocorrectan
improperintegrationperformedbythedata
systemandmustalwaysinclude
documentationthatclearlystatesthereason
manualintegrationwasperformed.

75. Properdocumentationisvitalwhen
conductingmanualintegrations.The
followingisanexampledocumentation
requirement:
Printtheimproperlyintegratedpeak.initial,
dateandprovideareasonontheoriginalforthe
manualintegration.Performthenecessary
manualintegration.Printthemanually
integratedpeak,initialanddate.Submitthe
manualintegrationdataalongwiththeoriginal
automaticintegrationdataaspartofthefinal
datapackage.

76. GENERALOBSERVATIONS
Thefundamentalprincipleofquantitative
integrationisthatsamplesshouldbeintegratedin
thesamestylechosenforintegratingcalibration
standards.
Ifproperlydocumentedandconductedina
scientificallydefensiblemanner,manual
integrationsareperfectlyacceptable.

77. WHATCANLABSDOTOPREVENT
IMPROPERACTIVITIES
Developadetailedstandardoperatingprocedure
thatincludesexamplesanddocumentation
requirements.
Enforceazerotolerancepolicyforanyimproper
activities.
Haveallanalystssignanethicsstatement.
Electronicallyreviewrandomdatafiles.

78. Questions?

79. GC/MSInterferences
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•
•
WhatareInterferences?
Anycompoundormixtureofcompoundsthat
elutesatthesametimeasthecompoundof
interest.Thereforethecompoundofinterestcan
notbeproperlyidentifiedorquantified.
EPAOfficeofWaterSays:
“Statingthat‘thesamplecouldn’tbeanalyzed’
isnotsufficientandwillnotbeacceptedas
justificationforaclaimofmatrixinterference.
”

80. InterferencesinGC/MS
Analysis
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•
•
Problemstheycause
quantitationaccuracyoftargetsmaybe
negativelyimpacted
canmakeidentificationoftargetamong
interferencesdifficultorimpossible
ifdilutionisrequired,mayraisedetectionlimits
aboverequiredregulatorylimits.

81. Interferences-Whatdotheylooklike
(Example1)
interferences
Extractcouldonlybeconcentratedto5mls.

82. Interferences-WhatDoTheyLookLike
(Example2)
a-Napthalene
b-dimethylphthalate
c-diethylphthalate
d-di-n-butyl-phthalate
a bcd
-Canonlyconcentrateto5mls.
-dilutedextract1:5
-totaldilutionfactor=25x

83. Interferences-WhatAreThey
(Example2)
1,3-dichloro-2-propanol
(achlorinatedalcohol)
1-methyl,2,4-diisocyanatobenzene
(adiisocyanate)

84. Interferences-WhatCanBeDone
(Example2)
•
•
–
–
•
–
•
•
–
–
AnalyzeBase/NeutralsandAcidFractionsSeparately-mayisolate
interferencesintofractionoflessinterest
PerformGPCAnalysistoremoveanypotentialhighmolecularweight
interferences
mayhelpforsamplesthatcanonlybeblowndownto5mls.
noguarranteethatGCorGC/MSanalysisisseeingallofthesample
PerformAppropriateCleanUps
methodsexistforcleaningupsamplessothatanalytesofinterestcanbe
analyzed
GPCandCleanupscanbeperformedonthesamesample.
Identifyinterferencesandcleanupwastestream
permitteelikelyhasmostintimateknowledgeoftheirownwastestream.
Additionalnon-EPAmethodtestingmaybeappropriatetoidentify
interferences.

