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J
ournal of
AOAC I
nternational
V
ol.
98, N
o.
5, 2015
1445
Table 9. Method efficiency for the determination of 20 pesticides in aged oolong tea by GC/MS, GC/MS/MS, and LC/MS/MS
GC/MS (16 laboratories)
GC/MS/MS (14 laboratories)
LC/MS/MS (24 laboratories)
No.
Pesticide
No. of
labs
Avg. C.,
μg/kg
S
r
,
μg/kg RSD
r
, %
S
R
,
μg/kg RSD
R
, %HorRat No.
Pesticide
No. of
labs
Avg. C.,
μg/kg
S
r
, μg/
kg
RSD
r
,
%
S
R
, μg/
kg
RSD
R
,
% HorRat No. Pesticide
No. of
labs
Avg. C.,
μg/kg
S
r
,
μg/kg RSD
r
, %
S
R
,
μg/kg
RSD
R
,
% HorRat
1
Trifluralin
16
359.6 14.2 3.9
60.1 16.7 0.9 1
Trifluralin 14 325.8 19.1 5.9 113.0 34.7 1.8 1 Acetochlor
23 77.5 3.9 5.0 19.9 25.6 1.1
2
Tefluthrin
14
169.3
5.1
3.0
15.1 8.9 0.4 2
Tefluthrin 14 154.5 8.9 5.8 48.7 31.5 1.5 2 Benalaxyl
22 44.5 2.3 5.1 7.5 16.8 0.7
3
Pyrimethanil
15
173.2
4.2
2.4
25.2 14.6 0.7 3 Pyrimethanil
14 167.0 9.2 5.5 49.2 29.4 1.4 3 Bensulide
24 131.7 10.4 7.9 36.4 27.6 1.3
4
Propyzamide 15
209.9
9.1
4.3
31.1 14.8 0.7 4 Propyzamide 13 192.0 10.9 5.7 42.5 22.1 1.1 4 Butralin
22 34.2 2.8 8.2 9.3 27.3 1.0
5
Pirimicarb
14
189.0
6.0
3.2
20.6 10.9 0.5 5
Pirimicarb 13 179.9 9.3 5.2 46.4 25.8 1.2 5 Chlorpyrifos
24 341.9 24.0 7.0 103.3 30.2 1.6
6
Dimethenamid 15
77.6
2.2
2.8
11.5 14.8 0.6 6 Dimethenamid 14 72.4 3.9 5.4 20.4 28.1 1.2 6 Clomazone 22 40.2 3.3 8.1 9.1 22.7 0.9
7
Fenchlorphos 16
320.6 11.0 3.4
54.0 16.9 0.9 7 Fenchlorphos 14 298.8 19.0 6.4 101.9 34.1 1.8 7 Diazinon
23 34.6 1.8 5.3 9.8 28.3 1.1
8
Tolclofos-methyl
13
178.8
3.6
2.0
18.2 10.2 0.5 8
Tolclofos-
methyl
13 169.7 8.6 5.1 45.5 26.8 1.3 8 Ethoprophos 24 37.9 3.1 8.1 13.1 34.6 1.3
9
Pirimiphos-
methyl
15
170.1
4.2
2.5
24.9 14.7 0.7 9 Pirimiphos-
methyl
14 163.1 15.6 9.6 53.4 32.7 1.6 9 Flutolanil
23 44.5 2.7 6.0 9.4 21.1 0.8
10
2,4’-DDE
14
700.0 25.2 3.6
70.7 10.1 0.6 10 2,4’-DDE 13 631.5 33.3 5.3 196.0 31.0 1.8 10 Imidacloprid 24 94.6 6.0 6.3 30.6 32.3 1.4
11
Bromophos-
ethyl
16
175.1
5.0
2.9
22.3 12.8 0.6 11 Bromophos-
ethyl
14 155.6 9.0 5.8 47.0 30.2 1.4 11 Indoxacarb 23 44.0 3.5 8.0 8.2 18.6 0.7
12
4,4’-DDE
15
692.4 24.0 3.5
85.5 12.4 0.7 12 4,4’-DDE 14 630.1 30.8 4.9 183.4 29.1 1.7 12 Kresoxim-
methyl
22 441.6 22.7 5.1 84.4 19.1 1.1
13
Procymidone 15
204.1
6.1
3.0
24.6 12.0 0.6 13 Procymidone 14 186.1 9.8 5.3 54.2 29.2 1.4 13 Monolinuron 24 40.7 3.7 9.1 12.6 31.0 1.2
14
Picoxystrobin 15
416.2 18.3 4.4
42.1 10.1 0.6 14 Picoxystrobin 14 373.6 19.4 5.2 85.3 22.8 1.2 14 Picoxystrobin 22 44.3 3.1 7.0 9.0 20.2 0.8
15
Quinoxyfen
15
193.6 10.1 5.2
22.4 11.6 0.6 15 Quinoxyfen 14 182.4 9.2 5.0 54.1 29.6 1.4 15 Pirimiphos-
methyl
23 36.2 2.5 6.8 8.9 24.5 0.9
16
Chlorfenapyr
15
1642.6 58.5 3.6 199.4 12.1 0.8 16 Chlorfenapyr 13 1511.9 84.7 5.6 332.7 22.0 1.5 16 Propoxur
24 101.2 6.7 6.6 31.5 31.2 1.4
17
Benalaxyl
15
208.0 11.8 5.6
30.9 14.9 0.7 17 Benalaxyl
14 194.1 8.9 4.6 48.1 24.8 1.2 17 Quinoxyfen 24 192.9 13.0 6.7 54.8 28.4 1.4
18
Bifenthrin
15
199.2 11.6 5.8
24.9 12.5 0.6 18 Bifenthrin 14 183.8 9.3 5.0 51.0 27.7 1.3 18 Tebufen-
pyrad
24 41.0 2.6 6.3 11.4 27.7 1.1
19
Diflufenican 15
209.4
9.5
4.5
28.1 13.4 0.7 19 Diflufenican 13 191.3 11.6 6.1 41.6 21.7 1.1 19 Triadimefon 23 42.1 2.5 5.8 9.5 22.6 0.9
20
Bromopropylate 15
409.7 21.0 5.1
59.9 14.6 0.8 20 Bromopro-
pylate
14 387.2 22.1 5.7 84.9 21.9 1.2 20 Trifloxys-
trobin
24 40.9 2.8 6.9 11.5 28.0 1.1