Simultaneous sampling and analysis of indoor air infested by Cimex lectularius L. (Hemiptera: Cimicidae) with solid phase microextraction, thin film microextraction and needle trap device

Sanja Risticevic1, In-Yong Eom2, Janusz Pawliszyn1

1 Department of Chemistry, University of Waterloo, Waterloo, ON, Canada; 2 Department of Life Chemistry, Catholic University of Daegu, Gyeongsan, Korea

Air in a room infested by Cimex lectularius L.(Hemiptera: Cimicidae) was sampled simultaneouslyby three different sampling devices including solidphase microextraction (SPME) fiber coatings, thinfilm microextraction (TFME) devices, and needletrap devices (NTDs) and then analyzed by gaschromatography-mass spectrometry (GC-MS).

The results presented in the current study illustratecomprehensive characterization of infested indoorair samples through the use of three different non-invasive SPME formats and identification of novelcomponents comprising C. lectularius pheromone,therefore, promising future alternatives for use ofpotential synthetic pheromones for detection ofinfestations.

thermodynamic theory of SPME

ne = (Kfs.Vf

.Vs. Co ) / (Kfs

.Vf +Vs)

nemass extracted at equilibrium;

Kfsfibre coating/sample matrix distribution constant of analyte;

Vfcoating volume;

Vssample volume;

Coconcentration of analyte;

A surface area of extraction phase;

dn/dtextraction rate;

Dsdiffusion coefficient;

δthickness of boundary layer;

(b- a)extraction phase thickness;

teequilibrium time

Kfs.Vf << Vsi

↓ Kfsii

ne = Kfs.Vf

. Co

sample volume independent

SPME Devices & Sampling Conditions

thin film microextraction device; TFME

extraction time 3.5 hr

sample introduction

sampling method for TFME devices & SPME coatings

Electric Fan

Wind direction

SPME fibers

TFME devices

needle trap device; NTD

NH PS

SP SH SB

3 cm 10 cm

12 cm

SBsorbent;

SPspiral plug;

SHside hole;

NHneedle head;

PSPTFE sealer

sampling method for NTD devices

extraction time 20 min

Vacuum Pump

Side sealer

Flow restrictor

Adaptor NTD

sampling indoor air by providing

agitation

sampling indoor air by providing active sampling

performance of TFME devices

discrimination of low-boiling point compounds

performance characteristics# of peaks tentatively identified: 22;

poor retention capacity of PDMS membrane;

volatile analyte losses due to prolonged times between sampling & GC-MS analysis;

suitable for more biased & targeted screening studies involving high boiling point components

TIC chromatogram;

highly infested air sample

performance of SPME & NTD devices

*

*

*

TIC chromatograms;

highly infested air sampleNTD

SPMEDVB/CAR/PDMS fibre coating

(E)-2-hexenal

(E)-2-octenal

two major components of C. lectularius alarm pheromone

&

(E)-2-octenal

↑ fibrecoating/sample matrix distribution constant

Introduction & Theory Results & Discussion Results & Discussion - continuedperformance characteristics

SPME

NTD

suitable for volatile & semivolatile analytes: non-particulate bound & have high Kfs values (mid-elution region)

suitable for sampling of analytes from access-restricted areas & narrow openings; suitable for unbound & particulate-bound analytes

biomarkers of infestation

RSD (n=3); %SPME1.4% (alpha-terpineol) to 26.1% (3-carene)

TFME1.2% (2-methylhexadecan-1-ol) to 10.1% (hexyl cinnamic aldehyde)

0

20

40

60

80

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Analyte Code

Nor

mal

ized

Res

pons

e; %

area of higher infestationarea of lower infestation

1) D-limonene,

2) 2-ethylhexanol,

3) (E)-2-octenal,

4) nonanal,

5) L-menthol,

6) alpha-terpineol,

7) decanal,

8) tetradecane,

9) longifolene,

10) pentadecane,

11) hexadecane,

12) diethyl phthalate,

13) cedrol,

14) heptadecane

ConclusionsThis study illustrated the comparison of performancecharacteristics of SPME, TFME & NTD devices insampling of C. lectularius infested indoor air samples,pheromone characterization & detection of biomarkersof infestation.

AcknowledgementsDow AgroSciences (Indianapolis, IN, USA);GERSTEL (Linthicum, MD, USA);NSERC