WO1994026166A2

WO1994026166A2 - Cartridges for developing latent fingerprints

Info

Publication number: WO1994026166A2
Application number: PCT/US1994/005249
Authority: WO
Inventors: John F. Eisele; Terrance P. Smith; David E. Weaver; Everett J. Clary; Robert J. Shem; George M. Taft, Jr.
Original assignee: Minnesota Mining And Manufacturing Company
Priority date: 1993-05-11
Filing date: 1994-05-11
Publication date: 1994-11-24
Also published as: ZA943123B; AU6947094A; IL109155A0; WO1994026166A3

Abstract

A cartridge useful in detecting fingerprints comprises a housing (1) with a chamber therein and an outlet from said chambers, in said chamber. In said chamber is a solid granulated cyanoacrylate (8), or a thermally stable porous of fibrous support (5) impregnated with a liquid cyanoacrylate ester (6), and in one embodiment, a volatile fluorescent dye with a molecular weight between 100 to 500 Daltons and a quantum efficiency in fluid benzene solution at ambient temperature of greater than 10-4.

Description

CARTRIDGES FORDEVELOPINGLATENTFINGERPRINTS

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fingerprint developing devices and methods using cyanoacrylate and particularly to fingerprint developing devices and methods using a liquid form of cyanoacrylate that is vaporized and then propelled at some velocity toward the object to be tested, and to devices and methods using a combination of cyanoacrylate and a fluorescent dye. This invention also pertains to the use of a class of volatile fluorescent compounds that are particularly useful in the enhancement and visualization of latent fingerprints.

Description of the Prior Art

It is well known in the art that cyanoacrylate, in vapor form, adheres to fingerprints. Once the vapor cures, the cyanoacrylate forms a white polymer substance that reveals the fingerprint. This technique is known as developing a latent fingerprint. Although this process produces good results, the present technology for developing latent prints involves a time consuming process that must be performed in closed quarters. Current technology uses sheet packets of thick liquid cyanoacrylate. The cyanoacrylate is spread on sheets of material and then sealed. To use, the packet is opened by pulling the two sheets apart which then exposes the cyanoacrylate to the air. Typically, these sheets are placed in a closed vessel such as a large aquarium with the object to be examined. The cyanoacrylate vapors can then adhere to the object, developing any prints that might be on the object. This process can take up to six hours. One system calls for placing several packets throughout a room and then sealing the room for up to 24 hours to develop any prints that may be inside. Various methods have been described for the enhancement and subsequent visualization of fingerprints. Many of these techniques are discussed in chapters 3, 4, and 5 of Henry C. Lee and R. E. Gaensslen "Advances in Fingerprint Technology", Elsevier, New York, 1991. One of the best methods for developing latent prints is to expose the article, suspected of containing the prints, to cyanoacrylate vapors. The vapors are preferentially deposited onto the fingerprint residue. It is generally believed that various components in the fingerprint residue cause the cyanoacrylate to undergo a polymerization reaction whereby an enhanced image of a fingerprint results.

