© Benaki Phytopathological Institute
Vlastaras
et al.
64
the case of routine analysis, the acceptable
recoveries are between 60 and 140% (3).
The precision of the method was estimated
by assessing the relative standard deviation
(RSD) values under repeatability conditions
(same analyst, same instrument, same day).
Repeatability with RSD≤ 20% is considered
acceptable (3).
As shown in Table 3,
mean recoveries
of the tomato samples at the LCL were be-
tween 73.2 – 117.9% with a RSD between 1
– 16.72% and at the 10*LFL between 86.5 –
108.5% with a RSD between 0.37 – 7.3% for
most of the analytes studied. These results
generally indicate good method accuracy.
As shown in Table 4, mean recoveries of
the grape samples at the LCL were between
71.5 – 120.6% with a RSD between 0.87 –
Table 3.
Average recovery values and relative standard deviation (RSD) for the 44 analytes in
tomatoes, as derived from the fortification experiments in both detection systems.
Analyte
LFL
1
(mg/Kg)
Recovery % ± RSD 10*LFL
1
(mg/Kg)
Recovery % ± RSD
acephate
0.02
35.7±9.23
0.2
20.3±4.81
acrinathrin
0.05
87.9±6.74
0.5
100.7±1.67
aldrin
0.01 (MRL)
87.0±8.23
0.1
100.2±4.61
atrazine
0.10 (MRL)
93.5±2.18
1.0
89.9±1.23
azinphos-methyl
0.10
103.9±3.81
1.0
90.4±7.30
benalaxyl
0.10
103.3±6.78
1.0
98.8±1.35
bifenthrin
0.1
90.0±5.97
1
99.9±2.87
cadusafos
0.05
91.4±4.74
0.5
96.6±1.07
chlorpyrifos-methyl
0.10
97.5±3.06
1.0
98.2±1.81
cyfluthrin
0.05 (MRL)
90.2±8.42
0.5
101.2±1.77
deltamethrin
0.05
91.2±12.18
0.5
98.3±2.27
demeton -S- methyl
0.10
73.2±7.18
1.0
86.5±2.15
diazinon
0.02
96.0±2.85
0.2
98.1±1.37
dichlofluanid
0.1
100.1±9.55
1
86.8±2.00
dichlorvos
0.10 (MRL)
39.4±53.55
1.0
66.1±12.3
dieldrin
0.01 (MRL)
91.0±9.32
0.1
103.9±2.63
dimethoate
0.02
101.2±2.00
0.2
90.2±2.64
endosulfan a
0.05
90.3±8.03
0.5 (MRL)
100.1±1.24
esfenvalerate
0.05 (MRL)
90.8±9.65
0.5
99.7±1.40
ethion
0.10 (MRL)
101.3±2.26
1.0
97.6±1.6
fenpropathrin
0.05
89.5±9.03
0.5
101.1±1.60
fenthion
0.05
96.0±2.30
0.5
95.8±1.0
flucythrinate
0.05 (MRL)
94.9±16.72
0.5
98.4±2.32
fluquinconazole
0.10
104.4±5.75
1.0
93.8±3.68
kresoxim-methyl
0.1
90.8±8.66
1
101.7±1.26
metalaxyl
0.05 (MRL)
109.8±4.84
0.5
93.0±1.7
methidathion
0.02 (MRL)
85.1±5.42
0.2
94.9±2.8
myclobutanil
0.10
117.9±3.79
1.0
96.9±1.0
omethoate
0.10
46.2±6.41
1.0
37.4±5.4
parathion ethyl
0.05 (MRL)
100.3±2.35
0.5
96.4±1.90
parathion-methyl
0.05
96.6±1.05
0.5
92.3±1.59
penconazole
0.05 (MRL)
114.3±4.43
0.5
95.3±1.23
pendimethalin
0.05 (MRL)
87.3±9.90
0.5
99.4±1.5
permethrin
0.05 (MRL)
84.7±14.57
0.5
108.5±4.66
phosalone
0.05
107.7±3.44
0.5
105.1±2.59
prometryn
0.10
100.2±2.19
1.0
97.2±1.55
propiconazole
0.05 (MRL)
120.1±10.79
0.5
103.4±1.80
pyrazophos
0.05 (MRL)
106.6±3.50
0.5
99.4±4.58
simazine
0.10
96.4±2.48
1.0
89.7±1.03
terbuthylazine
0.1
111.7±14.73
1
97.7±3.22
tetraconazole
0.10
115.3±2.81
1.0
95.5±1.28
triadimenol
0.1
114.3±4.23
1
97.7±0.37
triazophos
0.02 (MRL)
102.2±4.33
0.2
97.8±2.5
trifluralin
0.05
87.6±11.39
0.5
98.3±2.89
1
LFL: lowest fortification level; 10*LFL: tenfold fortification level
1...,24,25,26,27,28,29,30,31,32,33 35,36,37,38,39,40,41,42,43,44,...59