Hebestreit TD AmbientAir

7/27/2019 Hebestreit TD AmbientAir

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Food and Environmental

Solutions Seminars 2011

Moritz Hebestreit, PhD

Applications Chemist

Agilent Technologies

Europe, Middle East, Africa and India

Neue Mglichkeiten zur berwachung der Um-gebungsluft mit Thermodesorption und GC/MS


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Monitoring Ambient Air byTD and GC/MS


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What is Thermal Desorption?

Sorbent Material

Sample Matrix

e.g. Chamber or

micro-chamber air


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Sample passes onto the sorbent

Compounds of interest are adsorbed on the

sorbent surface


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Lighter gases such as nitrogen pass

through the sorbent


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Sorbent is now heated in a reversed flow of

clean carrier gas (back flushed)


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It is a simple extension of the technique of Gas Chromatography andis a sample introduction technology for difficult or real-world

samples

Compounds are released from the sorbent into

the flow of carrier gas


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2 Stage Thermal Desorption

Would lead to very wide chromatographic peaks and lowsensitivity

PROBLEM: Compounds are released SLOWLY from the

sorbent tube


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SOLUTION: Use a narrow secondary trap

STAGE 1

Transfer compounds from

tube to secondary trapElectrically cooled

narrow bore cold trap


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Cold trap heated rapidly (100C/sec) for sharp

chromatographic peaks Backflush of cold trap for greater volatility range

STAGE 2

Rapid transfer of

compounds from cold

trap to GC


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Cold Trap

Narrow design allows splitless injection

Use sorbent(s) to suit specific application

15 standard traps + custom packed traps available from

Markes

Flow during focusing /

sampling onto trap

Flow during trap

desorption

Restricted narrow

bore inlet / outlet endof trap


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Key Component - Heated Valve

Fused silica of column

or transfer line

inserted hereSplit filter or

SecureTD-Q tube

attaches here

Sample tube

connects here

Inlet / outlet end of

focusing trap

connects here

The sample flow path through the valve assembly is uniformly-

heated, short (< 10 cm total) and narrow to eliminate condensation


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Heated valve

To GC

PatentedTD valve: All applications & sample re-collection

Patented heated valve is inert and low volume: Allows quantitative

recovery of high & low volatility and reactive compounds

The heated valve isolates the TD system allowing method compliance:

leak testing, backflush trap desorption, purge to vent, overlap mode, etc.

Time

Intensity

Stage 1: Primary (tube) desorption with optional (inlet) split


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Heated valve

To GC

Time

Intensity

Stage 2: Secondary (trap) desorption with optional (outlet) split

Patented TD valve:All applications & sample re-collection

Repeat analysis of re-collected samples makes it easy to validate

analyte recovery through the TD flow path

A change to the overall VOC profile indicates any bias


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Using Re-collection (SecureTD-Q)

2 L phthalate solution in methanol with 21:1 single

split 20 re-collection, repeat analyses

Good match between expected decay (lines) andobserved decay (points)

Demonstrates quantitative recovery

Validation of routine methodsDemonstrating quantitativerecovery of high boilers

Repeat desorption of a mixed phthalate std

di-ethyl- to di-n-decylphthalate

Repeat analysis shows quantitative recovery

without bias, across the analyte range

NB: ASTM Method D6196 references quantitat ive re-collect ion for validation

DEHPDDP

Original

Repeat


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ULTRA 2 DiffLokTM capsInert or Stainless steel

outer body (shown transparent)

O-ring forsealing tube

into cap

Threaded diffusion-locking insert in plain,cylindrical body.

Sample tubepushes into

cap here

Coned end forAuto-alignmentwith tube nozzle

on ULTRA (the TDautosampler)

Patented DiffLok caps provide a very effective seal for tubes on ULTRA 2 preventing

artifact ingress and loss of analytes

DiffLok caps allow gas to flow when pressure is applied & can stay on the tubes

throughout TD operation This makes automatic TD simple and mechanically robust

Schematic of DiffLok Cap as

used to seal tubes on ULTRA


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Unique SafeLok sorbent tubes

SafeLok tubes reduce risk of artefactingress and loss of sampled analytes

They make it easier to handle tubes in the

field (e.g. capping/uncapping) without risk

of contamination

They also facilitate collection and analysisof air samples from ultra-clean

atmospheres.

