Chris Rawlinson, Justin Frosina

British American Tobacco Group Research & Development, Southampton UK

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Non-targeted Analysis of Emissions From E-cigarettes

Non-Targeted Screen

Overview

• Why is a non-targeted approach required?

› Appropriate stewardship

• Challenges

› Matrix

• Existing methodology

› Not sensitive enough

• New E-cigarette Screen

› 50 fold increase in sensitivity

› 4 x faster

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Why is a non-targeted approach required?

• Requirement to assess delivery at trace levels:

› Product Stewardship

› Thermal degradation of components in formulation

› Impurities and contaminants

› Product Development

› Flavour transfer

› Formulation/Device fingerprinting

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Challenges

• No combustion, resulting in significantly ‘cleaner’ sample matrix compared to combustibles

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55mL 1R5F

55mL E-cigarette

Main Constituents

- Water - Glycerol/Propylene Glycol- nicotine- Potentially flavours

Delivery mechanism- Wick and heated coil- Flow or button actuated

Emissions- Liquid aerosol- Limited true gas phase

Challenges - High levels main constituents

E-cigarette Emission Screen

E-cigarette Summary

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6

E-Cigarette Screen

TD-GC-TOFMS + Heart Cutting

Summary of Existing Approach

GC-MS Combustible Scan Method

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Approach Results Method Performance

CFP Solvent Extract

15mL Solvent resulting in large dilution -1µL Injection

CFP SPME Analysis

SPME fibres selective and significant artefacts

detected in blanks

Tedlar BagLimited true ‘vapour

phase’

E-cigarette Emission Screen

Method Requirement

• Whole emission non-targeted screen

› Qualititative characterisation of emissions

› GC/LC - amenable components

• Semi-Quantitative

› Referenced to ISTD (order of magnitude assessment)

• 5ng/puff Threshold

› Addressing toxicant thresholds

• Defined Sampling Conditions

› Agreed standard approach

› Flexibility remains important

• Data management

› Automated approach

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Instrumental Set-up

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E-cigarette Emission Screen

ALMSCO Bench TOF-dx Agilent 7890B MARKES TD100

E-cigarette Emissions Screen

Sample Generation

• A14/LX1 Linear Syringe Drive Engine

› Consistent and flexible delivery

› Rapid sampling

› 1x 80ml 3 second puff per sample

› Disposable Tygon connector

› Zero ‘dead volume’

› Impact Vs Adsorption?

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E-cigarette Emissions Screen

Sampling – TD Tubes

• Dual bed sorbent

1. Tenax - Polymer based sorbent:

› General purpose sorbent

› Suitable for C6 – C30

› Limited water retention

› Stable to 320°C

2. Sulficarb - Molecular sieve:

› Strong sorbent – Light volatiles

› C3 – C6

› Requires water management

› Stable to 360°C

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E-cigarette Emissions Screen

Analysis – TD Automation

• Whole emissions captured on TD tube

• Automated ISTD addition› TO-14A tuning mix

› 11ng bromochloromethane

› 14.5ng 1-bromo-4-fluorobenzene

› 10ng chlorobenzene-d5

› 9.5ng 1,4-difluorobenzene

• Recollection system utilised to identify:› True components present in emission

› Components undergoing thermal degradation

but also present in emissions

› Tube/system artefacts

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E-cigarette Emissions Screen

Analysis - Recollection Explained

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3 second

E-cigarette Emissions Screen

Recollection Explained

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1

2

3

Some degradation during desorption but majority present as a result of emission: Small increase/injection

True emission component: Reducing/injection

Tube artefact: Doubling/injection

E-cigarette Emissions Screen

Why Heart-Cutting ?

• Major constituents limit detector life

› Overloaded peaks not representative

1. Manage major constituents by reducing overall loading:

› Reduction in sensitivity due to increased splits

› Unable to achieve 5ng/puff threshold

2. Managing major peaks by heart cutting to FID

› Sensitivity can be improved by reducing splits

› Ability to detect compounds present at 5ng/puff and lower

› Trace level components detectable

› Increase detector lifetime

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E-cigarette Emissions Screen

Heart-Cutting Explained

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FID/other Detector

TOF MS

GCDeans Switch

E-cigarette Emissions Screen

TD-GC-TOFMS with Heart cutting

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PG

Gly

cero

lNic

otine

FID

TOFMS

E-cigarette Emissions Screen

TD-GC-TOFMS with Heart cutting

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PG

Gly

cero

l

Nic

otine

~5ng/Puff

~5ng

10ng C

hlo

robenzene-d

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E-Cigarette Emissions Screen

Data Management - Automation

• Chemometrics platform under development› Automated component identification (multiple data files - multiplicity

threshold)

› Removes analyst subjectivity

› High throughput (< 5 minutes per sample)

› Multivariate statistical analysis

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E-Cigarette Emissions Screen

Data Management

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• Approximately 40-100 components detected at or above 5ng/puff

› Product Dependent

› Approximate C3-C13 range

RT (min) Peak Area

Peak Identification Match Factor CAS #Recollection

InterpretationEstimated mass on tube (ng)

7.202 75819119 Allyl alcohol 746 107-18-6 G 600

19.809 62969489 Glycerol + Nicotyrine 702 + 771 56-81-5 + 487-19-4 G 498

18.675 48479488 Myosmine 889 532-12-7 G 384

31.691 34136399 Cotinine 930 486-56-6 G 270

6.550 29355053 Hydroxymandelic acid ethyl ester di-TMS 696 unknown G 232

4.837 25163696 Octamethylcyclotetrasiloxane 896 556-67-2 G 199

15.482 22330272 Hexaoxacyclo octadecane 784 17455-13-9 G 177

23.572 21773939 Dioxolane-dimethanol 689 54120-69-3 G 172

8.316 21079900 Dodecamethylcyclohexasiloxane 658 540-97-6 G 167

11.232 19012572 Acetic acid 821 64-19-7 A 150

E-cigarette Emissions Screen

Thermal Desorption Approach

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E-Cig Vapour(whole)

TD Tube TD-GC-TOFMS

E-cigarette Emissions Screen

Summary

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Approach Results Method Performance

CFP Solvent Extract (60 mins)

15mL Solvent resulting in large dilution –1µL Injection

CFP SPME Analysis(70 mins)

SPME fibres selective and significant artefacts

detected in blanks

Tedlar Bag(18 mins)

Limited true ‘vapour phase’

TD

(36 mins)<5ng/puff detection

capability, one analysis

• <5ng/puff Sensitivity• Single analysis (GC)• Fully automated process• Analyst subjectivity removed• Robust data

What Next?

• Plan for ‘validation’

› Against target compound list

› Extremes of operation

› Optimise collection media

• Heat-not-Burn Screen under development

› More complex emissions

› Wide range of potential operating conditions

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Thank you for listening

Questions?

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