Thermal Desorption Aerosol Gas Chromatography (TAG)/

Mass Spectrometry Development

Wen Xu, Build Team, John Jayne09/08/2018

AMS User’s meeting

What is TAG and Why we need TAG

• TAG = Thermal desorption + Gas Chromatography

• AMS only gives total organics with No/Minimal molecular information. TAG complements AMS data by adding molecular information.

• Molecular tracers (specific molecules identified in various sources) identified by TAG could be used for source apportionments.

2

What makes ARI TAG different from others

• Online (eliminates sample collection, transportation, storage, and preparation process)

• In-situ derivatization• Liquid injection for internal/external calibration• Optional light weighted portable mini GC oven (ADI)

3

GERSTEL TDS 3C / TDS-A2

MarkesTD 100-xr

TAG theory of operation

MSGC Column

ValvelessManifold

CollectionThermal DesorptionCell

FocusingTrap

Carrier He in

Sample in

Pump out

Step 0

Inner surface of CTD, impactor, and VLM is Inertium® (from AMCX) coated

4

TAG theory of operation

MSGC Column

ValvelessManifold

CollectionThermal DesorptionCell

FocusingTrap

Carrier He in Pump out

Vent

Step 1

5

TAG theory of operation

MSGC Column

ValvelessManifold

CollectionThermal DesorptionCell

FocusingTrap

Carrier He in Pump out

Back FlushStep 2

6

TAG theory of operation

MSGC Column

ValvelessManifold

CollectionThermal DesorptionCell

FocusingTrap

Carrier He in

Sample in

Pump out

Step 3

7

TAG theory of operation

MSGC Column

ValvelessManifold

CollectionThermal DesorptionCell

FocusingTrap

Carrier He in Pump out

Vent

Step 1

8

Particle humidification, collection, removal, and flow measurement system

Flow measurement element RH/T box

Pump

RHT sensor

RHT sensor

Sample

HEPA HEPA

Auto Valve

3/2 solenoid valve

Humidifier

9

Particle humidification, collection, removal, and flow measurement system

Flow measurement element RH/T box

Pump

RHT sensor

RHT sensor

Filter

HEPA HEPA

Auto Valve

3/2 solenoid valve

Humidifier

10

Particle humidification, collection, removal, and flow measurement system

Flow measurement element RH/T box

Pump

RHT sensor

RHT sensor

Bypass

HEPA HEPA

Auto Valve

3/2 solenoid valve

Humidifier

11

Derivatization (N-Methyl-N-trimethylsilyl-trifluoroacetamide, MSTFA)

Test tube1 Test tube2

MSTFA

Helium flow direction

To the 1/16’’ Swagelok tee

From the 1/16’’ Swagelok union on the ASCO solenoid valve

Test tube cap

Test tube cap

R-COOH R-COO(Si(CH3)3)R-OH R-O(Si(CH3)3)-NH + MSTFA = -N(Si(CH3)3)-SH -S(Si(CH3)3)… …

12

Standard liquid injection system7 port/6 position selector valve 6 port/2 position switching valve

Load sample 1 into “sample” loop

Inject sample 1 from “sample” loop into CTD

He

CTD

MXP7970 MXP7900

MXP7970 MXP7900

He

CTDWaste

Waste13

Helium flow distribution

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Helium flow distribution

15

CTD Transfer

Helium flow distribution

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Back Flush

Desktop software for sequence creation and data logging

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TAG sequence Builder

Desktop software for sequence creation and data logging

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TAG Run Builder

Desktop software for sequence creation and data logging

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TemperatureFlowRHPressureOverview

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Desktop software for sequence creation and data logging

Set and ReadFlowPressureRHAmbient TemperaturesAIODIOGC Ready, …

Configurable names

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Desktop software for sequence creation and data logging

Set and ReadOctal TemperaturesPID Ramp/Soak profiles

Configurable names

Two different types of instrument

Stand alone TAGand Agilent GC/MS

TAG EI-HTOF

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Systems delivered

• 2 Stand alone TAG• 1 TAG EI-HTOF• 2 TAG-AMS• 3 sets of TAG parts

23

Sample data from ambient

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Liquid Internal standard

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Problems list encountered up to date• Liquid water condensation into the system, leading to failure of Focusing trap and/or RHT sensors• Outgas of the HEPA filters, causing problem with filter (gas) channel. Denuder might be better• Clogging of 9-jet impactor. Replacing it requires dissemble the ICTD from the manifold• Transfer line failure (both user fault and mechanical leakage) from GC to MS (specific for the EI-

HTOF)• 24V power supply failure• Might still have cold spots for (CTD-VLM arm and VLM-Trap arm)• Retention time from mini-GC oven Not stable (does not apply to stand alone TAG)• Intermittent loss of Octal temperature controller set temperature command• The DVZ, and standard injection test tube connections are limiting the high end pressure of GC… many moreRecently, ARI auto value leaking

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We are building our own system to work on resolving those issues !