85. Clean-UpTechniquesfromSW-846
(standalonemethodsstrictlyforcleanups)
•
•
•
•
•
•
•
•
•
•
•
•
•
AnalytesofInterest Methods
Aniline&anilinederivatives 3620
Phenols 3630,3640,8041a
Phthalateesters 3610,3620,3640
Nitrosamines 3610,3620,3640
Organochlorinepesticides&PCBs 3610,3620,3630,3660,3665
Nitroaromaticsandcyclicketones 3620,3640
Polynucleararomatichydrocarbons 3611,3630,3640
Haloethers 3620,3640
Chlorinatedhydrocarbons 3620,3640
Organophosphoruspesticides 3620
Petroleumwaste 3611,3650
Allbase,neutral,andacid 3640
prioritypollutants

86. InterferencesinGC/MSAnalysis
•
–
–
•
•
•
•
FromtheEPAOCPSF(OrganicChemicals,PlasticsandSyntheticFibers)
rule’sGuidanceonEvaluation,Resolution,andDocumentationofAnalytical
ProblemsAssociatedwithComplianceMonitoring
“Statingthat‘thesamplecouldn’tbeanalyzed’isnotsufficient
andwillnotbeacceptedasjustificationforaclaimofmatrix
interference.”
EPAprovidesforflexibilityinwastewatermethodsandallowsuseof
cleanupsetcprovidedmethodQA/QCaremet.
AsperFedReg.49FR43234
Departmentcanrequireadditionalworktobeperformedtogetat
anaccuratenumber.Notjusttaketheeasywayoutandsay
interferencesarepresent.
Alternatemethods
useofclean-upprocedures

87. MassSpectralLibraries
•
–
•
–
Whataremassspectrallibraries?
Acompendiumofelectronimpactmassspectra
collectedfromavarietyofsources
Whyaretheyimportant?
Identifyingnon-targetortentativelyidentified
compounds(TICs),reliesexclusivelyonthese
libraries

88. MassSpectralLibraries
•
–
»
»
»
–
»
»
Whyaretheyimportant-cont.?
SiteRemediationforexampletypicallyrequests:
VOAs+10TICs
BNs+15TICs
frequentlydrinkingwatermethods
IfTICsarefound,properidentificationisvery
important
mayneedcorrectIDforremediation
mayneedtoprovidedatatoCountyHealthDeptand
OwnersofPotableWell(asinBUST)

89. MassSpectralLibraries
•
–
»
»
–
»
Whyaretheyimportant-cont?
WasteWaterPermitting:
someindustriesindicatethatinterferencesarepresent
whichprecludethemanalyzingthesampletopermit
detectionlimits
Identificationofinterferencescanbeusedtodetermine
whatoptionsforcleanupmayexist.Interferencesmay
alsobeenvironmentallyunfriendlycompoundsthatmay
needtoreviewed.
BureauofSafeDrinkingWater
BSDWreportingformhasabilitytoenterTIC
observationsfromalaboratory.

90. MassSpectralLibraries
•
•
–
–
–
•
•
•
–
–
Howmanylibrariesarethere?
NIST/NIH/EPAMassSpectralLibrary
NBS75K
NIST‘98
NIST‘02
WileyMassSpectralLibrary
CombinationWiley/NIST
CustomLibraries
industryspecific
proprietary

91. MassSpectralLibraries






ForNIST75KLibrary–
Approx50,000MassSpectra
Approx25,000Replicates
Thislibraryisveryold
Notverywellreviewed
VarietyofSourcesnotwellfiltered.
LabsshouldNOTbeusingthis!

92. MassSpectralLibraries









ForNIST98Library-(a75%increaseoverNBS75K
library)
107,886Compounds
107,829ChemicalStructures
129,136Spectra
21,250ReplicateSpectra
13,205CompoundswithReplicateSpectra
93AveragePeaksperSpectrum
78MedianpeaksperSpectrum
75%Increaseincoveragefromhighqualitysources
Labsshouldbeusingatleastthisrevision!

93. MassSpectralLibraries









ForNIST98Library
(wheredoesthis75%increasecomefrom?)
MassSpectrafromothersourceswereaddedin
ChemicalConcepts-includingProfHenneberg's
industrialchemicalscollection
GeorgiaandVirginiaCrimeLaboratories
TNOFlavorsandFragrances
AAFSToxicologySection,DrugLibrary
AssociationofOfficialRacingChemists
St.LouisUniversityUrinaryAcids
VERIFIN&CBDCOMChemicalWeapons

94. MassSpectralLibraries
•
•
•
•
•
•
•
•
ForNIST‘02Library-35%increaseincoverageoverNIST98
Library
27,750ReplicateSpectra
fromhighqualitysources
147,198CompoundswithSpectra
18,598CompoundswithReplicateSpectra
147,194ChemicalStructures
111AveragePeaks/Spectrum
174,948spectra
98MedianPeaks/Spectrum

