6
Three replicate extractions of pyrethroids spiked at 0.10 ng/mL in water were carried out using a
HyperSep C18 SPE cartridge. The extraction recoveries from plastic, non-silanized amber vials,
and Target DP Total Recovery Vials, 33 expansion borosilicate clear (Type 1, Class A), were
compared. The pyrethroids recoveries were measured to be 81%–117%, with relative standard
deviations (RSD) of 3%–12% (see Table 2 for individual pyrethroids measured at each
concentration). The extraction recovery was enhanced when using the high purity 33 expansion
glass vials as shown in Figure 5.
Figure 5: Comparison of extraction recoveries of pyrethroids using three different vial types
Peak Number
Compound
t
R
(min)
1
1,2,3,4-Tetra Chloronaphthalene (IS)
7.56
2
Bifenthrin
12.84
3
Permethrin isomer a
14.97
4
Permethrin isomer b
15.11
5
Cyfluthrin isomer a
15.58
6
Cyfluthrin isomer b
15.69
7
Cyfluthrin isomer c
15.76
8
Cyfluthrin isomer d
15.81
9
Cypermethrin isomer a
15.94
10
Cypermethrin isomer b
16.06
11
Cypermethrin isomer c
16.12
12
Cypermethrin isomer d
16.16
Table 3: Peak indentification
81.8
101.8
49.5
85.7
117.1
46.3
85.6
112.2
8.1
101.6
117.1
62.6
84.7
113.9
62.6
% Recovery
Bifenthrin
20
0
140
40
60
80
100
120
Permethrin
isomer a
Permethrin
isomer b
Cyfluthrin
total isomers
Cypermethrin
total isomers
Plastic vial
Target DP 33 expansion vial
Non-silanized amber vial
