Overview of GCMS System - WordPress.com · Overview of GCMS System Waters Korea ©2009 Waters...

2009-07-30

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©2009 Waters Corporation

Overview of GCMS SystemOverview of GCMS System

Waters Korea

©2009 Waters Corporation 2

�Nitrogen

�Helium

�Hydrogen

Components of a GC SystemComponents of a GC System

Carrier Gas Injector Column DetectorData

Acquisition System

Thermostatted Enclosure (Oven)

�Split/Splitless

�On-column

�PTV

�SPME

�Headspace

�Purge and Trap

�AutoSampler

�Packed

�Capillary

�FID

�ECD

�TCD

�NPD

�FPD

�MS(Quard, Tof, Sector, Ion trap)

FID

Capillary Column

Spl

it/S

plitl

ess

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Ionizations for GCMSIonizations for GCMS

EI(Electron Impact) CI(Chemical Ionization)

FI/FD(Fiel Ionization)


CI v. EICI v. EI

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Chemical IonizationChemical Ionization


Common Fragment Ions

m/z Ion Functional Group

15 CH3+ Methyl, alkane

29 C2H5+ OR HCO+ Alkane, aldehyde

30 CH2=NH2+ Amine

31 CH2=OH+ Ether or alcohol

43 C3H7+ OR CH3CO

+ Alkane, ketone

45 CO2H+ OR CHS+ Carboxylic Acid, thiophene

50,51 C4H2+•, C4H3

+ Aryl

77 C6H5+ Phenyl

83 C6H11+ Cyclohexyl

91 C7H7+ Benzyl (Tropylium ion)

105 C6H5C2H4+

CH3-C6H4-CH2+

C6H5CO+

Substituted Benzene Di-

substituted Benzene

Benzoyl

Stability of Molecular Ions

Aromatics>

Conjugated Alkenes>

Cyclic Compounds>

n-Alkanes>

ketones>

Amines >

Esters>

Ethers>

Carboxylic Acids, Aldehydesand Amides

Characteristic Fragment Ions Characteristic Fragment Ions Observed in EI SpectraObserved in EI Spectra

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Chemical IonizationChemical Ionization


Positive Chemical Positive Chemical IonizationIonization

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Negative Chemical IonizationNegative Chemical Ionization


� Principle :

� ion source is filled with reagent gas (eg. CH4) and 30-70 eV

� electrons are slowed down to thermal energy.

� These electrons can be “captured” by molecules that have

electronegative functional groups such as oxygen, sulphur

(cfr. Electron capture GC) and halogens.

� Gives rise to the formation of M●- ions

Negative Chemical IonisationNegative Chemical Ionisation

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CI vs EI CI vs EI –– Butyl caprylateButyl caprylate

m/z60 80 100 120 140 160 180 200 220 240 260

%

0

100

%

0

100201.2

145.1127.1

199.2173.2

218.2

229.2 241.2

145.1

127.1

56.1

101.173.0 146.1


FI Ionisation Theory FI Ionisation Theory

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FI Source Arrangement FI Source Arrangement


FI vs CI vs EI FI vs CI vs EI -- SensitivitySensitivity

Time5.00 6.00 7.00 8.00 9.00 10.00 11.00

%

0

100

5.00 6.00 7.00 8.00 9.00 10.00 11.00

%

0

100

5.00 6.00 7.00 8.00 9.00 10.00 11.00

%

0

100

FI Example Data TOF MS

TIC2.76e3

PCI Example Data TOF MS CI+ TIC

5.61e4

EI Example Data TOF MS EI+ TIC

7.67e4

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FI vs CI vs EI FI vs CI vs EI –– Butyl caprylateButyl caprylate

m/z60 80 100 120 140 160 180 200 220 240 260

%

0

100

%

0

100

%

0

100200.2

56.1 145.3116.4 157.1201.2

201.2

145.1127.1

199.2173.2

218.2 229.2

145.1127.1

56.1101.173.0 146.1


NIST Library

Acquired SpectrumM+. Predominant

Theoretical M+.

