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

1

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Objectives

2

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)

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Methods for the Direct Analysis of ETO

3

Authors & Journal Sample matrix Method

Gordon et al.

57th TSRC (2003)

Mainstream cigarette smoke

GC-MS

Dong et al.

62th TSRC (2008)

Mainstream cigarette smoke

GC-MS

Masters et al.

Coresta (2009)

Mainstream cigarette smoke

GC-MS

Gillman et al.

Coresta 2012

Mainstream cigarette smoke GC-MS

Otte et al.

Coresta 2013

Mainstream cigarette smoke GC-MS

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Physicochemical Properties

4

Appearance: colorless gas

Molecular formula: C2H4O (MW=44.05)

BP: 10.8°C

MP: -111°C

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

EI Mass Spectrum

5

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

Rela

tive A

bun

dance (

%)

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

6

Potential Interference Peaks

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Direct Method : Analytical Conditions

7

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Direct Method: Chromatogram (3R4F Smoke )

8

m/z=47

Methanethiol

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

m/z=44 Ethylene oxide

RT time window

TIC

2.6 3.6 4.6 5.6 6.6 7.6 min

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Direct Method: Analytical Conditions

9

Instrument Parameters

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

Injector temperature 220°C

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

Injection volume 1 µL

Transfer line temperature 200°C

Source temperature 230°C

MS quad 150°C

Ionization mode Scan

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Direct Method: Chromatogram (3R4F Smoke )

10

3.7 4.7 5.7 6.7 7.7 8.7 min

TIC

MeOH

44 m/z=44

Ethylene oxide ?

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Effects of Interference Peak on ETO Analysis

11

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Reaction Sequence: Indirect Method

12

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Experimental Steps

13

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Analytical Conditions

14

Instrument Parameters

Column ZB-1 (60 mX0.25 mmX1.0 µm)

Injector temperature 250°C

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

Injection volume 1 µL

Transfer line temperature 250°C

Source temperature 230°C

MS quad 150°C

Ionization mode SIM

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

MS Quantization Parameters

15

Component

RT

Quantifier

ion

Dwell

time

Qualifier

ion

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

2-bromoethanol

(ETO-HBr)

6.373

124

100

107/95

D4-2-bromoethanol

(ISTD)

6.329

128 100 NA

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Optimization of Derivatization Time

(3R4F smoke)

16

2450

2500

2550

2600

2650

2700

2750

2800

2850

1 10 40 70 100 130 160 190 220 250

Re

sp

on

se

Derivatization time (min)

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Optimization Amount of Derivatization

Reagent (3R4F Smoke)

17

0

200

400

600

800

1000

1200

1400

10 25 50 100 200 300 500 600

Re

sp

on

se

Volume (µL) of 48% aqueous HBr

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Linear Concentration Range

Std

level

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

18

Y=0.392x

R2=0.999

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Method Characteristics

19

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Mainstream Smoke Analysis (3R4F)

20

ETO-HBR

ISTD

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

E-cigarette Aerosol Analysis

ETO-HBR

ISTD

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Method Comparison (Derivatization vs Direct analysis)

22

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.

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Summary

23

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)

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA

Acknowledgements

24

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

2014

_ST

71_L

iuX

inyu

.pdf

Con

gres

s201

4 -

Doc

umen

t not

pee

r-re

view

ed b

y C

OR

ES

TA