They allow pumped sampling at low flow

rates over extended periods (< 1 mL/min)

Same mass of sorbent and same externaldimensions as standard tubes

* Patent Numbers: GB 2337513, US 6,564656 B1

Threaded DiffLok inserts protect both ends

of the sorbent tube


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TubeTAG: Tracking Air monitoring samplesin transit

A patented unique tool for tracking

TD tubes in transit during field

monitoring

Consists of RFID tag assemblies

for attaching onto sorbent tubes

(various types and sizes), a

read/write device (TAGSCRIBE) and

software

Tags are re-usable indefinitely

Patent # US 6.446,515 B2. Priority: 2002


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The TubeTAG advantage for air monitoring

TubeTAG is a genuine breakthrough in TD technology. It

allows the user to immediately identify the sorbent in each

tube, when it needs repacking and whether or not it has a

history of leak test failures, back-pressure anomalies, etc.

Tube Information

Sorbentpacking

# thermalcycles

Impedance

Leak test info

SampleInformation


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What can TD-GC/MS do?

Any volatile or semi-volatile organic compounds which meet thefollowing criteria: < n-C40, bpt n-C40 Compounds which dont work well with GC (including formaldehyde)

Methane


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Thermal Desorption systems

UNITY 2

A universal platform forsingle tube thermaldesorption

TD-100

Automated TD system forup to 100 RFID-tagged or

untagged tubes


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Standard methods

See TDTS 3: National and International Standard Methods Relating toSpeciated Monitoring of Vapour-phase Organic Chemicals in Air


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Online air monitoring applications

Extracted ion 69

Extracted ion 119

Extracted ion 127

Extracted ion 30

CF4

C2F6

C2F6

SF6

N2O

Green house gas analysis

Acetylene up to 2L of sample takenwithout breakthrough

Diurnal profiling of ozone precursors

Key:

Blue (3 am)

Red (12 noon)

Green (5.30 pm)


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Canister analysis methods (e.g. US EPA TO-15)Method summary

Grab sampling using canisters is easy, TWA monitoring is not

Samples may be stored for up to 30 days

A small volume of air from the canister (typically ~500 mL) can be

introduced straight to the focusing trap of the desorber

Trapping conditions are set such that water is selectively eliminated

during the trapping process.

Analysis by GC/MS

CIA 8 UNITY 2 GC/MS

Ambient Air


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Source: TDTS 81

Air toxics in canisters: US EPA Method TO-15

1 L of a 1 ppb air toxics

mix analysed splitless

and cryogen-free using

UNITY-CIA 8


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Air monitoring: Canisters or tubes?

Use canisters:

1. For non-polar compounds

2. Preferably at trace levels for ultra-

volatiles

3. When you have to

Canister limitations

1. Expense (500 -1000 each)

2. Poor recovery of anything higher boiling

than Xylene3. Cleaning needs expensive vacuum

equipment, at least 3 cleaning cycles

and verification with GC/MS

C i t t b ?


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Profiles of soil gas contaminated with keroseneobtained using:

a) canister samplingwith TO-15 analysis (blue)

b) sorbent tube sampling with TO-17 analysis (red)

Canisters or tubes?Tubes Canisters

Perception World-wide acceptance Gold standard for US ambient air market

Applications Ambient air, indoor air, vaporintrusion, industrial hygieneMaterial emissionsFood & flavorChemical weapons

Ambient air, indoor air, vapor intrusion,emergency response

Handling Light weight for personal monitoringand general ease of use

Larger and heavier; more costly to ship

Sampling C3- C40 Concentration range ppt to % C2-C10 Concentration range ppt to low ppm

Cleaning Analytical process automaticallycleans tube for re-use

Canister cleaning requires separateequipment as additional step prior tobackground certification and sampling.