95. MassSpectralLibraries
•ComparisonofNIST/NIH/EPALibraries-different
revisions
NBS75K NIST98 NIST‘02
TotalSpectra 75,000 129,136 174,948
TotalReplicates20,000 21,250 27,750

96. MassSpectralLibraries
•
–
•
•
•
WileyRegistryofMassSpectralData-7th
Edi
tion
theworld'slargestreferencedatabaseof
over250,000Electron-Impactmassspectra
WileyLibrarymayormaynotincludeNISTlibrary
Wileycontainsmassspectrathatarenotaswellreviewed.
Stillveryuseful,ifNISTlibrarycomesupshort.

97. WhyMSLibraryVersionisImportant
(example)
•
•
•
–
AirAnalysisExamplefrom1996(TO-14)
Samplesconsistentlyshowedlargepeakinthe
analysisbutcompoundcouldnotbeidentifiedby
library.
Librarysearchresultwassopoor,evenagoodquality
TICcouldnotbeobtained.
AtthetimetheNBS75Klibrarywastheonlyone
available.
Pre1998

98. MassSpectralLibraries
(exampleofwhyversionoflibraryisimportant)

99. MassSpectralLibraries
(exampleofwhyversionoflibraryisimportant)

100. MassSpectralLibraries
(exampleofwhyversionoflibraryisimportant)

101. MassSpectralLibraries
(exampleofwhyversionoflibraryisimportant)
•
•
•
Synonyms
1,1-Dichloro-1-fluoroethane
Ethane,1,1-dichloro-1-fluoro-
Freon141

102. MassSpectralLibraries
•LibrarySearchAgainstNIST98Library
producedanexcellenthit.
Freon141
BestHit
NBS75K
BestHit
NIST98

103. Summary
MassSpectralLibraries
•
•
•
Identitiesofnon-targetcompounds
(TICs)maybedependentontheversion
oflibrarybeingused.
MostlaboratoriesstilluseNBS75K
library.
Beawarethatotherlibrariesexist.

104. DioxinsandPCBAnalysis
Using
GC/HighResolutionMass
Spectrometry
(actuallyhighresolutiongaschromatography/highresolutionmass
spectrometry-HRGC/HRMS)

105. Overview
•
•
•
•
•
•
•
ReviewofEPADioxinsandPCBstructures&
methods
TypicalMassSpectrometryInstrumentation
WhyHighResolutionMassSpectrometry?
HighResolutionMassSpectrometry(MS)Overview
UseofIsotopicallyLabeledTargets
Comparisonof‘PCBcongener’andAroclormethods
ToxicityEquivalents(TEQs)andTEFs

106. Dioxin/Furans/PCBs
(ChemicalStructures)

107. DioxinAnalysisTarget
Compounds
•
•
Both1613and
8290analyze
forthese17
“Dioxinsand
Furans”
Drinkingwater
regulatesonly
the2,3,7,8-
TCDD

108. PCBTerminology
•
•
•
•
•
•
•
PCBs(canmeananything)
Aroclors(mixtureofPCBs)
PCBCongeners(209individual)
‘Dioxin-Like’PCBs
CoplanarPCBs
WHOPCBs-alistof12specificPCBs
Homologs(allcongenershavingsame#of
chlorinesattached)

109. MorePCBTerminology
•
•
•
•
•
•
•
•
•
•
•
•
•
BZ/IUPAC
Congener
Number PrefixtoChlorobiphenyl
PCB-77 3,3',4,4'-Tetra-Chlorobiphenyl
PCB-81 3,4,4',5-Tetra-
PCB-105 2,3,3',4,4'-Penta-
PCB-114 2,3,4,4',5-Penta-
PCB-118 2,3',4,4',5-Penta-
PCB-123 2,3',4,4',5'-Penta-
PCB-126 3,3',4,4',5-Penta-
PCB-156 2,3,3',4,4',5-Hexa-
PCB-157 2,3,3',4,4',5'-Hexa-
PCB-167 2,3',4,4',5,5'-Hexa-
PCB-169 3,3',4,4',5,5'-Hexa-
PCB-189 2,3,3',4,4',5,5'-Hepta-
atotalof209PCBcongeners e.g.PCB1--->PCB209