(mainlib ) Phenol, 2,6-d imethyl-10 20 30 40 50 60 70 80 90 100 110 120 130

0

50

100

15 18 26

27

29 3138

39

40

41

42

43

45 47 49

50

51

53

55 60 62

63

64

65

6668 74 76

77

78

79

80 82 86 89

91

93

95 98

103

107

122

OH

13:28:17

m/z55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130

%

0

100

%

0

100

APGC160408RUN007_8270 998 (4.491) Cm (995:1001-(965:986+1007:1053)) TOF MS AP+ 2.98e3122.0723

107.0498

121.0658 123.0782

APGC160408RUN007_8270 (0.021) Is (1.00,0.10) C8H10O TOF MS AP+ 9.12e12122.0732

123.0766

2,4-Dimethylphenol

APGC Ionization APGC Ionization Example: Charge TransferExample: Charge Transfer

2,4-Dimethylphenol

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Mass Spectrometers for GCMass Spectrometers for GC

� Quadrupoles

—Single

—Triple (aka tandem)

� Quadrupole Ion Trap

� Time of Flight

—Low Resolution

—Elevated Resolution

� Magnetic Sector

—Many possible configurations – EBE, BE common



� Advantages

+ Ease of use

+ Cost

+ Dynamic range

O Disadvantagesー No MS/MS ー Mass accuracyー Resolving powerー Scanning instrument

Single Quadrupole

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� Advantages

+ Ease of use

+ MS/MS Capability

+ Excellent Dynamic range

O Disadvantagesー Mass accuracyー Resolving powerー Scanning instrument

Triple Quadrupole



� Advantages

+ Ease of use

+ Cost

+ MS/MS

+ Full scan sensitivity

+ Low speed for Multi-residues

O Disadvantagesー Mass accuracyー Resolving powerー Dynamic rangeー Scanning instrument

Ion Trap

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� Advantages

+ Mass accuracy

+ Excellent resolving power

+ Excellent dynamic range

+ Linked scan functions

O Disadvantagesー Complexー Costー Sizeー Scanning instrument

Sector



� Advantages

+ Ease of use

+ Dynamic range

+ Excellent sampling rate

+ No spectral skew

+ High full scan sensitivity

O Disadvantagesー No MS/MS ー Mass accuracyー Resolving power

TOF

(Low Resolution)

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� Advantages

+ Ease of use+ Good sampling rate+ No spectral skew+ High full scan sensitivity+ Resolving power+ Mass accuracy

O Disadvantagesー No MS/MS ー Dynamic Range

TOF

(High Resolution)


‘Non‘Non--skewed’ spectraskewed’ spectra

Quadrupole

TOF

≠≠≠≠

=

oa-TOF

Fewer points required across

the peak for accurate

quantification

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Trend in Analytical Method DevelopmentTrend in Analytical Method Development

Sample

Preparation

Compound

SpecificGeneric Generic Generic

Separation /

Detection

Compound

Specific

Compound

SpecificGeneric Generic

Data

Processing

Compound

Specific

Compound

Specific

Compound

SpecificUntargeted

ResultsGC-ECD

GC-MS (SIR)

GC-MS (SIR)

GC-MS/MSGC-TOF >GC-TOF


Waters GC/MS SystemsWaters GC/MS Systems

GCT Premier Quattro micro GC

AutoSpec Premier

Xevo APGC

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GC/MS ApplicationsGC/MS ApplicationsApplications QMGC (MS/MS) GCT P (HR-TOF) Autospec P (Sector) APGC (MS/MS) APGC (Q-tof)Flavors/Fragrans ResearchFlavors/Fragrans MonitoringCore Analytical LabPetroChemical AnalysisImpurity IDImpurity Monitoring(Food safety, Pesticides..)Environmental Applications(Dioxin, POPs..)Metabonomics/Biomarker DiscoveryMetabonomics/Biomarker MonitoringToxicology, Forensics, Drug Screening


Why GC/MSMSWhy GC/MSMS System?System?

� Analysis of 100 or more multi residues in single run

- Common GC Detectors: NPD, ECD…??? – NO!!!

- LODs at or lower than the reporting level

� Single quadrupole and ion trap suitable for simple matrices where

LOD > 0.01mg/kg required

- Insufficient selectivity for baby food and complex food matrices,

e.g. garlic, ginger, herbs, spices etc.

� Selective MS detection method(MRM)

- require to compensate for less selective sample prep.

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What can it be used for?What can it be used for?

� Versatility:

� Use to provide mass spectral information

� Use to provide structural information

� Use for fragment scan analysis

� Use to identify compounds in a mixture

having common functional groups

� Use to provide structural information

� Use to monitor highly specific and characteristic precursor

to product ion transitions for the quantitation of

trace levels of target compounds in complex matrices


Why MSMS?Why MSMS?MS v. MS/MS Example : Ethion 13.14minsMS v. MS/MS Example : Ethion 13.14mins

MRM SIR

MS/MSData

MSData

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Why GC/MSMS(Identification Points)?Why GC/MSMS(Identification Points)?

