1. Analysis of Pesticides and Contaminants using
HS-SPME-GC/MS and DRS Detection
Blair Surridge, Tyler Dyer, Rene Bilideau, Paloma Bertolin Presoti

2. Applied Research at Camosun College
 Provides funding to support collaborations with local companies
in commercialization, technology transfer, or technology
adaptation type projects

3. Project Goals
 Develop a HS-SPME-GC/MS method for the analysis of a
large number of pesticides and contaminants in fruits and
vegetables
 Evaluate the use of DRS as a detection and quantification
method for pesticides and contaminants.

4.  Selection of Pesticides and Contaminants
 Development of a HS-SPME Method
 AOAC QuEChERS Method 2007.01
 SPME vs QuEChERS Method Performance
Characteristics
 Analysis of Fruits/Vegetables Samples
Outline

5. Selection of Pesticides
Compound selection was based on frequency of detections
12845 samples
3078 samples

6. Selection of Pesticides
A page-by-page review was carried out

7. Compounds Selected For
Method Validation
73 compounds prepared
into 4 solutions were
purchased for use in the
project
Fluoranthene
2,4,4'-Trichlorobiphenyl (PCB 28)
2,2',4,5,5'-Pentachlorobiphenyl (PCB 101)
2,2',5,5'-Tetrachlorobiphenyl (PCB 52)
2,2',4,5,5'-Hexachlorobiphenyl (PCB 153)
2,2',3,4,4',5,5'-Heptachlorobiphenyl (PCB
180)
Phenanthrene
Pyrene
bis(2-Ethylhexyl)phthalate
2,4'-DDE
2,4'-DDD
2,4'-DDT
a-Chlordane
g-Chlordane
Chlorothaloni
Chlorpyrifos
Diazinon
Dimethoate
Ethion
Fenthion
Imazalil
Malathion
Methyl parathion
Mirex
Phosalone
Phosmet
Prochloraz
Trichlorfon
Azoxystrobin
Bifenthrin
Buprofezin
Captan
Carbaryl
Carbofuran
Clofentezine
Cypermethrin
Difenoconazole
Diphenylamine
Fludioxonil
Metalaxyl
Myclobutanil
Permethrin
Pirimicarb
Pyraclostrobin
Pyrifenox
Pyrimethanil
Simazine
Thiabendazole
Triadimenol
Atrazine
Trifloxystrobin
Aldrin
a-BHC
b-BHC
g-BHC
d-BHC
p,p'-DDD (4,4')
p,p'-DDE (4,4')
p,p'-DDT (4,4')
Dieldrin
Endosulfan I
Endosulfan II
Endosulfan sulfate
Endrin
Endrin aldehyde
Endrin ketone
Heptachlor
Heptachlor epoxide (isomer B)
Methoxychlor

8. GC/MS Conditions
GC : Agilent 7890 with CTC CombiPal including SPME/Headspace
 Column: ZB-5MS, 30m x 0.25mm x 250µm (Phenomenex)
 Injection volume: 1µL
 Inlet Conditions: Pulsed Split less at 270oC, constant pressure
 Retention Time Locking: Methyl chlorpyrifos , 12.7 min at 22.5 psi
Mass Spec : Agilent 5975C
 Ionization mode: EI (+) ion
 Source Temp: 250oC
 Acquisition: SIM (5 time segments)
 mass scan: 50-400 m/z
0
50
100
150
200
250
300
350
0 10 20 30
Temperature(oC)
Time (mins)
Column Oven Temperature
Program

9. Example Chromatogram
 TIC from SIM acquisition
5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
2000000
Abundance
TIC: 08dec14_001.DDATASIM.MS

10. Sample Homogenization
 Use of an Osterizer food processor

11. Headspace SPME
Method
sample + aqueous extracting solvent
SPME extraction on to fiber
(extraction temperature and time)
Desorption in GC inlet
Analysis by GC/MS (SIM & open scan
acquisition)

12. Effect of Solution pH
0
200000
400000
600000
800000
1000000
1200000
NaH2PO4 pH4
NaCl pH 7
NaH2PO4 pH 8
Response
All solvent solutions
contained 1%MeOH
Incubation temperature 100 0C, Incubation time 20min
using a 150ng/g spiked organic grape sample

13. Effect of Extraction Temperatures
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
40◦C +
20min
60◦C +
20min
80◦C +
20min
100◦C +
20min
120◦C +
20min
140◦C +
20min
Diphenylamine
0
2000
4000
6000
8000
10000
40◦C +
20min
60◦C +
20min
80◦C +
20min
100◦C +
20min
120◦C +
20min
140◦C +
20min
Phosmet
0
2000000
4000000
6000000
8000000
10000000
12000000
40◦C +
20min
60◦C +
20min
80◦C +
20min
100◦C +
20min
120◦C +
20min
140◦C +
20min
Phenanthrene
0
500000
1000000
1500000
2000000
2500000
40◦C +
20min
60◦C +
20min
80◦C +
20min
100◦C +
20min
120◦C +
20min
140◦C +
20min
Diazinon
Optimal Temperature:
110oC