110. StillMorePCBTerminology
•
–
–
•
–
–
‘PCBsasArochlors’
nolongerreferringtoindividualPCBs
Arochlorsarecomplexmixtures
Oftendesignated‘AroclorXXXX’
e.gAroclor1242
onaverage,thismoleculecontains42%byweightofChlorine

111. •
–
–
•
–
–
–
–
–
–
–
DioxinAnalyses
EPAMethod1613B
1-
Fordrinkingwaterandwastewateruse
EPAMethod8290-forSHWsamples
‘PCBCongener’AnalysisMethods
EPAMethod1668-RevisionA
canbeusedforallmatrices
datedDecemberof1999
containsall209possiblePCBcongeners
EPAMethod8082-usuallyusedforAroclors-SHWSamples
hastheoptiontoperformlimitedsetof19congeners
canbemodifiedtodoothercongeners
1
asoldNPDESpermitsrequiringdioxinanalysesby613,theywillbereissuedwith
requirementfor1613B
MethodOverview

112. •
»
»
»
‘PCBasAroclors’AnalysisMethods
EPAMethod508and608-forDrinkingand
Wastewater
EPAMethod8082-solidandhazardouswaste
samplesuse
alloftheseareGC/ECDtechniques
MethodOverview

113. DioxinandPCBAnalysis
(Whyanalyzeforthem?)
•
–
–
–
–
DioxinsandPCBshavebeenshowntobe
toxicatvaryinglevels.
e.g.DrinkingWaterMCLs(NJStateStandards)
2,3,7,8-TetraChloroDibenzoDioxin(TCDD)
3x10
-5
ppb or 0.00003ppb
PCBs
0.5ppb

114. –
–
–
–
WhydidEPAchooseGC/High
ResolutionMassSpectrometryto
analyzeforDioxinsandPCBs?
MCLsforthesecompoundsareverylow
Needsensitivemethod(s)capableoflowdetectionlimits
Provideahighlevelofconfidenceincompoundidentification
Needtominimizeeffectofinterferences

115. –
–
•
•
–
–
HowDoesGC/HighResolutionMass
SpectrometryAccomplishThese
Criteria?
1)NeedforVeryHighIdentificationCertainty/Minimize
Interferences
HighResolutionMassAnalysis
UseofChlorineIsotopeMasses
twomassesforeachtarget
IsotopeRatiosmustmeettheoreticalvalue
2)Needforverylowdetectionlimits
CombinationofHighVoltageOperationandSelectedIon
MonitoringScan(SIM)
Concentratesampletoulrangeinsteadofml.

116. NominalandExactMassesforCommonElements

117. WhatisHighResolutionMass
Spectrometry
•HighResolutionMassSpectrometryiscapableofobtaining
massspectraandmeasuringmassestoapproximatelythe
fourthdecimalplace.
C
12
H
4
35
Cl
4
O
2
MW=
319.896542
C
12
H
4
37
Cl
1
35
Cl
3
O
2
MW=321.8936
320

118. VG70-250SEHighRes.MS
HP5973LowRes.MS
SpecializedMSInstrumentation

119. WhatisMassResolution?
VerySimply-Theabilitytodistinguishbetween
differentmasses.
e.g.Canwedistinguishmass78from79?
Canwedistinguishbetweenmass78.003and78.004?
Aquantitativeapproachtodetermininghowwellwecan
distinguishdifferentmassesiscalled‘ResolvingPower’.
Differentthanchromatographicresolution.