MS-based confirmatory method

Require 3 or 4 points

(Decision 657/2002/EC)


Analysis of Persistant Organic Pollutants Analysis of Persistant Organic Pollutants

(POPs) by GC/MS/MS(POPs) by GC/MS/MS

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Global concerns about POPsGlobal concerns about POPs

� Toxicity

— POPs have been linked to adverse health effects in humans and wildlife by many studies

� Persistence

— POPs resist natural degradation processes and can remain in the environment for a long time

� Long-range Transport

— POPs generated in one region can travel large distances by wind, water and, to a lesser extent, migratory species

� Bioaccumulation

— POPs are readily absorbed into fatty tissue and become more concentrated as they move up the food-chain

� Compounds of interest include

— Poybrominated Diphenyl ethers (PBDEs)

— Dioxins and Furans

— Polychlorinated biphenyls (PCBs)


Why use tandem MS/MSWhy use tandem MS/MS

� Traditionally an application for high resolution MS

—Offers ultimate sensitivity and high selectivity

— But at a price (capital and on-going costs)

� Some low resolution work on single quads and ion traps

but often limited quantitative applicability

—Matrix effects may dictate multiple sample clean-up steps

— Limited use of 13C12 internal standards for quantitation

� Tandem quad MS/MS potentially offers …

—Cost effective ease of use

— Good sensitivity and dynamic range

— Highly selective analysis eliminating potential interferences

— Good quantitative accuracy on real samples using 13C12

internal standards for screening applications.

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Application:PBDEs backgroundApplication:PBDEs background

� Substantial use; production of PBDEs peaked at >65k

tonnes

� Widespread use as flame retardants, in electronics,

furniture, automotive and other consumer industries

� Persistent and bioaccumulative compounds meeting

Stockholm Convention requirements for POPs.

� Found in many biota and human adipose tissue at

increasing levels over past 30 years

� Concerns over long term effects on human health,

notably as neurodevelopmental disruptors


Approaches to PBDE analysisApproaches to PBDE analysis

� Historically, methods have relied upon GC-HRMS, or

GC-LRMS

—GC-HRMS :- expensive, operated in EI+ ion mode allowing

use of 13C12 labelled internal standards – highly selective,

highly sensitive

— GC-LRMS :- relatively cheap, CI- ion mode generally

detect Br- (79/81), use of 13C12 labelled internal standards

very limited, low selectivity, sensitive

� More recently, GC-MS/MS has been used

— Provides relatively cheap, easy to use option

— Highly selective method for PBDEs in EI+

— Allows use of 13C12 labelled internal standards for accurate

quantitation

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Advantages of GC tandem quad Advantages of GC tandem quad MS/MS for PBDE analysisMS/MS for PBDE analysis

� PBDEs fragment readily, giving highly specific patterns

— Can generate a highly selective MS/MS experiments

— Minimise interferences present in other techniques

� QmGC mass range (to m/z 1500) allows the determination of

Deca BDE, using MRMs from the molecular ion cluster

— Can obtain ‘true’ confirmation of the presence of the target compound

� Stable instrument calibration. (Single calibration may last for

months)

— No need for a daily location and regulation of reference peaks as with

high resolution MS instruments

— No need to work with reference compound across a wide mass range

— No need to have reference compound present during analysis

o Maintains source cleanliness

o Reduces background chemical noise


Instrument calibrationInstrument calibrationTris(perfluoroheptyl)Tris(perfluoroheptyl)--1,3,51,3,5--triazinetriazine

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BDE#47 BDE#47 Full scan spectrumFull scan spectrum

� Full scan mass spectrum for 2,2’,4,4’-TetraBDE (BDE#47)

— See molecular ion cluster

— And most abundant fragment is [M-Br2]+ for tri-deca BDEs


BDE#47 BDE#47 Product scan spectrum from [M]Product scan spectrum from [M]++

� Product scan mass spectrum for BDE#47

— Spectra dominated by Br2 loss from the [M]+ for di-deca BDEs

— Provides good product ion candidates for sensitive, selective

MRMs

-2Br

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BDE#47 BDE#47 Product scan spectrum from [MProduct scan spectrum from [M--BrBr22]]

++

� Daughter scan mass spectrum for BDE#47

— Shows loss of COBr2 in this case,,from the M-Br2 major fragment

ion

— Again good product ion candidates for MRM

-COBr2


Development of analytical methodDevelopment of analytical method

• Analysis performed on three GC columns to assess relative

sensitivity and separation

— All injections made in splitless mode

— Temperature programs designed to provide adequate separation

across mono-deca BDE range

— Calibration using multi-level standards (27 native components)

— Quantify using internal standard method with 13C12 congeners

(one for each level of bromination)

— For each congener and 13C12 internal standard two MRMs were

recorded allowing for quantitation and confirmatory analysis in a

single run

— MRM experiment arranged in 10 function windows corresponding

to mono-deca BDEs and overlapped in time where necessary to

collect full data set for each level of bromination.