14. Effect of Extraction Time
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
10min 20min 45min 60min
Cyprodinil
0
1000000
2000000
3000000
4000000
5000000
6000000
10min 20min 45min 60min
Phenanthrene
0
500000
1000000
1500000
2000000
2500000
10min 20min 45min 60min
Response
Incubation Time (min)
Diphenylamine
0
200000
400000
600000
800000
1000000
1200000
1400000
10min 20min 45min 60min
Diazinon

15. Extraction Times (cont’d)
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
10min 20min 45min 60min
Atrazine
0
500000
1000000
1500000
2000000
2500000
3000000
10min 20min 45min 60min
Bifenthrin
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
10min 20min 45min 60min
Myclobutanil
0
200000
400000
600000
800000
1000000
1200000
1400000
10min 20min 45min 60m
Diazinon
Optimal Time: 20 min

16. Incubation temperature 110 0C, Incubation time
20min using a 150ng/g spiked organic grape sample
Diphenylamine
Cyprodinil
PCB 101
Methyl Parathion
Diazinon
Phosmet
Phosalone
Atrazine
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
4000000
4500000
Response
Fiber
Effect of Fiber Type

17. Effect of Fiber Type
0
10
20
30
40
50
60
70
80
90
100
PDMS/DVB vs
Polyacrylate
PDMS/DVB vs 30um
PDMS
PDMS/DVB vs
DVB/CAR/PDMS
PDMS/DVB vs 100um
PDMS
%Difference
Comparisons
%Difference of DMS/DVB vs the other fibers

18. Developed Headspace
SPME Method
1.0 gram of sample + 3mL of 1% MeOH in
NaCl sat’d water
SPME for 20minutes with a 65µm
PDMS/DVB fiber at 110oC
Desorption in GC inlet at 270oC for 2
minutes
Analysis by GC/MS (SIM & open scan
acquisition)

19. SPME Calibration Data
 Carried out in Grape Matrix
 External standard
 No sample manipulation
steps!
Level
Concentration
(ng/mL) Response
CS1 2.5 9271
CS2 5.0 17274
CS3 10.0 33599
CS4 20.0 69378
CS5 30.0 89799
CS6 50.0 177069
CS7 90.0 282137
CS8 150.0 461282
Incubation temperature: 110 0C
Incubation time: 20min
SPME Fiber: 65 um PDMS/DVB

20. SPME Calibration In Matrix
 No significant difference observed
0
10000
20000
30000
40000
50000
0 100 200 300 400
Response
Concentration (ng/g)
Diphenylamine
Grape
Tomato
No Matrix
Raddish
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
0 100 200 300 400
Concentration (ng/g)
Phenanthrene
Grape
Tomato
No Matrix
Raddish

21. QuEChERS Method 2007.01
 Quick, Easy, Cheap, Effective, Rugged and Safe
(QuEChERS)
 Method AOAC 2007.01
 Use of dSPE material containing(C18 and PSA)

22. SPME vs QuEChERS
Level
Ciprodinil
Concentration
(ng/g) Response
CS1 2.5 9271
CS2 5.0 17274
CS3 10.0 33599
CS4 20.0 69378
CS5 30.0 89799
CS6 50.0 177069
CS7 90.0 282137
CS8 150.0 461282
Level
Ciprodinil
Concentration
(ng/g) Response
CS1 5 558
CS2 10 1095
CS3 20 2299
CS4 40 4745
CS5 60 5905
CS6 100 11455
CS7 180 19153
CS8 300 31102
~10x

23. Detection Limits (in Strawberries)
Selected
Analytes
RT (min) Ion
(m/z) SPME
LOD (ng/g)
QuEChERS
LOD (ng/g)
%
Recovery
QuEChERS
% Recovery
SPME
Organophosphates
Chlorpyrifos 12.7 197 0.06 5.4 108 166
Ethion 15.7 231 3.73 2.8 113 177
Fenthion 12.9 278 0.10 1.8 98 155
Malathion 12.7 125 13.24 NA 106 103
Organochlorines
Aldrin 12.9 66 0.04 3.3 79 147
a-BHC 9.9 183 0.02 2.9 131 117
b-BHC 10.4 219 0.04 15.4 95 92
a-Chlordane 14.2 375 0.01 0.5 92 138
g-Chlordane 14.4 375 0.03 1.1 95 141
Chlorothalonil 10.9 266 1.95 18.8 100 88
2,4’-DDT 16.4 235 0.06 0.7 93 165
Dieldrin 11.9 263 3.02 3.1 103 107
Organonitrogens
Buprofezin 15.0 105 0.09 12.8 98 135
Cyprodinil 13.5 224 0.10 2.6 Na 130
Diphenylamine 9.1 169 0.13 2.6 101 93.7
Triazine 18.5 239 1.26 3.6 74 132
Permethrin 19.4 183 NA 1.4 105
Contaminants
Anthracene 11.1 178 0.08 2.8 101 122
Phenanthene 10.9 178 0.04 2.7 92 121
PCB 28 11.9 256 0.03 1.8 85 131
PCB 101 14.3 326 0.04 1.3 86 117