120. ResolvingPower
bydefinition:
ResolvingPower(R.P.)=m/m
ppm=R.P./1x10
6
aresolvingpowerof10,000=100ppm
***AllHighResolutionEPAMethodsuseanR.P.of10,000***

121. CalculationofMassResolution

122. ResolutionExample
we’reaskedtoseparateathreecomponentgas
mixturecontaining
carbonmonoxide
nitrogen
ethylene

123. CalculatingMolecularWeights
nominalmass accuratemass
carbon
monoxide-CO 1x12=12 1x12.0000=12.0000
+1x16=16+1x15.9949=15.9949
28 27.9949
nitrogen-N
2
2x14=28 2x14.0031=28.0062
28 28.0062
ethylene-C
2
H
4
2x12=24 2x12.0000=24.0000
+4x1=4+4x1.0078=4.0312
28 28.0312

124. WhatResolutionDoWeNeedtoSee
All3Components?
carbon
monoxide-CO1x12.0000=12.0000
+1x15.9949=15.9949
27.9949
nitrogen-N
2
2x14.0031=28.0062
28.0062
ethylene-C
2
H
4
2x12.0000=24.0000
+4x1.0078=4.0312
28.0312
0.0113
0.025

125. WhatResolutionDoWeNeedtoSee
All3Components?(cont’d)
nominalexact massResolvingPower
mass mass Needed(m/m)
CO 2827.9949
0.0113 2,478
N
2
2828.0062
0.0250 1,120
C
2
H
4
2828.0312
-Needatleast2,500toseeallthreecomponents.

126. LowandMediumResolutionMassSpectra
ofTernaryMixture

127. ApplicationstoDioxins/PCBCongener
Analyses
(2,3,7,8-TetrachloroDibenzoDioxin(TCDD))

128. 2,3,7,8-TCDD C
12
H
4
Cl
4
O
2
NominalMass ExactMass
C 12x12=144 12x12.000000=144.000000
H 4x1=4 4x1.007825=4.031300
Cl 4x35=140 4x34.968853=139.875412
O 2x16=32 2x15.994915=31.989830
320 C
12
H
4
35
Cl
4
O
2
319.896542
37
Cl=36.9659 C
12
H
4
37
Cl
4
O
2
321.8936
CalculationofMassfor2,3,7,8-TCDDAnalysis

129. TableFromEPAMethod1613B
m/z320&322

130. NominalMass ExactMass
C 12x12=144 12x12.000000=144.000000
H 4x1=4 4x1.007825=4.031300
Cl 6x35=210 6x34.968853=209.813118
358 C
12
H
4
35
Cl
6
357.844418
37
Cl=36.9659 C
12
H
4
37
Cl
1
37
Cl
3
O
2
359.8415
C
12
H
4
37
Cl
2
37
Cl
2
O
2
361.8385
SameCalculationforPCBCongeners
HexaChloroBiphenyl C
12
H
4
Cl
6

131. FromTable7ofEPAMethod1668A
m/z360
362
364

132. IsotopeRatioQA/QCRequirements
(fromEPA8290)
(sameas1613B&1668A)
15%

133. CommonChemicalInterferencesintheGC/MSdetermination
of2,3,7,8-TCDD

134. SelectedIonMonitoring-BetterDLs
(SectorInstrumentsUseVoltageScanningforAccuracy)
FullScan
Detectallmasses
overagivenscan
range.
e.g.m/z100-500
SIM
Lookonlyfor
massesrelevent
totargets

135. HighResolutionMSAdvantages
•
–
–
–
–
•
–
–
–
EnhancedIdentificationCapabilities
Abilitytoanalyzeexactmassesprovidesforbetter
identificationcapabilityoverLRMS
Detectingmultipleisotopes(chlorine)addsyetanotherlevel
ofconfidenceincompoundidentification
Eliminatesorminimizesinterferencesin‘dirty’samples
Cleanupsaretherulenottheexception
EnhancedSensitivity
HighResolutionMassSpectrometersoperateatHigh
Voltage(8KV)
VoltageScanningSelectedIonMonitoring(SIM)
ConcentrationofSampledowntoulasopposedtoml’s.

