Enhancement of polycyanoacrylate-developed fingerprints
First Claim
1. A method of enhancing the contrast of polycyanoacrylate-developed fingerprints, comprising(a) treating polycyanoacrylate-developed fingerprints with a composition comprising metal chelate of structural formula I, ##STR7## wherein R is an aromatic group capable of absorbing UV light, X is an electron attracting group, and M is a suitable metal ion which upon exposure to sufficient UV radiation, intramolecularly receives UV energy absorbed by the chelate and emits the energy as visible fluorescence in a narrow wavelength emission band characteristic of the metal, a suitable water soluble organic solvent, and water;
- and wherein the pH of the composition is 3 to 10, to form a two-phase solution of (i) the solvent and water including dissolved chelate and (ii) the solvent, excluding water but including dissolved chelate, in the cyanoacrylate polymer,(b) evaporating the solvent leaving the chelate trapped in the cyanoacrylate polymer, and(c) illuminating with a suitable UV light source to excite the chelate.
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Abstract
The invention disclosed relates to a composition and method for enhancing the contrast of polycyanoacrylate-developed fingerprints and the like. The composition includes a metal chelate of the structural formula ##STR1## wherein R is a UV-absorbing aromatic group, X is an electron attracting group and M is a suitable metal ion, a suitable water-soluble organic solvent and water, at a pH of 3 to 10.
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Citations
21 Claims
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1. A method of enhancing the contrast of polycyanoacrylate-developed fingerprints, comprising
(a) treating polycyanoacrylate-developed fingerprints with a composition comprising metal chelate of structural formula I, ##STR7## wherein R is an aromatic group capable of absorbing UV light, X is an electron attracting group, and M is a suitable metal ion which upon exposure to sufficient UV radiation, intramolecularly receives UV energy absorbed by the chelate and emits the energy as visible fluorescence in a narrow wavelength emission band characteristic of the metal, a suitable water soluble organic solvent, and water; - and wherein the pH of the composition is 3 to 10, to form a two-phase solution of (i) the solvent and water including dissolved chelate and (ii) the solvent, excluding water but including dissolved chelate, in the cyanoacrylate polymer,
(b) evaporating the solvent leaving the chelate trapped in the cyanoacrylate polymer, and (c) illuminating with a suitable UV light source to excite the chelate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19)
- and wherein the pH of the composition is 3 to 10, to form a two-phase solution of (i) the solvent and water including dissolved chelate and (ii) the solvent, excluding water but including dissolved chelate, in the cyanoacrylate polymer,
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12. A kit for enhancing the contrast of polycyanoacrylate-developed fingerprints, comprising in combination
(a) an organic compound of the structural formula ##STR8## wherein R is an aromatic UV absorbing group and X is an electron attracting group, (b) a suitable europium III salt, dissolved in an aqueous solution adjusted to a pH of about 8 by a suitable mineral acid and a suitable buffer pH 8, and (c) kit means to separately contain and maintain apart until use, predetermined amounts of (a) (b).
Specification