Slides from Users

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HKPolyU

Slides from Users

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Peak

Are

a of

C24

D50

Local time

Test #1 (N=73) Test #2(28) Test #3 (N=59)

HKUST

Alkanes iso and anteiso alkanes Hopanes and steranes PAHsheptadecane(n-C17) iso-Nonacosane(iso-C29) 22,29,30-Trisnorneophopane (Ts) acenaphthylene152

prstane(i-C19) anteiso-Nonacosane(anteiso-C29) 22,29,30-Trisnorphopane (Tm) acenaphthene154octadecane(n-C18) iso-Triacontane(iso-C30) ab-Norhopane (C29ab-hopane) fluorene166

phytane (i-C20) anteiso-Triacontane(anteiso-C30) 22,29,30-Norhopane (29Ts) phenanthrene178nonadecane(n-C19) iso-Hentriacontane(iso-C31) aa-+baNorhopane (C29aa- +ba-hopane) anthracene178

icosane(n-C20) anteiso-Hentriacontane(anteiso-C31) ab-Hopane (C30ab-hopane) fluoranthene202heneicosane(n-C21) iso-Dotriacontane(iso-C32) aa-Hopane (C30aa-hopane) pyrene202

docosane(n-C22) anteiso-Dotriacontane(anteiso-C32) ba-Hopane (C30ba-hopane) cyclopenta[cd]pyrene226tricosane(n-C23) iso-Tritriacontane(iso-C33) abS-Homohopane (C31abS-hopane) benzo[c]phenanthrene 228

tetracosane(n-C24) anteiso-Tritriacontane(anteiso-C33) abR-Homohopane (C31abR-hopane) benz[a]anthracene 228pentacosane(n-C25) abS-Bishomohopane (C32abS-hopane) chrysene228hexacosane(n-C26) abR-Bishomohopane (C32abR-hopane) triphenylene228

squalane(i-C30) 22S-Trishomohopane (C33) benzo[b+k]fluoranthene252heptacosane(n-C27) 22R-Trishomohopane (C33) benzo[a]fluoranthene252

octacosane(n-C28) 22S-Tretrahomohopane (C34) benzo[e]pyrene252nonacosane(n-C29) 22R-Tretrahomohopane (C34) benzo[a]pyrene252

tracontane(n-C30) 22S-Pentashomohopane (C35) perylene252hentriacontane(n-C31) 22R-Pentashomohopane (C35) indeno[1,2,3-cd]pyrene276

dotriacontane(n-C32) benzo[ghi]perylene276tritractotane(n-C33) aaa 20S+baa 20R-Cholestane 217 dibenzo[a,h]anthracene278

tetratriactoane(n-C34) abb 20R-Cholestane 218 benzo[b]chrysene278pentatriacontane(n-C35) abb 20S-Cholestane 218 dibenzo[a,c]anthracene278hexatriacontane (n-C36) aaa 20R-Cholestane 217 picene278

heptatreacontane(n-C37) aaa 20S 24S-Methylcholestane 217 coronene300octatreacontane(n-C38) abb 20R 24S-Methylcholestane 218 dibenzo[a,e]pyrene302nonatriacontane(n-C39) abb 20S 24S-Methylcholestane 218 302

tetracontane (n-C40) aaa 20R 24R-Methylcholestane 217 1,3,5-triphenylbenzene 306aaa 20S 24R/S-Ethylcholestane 217

abb 20S 24R-+baa 20R 24R-Ethylcholestane 218abb 20S 24R-Ethylcholestane 218aaa 20R 24R-Ethylcholestane 217

Semi-Volatile

Hopanes and low volatility species can’t be detected

in ambient samples!

DetectedNot detected

Slides from Users

HKUST

Slides from Users

30

Dicarboxylic acid Succinic acidGlutaric acidAdipic acidPimelic acidSuberic acidAzelaic acid

Hydroxyl-carboxylic acid Malic acidCitramalic acidTartaric acidCitric acidGlyceric acid

Aromatic acid 3-hydroxybenzoic acid4-hydroxybenzoic acidVanillic acidIsophthalic acidSyringic acid1,2,3-benzenetricarboxylic acid1,2,4-benzenetricarboxylic acid1,3,5-benzenetricarboxylic acidTerephthalic acid

Fatty acid Palmitic acidStearic acidCholesterolOleic acid

Saccharides GlycerolGalactosanMannitol MannosanLevoglucosanGlucoseSucrose

Isoprene SOA tracers 2-methylglyceric acid *2-methylthreitol *2-methylerythritol *cis-2-methyl-1,3,4-trihydroxy-1-butane *3-methyl-2,3,4-trihydroxy-1-butane *trans-2-methyl-1,3,4-trihydroxy-1-butane

α-pinene SOA tracers Pinonic acidPinic acid *3-hydroxyglutaric acid *3-hydroxy-4,4-dimethylglutaric acid *3-methyl-1,2,3-butanetricarboyxlic acid *3-acetylglutaric acid *3-isopropylglutaric acid *

β-caryophyllene SOA tracer β-caryophyllinic acid *Naphthalene Phthalic acidToluene SOA tracer 2,3-dihydroxy-4-oxopentanoic acid *

Volatility ↑

Polar acids & SOA tracers

DetectedNot detected

HKUST

Slides from Users

31

There is significantly difference on the two groups at 95% confidence level

Trial one Trial two

→ No significantly difference between filtered and total phase sampling !!! ???

HKUST

Slides from Users

32

Cold spots?

HKUST

Shift of retention in mini GC

33

Peak shifts : 13 sDouble the peak width

Shift of retention in Agilent’s GC

34

Peak position on top of each other

Alternative mini GC oven used for Fast-GC

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http://www.aerodyne.com/sites/default/files/u17/FastGC_Vocus.pdf

Project Leader: Brian LernerEmail: blerner@aerodyne.com

We might be able to modify the design to accommodate higher max temperature for TAG

Adding extra heater on the arms of Ironman

36

Alternative Filter Collection Thermal desorption Cell (F-CTD)

37

I-CTDF-CTD

New rack mount electronics

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c-TAG

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VOC column:Targeted: C5~C16

SVOC column:Targeted: C12~C40Filter CTD

Sorbent tube

6 port chromatography valve

VOC TAG calibration systemAdapted from PTR calibration

EI-HTOF inlet

Ball Valve

Zoomed in view of the FCTD

40

Filter CTD

SVOC Purge Tee

Purge upstream

Purge downstream

Valveless manifold

Ball Valve