136. ApproximateMethodDetection
Limits
•
•
•
•
DependsonMatrix
Method Aqueous Other
Method16685-300ppq 1-25ppt
Method1613B3ppq 1ppt
Method829010ppq 1ppt

137. •
•
•
•
•
•
•
•
•
•
•
highcapitalcost(approx.$400,000)
highermaintenance
maint.contract8%ofpurchasepriceannually.
skilledstaffrequired
analysiscostshigh
$1,000/analysis
specialfacilityrequirements
Vibration
Footprintislarge
Temp/HumidityControl
SpecialPowerRequirements
DisadvantagesofHRMS

138. UseofIsotopicLabeling
•
•
Methods1613B,8290and1668Aall
makeuseofIsotopicLabeling
13
Cand
37
Cllabeledtargetcompounds
areusedforquantitation(internal
standardsarealsoused)

139. UseofIsotopicLabeling
•
–
•
–
•
–
Methods8290-Dioxins/Furans
9outofthe17targetsarelabeled
Methods1613B-Dioxins/Furans
15outof17targetsarelabeled
Methods1668A-PCBCongeners
27outof209arelabeled.

140. BenefitsofIsotopicLabeling
•
–
–
•
–
–
•
Isotopicallylabeledtargetcompoundswill
behaveidenticallytotargetsofinterest.
Iftargetsarelostduringprocessing,labeled
standardswillalsobelost.Correctsforrecovery
100%
Providesformoreaccuratequantitationoftargets.
Isotopicallylabeledtargetcompoundselute
secondspriortotargetofinterest
Enableanalysttoreadilyidentifythetarget
Ifinterferencesarepresent,thisisextremely
helpful
ThistooincreasesIDaccuracy

141. SampleChromatogram
(showingIsotopicallyLabeledStandards)

142. SampleChromatogram
(TypicalRawDataPage–Dioxins-HxCDD)
Target
HxCDD
Labeled
HxCDD
Interfering
Compounds
LockMass
CheckChannel

143. PCBCongenerAnalysisvs.AroclorAnalysis
(pros)
•
–
•
•
•
•
ThetoxicityofPCBsisverycongenerspecific
measurementonanAroclorbasismaynotaccuratelyreflecttoxicity.
IdentificationofaPCBismoredefinitive.Interferencesaremoreeasily
detected.
Quantitationofindividualcongenersismoreaccuratethanestimating
Aroclors
Compositionofweathered,degradedandmetabolizedPCBmixtures
canbemeasuredandinterpretedeasierusingcongenervs.Aroclor
analysis
Aroclorconcentrationscanbeestimatedusingcongenerconcentrations
(dependingonthelistofcongenersbeinganalyzedfor)

144. PCBCongenerAnalysisvs.AroclorAnalysis
(cons)
•
•
–
•
–
•
•
–
–
•
Veryhighcost(typicallygreaterthan$1,000
TEFsarenotavailableforallcongeners
WorldHealthOrganization(WHO)hasalistof12TEFs
Comparabilityamonglaboratories
labsvaryinhowtheyperformPCBcongeneranalysis
differentlabsmayusedifferentcolumns(differentcoelutions)
PCBcongenerIDcomparability
nogoodPEsamplesareavailable(someSRMs)
thereisa“NISTIntercomparisonExerciseforOrganicContaminantsinthe
MarineEnvironment”
cost$2500fortwomatrices

145. ComparisonofEPAMethod8082
and1668A
•
–
–
–
–
–
–
–
•
–
–
–
8082
DLs
Cost$75-$300
AroclorUsingGC/ECD
MaynotmeetDQOs.
ArocloranalysismayoverorunderestimatedPCBconcentrations.
Doesnotmeasureindividualcongenersbutratherreliesnotapattern
recognition
Arocloranalysismayseverelyunderestimatetoxicity.
1668A
PCBCongenersusingGC/HRMS
DetectionLimits
Cost>$1,000

146. EPAMethod1668AMisnomers
•
–
–
•
•
–
–
•
–
All209congenersareanalyzedfor,BUT
Doesnotprovidequantitativevaluesforeachofthe209
individually
Notall209arequantitatedinthesamemanner.
Multipointvs.singlepointcalibration
Notall209congenersarechromatographically
resolved
about130congenersarefullyresolved
everythingelseisreportedascoelutions
Analyzedunderlowvoltageconditions
notat70eV(Typically30-40eV)

