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J
ournal of
AOAC I
nternational
V
ol.
98, N
o.
5, 2015
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Table 5. Method efficiency for the determination of 20 pesticides in fortified tea samples by GC/MS/MS (14 laboratories)
Green tea
Oolong tea
Avg. C., μg/kg
Rec., %
Avg. C., μg/kg
Rec., %
No.
Pesticide
No. of
labs No. 1 No. 2
Avg. C.,
μg/kg No. 1 No. 2
Avg.
rec., %
S
r
,
μg/kg
RSD
r
,
%
S
R
,
μg/kg
RSD
R
,
% HorRat
No. of
labs No.6 No.7
Avg. C.,
μg/kg No.6 No.7
Avg.
rec., %
S
r
,
μg/kg
RSD
r
,
%
S
R
, μg/
kg RSD
R
, % HorRat
1
Trifluralin
11 183.7 182.5 183.1 91.9 91.2 91.5 7.3 4.0 22.4 12.2 0.6
13 87.3 87.1 87.2 87.3 87.1 87.2 1.2 1.4 14.2 16.2 0.7
2
Tefluthrin
13 92.1 92.6 92.2 92.1 92.6 92.3 3.6 3.9 10.7 11.6 0.5
13 43.8 43.8 43.8 87.5 87.6 87.6 1.0 2.3 7.4 16.8 0.7
3 Pyrimethanil
13 89.3 90.1 90.1 89.3 90.1 89.7 3.6 4.0 10.6 11.8 0.5
12 41.0 41.3 43.4 81.9 82.6 82.3 1.0 2.4 5.8 13.3 0.5
4 Propyzamide 13 93.9 95.2 94.6 93.9 95.2 94.6 3.3 3.5 9.5 10.1 0.4
14 41.9 41.6 41.8 83.8 83.3 83.5 1.1 2.7 9.9 23.8 0.9
5
Pirimicarb
12 91.7 93.0 92.5 91.7 93.0 92.4 2.9 3.2 8.6 9.3 0.4
12 42.9 43.1 43.0 85.8 86.2 86.0 1.1 2.7 4.0 9.4 0.4
6 Dimethenamid 13 37.4 37.6 37.5 93.4 94.1 93.7 1.4 3.7 4.5 12.0 0.5
12 17.0 17.5 17.5 84.8 87.7 86.3 0.6 3.5 2.3 13.4 0.5
7 Fenchlorphos 12 175.4 172.8 172.6 87.7 86.4 87.0 7.2 4.2 15.4 8.9 0.4
14 77.0 77.1 77.1 77.0 77.1 77.1 1.6 2.1 18.2 23.6 1.0
8 Tolclofos-methyl
13 92.0 93.3 92.6 92.0 93.3 92.6 3.2 3.4 8.1 8.8 0.4
14 40.4 40.4 40.4 80.7 80.8 80.8 1.0 2.6 9.5 23.6 0.9
9 Pirimiphos-
methyl
12 91.9 93.0 92.5 91.9 93.0 92.4 3.3 3.6 6.4 6.9 0.3
12 41.8 43.6 43.2 83.6 87.1 85.4 1.0 2.4 6.0 14.0 0.5
10 2,4
'
-DDE 12 358.0 364.6 361.0 89.5 91.2 90.3 13.6 3.8 36.2 10.0 0.5
11 171.3 172.1 171.7 85.7 86.1 85.9 2.9 1.7 19.6 11.4 0.5
11 Bromophos-ethyl
12 92.7 92.3 92.0 92.7 92.3 92.5 2.8 3.1 7.9 8.6 0.4
12 44.3 43.8 44.6 88.7 87.5 88.1 0.9 2.0 6.5 14.6 0.6
12 4,4
'
-DDE 11 357.7 364.6 360.6 89.4 91.2 90.3 15.0 4.2 23.7 6.6 0.4
12 174.9 176.8 175.9 87.5 88.4 87.9 3.5 2.0 20.0 11.4 0.5
13 Procymidone 13 91.8 93.1 92.5 91.8 93.1 92.4 3.5 3.8 12.1 13.1 0.6
14 39.3 40.2 39.7 78.6 80.4 79.5 1.4 3.6 13.0 32.7 1.3
14 Picoxystrobin 13 183.9 187.5 185.7 91.9 93.7 92.8 7.9 4.3 20.9 11.3 0.5
12 86.7 90.6 90.0 86.7 90.6 88.6 2.1 2.3 13.0 14.5 0.6
15 Quinoxyfen 13 90.3 92.9 91.6 90.3 92.9 91.6 4.3 4.7 11.9 13.0 0.6
12 40.6 42.3 42.1 81.2 84.5 82.9 1.2 2.8 6.2 14.7 0.6
16 Chlorfenapyr
12 744.9 755.1 749.1 93.1 94.4 93.8 36.4 4.9 67.4 9.0 0.5
10 334.1 337.4 335.8 83.5 84.3 83.9 10.3 3.1 23.5 7.0 0.4
17 Benalaxyl
13 90.8 92.7 91.7 90.8 92.7 91.8 4.7 5.1 12.2 13.3 0.6
12 44.5 43.8 44.8 89.1 87.6 88.3 2.4 5.4 6.5 14.6 0.6
18 Bifenthrin
13 96.9 97.3 97.2 96.9 97.3 97.1 5.5 5.6 14.4 14.8 0.7
11 45.0 45.8 45.4 90.0 91.6 90.8 2.2 4.9 5.1 11.1 0.4
19 Diflufenican 12 93.5 97.0 94.5 93.5 97.0 95.3 5.0 5.3 10.5 11.2 0.5
14 41.4 41.6 41.5 82.8 83.3 83.0 1.4 3.4 12.0 28.8 1.1
20 Bromopropylate 12 188.5 191.7 188.9 94.3 95.8 95.1 11.3 6.0 17.3 9.1 0.4
12 83.5 87.2 86.6 83.5 87.2 85.3 2.9 3.3 14.3 16.5 0.7