Forensics Journal - Stevenson University 2011 | Page 23

FORENSICS JOURNAL

TABLE 7: AVERAGE GRADE IN COMPARISON TO TOTAL Rf
INCONSISTENCIES
TRIAL

AVERAGE
GRADE

FIGURE 3: PLATE 1 OF BLACK INKS RUN IN SOLVENT
SYSTEM AFG PHOTOGRAPHED AT 366 NM

TOTAL
INCONSISTENCIES

AIG

1

9

BEG

3

12

AEG

3

13

BIH

2

13

ADG

3

19

AFG

3

23

AFH

1

30

BIG

1

31

CEH

2

37

AIH

3

37

BFH

2

39

CIG

1

43

CDG

2

FIGURE 4: PLATE 1 OF BLACK INKS RUN IN SOLVENT
SYSTEM CFG PHOTOGRAPHED AT 366 NM

47

BEH

2

54

BDG

3

59

BDH

1

63

CFH

1
2

76

BFG

2

FIGURE 5: PLATE 1 OF BLACK INKS RUN IN SOLVENT
SYSTEM AFG PHOTOGRAPHED AT 254 NM

68

CDH

84

CIH

2

107

ADH

1

108

AEH

2

122

CEG

1

178

CFG

1

184

The plates were photographed under UV light at 254 nm and 366
nm. The photographs of solvent system combinations AFG and CFG
were compared to determine if the fluorescent bands differed. AFG
was determined as the solvent system combination showing the best
separation and clarity, while CFG was determined to be the solvent
system combination showing worst separation and clarity and the
highest number of Rf discrepancies. Figures 3 and 4 show black inks
under 366 nm for solvent systems AFG and CFG respectively. Figures
5 and 6 show black inks under 254 nm for solvent systems AFG and
CFG respectively. The images show that the fluorescent bands are
relatively identical for the best and worst solvent systems. These show
results that various light sources should be used to view TLC plates,
even if different solvent grades are used.

FIGURE 6: PLATE 1 OF BLACK INKS RUN IN SOLVENT
SYSTEM CFG PHOTOGRAPHED AT 254 NM

21