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Slide 1
Abdou Mekebri, Ph.D.
November 2, 2011
CALIFORNIA DEPT OF FISH AND GAMEOFFICE OF SPILL PREVENTION AND RESPONSE
FISH AND WILDLIFE WATER POLLUTION CONTROL LABORATORY
Recent Advances in the Analysis of Pyrethroid Insecticides in Surface Water and
Sediments
Slide 2
2009 Expert Tour
Outline
�Aquatic Toxicity of Pyrethroids
�GC/QQQ with Chemical
Ionization and Backflushing
�Results
�Conclusions
Slide 3
Why go to Lower Detection Limits?
�There is a direct (toxic) effect to aquatic and terrestrial
organisms from pyrethroid exposure and an indirect
effect because of the threat to their food supply.
�Synthetic pyrethroids are known endocrine disruptors
and many may be carcinogenic (USEPA).
�Synthetic pyrethroids are extremely toxic to aquatic
organisms with LC50 values < 1 ppb.
Slide 4
Toxicity in Water and Sediment
Pesticide Water Sediment
LC50
(ng/L)Organism LC50
(µg/kg)Organism
Bifenthrin 70 Hyalella azteca1 4-10 Hyalella azteca2
Cyfluthrin 140 Ceriodaphnia dubia1 4-10 Hyalella azteca2
Cypermethrin 1.5 Hyalella azteca3 3-6 Hyalella azteca3
Esfenvalerate 70 Ceriodaphnia lacustris1 4-10 Hyalella azteca2
λ-Cyhalothrin 4 Hyalella azteca4 4-10 Hyalella azteca2
Permethrin 30 Hyalella azteca1 4-10 Hyalella azteca2
1 From previous slide
2 Amwag et al., 2005, Environ. Toxicol. Chem., 24, 966-972.
3 Maund et al., 2002, Environ. Toxicol. Chem., 21, 9-15.
4 Maund et al, 1998, Pestic. Sci., 54, 408-417.
Slide 5
Detection Limits Needed
Optimal MDL use LC50/10
- Water: ~ 0.2 ng/L
- Sediment: ~ 0.3 ng/g
MDL equal to LC50
- Water: ~ 2 ng/L
- Sediment: ~ 3 ng/g
Slide 6
Improving MDLs
� Larger sample and/or injection volumes
� Use of MS/MS – lowers background noise
� Negative Chemical Ionization (nCI) – effective for
pyrethroids with Cl, F, or Br
Slide 7
PFE PFE
GPC GPC
Liq/Liq-SPE
SEDIMENT TISSUE WATER
PYRETHOID EXTRACTION METHODS
GC/ECDGC/MS/MS – EI - NCI
FLORISILFLORISILFLORISIL(if needed)
PFE: Pressurized Fluid ExtractionGPC: Gel Permeation Chromatography
DFG Sample Preparation/Analysis
Slide 8
Advantage Disadvantage
very sensitive (1-5 pg on column) dual column required for
confirmation, therefore dual data
processing
specific for halogenated compounds rely on retention times for
confirmation
excellent screening tool requires extensive clean-up
(sediment and tissue)
affordable extensive matrix interference
easy to operate cannot distinguish between
deltamethrin and tralomethrin
Analytical Instrument Comparison for Pyrethroids
Instrument: GC-ECD
Slide 9
sensitivity comparable with ECD
(2-10 pg)
narrow linearity range
MS spectra confirmation trap clean-up needed for tissue
no matrix interference requires experienced MS chemist
less data handling cannot distinguish between
deltamethrin and tralomethrin
short run time