Cost $50 $130 each $200 - $700 each


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Active (pumped) samplingTO-17 summary:

Pre-screen area using 2 tubes in parallel (50 mL/min, 1 & 4 L) to

identify type/level of VOCs. Confirm sorbent selection. Sample air

Store capped tubes up to 30 days (below 4C if multi-sorbent)

TD-GC/MS analysis steps:

Leak test then add gas phase IS and/or dry purge in sampling direction

Prepurge then desorb tube with carrier gas flowing in reverse direction

Refocus analytes in electrically-cooled trap and desorb rapidly inbackflush direction

Analyse by GC/MSPump

Sampling

direction

Weak

Medium

Strong

Sampling Analysis Result


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Food and EnvironmentalSolutions Seminars 2011

Source: TDTS 86

Air toxics on sorbent tubes: US EPA Method TO-17

10:1 Split desorption of

Air Toxics tube loaded

with 1 L of 1 ppb std


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Easy-VOC Pumped tube sampling made easy

Grab sampling for sorbent tubes: Reliable sampling of 50 or

100 ml volumes (or multiples of same)

Kit includes: hand pump, Safelok tubes and caps. Main features

Ease of use

Humidity effects Negligible

Breakthrough? Minimised

Use of SafeLok tubes and push on caps simplifies operation and

prevents over tightening of storage caps

no need for calibrated pumps

Easy-VOC- For soil gas, workplace air & stack gas.


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Comparisons of Easy-VOC with standardpumped sampling

Comparison with FLEC constant flow pump (Black) and Hand

pump (Red & Blue) equal performance


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Extending the volatility range

Smaller volume less chance of breakthrough, solighter compounds can be retained.

Propane

Isobutane

2-butene

TD i t j t f t l l


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TD isnt just for trace levels:

High-concentration industrial emission samples

Pumped sampling of 1 L stack gas with

TD-GC/MS analysis

Sample splitting during both primary (tube)

and secondary (trap) desorption. Total split

ratio: 3000:1

Quantitative re-collection ofboth spl i tsallows repeat analysis for confirmation


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Passive (diffusive) sampling for workplace andenvironmental air monitoring

Vapours migrate across the air gap at a constant uptake

rate

Diffusive sampling is a slow process, typically sample for

complete shift (workplace/personal exposure) or

days/weeks (environmental air monitoring)

Brass cap

Diffusion cap

(fitted to

sampling endof tube)

Ambient conc. of

vapours in the

environment

Zero conc. of

vapours at the

sorbent surface

Airgap

Note: Diffusive (passive) sampling wont work with glass orSafeLok tubes. Use standard stainless steel or Silcosteeltubes


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Typical applications for air monitoring in industry

Industrial perimeter

monitoring

Workplace air monitoring

Monitoring guidelines (sorbents, uptake

rates, sampling volumes, etc.) available from

standard methods (and from Markes)

(Occupational hygiene)

Stack and fugitive

emissions


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Breath sampling for occupational hygiene(Bio-VOC)

Solvents in the breath of shoe workers

Breath sampling is anotherapplication for TD-GC/MS

It allows assessment of the total

exposure inhalation, skin

absorption, ingestion

Key applications include: People working with chemicals

absorbed by the skin

People wearing protective

equipment (How effective is it)

Chronic exposure causing build

up of chemicals in the body

Environmental exposure studies

S i li t li ti f i it i i


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Specialist applications for air monitoring inindustry

Soil gas and vapourintrusion assessments

Atmospheric Research

Mapping criteria pollutants in

ambient air, diurnal changes

In s itumonitoring of undergroundcontamination

S i li t li ti f i it i i i d t


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Specialist applications for air monitoring in industry

Indoor air quality andtracer gases used forventilation studies

Landfill gas monitoring

Biogenicemissions

Odorous industrialemissions


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Online monitoring of odorous sulphur compounds inambient & industrial air (UNITY-Air Server)

Gas standards at 20 ppb and 10 ppb levels

Target compounds:

H2S (hydrogen sulphide)

CH3SH (methanethiol/me.mercaptan)

C2H6S (dimethyl sulphide)

C2H6S2 (dimethyl disulphide)

3 channels with H2S focusing trap at -

15C to -30C and flow path at 80C.

GC-PFPD

Performance in field operation:

Detection limits: 0.15 ppb

Retention time stability: 87% for all analytes

Input from Agilent?


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Input from Agilent?