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15m DB115m DB1--HTHTseparation of 27 congenersseparation of 27 congeners


� Best separation given by 20m DB5-ms, 15m DB1-HT

separation ‘fit for purpose’ <50% valley

GC separation of critical congener pairGC separation of critical congener pair

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Comparative sensitivity Comparative sensitivity between columnsbetween columns

0

2

4

6

8

10

12

14

16

18

20

LO

D (

pg

on

co

lum

n)

BD

E#3

BD

E#7

BD

E#1

5

BD

E#1

7

BD

E#2

8

BD

E#4

9

BD

E#7

1

BD

E#4

7

BD

E#6

6

BD

E#7

7

BD

E#1

00

BD

E#1

19

BD

E#9

9

BD

E#8

5

BD

E#1

26

BD

E#1

54

BD

E#1

53

BD

E#1

38

BD

E#1

56

BD

E#1

84

BD

E#1

83

BD

E#1

91

BD

E#1

97

BD

E#1

96

BD

E#2

07

BD

E#2

06

BD

E#2

09

PBDE

15m HT1 30m HT1 20m DB5

The limits of detection and quantification were calculated for each of the three GC columns.


Quantitative resultsQuantitative results

� Five Bio-solid and a number of air emission samples were

analysed as part of the sequence

� Each sample had been previously acquired by high resolution

methods using an AutoSpec Ultima NT

—MTM Research Centre, Örebro University, Sweden

— Ontario Ministry of Environment, Toronto, Canada

� BDEs #47 & #209 used as examples of the comparative

quantitative results obtained.

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Quantitative resultsQuantitative resultsfor BDE#47 and BDE#209for BDE#47 and BDE#209

Matrix GC-MSMS (ng/g) GC-HRMS (ng/g)Liquid stabilised biosolid 482 530Liquid stabilised biosolid 311 350dewatered biosolid 435 490Fish tissue 8.81 8.8Freeze dried fish tissue 139 150

Comparative data for BDE#47

Matrix GC-MSMS (ng/g) GC-HRMS (ng/g)Liquid stabilised biosolid 297 340Liquid stabilised biosolid 264 290dewatered biosolid 1630 1700Fish tissue 0.32 0.4Freeze dried fish tissue 0.4 0.3

Comparative data for BDE#209


MS/MS v HRMS Comparative dataMS/MS v HRMS Comparative data

0

400

800

1200

1600

0 500 1000 1500

GC/MS/MS (ng/g)

GC

/HR

MS

(n

g/g

) R2=0.9991Bias 4%

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BDE#47 in a fish tissue extractBDE#47 in a fish tissue extract8.8ng/g8.8ng/g


BDE#209 in a biosolid extractBDE#209 in a biosolid extract297ng/g297ng/g

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Summary of PBDEs analysis by GC Summary of PBDEs analysis by GC tandem quadrupole MS/MStandem quadrupole MS/MS

� Simple, stable instrument calibration over broad mass

range

� Sensitive and highly selective MRMs selected allowing

quantitation and confirmatory analysis in single run

� Rapid analysis achieved on short columns

� Good calibration linearity and stability using 13C12

internal standards

� Excellent agreement with HR-MS for real samples

� Waters Application Note “A study of the analysis of

polybrominated diphenyl ether flame retardants by

GC/MS/MS” www.waters.com


Dioxin Screening with the Dioxin Screening with the

Quattro Micro GCQuattro Micro GC

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Application: Dioxins/Furans Application: Dioxins/Furans backgroundbackground

� PCDDs/PCDFs consist of 210 individual congeners, 17 of

which are targeted as “toxic”.

O

O

Cl

Cl

Cl

Cl

OCl

ClCl

Cl

Cl

75 congeners 135 congeners

• Produced unintentionally in various industrial and combustion processes.

