Determination of Ethylene Oxide (ETO) in Mainstream ... · GC-MS Dong et al. th62 TSRC (2008)...

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LABSTAT INTERNATIONAL ULC.

262 Manitou Drive

Kitchener, Ontario, Canada N2C 1L3

Phone: (519) 748-5409 Fax: (519) 748-1654 Web: www.labstat.com

Xinyu LIU, Peter JOZA , Andrew MASTERS, Bill RICKERT

Determination of Ethylene Oxide (ETO) in

Mainstream Cigarette Smoke Using

Hydrobromic Acid Derivatization and Gas Chromatography-Mass Spectrometry Method

2014 CORESTA CONGRESS

October 12-16, 2014

Québec City, Canada

Objectives

To develop a reliable method for the

analysis of ethylene oxide in tobacco smoke

To analyze low concentrations of ethylene

oxide in new generation products (e.g. e-

cigarette aerosols and heat-not-burn

emissions)

Methods for the Direct Analysis of ETO

Authors & Journal Sample matrix Method

Gordon et al.

57th TSRC (2003)

Mainstream cigarette smoke

Dong et al.

62th TSRC (2008)

Masters et al.

Coresta (2009)

Gillman et al.

Coresta 2012

Mainstream cigarette smoke GC-MS

Otte et al.

Coresta 2013

Mainstream cigarette smoke GC-MS

Physicochemical Properties

Appearance: colorless gas

Molecular formula: C2H4O (MW=44.05)

BP: 10.8°C

MP: -111°C

EI Mass Spectrum

Mass library: Wiley, NIST/EPA/NIH, FFNSC

tive A

dance (

Potential Interference Peaks

Direct Method : Analytical Conditions

Instrument Parameters

Column DB-5ms (60 mX0.25 mmX1.0 µm)

Injector temperature 220°C

Oven temperature 35 °C for 6.5 minutes; 20 °C per minute to 210 °C;

hold 3 minutes.

Column flow 1.5 mL/min

Injection mode Split mode with a split ratio 20:1

Injection volume 1 µL

Transfer line temperature 200°C

Source temperature 230°C

MS quad 150°C

Ionization mode Scan

Direct Method: Chromatogram (3R4F Smoke )

m/z=47

Methanethiol

Match 808, R. Match 962, Prob. 92.7%

m/z=44 Ethylene oxide

RT time window

2.6 3.6 4.6 5.6 6.6 7.6 min

Direct Method: Analytical Conditions

Column: DB-624 ms (60 mX0.25 mmX1.4 µm)

Column temperature 35 °C for 10 minutes; 20 °C per minute to 250°C; hold 3

minutes.

Column flow 1.5 mL/min

Injection method Split mode with split ratio 20:1

MS quad 150°C

Ionization mode Scan

Direct Method: Chromatogram (3R4F Smoke )

3.7 4.7 5.7 6.7 7.7 8.7 min

44 m/z=44

Ethylene oxide ?

Effects of Interference Peak on ETO Analysis

Reaction Sequence: Indirect Method

C2H4O (Ethylene Oxide) + HBr (Hydrobromic Acid)

BrC2H4OH (2-Bromoethanol)

Eliminate the interference from common trapping

solvent (e.g. methanol)

Provide more specific ion m/z=124 for reliable

quantitation analysis

Experimental Steps

Add 1.0 g anhydrous Na2SO4

Centrifuge 5min at 2500 rpm

GC/MS analysis

Accurately transfer 2 mL sample

Add 0.3 g Na2CO3 , wait for 30 min

Spike 200 µl ISTD (D4-2-bromoethanol )

Transfer supernatant in vial

Add 200 µl 48% HBr, wait 5 min

Analytical Conditions

Column ZB-1 (60 mX0.25 mmX1.0 µm)

Oven temperature 100 °C for 10 minutes; 20 °C per minute to 250 °C; hold 3

minutes

Column flow 1mL/min

Injection method Split mode with split ratio 10:1

MS quad 150°C

Ionization mode SIM

MS Quantization Parameters

Component

Quantifier

Qualifier

(min) (m/z) (ms) (m/z)

2-bromoethanol

(ETO-HBr)

107/95

D4-2-bromoethanol

(ISTD)

128 100 NA

Optimization of Derivatization Time

(3R4F smoke)

1 10 40 70 100 130 160 190 220 250

Derivatization time (min)

Optimization Amount of Derivatization

Reagent (3R4F Smoke)

10 25 50 100 200 300 500 600

Volume (µL) of 48% aqueous HBr

Linear Concentration Range

2-Bromoethanol

(µg/mL)

1 21.1

2 16.9

3 12.6

4 8.43

5 4.21

6 2.11

7 0.843

8 0.421

9 0.211

10 0.084

Y=0.392x

R2=0.999

Method Characteristics

Recovery (Accuracy)

Laboratory Reagent Blank (LRB) (ng/cig) 0.00

Laboratory Fortified Blank (LFB) (%) 83.6-92.0

Laboratory Fortified Matrix (LFM) (%) 81.1-94.4

Detection Limit

Limit of Detection (LOD) (ng/cig) 33.7

Limit of Quantification (LOQ) (ng/cig) 112

Mainstream Smoke Analysis (3R4F)

ETO-HBR

2.9 3.4 3.9 4.4 4.9 5.4 5.9 6.4 6.9 7.4 Min

m/z=124

m/z=128

E-cigarette Aerosol Analysis

ETO-HBR

2.8 3.3 3.8 4.3 4.8 5.3 5.8 6.3 6.8 7.3 Min

m/z=128

m/z=124

Method Comparison (Derivatization vs Direct analysis)

Method Sample Sample Replicates Mean Std. Dev. RSD

ID Matrix [n] [µg/cig] [µg/cig] [%]

Direct analysis*

3R4F MS ISO 70 23.9 6.83 28.6

3R4F MS Intense 57 65.3 12.8 19.6

HBr-derivatization

3R4F MS ISO 19 8.37 1.74 20.8

3R4F MS Intense 112 24.6 4.58 18.6

E-cig** MS Intense 3 0.212 0.022 10.3

*DB-5 column, full scan mode , ion-trap detector was used.

** Example for demonstration.

Summary

The Hydrobromic acid-derivatization method can

be used to effectively solve sample matrix

interference

The developed method can be applied to analyze

ethylene oxide in cigarette smoke and in new

generation products ( e.g. e-cigarette aerosols and

heat-not-burn emissions)

Acknowledgements

Labstat International ULC Sample Preparation Technician and Analytical Team (Mr. MingZhong Cui, Mrs. Helena Coetzer, Mrs. Gabriela Pop, Mr. Ali Ahmed)

Determination of Ethylene Oxide (ETO) in Mainstream ... · GC-MS Dong et al. th62 TSRC (2008)...

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