24. Summary of DRS Detection
 Agilent’s G1672AA (Pesticide and endocrine disruptor RTL and mass
spectral library, 926 entries)
 NIST ‘08 mass spec library
Extraction
method used
10ppm
DRS
10ppm
SIM
5ppm
DRS
5ppm
SIM
1ppm
DRS
1ppm
SIM
0.5ppm
DRS
0.5ppm
SIM
0.05ppm
DRS
0.05ppm
SIM
QuEChERS
Organic Grape
Matrix
64/68 68/68 56/68 68/68 37/68 68/68 28/68 59/68 7/68 28/68
QuEChERS
No Matrix 68/68 68/68 56/68 68/68 42/68 68/68 25/68 59/68 7/68 28/68
SPME N/A N/A N/A N/A 53/68 68/68 52/68 68/68 39/68 61/68
QuEChERS
Strawberry
Matrix
63/68 68/68 N/A 68/68 43/68 68/68 24/68 58/68 6/68 28/68
QuEChERS
Potato Matrix 64/68 68/68 N/A 68/68 40/68 68/68 23/68 54/68 6/68 22/68

25. MRL Data
Select Compounds Grape MRL values
(ppm)
QuEChERS DRS detection SPME DRS Detection
Organophosphates
Chlorpyrifos 0.01 No Yes
Malathion 8.0 Yes Yes
Phosalone 5.0 Yes Yes
Diazinon 0.75 Yes Yes
Phosmet 10 Yes Yes
α-Chlordane 1.0 No Yes
Organochlorines
Heptachlor 0.2 No Yes
α-BHC 1.0 Yes Yes
2,4’-DDT 1.0 Yes Yes
Heptachlor epoxide 0.5 No Yes
Aldrin 0.2 No Yes
Organonitrogens
Thiabendazole 10 Yes Yes
Cyprodinil 2 Yes Yes
Buprofezin 1.0 Yes Yes
Diphenylamine 5.0 Yes Yes
Trifloxystrobin 2.0 Yes Yes
Pyrimethanil 5.0 Yes Yes

26. Results from Survey
 A 103 local samples (domestic, import, and unknown)were tested using both
the standard AOAC extraction protocol and the developed HS-SPME methods
 Below is a list of detection information from the results
Sample Type
Compound
Name
Chem
station
amount
(ppm)
DRS amount
(ppm)
QuEChERS SIM
detection?
SPME SIM
detection?
DRS detect
(Q or S)?
Match
Quality
MRL Value
(ppm)
Green Grapes Cyprodinil 2.19 2.41 Yes Yes Both 98 2
Buprofezin 0.38 0.51 Yes Yes Both 81 1
California
Strawberry Cyprodinil 0.24 0.12 Yes Yes Both 85 2
Quinoxyfen 0.08 Yes Yes Both 86 0.9
BC strawberry Cyprodinil 0.37 0.59 Yes Yes Both 97 2
Fludioxonil 0.70 0.72 Yes Yes Both 84 3
Boscalid
(Nicobifen) 0.59 Yes Yes Both 91 4.5
Potato Chlorpropham 0.79 Yes Yes Both 98 15
Bisphenol A 0.34 Yes Yes Both 90 N/A
Basil Azoxystrobin 2.95 1.07 Yes
Not enough
sample Q 92 0.5-10
Metalaxyl 3.98 2.06 Yes
Not enough
sample Q 99 0.1-1.0

27. Results from Survey
 More results
Sample Type Compound Name
Chem station
amount (ppm)
DRS
amount
(ppm)
QuEChERS
SIM
detection?
SPME SIM
detection? DRS detect (Q or S)?
Spartan Apple Pyrimethanil 0.12 - Yes Yes no
Paprika Ethoxyquin N/A 9.80 Yes Yes Both
Chili Powder Ethoxyquin N/A 41.36 Yes Yes Both
Garlic Powder Anthracene 0.07 0.06 Yes Yes Both
Cherry Tomato Buprofezin 0.07 0.05 Yes Yes Both
Piperonyl
butoxide 5.14 Yes Yes Both
Pyriproxyfen 0.26 Yes No
Red Pepper Chlorpyrifos 0.32 0.19 Yes Yes Both
Tea Bifenthrin 0.141 0.13
Raspberry Iprodione 0.07 Yes Yes Both

28. E.G.Chromatogram - Cyprodinil
 Measured concentration was 2.1 ppm from grape
sample

29. Hot off the press!

30. Conclusions
 A simple and highly automated screening method
capable of measuring a diverse set of pesticides and
contaminants was developed and evaluated
 More work is needed regarding…..
 quantitation and the use of internal standards.. Use of
triphenylphosphate
 Confirmation is required for the detected pesticides
above the MRL level

31. Acknowledgments
 Special thanks to the following organizations
SCIENCE
WITHOUT
BORDERS
BRAZILIAN
SCHOLARSHIP
PROGRAM
 Special thanks to the
students
 Paloma Bertolin
 Tyler Dyer
 Brenna Stanford