Instrument: GC-MS Ion trap in MS-MS mode
Advantage Disadvantage
Slide 10
sensitivity comparable with
GC-MS-ion trap
not as sensitive as GC-MS-QqQ due
to polarity of compounds
best result will be obtained by APCI requires specially trained MS
chemist
distinguishes between deltamethrin and
tralomethrin
very expensive
excellent for thermo labile compounds
minimum sample clean-up required
excellent linearity
very promising for chiral separation
green chemistry
Instrument: LC-MS-MS
Advantage Disadvantage
Slide 11
extremely sensitive (0.1-2.0 pg on
column)
maintenance needed frequently
excellent for trace level in sediment
and tissue
very experienced MS chemist
needed
detects halogenated and
non-halogenated pyrethroids
expensive
best analytical tool for pyrethroids cannot distinguish between
deltamethrin and tralomethrin
Instrument: GC-MS Triple-quadrupole (QqQ)
Advantage Disadvantage
Slide 12
Instrumentation & Backflush Configuration
Purged Ultimate Union
Vent
Aux EPC
QQQ
MS
Purged UnionMM Inlet
Agilent 7890A/7000B GC/QQQWith Chemical Ionization
Two 15 m XLB
Slide 13
Vent
Aux EPC
QQQ
MS
Purged UnionInlet
Agilent 7890A 7000B
Two 15 m HP-5MS UI
Injection & analysis During Backflush
Mid-column Backflush
Vent
Aux EPC
QQQ
MS
Purged UnionInlet
Agilent 7890A 7000B
Two 15 m HP-5MS UI
Begin backflushing after last analyte passes purged union
or during post run
Slide 14
Bifenthrin, 1 ppb Standard: NCI-SIM and NCI-MRM (methane)
MRM transition: 386→205 (green)SIM ion: 386 (purple)
SIM
S/N = 55
MRM
S/N = 7158
Slide 15
Comparing Methane and Ammonia Reagent Gases for NCI GC/MS/MS Analysis of Pyrethroids
Fenvalerate I
Esfenvalerate
Ammonia
Methane
Slide 16
Pyrethroids-50fg (n=8)-NCI
Slide 17
Pyrethroids-20fg-NCI-large volume injection
Slide 18
Cypermethrin MRM by NCI Ammonia
0.020-10 µg/L
Slide 19
Deltamethrin MRM by NCI Methane
0.050-10 µg/L
Slide 20
Sediment-100fg spike
Slide 21
GC/ECD DB5 - Sediment Extracts
min10 15 20 25 30 35 40
Hz
500
1000
1500
2000
2500
ECD1 A, (L-200-10-SED_RR\L-200-10-SED_RR 2010-07-27 15-51-46\049F4901.D)
DB
OB
Bif
en
thri
n
DB
CE
Cy
h,L
-2
Pe
r-tr
an
s
Cy
f-1
Cy
f-2
Cy
f-4 C
yp
-1 C
yp
-2 C
yp
-3 C
yp
-4
Esf
-1
Es
f-2
De
ltam
eth
rin
Sediment - F4
ECD2 B, (L-200-10-SED_RR\L-200-10-SED_RR 2010-07-27 15-51-46\049F4901.D)
min10 15 20 25 30 35 40 45
Hz
250
500
750
1000
1250
1500
1750
2000
ECD1 A, (L-200-10-SED_RR\L-200-10-SED_RR 2010-07-27 15-51-46\026F2601.D)
DB
OB
Bife
nth
rin
Fe
np
rop
ath
rin
DB
CE
Cyh
,L-1
Cy
h,L
-2
Pe
r-c
is P
er-
tra
ns
Cy
f-3
Cyp
-2 C
yp-3
Es
f-1 D
elta
me
thri
n
Sediment - F2
Slide 22
Lambda-cyhalothrin MRM-NCI-MSMS
0.020 µg/L standard
methane
ammonia
Slide 23
Sediment Sample Extract by NCI - methane
deltamethrin
5.01 ng/g
es-fenvalerate
0.81 ng/g
Slide 24
22.5 25 27.5 30 32.5 35 37.5 40
Hz
0
2000
4000
6000
8000
10000
12000
14000