• Listed in the Stockholm Convention “dirty dozen”

• Extensive legislation and monitoring in the environment and food chain due to bioaccumulative nature and toxicology findings


PCDD/DFs analytical challengesPCDD/DFs analytical challenges

� Correctly identifying and quantifying 17 toxic congeners

among 193 others.

� Low levels present; typically ppb and ppt.

� Matrix effects (significant clean-up may be required).

� Resolving interferences from related compounds such as

PCBs which are often at much higher levels.

� Traditional solution has been to use GC with high

resolution magnetic sector mass spectrometry.

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� In recent years, screening has become more and

more common

—Screening is a lower cost alternative for large studies

—Screening methods should be simple to operate, rapid

and cost effective, when compared with confirmatory

high resolution analyses

� Screening of sites/samples is now accepted by

legislation (European Union) for food safety

monitoring

— Although at least 10% of samples must be confirmed by

high resolution (e.g. AutoSpec Premier) analysis

Background to Dioxin ScreeningBackground to Dioxin Screening


� GC-MSMS methods can provide a highly selective screening

method

—Chemical determination giving comparable TEQ results when

compared with high resolution

� Dioxins/Furans give a highly specific fragmentation

—Good degree of selectivity, easy to set up, can do confirmatory

analysis

� MRM analysis

—Records compound specific transitions for each target analyte

— High selectivity, High sensitivity, no interference from PCBs

Advantages of GC/MS/MS Advantages of GC/MS/MS for Dioxin screeningfor Dioxin screening

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� MRM conditions

— Firstly, acquire standard in product scan mode, to identify the

most intense product ions, from the two most intense ions of

the molecular ion cluster of each target compound

— Example of product scan of m/z 339.9, (PeCDFs)

— Most intense product ion found to be M-[CO35Cl] for all of the

PCDD/Fs, or M-[13CO35Cl] for the 13C12 labelled internal

standards

Dioxin/Furans Fragmentation patternDioxin/Furans Fragmentation pattern


� MRM optimisation

—Daughter scans repeated at different collision cell energies to

optimise transition sensitivity

� MRM experiment

— Two transitions monitored for each dioxin, furan and 13C-

labelled dioxins and furan internal standards

� Multiple function acquisition

— Five acquisition functions created, function 1 monitoring tetra-

chlorinated congeners, function 2 monitoring penta-chlorinated

congeners, through to function 5 monitoring octa-chlorinated

congeners

Quattro Micro GC Quattro Micro GC Experimental conditionsExperimental conditions

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� Overlapping functions

— 1,2,8,9-TCDF and 1,3,4,6,8-PeCDF acquired

Quattro Micro GC Quattro Micro GC GC Separation GC Separation –– acquired peaksacquired peaks


� Temperature ramp optimised to satisfy EU legislation

— Separation of 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF must be

<25% valley. A 13% valley separation is obtained under these

conditions. This chromatogram is injection number 80 from the batch

runs.

� OCDF elutes <20mins

— Rapid analysis time, maintaining required separation, maximum

throughput

Quattro Micro GC Quattro Micro GC GC ConditionsGC Conditions

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� Reproducibility

—%RSD values calculated for 25 injections, as part of a series of >80 injections

— RRF, ion ratio and retention times all show low %RSD values

— Indicates stable response and chromatography over extended time period

Quattro Micro GC Quattro Micro GC ReproducibilityReproducibility


Quattro Micro GC Quattro Micro GC calculated concentrationscalculated concentrations

� Single sample injection from

each day selected

—Calculated concentration

compared with Certified values

and confirmed by confirmatory

(HRGC-HRMS) analysis on Waters

AutoSpec Ultima NT

— Certified values are

Carp 18.2 ng/kg

Flyash 900 ng/kg

� Good agreement with certified

values

—Confidence in results

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Quattro Micro GC Quattro Micro GC

TCDFs in flyashTCDFs in flyash


Quattro Micro GC Quattro Micro GC

TCDFs in carpTCDFs in carp

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Summary PCDD/DFs analysis by GC Summary PCDD/DFs analysis by GC tandem quadrupole MS/MS tandem quadrupole MS/MS

� Rapid screening method to compliment high resolution

MS for all toxic and non-toxic congeners

� High selectivity achieved using MRM experiments

minimizes interferences and enables confirmatory

analysis in one run

� Stable and robust calibration enables accurate

quantitation

� Excellent agreement with high resolution MS

� Waters Application Note “A single injection screening

method for tetra-octa chlorinated PCDD/Fs in fish and

flyash matrices using GC triple quadrupole MS/MS”

www.waters.com


Conclusions Conclusions

� The Quattro micro GC has demonstrated …

—Good sensitivity and high selectivity enabling quantitation and

confirmation of significant POP classes including dioxins/furans

and PBDEs.

