Forensics Journal - Stevenson University 2011 | Page 22

STEVENSON UNIVERSITY

TABLE 6: Rf VALUES OUTSIDE 95% RANGE OF AVERAGE Rf VALUES FROM AFG PLATES
SOLVENT
SYSTEM

BLACK
BP
OVER

ADG

3

BDG

BLACK
BP
UNDER

BLACK
NBP
OVER

8

AEG

1

CEG

BLUE
BP
UNDER

BLUE
NBP
OVER

BLUE
NBP
UNDER

TOTAL
INCONSISTENCIES

4

1

3

3

19

43

3

37

17

59

15

12

47

4

2

13

2

5

1

12

30

3

9
1

6

BEG

BLUE
BP
OVER

5
4

CDG

BLACK
NBP
UNDER
1

50

1

BFG

10

12

22

40

84

CFG

32

49

52

51

184

41

34

108

21

24

63

35

36

76

46

52

122

2

24

7

54

8

BDH

17

7

24

1
1

8

178

AFG

ADH

6

55
1

23

CDH

5

AEH

21

BEH

21

CEH

16

1

11

2

5

1

1

AFH

1

3

2

2

2

9

2

BFH

10

6

3

17

3

CFH

20

14

2

13

18

AIH

3

11

15

BIH

8

1

1

1

1

1

13

CIH

30

1

8

1

36

AIG

2

3

1

BIG

12

8

CIG

21

18

3

1

5

37
9

30
39
68

3

37
107

1

1

9

8

1

31

1

1

1

2

The number of total inconsistencies, found in Table 6, was compared
to the average grade of each solvent system. The average grade was
computed using the three grades found in Table 5. The side-by-side
comparisons can be found in Table 7. The average grade and total
inconsistencies of the Rf values were compared side-by-side to determine any trends. The solvent system combinations were then placed

1

31
1

43

in order by the number of total inconsistencies. There was a general
trend that showed plates with smaller numbers of outlying Rf values
had a lower score for separation and clarity. However, not all plates
had the same correlation. Both the plate with the smallest number of
outliers and the greatest number of outlying Rf va