147. ProficiencyEvaluation(PE)SamplesforDioxin
andPCBAnalysis
•
•
•
•
–
–
–
•
•
PEsamplesfor2,3,7,8-TCDD-Available
PESamplesforAroclors-Available
PEsamplesforPCBcongeners-NOTAVAILABLE
Forcongeners
SRMsareavailablefromNIST
SomestandardsavailablefromCIL,Wellington,others?
Stillaproblem
noneoftheabovecontainalloftheWHOPCBs-presumablythemostimportant
ones.
Needtogowithareliablelab

148. DioxinsandPCBAnalysis
HoldTimes
•
–
–
•
–
From1613BDioxins
8.4.1Therearenodemonstratedmaximumholdingtimesassociatedwith
CDDs/CDFsinaqueous,solid,semi-solid,tissues,orothersamplematrices.If
storedinthedarkat0-4°Candpreservedasgivenabove(ifrequired),aqueous
samplesmaybestoredforuptooneyear.Similarly,ifstoredinthedarkat<
-10°C,solid,semi-solid,multi-phase,andtissuesamplesmaybestoredforup
tooneyear.
8.4.2Storesampleextractsinthedarkat<-10°Cuntilanalyzed.Ifstoredinthe
darkat<-10°C,sampleextractsmaybestoredforuptooneyear.
From1668APCBCongeners
8.5.1Therearenodemonstratedmaximumholdingtimesassociatedwiththe
CBsinaqueous,solid,semi-solid,tissues,orothersamplematrices.Ifstored
inthedarkat0-4ECandpreservedasgivenabove(ifrequired),aqueous
samplesmaybestoredforuptooneyear.Similarly,ifstoredinthedarkat<
-10EC,solid,semisolid,multi-phase,andtissuesamplesmaybestoredforup
tooneyear.

149. ReportingDioxinandPCBDataResults
–
–
•
TwoApproaches
1)Provideaquantitativevalueforeachtarget
compound
2)Reportasinglenumber–aToxicityEquivalent
ThisapproachusedfrequentlyforRiskAssessment
purposes,Dioxins/Furans/PCBsareoftencombined
togetherasaToxicEquivalentQuantity(TEQ)
TocalculateTEQ,needtouseToxicEquivalencyFactors
(TEFs)

150. TEFsandTEQs
•
ToxicEquivalentQuantity(TEQ)
Overtheyears,researchershavedetermined
therelativetoxicitiesforavarietyofdifferent
compoundswiththemosttoxic-
2,3,7,8-Tetrachlorodibenzodioxin
-beingassignedatoxicequivalencyfactor
(TEF)ofOne(1)

151. TEFsandTEQs
•
TEFfor2,3,7,8-TCDD=1
TEF=ToxicEquivalencyFactors.A
methodofweightingthetoxicityof
individualdioxin/furan/coplanarPCB
compounds,ascomparedto2,3,7,8-
TCDD.

152. TEFsandTEQs
•
•
•
•
•
•
•
•
•
•
1994WHOTEFs(1)1997WHOTEFs(2)
Humans/MammalsFish Birds
PCB-77 0.0005 0.0001 0.0001 0.05
PCB-81 -- 0.0001 0.0005 0.1
PCB-105 0.0001 0.0001 <0.000005
0.0001
PCB-114 0.0005 0.0005 <0.000005
0.0001
PCB-118 0.0001 0.0001 <0.000005
0.00001
PCB-123 0.0001 0.0001 <0.000005
0.00001
PCB-126 0.1 0.1 0.005 0.1
PCB-156 0.0005 0.0005 <0.000005
0.0001
PCB-157 0.0005 0.0005 <0.000005
0.0001
PCB-167 0.00001 0.00001 <0.000005
0.00001

153. CalculatingTEFsandTEQs
•

154. CalculatingTEFsandTEQs
•

155. Summary
•
•
•
PCBCongenerDatacanbeobtainedbytwo
methods:EPAMethod8082and1668A.
GC/HighResolutionMassSpectrometry
providesfortheanalysisofcompoundswith
excellentidentificationcapabilityand
sensitivity.
PPQdetectionlevelscanonlybeachieved
usingGC/HighResMassSpectrometry