16000
ECD1 A, (L-333-11\L-333-11 2011-10-17 10-07-09\008F0801.D)
ECD - Round Robin Sediment Extract – 2011
Slide 25
NCI - Round Robin Sediment Extract – 2011
Slide 26
NCI - Round Robin Sediment Extract – 2011
Slide 27
MS/MS-EI-Signal to Noise and ELOD
Estimated Limit of Detection (ELOD)
Synthetic pyrethroid std conc µg/L MS/MS-EI-S/N Sediment ng/g
Allethrin 0.500 629 1.50
Parallethrin 0.500 325 0.80
Resmethrin 0.500 501 0.80
Bifenthrin 0.500 1408 0.30
Fenpropathrin 0.500 165 1.20
Tetramethrin 0.500 262 0.50
Phenothrin 0.500 686 0.50
Cyhalothrin 0.500 197 0.35
Permethrin cis 0.500 423 0.75
Permethrin trans 0.500 362 0.95
Cyfluthrin 0.500 24.5 0.35
Cypermethrin 0.500 40.0 0.45
Es-fenvalerate 0.500 57.4 0.25
Deltamethrin 0.500 30.9 0.50
Slide 28
MS/MS-NCI-Signal to Noise and ELOD
MS/MS-NCI-Signal to Noise S/N
Estimated Limit of Detection (ELOD)
Synthetic pyrethroid
std conc µg/L Methane Ammonia Water ng/L Sediment ng/g
Bifenthrin 0.050 973 2345 0.10 0.08
Cyhalothrin 0.050 683 1890 0.20 0.1
Permethrin 0.050 25 150 1.00 1.5
Cyfluthrin 0.050 277 1217 0.20 0.2
Cypermethrin 0.050 336 1410 0.20 0.18
Es-fenvalerate 0.050 2757 6450 0.05 0.05
Deltamethrin 0.050 190 463 0.15 0.3
Slide 29
Pyrethroid Method Detection and Reporting Limits for Water, Sediment and Tissue - ECD
Sample Matrix Water Sediment Tissue
Pyrethroid Pesticides
MDL RL MDL RL MDL RL
ppb (ug/L)
ppb (ug/L)
Dry wt ppb (ng/g)
Dry wt ppb (ng/g)
Fresh wt ppb (ng/g)
Fresh wtppb (ng/g)
Bifenthrin 0.001 0.002 0.50 1.00 0.65 2.00
Cyfluthrin 0.002 0.004 2.00 4.00 2.70 6.00
Cypermethrin 0.004 0.004 2.00 4.00 1.70 4.00
Deltamethrin 0.002 0.004 2.00 4.00 0.60 2.00
Es/Fenvalerate 0.001 0.002 1.00 2.00 1.70 4.00
Fenpropathrin 0.002 0.004 2.00 4.00 1.35 4.00
Lambda-cyhalothrin 0.001 0.002 1.00 2.00 1.50 4.00
Permethrin 0.003 0.005 4.00 8.00 2.20 6.00
Slide 30
Analysis of Deltamethrin(a) and Tralomethrin(b) using LC/MS
a
b
2x10
0
0 .05
0.1
0 .15
0.2
0 .25
0.3
0 .35
0.4
0 .45
0.5
0 .55
0.6
0 .65
0.7
0 .75
0.8
0 .85
0.9
0 .95
1
1 .05+ Sc an (0 .991-1 .333 min , 39 sc ans) W o rk listD a ta6 .d
523.00000100
1x10
0
0.1
0.2
0 .3
0 .4
0 .5
0 .6
0 .7
0 .8
0 .9
1
1.1
1 .2
1 .3
1 .4
1 .5
1 .6
1 .7
1 .8
1 .9
+ Sc an (2 .415-2 .722 min , 41 sc ans) W o rk listD a ta7 .d
682 .78569100
703.7357450
104.993017 159.00000
5
Counts (%) v s. M ass-to -Cha rge (m/ z)
40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760
b
a
Slide 31
Conclusions
� Analysis of pyrethroids by GC-MSMS-NCI yields low detection limits that are necessary for toxicity of these analytes
� GC-NCI-MSMS is at least 5 times more sensitive than GC-EI-MSMS but is not suitable for all pyrethroid pesticides
� Ammonia NCI is 5-10 times more sensitive than methane
� LC-MS is necessary to distinguish between deltamethrin and tralomethrin
Slide 32
Thank You
Any questions?
