1. New perspectives in the use of ink evidence in forensic science: Part I. Development of a quality assurance process for forensic ink analysis by HPTLC 
Cedric Neumann, Pierre Margot 
Forensic Science International 
Volume 185, Issue 1, Pages (March 2009)
DOI: /j.forsciint
Copyright © 2008 Elsevier Ireland Ltd Terms and Conditions

2. Fig. 1
HPTLC plate with the chosen 13 inks. Tracks 1, 9 and 18 are dye ladders, track 16 is an extractor blank and track 17 is a paper blank.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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3. Fig. 2
Representation of the scan of the elution track of an ink sample when the elution track is simultaneously scanned at 31 different wavelengths (x-axis: migration distance in mm; y-axis: wavelengths in nm; z-axis: absorption intensity in a.u.).
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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4. Fig. 3
Correspondence between the raw migration distances in millimeters of the dye components from 60 standard ladders eluted on 20 plates and their position in the new coordinate systems. The base line is set to 3 in the new coordinate system and the solvent front to 395 (x-axis: new coordinate system; left y-axis: raw migration distances; right y-axis probability density of the position of the raw migration distances in the new coordinate system).
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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5. Fig. 4
Presentation of the concept of the calibration process. The new coordinate system is fitted to the 3 ladders on each plate. The new coordinates for the other elution tracks of the plate are computed from these 3 ladders by linear interpolation.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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6. Fig. 5
Illustration of the calibration process on an actual HPTLC plate.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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7. Fig. 6
Reproducibility of the measurement of the component locations by the TLC Scanner on 10 different acquisitions of the same plate. The mean location of each dye component is plotted against its absolute standard deviation.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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8. Fig. 7
Reproducibility of the measurement of the component absorption intensities by the TLC Scanner on 10 different acquisitions of the same plate. The mean absorption intensities of the dye components are compared to their respective standard deviation.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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9. Fig. 8
Reproducibility of the measurement of the component absorption intensities by the TLC Scanner on 10 different acquisitions of the same plate. The mean absorption intensities of the dye components are compared to their respective relative standard deviation (standard deviation divided by the mean intensity).
Forensic Science International  , 29-37DOI: ( /j.forsciint )
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10. Fig. 9
Reproducibility of the ink dye components location when this location is calibrated using the Rf values compared to the reproducibility when the components location is calibrated using the 5 points ladder. The ink samples were analysed 10 times on different HPTLC plates using the same batch of solvent system preparation.
Forensic Science International  , 29-37DOI: ( /j.forsciint )
Copyright © 2008 Elsevier Ireland Ltd Terms and Conditions