— Strong performance in terms of working mass range, calibration

linearity and stability, and ion ratio accuracy and precision. All

critical factors for quantitative accuracy

— Excellent correlation with high resolution MS for real samples.

� GC tandem quadrupole MS/MS can provide …

— A sensitive, rapid, cost effective method for analysis of PBDEs

enabling accurate quantitation and confirmatory analysis in one

run.

— A rapid, robust and cost effective screening method for

dioxins/furans with excellent quantitative accuracy

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Multiresidue Analysis of Priority Multiresidue Analysis of Priority

Pollutants in Surface Waters using Pollutants in Surface Waters using

Exact Mass GCExact Mass GC--TOF/MSTOF/MS


Compound ListCompound ListBenzidines

Benzidine

3,3’-dichlorobenzidine

Chloroanilines

2-chloroaniline

3-chloroaniline

4-chloroaniline

2,6-dichloroaniline

2,4-dichloroaniline

2,5-dichloroaniline

2,3-dichloroaniline

3,5-dichloroaniline

3,4-dichloroaniline

4-chloro-2-nitroaniline

Chloronitrotoluenes

2-chloro-6-nitrotoluene



Miscellaneous

Biphenyl

Tributhyl phosphate

Trifluralin

Propanil

BentazonePyrazon

Chlorophenols

2-chlorophenol

2,4-dichlorophenol

3-chlorophenol

4-chlorophenol

4-chloro-3-methylphenol

2,3,5-trichlorophenol





2-amino-4-chlorophenol

Chlorotoluidines

2-chloro-4-toluidine

Voltaile Amines

Cumene

PCBs

PCB 28 PCB 52 PCB 101 PCB 77 PCB 118 PCB 153 PCB 138 PCB 126PCB 180 PCB 169

Chloronitrobenzenes

1-chloro-3-nitrobenzene



3,5-dichloronitrobenzene

2,5-dichloronitrobenezene




1-chloro-2,4-dinitrobenzene

PAHs

Naphthalene

Phenanthrene

Anthracene

Fluoranthene

Benzo[b]fluoranthene

Benzo[k]fluoranthene

Benzo[a]pyrene

Indeno(1,2,3-cd)pyrene

Benzo[ghi]perylene

Dibenz(a,h)anthracene

Phenylureas

Monolinuron

Linuron

Organochlorines

Hexachlorobenzene

α-Hexachlorocyclohexane

β-Hexachlorocyclohexane

Lindane

δ-Hexachlorocyclohexane

Heptachlor

Aldrin

Isodrin

o,o'-DDE

α-Chlordane

α-Endosulfan

o,p'-DDE

γ-Chlordane

Dieldrin

p,p'-DDE

o,p'-DDD

Endrin

β-Endosulfan

p,p'-DDD

o,p'-DDT p,p'-DDT

Triazines

Simazine

Atrazine

Organophosphorus

Dichlorvos

Mevinphos(Z)

Mevinphos(E)

Omethoate

Demeton-S-methyl

Dimethoate

Demethon-O

Disulfoton

Fenitrothion

Fenthion

Malathion

Parathion-ethyl

Parathion-methyl

Azinphos-methyl

Azinphos-ethyl Coumaphos

Halogenated Compounds

Hexachlorobutadiene

1,2-dichloronaphthalene

1,2,3,4-tetrachloronaphthalene

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� Extract, detect, locate and identify all components

—Minimal non-selective sample preparation for a wide range of

compound groups with different polarities

— Simple high resolution GC separation to minimise matrix

interference whilst maintaining resolution of critical pairs

— High sensitivity

— Full mass spectrum

— Automated peak detection and deconvolution of all components

in the sample

— Automated production of background subtracted spectra for each

component

— Automated library search and identification

— Exact mass may help identification

— Estimate the concentrations of all the components in the sample

Screening RequirementsScreening Requirements


GCT PremierGCT PremierOrthogonal Acceleration TOFOrthogonal Acceleration TOF

� Rapid full spectral sampling and acquisition rates

—Non skewed spectra

— Narrow chromatographic peaks

— Accurate chromatographic peak profiling enabling deconvolution

� Non scanning instrument with a high duty cycle

—High full scan sensitivity

� Predictable scan law

—Routine exact mass calibration with a single lock mass

� Elevated Resolution

— Enhanced selectivity

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GCT PremierGCT Premier

� Plug in EI/CI ion volumes for rapid change over

� Resolution

—Greater than 7000 (Full width half maximum)

