Table E: Sampling frequency influence
Variation between weekly and 4-weekly sampling

Dose

Dose

Underestimate

Overestimate

Sample

Average [U] (ug/L)

Min deviation

Max deviation

Ph1/Ph2 [U] Ratio

Inverse Min

38

9.31

0.04

2.63

0.90

23.69

28

1.26

0.32

3.59

0.90

3.11

33

1.06

0.38

2.55

0.90

2.66

15

114.00

0.46

1.31

0.90

2.17

22

5.06

0.49

1.58

0.90

2.04

13

18.78

0.50

2.27

0.90

2.02

29

0.94

0.50

1.77

1.42

2.00

18

3.99

0.53

1.39

0.90

1.90

34

0.78

0.55

2.41

1.40

1.81

37

48.33

0.57

1.35

1.24

1.76

32

0.96

0.59

2.18

0.90

1.71

14

2.88

0.62

1.76

0.42

1.61

11

84.07

0.63

1.59

0.90

1.58

26

0.63

0.64

2.37

0.90

1.55

27

0.92

0.64

1.74

0.85

1.55

7

128.56

0.66

1.24

0.69

1.51

25

0.62

0.67

2.56

0.90

1.49

16

21.01

0.69

2.38

0.68

1.44

36

12.80

0.71

1.73

2.29

1.41

23

18.91

0.73

1.21

0.94

1.37

30

0.53

0.74

1.44

0.94

1.34

6

a

3.19

0.75

1.25

0.90

1.33

10

23.24

0.75

1.26

0.90

1.32

39

22.01

0.77

1.40

0.90

1.30

8

58.77

0.77

1.36

0.90

1.30

24

0.52

0.79

1.52

0.90

1.26

35

1.55

0.81

1.30

2.02

1.23

7

a

214.71

0.84

1.22

0.87

1.18

20

0.57

0.85

1.23

0.90

1.18

6

3.14

0.85

1.19

0.62

1.17

5

31.38

0.85

1.18

0.87

1.17

12

243.42

0.88

1.36

0.35

1.13

2

20.50

0.88

1.23

0.90

1.13

3

36.18

0.91

1.06

0.93

1.10

21

7.33

0.91

1.16

0.90

1.10

1

156.54

0.93

1.09

0.90

1.07

31

0.42

0.94

1.13

0.90

1.07

19

2.96

0.94

1.19

0.90

1.06

9

73.39

0.95

1.05

0.90

1.05

17

48.85

0.99

1.60

0.90

1.01

4

38.28

0.99

1.02

0.90

1.01

* Data printed in bold are measured, others are estimated from the "global" mean