GC/MS

CFT (e.g. Backflush,

Splitter, 2D-GC)

RTL + DRS

ChemStation,

MassHunter

Dataanalysis

EM Saver

Normalized gain

Synchronous SIM/Scan

Libraries

5th generation of EPC

SamplingThermal

desorption

Cryogen-free

Universal: C2 to C40 +

reactive compounds

Repeat analysis

100 tubes

TubeTAG

Water management

Method compliant

Sorbent

Tubes

Canistersand Bags

Breath

Samples

Soil Gas

samples

MTS-32

no need forcalibrated

pumps


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Different Columns, Same GCRetention times vary from column-to-

column by as much as 0.5 min...

GC Column 1

Column 2

Column 3

Column 4


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Retention Time LockingRetention times match from column-to-

column AND instrument-to-instrument to0.030 min or better...

GC1

GC2

GC3

GC4

Column 1

Column 2

Column 3

Column 4


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Results for 5 Retention Time LockingRuns on GC/MS

RTLOCK1.D

RTLOCK2.D

RTLOCK3.D

RTLOCK4.D

RTLOCK5.D

17.345

16.940

16.567

16.214

15.885

-20 % pressure

-10 % pressure

nominal pressure

+10 % pressure

+20 % pressure


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5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00

5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00

5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00

DRS - TICs of surface water extracts

How many pesticides are

in these samples ?


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Seventeen (17) surface water samples

*CDFA is the California Department of Food and AgricultureData files courtesy of Dr. Mark Lee and Steve Siegel

34 min

~8 hrs

(ChemStation

Only)

Processing

Time

01False Positives

Same 37

+99 more

37

Targets Found

(not counting

ISTD)

Agilent DRS with927 Compound

Database

CDFA*


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DRS = MSD + AMDIS + NIST Search

MSD Chemstation

RTLock and ID targets based on r.t. and 4 ions andquantitate

AMDIS

ID targets based on deconvoluted full spectra and

qualify targets based on r.t. NIST Search

search targets using deconvoluted full spectra from

AMDIS against 191,000+ compounds

Automate the above and produce an easy to read

Report

What is AMDIS?


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Automatic Mass spectral Deconvolution andIdentification Software

Developed to automatically detect chemicals in violation of

Chemical Weapons Convention

Identify targetcompounds at low concentration levels in

complex matrices

Developed by National Institute of Standards and

Technology

Retention Time can be used as a qualifier, so RTL is

a big advantage

What is AMDIS?

A Single Chromatographic Peak May
http://images.google.com/imgres?imgurl=cic.nist.gov/lipman/vrml/images/nistlogo_lg.gif&imgrefurl=http://cic.nist.gov/lipman/vrml/&hl=en&h=421&w=691&prev=/images?q=NIST+Logo&svnum=10&hl=en&lr=&ie=UTF-8&oe=UTF-8


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A Single Chromatographic Peak MayContain Multiple Components

TIC

Component 1

Component 2

Component 3

TIC & Spectrum

TIC

Components and Mixed Spectra


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AMDIS DeconvolutionDeconvoluted components and spectra

Component 1

Component 2

Component 3

interference

Deconvolution

matrix

target

TIC

Components and Mixed Spectra


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Ease of use no need to learn deconvolution softwareAutomation part of a method or part of a sequence,

analyst can be doing other things

Quality program results are not subject to

changes in mood/attention of analyst

Sensitivity AMDIS will find answers that an analystmight miss

Confidence DRS will report the fewest falsepositive / negatives in the shortest time

DRS User Benefits

DRS A N t A il bl


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Comprehensive Pesticide Screening by GC/MSD using

Deconvolution Reporting Software pub # 5989-1157

New Tools for Rapid Pesticide Analysis in High Matrix Samples

pub # 5989-1716

A Blind Study of Pesticide Residues in Spiked and Unspiked Fruit

Extracts Using Deconvolution Reporting Software pub # 5989-1654

Building and Editing RTL Screener/Quant Databases and Libraries

pub # 5989-0916

Building Agilent GC/MSD Deconvolution Reporting Libraries for

Any Application pub # 5989-2249 (32 pages, so, use the videos !!!)