� Exact mass

— Less than 5ppm RMS

� Dynamic range

— 4 orders linear dynamic range

� Spectral acquisition rate

— 20 spectra per second


GCT Premier ParametersGCT Premier Parameters

� Electron Impact (EI+) with a mass range of m/z 50 → 550

� Acquisition Speed = 10 spectra / s

� 2,4,6-tris-(trifluoromethyl)-1,3,5-triazine lock mass

—m/z = 284.9949

� Dynamic Range Enhancement (DRE) On

� Low Mass Cut Off = 45

� Electron Energy = 70 eV

� Trap Current = 200 µA

� Source Temperature = 200 °C

� Interface Temperature = 280 °C

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� Agilent 6890 with CTC CombiPal autosampler

� Pulsed splitless injection, 1 µL

— 4 mm i.d. double taper deactivated liner

— 140 kPa pulse for 1.1 min

� J & W Scientific, DB-17MS, 30 m x 0.25 mm i.d., 0.25 µm

� Constant flow rate of 1.0 mL/min helium

� Oven temperature program

GC ConditionsGC Conditions

Ramp rate, °C/min Hold, min

40 °C 1

310 °C @ 15 °C/min 11

Total run time30min


Resolution of Critical PairsResolution of Critical Pairs

3- and 4-Chlorophenol

128.003

Mevinphos E and Z

192.020

o,p’-DDT and p,p’-DDD

235.008

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Total Ion Chromatogram Total Ion Chromatogram TICTIC

Cum

ene

Ben

zo(g

hi)p

eryl

ene


� 200 mL filtered water adjusted to pH 4.0 with 1N HCl

� Sample spiked with 500ng internal standards

� d5-nitrophenol, 2-fluorobiphenyl, p-terphenyl-d14

� Waters Oasis HLB 60 mg, 3cc SPE cartridge

� Conditioned with 6 mL DCM, 6 mL acetonitrile, 6 mL water

� Sample loaded @ ~ 6 mL/min

� Cartridge washed with 1mL water and N2 dried for 20 mins

� Elution with 2 x 2.5 mL DCM

� Volume adjusted to 0.5 mL with N2 @ ambient temperature

� 500ng recovery standard added

� d10-anthracene

� 400 fold concentration step during extraction

Extraction ProcedureExtraction Procedure

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Extraction ResultsExtraction ResultsSpiked Drinking WaterSpiked Drinking Water

• Good overall recovery @ 0.5 µg/L (n = 5)

– 4-chloroaniline and 3,4,5-trichlorophenol gave very low

recoveries (Mean recovery = 32% and 14%)

– DCM extract had no effect on chromatography

– Good recovery of low boiling point compounds

Mean Recovery Number of Compounds (%)

70 - 120% 79 (72%)

50 - 70% 9 (8 %)

< 50% 14 (13%)

>120% 8 (7%)


Extraction ResultsExtraction ResultsSpiked Drinking WaterSpiked Drinking Water

0

20

40

60

80

100

120

140

160

0 20 40 60 80 100

Compound Number

% R

ec

ov

ery

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Method LODsMethod LODs

No. Compounds

< 0.1 µg/L

No. Compounds

> 0.1 µg/L

InstrumentScreening 102 1

Confirmation 101 2

Method

Drinking WaterScreening 101 2

Confirmation 98 5

Surface WaterScreening 101 2

Confirmation 99 4

• Summary of LODs, based upon peak-to-peak S/N of 3:1

– Screening LOD is based on one exact mass per compound

– Confirmation LOD is based on two exact masses per compound

with a peak area ratio between them

– Instrument LOD is based on solvent standards

– Method LOD is based on mean recovery (n = 5) from 0.5 µg/L

spiked water extracts


Targeted Screening and Targeted Screening and ConfirmationConfirmation

� Compound list is known

— TargetLynx application manager

— Extracted exact mass chromatograms, 0.05 Da window

— Highlight samples that…

…do not pass quality control criteria

…have concentrations greater than the reporting level

— Screening is based on one exact mass chromatogram

— Confirmation is based on two exact mass chromatograms

with a peak area ratio between them

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Selectivity of Exact Mass Selectivity of Exact Mass ChromatogramsChromatograms

