Advances in Fingerprint Technology.pdf

Procedure
Xylene 50 mL
Petroleum ether 830 mL
1. Dip the paper containing latent prints into the freshly prepared solution
for 5 sec.
2. Allow the paper specimen to dry for 30 sec.
3. Repeat the dipping for another 5 sec (some indicate this step can be
omitted)
4. Heat the paper to 100°C for 10 min.
5. View the surface under alternative light sources as follows:
a. Video spectral comparator (VSC-1) using blue-green light
excitation — Fluorescence can be observed through a 610-nm filter.
b. A 12-W argon laser operated at 514 nm — Fluorescence can be
observed through a 550- or a 610-nm filter.
c. A mercury vapor lamp — Fluorescence can be observed through a
546-nm filter.
As noted above, Jungbluth 118 formulated DFO in a Freon substitute: 50 mg
DFO is dissolved in 4 mL methanol and 2 mL acetic acid; then 94 mL Genesolv
2000 is added. Geide 143 similarly formulated DFO in the Freon-substitute
solvent t-butyl-methyl ether. He noted that the solvent is highly flammable
and volatile and must be used with care in a hood. Bratton and Juhala 144
described a sandwiching procedure in which the test item was sandwiched
between DFO-treated filter papers and then subjected to 5% acetic acid
“steam” (from a steam iron), to get around the problem of solvent-caused
ink bleed on documents.
Ninhydrin Analogues
Almog, Hirschfeld, and Klug 145 synthesized several ninhydrin analogues:
benzo[e]ninhydrin (2,2-dihydroxybenz[e]-indane-1,3-dione), benzo[f]ninhydrin
(2,2-dihydroxybenz[f]-indane-1,3-dione), and 2,2-dihydroxy-
5-chloro-6-methoxyindane-1,3-dione. These compounds were tested for
their applicability to latent print detection. It was found that the ninhydrin
analogues developed latent prints with a sensitivity similar to that of ninhydrin
and that the quality of development was independent of the age of the
latent fingerprints. Benzo[f]ninhydrin performance in several solvent formulations
was recently compared directly with ninhydrin, and found to be
superior for certain surfaces, but not in the number of prints developed on
actual exhibits overall. 146