Pesticide Intermediate precisiona) LOQb) (ng L-1) Equationc) Standard Deviation (SD) SlopeIntercept σ2d) Tap Watere) DeionisedWatere)
Recoveries Recoveries
Fexpfor Area Fexpfor RS
% SDf) % SDf)
H-SI
DIA
H-AT
DEA
SI
AT		 1.18
1.39
1.33
1.71
1.05
1.28		 2.92
4.46
3.12
3.20
1.47
4.93		 96
88
90
81
95
100		 y = 120205 CHSI - 23728
y = 143618 CDIA - 37688
y = 108686 CHAT - 9760
y = 147826 CDEA - 31214
y = 70148 CSI - 16736
y = 112109 CAT - 5123		 14003
36842
18657
26269
13935
25808		 18197
14189
3569
2898
8061
1970		 0.9985
0.9929
0.9968
0.9965
0.9957
0.9943		 71.50
86.32
77.40
91.67
74.47
71.20		 3.20
5.63
1.13
4.22
4.15
3.82		 69.19
89.24
71.62
94.29
78.00
74.14		 2.06
2.65
0.76
2.99
3.72
0.56
a)F(5, 5) theorical=5.05
b)LOQ including enrichment factor (3333)
c)Peak area (y, no units) versus concentrations (μg L-1).
d)Regression coefficients
e)Mean of recoveries in spiked tap and deionized water samples at three different levels in triplicate.
f)Mean of standard deviations (SD) of recoveries in spiked tap and deionized water samples at three different levels in triplicate
Table 2: Analytical performance characteristics for the developed off- line SPE- HPLC-DAD method.