Replacing Multiple 50-Minute FPD/ELCD/SIM Analyses with One

15-Minute Full-Scan Analysis for 10x Productivity Gain 5989-7670

DRS App Notes Available


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Screening for Hazardous Chemicals in Homeland Security and

Environmental Samples Using GC/MS/ECD/FPD with a 731

Compound DRS Database pub # 5989-4834

Improved Forensic Toxicology Screening Using A GC/MS/NPD

System with a 725-Compound DRS Database pub # 5989-8582

Semivolatiles Retention Time Locked (RTL) DeconvolutionDatabases for Agilent GC/MSD Systems pub # 5989-7875

Screening for Pesticides in Food Using the Japanese Positive List

Pesticide Method: Benefits of Using GC/MS with Deconvolution

Reporting Software and a Retention Time Locked Mass Spectral

Database pub # 5989-7436

Can "Deconvolution" Improve GC/MS Detectability? 5990-5052

DRS App Notes Available

Commercial and RTL Databases


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Commercial and RTL Databases

F RTL D t b


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Free RTL Databasesat http://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/default.aspx

RTL GC/MS Databases for OrganotinDerivatives

Includes methyl, ethyl, and pentyl derivatives

VOC MS Library and RTL Databases for GCand MS

Includes the GC RT-locked database, the MSscreener database, and full-spectra library of 65volatile organic compounds

PCB Congener GC/MSD RTL Databases Includes two RT-locked screener databases andMS library for 209 PCB congeners.

Forensic Toxicology GC/MSD RTLDatabases

Includes an RT-locked screener database and MSlibrary for 277 drugs and other substances

Fatty Acid Methyl Ester GC and GC/MSDRTL Databases

Includes RT-locked GC retention time databasesand GC/MSD spectral libraries and screenerdatabases for 37 common FAMEs

Flavors RTL Databases for GC/FID andGC/MS

Includes RT-locked GC/FID and GC/MS retentiontime databases and mass spectral librarycontaining 409 compounds.

Allergens DRS Database for GC/MS Includes RT-locked GC/MS method, retentiontime databases and mass spectral librarycontaining 24 regulated allergens and theirisomers (total 32 target compounds and 1internal standard), installation guide and relatedapplication note.

Wh i i Ai T i ?
http://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcmsRtlOrganotin.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcmsRtlOrganotin.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsVocRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsVocRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsPcbCogenerRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcForensicRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcForensicRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFattyAcidRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFattyAcidRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFlavorsRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFlavorsRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GCMSAllergensDRS.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GCMSAllergensDRS.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFlavorsRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFlavorsRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFattyAcidRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcGcmsFattyAcidRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcForensicRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcForensicRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsPcbCogenerRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsVocRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/MsVocRtl.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcmsRtlOrganotin.aspxhttp://www.chem.agilent.com/en-US/Support/Downloads/Utilities/RetentionTimeLocking/Pages/GcmsRtlOrganotin.aspx


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Who are monitoring Air Toxics?

Contract laboratories

Research laboratories and universities

Government agencies in charge of

environmental monitoring regulations Industry/manufacturing monitoring personal

exposure

Agencies involved in land remediation

Health trusts interested in breath analysis fordisease marker recognition

Summary


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Summary

Whichever vapour-phase organic chemicals are of interest

Whatever your air monitoring application

Whether its VOCs

in whale breath

Photograph courtesy of: Dr. Rei Rasmussen,Oregon Graduate Institute, USA

or the most

polluted air on the

planet

F th i f ti


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Further information

Markes website

Thermal Desorption

Application notes

Brochures

Environmental applications guide

Further information


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TDTS 16Analysis of ozone precursors

TDTS 80 Evaluation of a Soil Gas sorbent tube for improving the

measurement of volatile and semi-volatile fuel vapors in soil contaminated land TDTS 81 EPA TO-15 canister analysis

TDTS 86 EPA TO-17 tube analysis

TDTS 87Analysis of Ultra volatile GHGs

TDTS 78 Low level odorants in drinking water

TDTS 29 VOC air monitoring technology and its application to contaminatedland

TDTS 47 The analysis of landfill gas compounds using thermal desorptionGC/MS and a RTL Database

TDTS 49 Fence-line and ambient monitoring of benzene and otherhydrocarbons using diffusive sampling and thermal desorption analysis

TDTS 37 Industrial air monitoring using pumped sampling onto sorbent tubesand the UNITY thermal desorber

TDTS 77 Using thermal desorption for industrial (stack) emission testing

Further information

Th k f tt ti !


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[email protected]

Thank you for your attention!

Questions???

Documents

Hebestreit TD AmbientAir