Chlorophenols (CP), 0.1 µg/L in Surface Water

2-CP 4-CP3-CP

1.0 Da

0.02 Da



Isodrin, 0.1 µg/L in Surface Water, Screening = 192.0379

1.0 Da

0.02 Da

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Isodrin, 0.1 µg/L in Surface Water, Confirmation = 194.9349

1.0 Da

0.02 Da


SensitivitySensitivityScreening versus ConfirmationScreening versus Confirmation

Dichlorvos, 0.1 µg/L in Surface Water

Screening109.006

Confirmation109.006

184.977

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Compound name: 2,5-DichloroanilineCorrelation coefficient: r = 0.999139, r^2 = 0.998278Calibration curve: 1.9991 * x + -0.305329Response type: Internal Std ( Ref 26 ), Area * ( IS Conc. / IS Area )Curve type: Linear, Origin: Exclude, Weighting: 1/x, Axis trans: None

Conc0 50 100 150 200 250 300 350 400 450 500

Re

spo

nse

0

200

400

600

800

1000

LinearityLinearity

2,5-Dichloroaniliner2 = 0.9983

Concentration Range1 - 500 pg/µL equivalent to

0.005 – 2.5 µg/L


TargetLynx BrowserTargetLynx Browser

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Untargeted ScreeningUntargeted Screening

� Compound list is unknown

—ChromaLynx application manager

— Automatic peak detection and deconvolution

— Automatic production of background subtracted spectra

— Automatic identification via library searching

— Exact mass confirmation


DeconvolutionDeconvolution

5 Components?

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Deconvolution with ChromaLynxDeconvolution with ChromaLynx

ChromaLynx found 7 Components!


Component 1Component 111--chlorochloro--33--nitrobenzenenitrobenzene

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Component 2Component 22,62,6--dichloroanilinedichloroaniline


Component 3Component 3DichlorvosDichlorvos

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Extracted Mass ChromatogramsExtracted Mass Chromatograms3 Components3 Components


Dichlorvos

2,6-dichloroaniline


Spiked Surface WaterSpiked Surface WaterChromaLynxChromaLynx

ChromaLynx found ~ 800 Components

180 compounds were spiked @ 0.5 µg/Lof which ~ 100 are in the targeted method

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Spiked Surface WaterSpiked Surface WaterDibenzofuranDibenzofuran


ConclusionsConclusions

� A method has been presented for the targeted confirmation

of > 100 priority pollutants using Oasis SPE cartridges and the

GCT Premier with TargetLynx

� A majority of the pollutants can be confirmed to concentration

levels of < 0.1 µg/L in surface waters using a single injection

technique and exact mass chromatograms

� The method can also be extended to larger numbers of

residues without loss in sensitivity due to the full spectrum

approach provided by TOF instruments

� This single injection can also be used to screen for non-

targeted residues in the same extract with ChromaLynx

� ChromaLynx enables automatic detection, deconvolution,

library searching and exact mass confirmation

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Standard Tune Page Parameters & Potential

Energy Diagrams


Outer Source TuningOuter Source Tuning

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Source ParametersSource Parameters

� There is a wide

range of

“acceptable”

parameters for the

tuning of the

Quattro micro GC

source!


MS1 Analyser ParametersMS1 Analyser Parameters

� Resolution at “default” setting (15) for MS1, MS2 Resolution settings do not effect MS1 Beam

� High Entrance and Exit (50 V) on collision cell

� Small DC voltage applied to collision rods (2)

� MS1 has “Optimum” Ion Energy (approx. 0.5*)

� MS2 has high Ion Energy (approx. 3)

� Note: SIR mode will use similar parameters, IE1 should increase to 1V and LM/HMRes1 should decrease to give FWHM of 0.8 Da

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MS2 Analyser ParametersMS2 Analyser Parameters

� Resolution at “default” setting (15) for MS2, MS1 Resolution settings do not effect MS2 Beam

� Low Entrance and Exit (2 V) on collision cell

� Small DC voltage applied to collision rods (2)

� MS2 has “Optimum” Ion Energy (approx. 0.5*)

� MS1 has high Ion Energy (approx. 3)

� Note: Small changes to entrance, collision and exit may effect sensitivity, and so should be tuned


MSMS Analyser ParametersMSMS Analyser Parameters

� Lower resolution & raise Ion Energy to get more sensitivity

� Entrance may optimise zero or slightly negative- v. important to tune

� This gives ions longer in the collision cell and may result in more fragmentation

� Collision Energy must be tuned!

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Any Question?Thank You

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