U.S. Patents 4,504,408 titled "Fluorescent Vapor Fumes For Use With A Self-Contained Fingerprinting Kit" and 4,613,515 titled "Fingerprint Development Kit and Process" describe methods of enhancing and visualizing fingerprints. In U.S. Patent 4,504,408, fluorescent cyanoacrylate vapors are generated by means of allowing a liquid monomeric cyanoacrylate to come in contact with an activator pad which has been previously impregnated with a fluorescent compound and a composition which contains two components A and B wherein A is a mixture of chloroethane and methanol and B contains a polymerization catalyst in a mixture of the following solvents: nitromethane and/or nitroethane, methanol, toluene. An alternative construction involved adding the cyanoacrylate and the fluorescent dye to a gauze pad which had been treated with the two component composition A and B referred to above. Both these processes involve the transfer of liquid(s) and the release of several volatile organic compounds, in addition to producing the desired fluorescent cyanoacrylate fumes. As a result, the above kit requires that the process be carried out in an enclosed area or preferably in an enclosed chamber. Also, once the liquid cyanoacrylate has been added, vapors are generated until the reaction has run its course, presumably when either one of the reagents (i.e., the monomeric cyanoacrylate or the catalyst) is either consumed or otherwise neutralized or when the heat generated is unable to sustain the production of the fluorescent cyanoacrylate vapors. No simple means of terminating the process once it has been started is given in this patent. In U.S. Patent 4,613,515 a kit is also described. This kit is comprised of the following: 1) a container of a liquid cyanoacrylate monomer or polymer precursor and a polymerization inhibitor, 2) a separate container containing an inert pad having sorbed therewith at least one catalyst for the polymerization of a monomeric cyanoacrylate ester or polymer precursor, and a fingerprint development enhancer. The preferred pad material is formed from either cotton or flax. Upon addition of the cyanoacrylate monomer to the pad a reaction ensues, producing cyanoacrylate vapors and in some constructions fluorescent vapors. The pad is intended for a one time use. As in the previous kit, the reaction, once initiated, is allowed to proceed until either one of the reagents is exhausted or the heat generated by the reaction is insufficient to generate fluorescent cyanoacrylate vapors. Other systems utilizing cyanoacrylate vapors have, also, been disclosed. WO 8801616-A teaches the use of solid Diels-Alder adducts of cyanoacrylate as monomeric cyanoacrylate precursors. When these adducts are heated, the adducts undergo a retro-Diels-Alder reaction whereby monomeric cyanoacrylate derivatives are generated. Some of the cyanoacrylate derivatives have covalently attached fluorescent dyes. This system has the advantage of using a solid composition, however, the high molecularity of some of the compositions and the resultant low vapor pressure of these fluorescent cyanoacrylate monomers limit the effectiveness of this approach. Other shortcomings of this system are discussed in a dissertation titled "Detection Of Latent Fingerprints With Cyanoacrylates: New Techniques Involving Coloured And Photoluminescent Compounds" by Siaw-Jan Yong, The Australian National University, GPO Box 4, Canberra, ACT 2601 on pages 64- 81. The above dissertation also discusses a device and a method for the volatilization of cyanoacrylates. This apparatus consists of a glass container that has been equipped with a controllable electric heating element attached to a heat conducting holder. The article suspected of having a fingerprint is suspended in the chamber by a wire. The holder is charged with monomeric or polymeric cyanoacrylate and the heating element turned on. This device provides an excellent means of controlling the rate of vaporization.

However, for field work it is somewhat cumbersome and requires an electric power source. A modified apparatus for the co-volatilization of cyanoacrylates and fluorescent compounds is also described. This apparatus is similar to the one previously described but contains a second, separate heating element. The co-volatilization experiments were accomplished by placing the cyanoacrylate on one holder and the fluorescent compound on the other holder. And then heating the two holders to separate temperatures to provide vapors of both species.

Other methods for visualizing fingerprints involve staining or dusting cyanoacrylate developed prints with a fluorescent dye or pigment or, alternatively, exposing cyanoacrylate developed prints to fluorescent dye vapors. These methods are discussed in the following references: J. Almog and A. Gabay, Journal of Forensic Science , 25, 1980, 408-409; J. Almog et. al., Journal of Forensic Science , 32, 1987, 585-596; E. R. Menzel, Journal of Forensic Science , 27, 1982, 918- 922. E. R. Menzel et. al. , Journal of Forensic Science , 28, 1983, 307-317; J. A. Burt and E. R.

Menzel, Journal of Forensic Science , 30, 1988, 364-370; C. A. Pounds and R. R. Grigg, Journal of Forensic Science , 35, 1980, 169-175; H. K. Korbus, R. N. Warrener, and M. Stoilovic, Forensic Science International, 23, 1983, 233-240.

Post-treatment of cyanoacrylate fingerprint images by pigments or stains has been disclosed in the following patents or patent applications: Japanese Patents: J02268744A and J63161940A; U.S. Patents 4,917,987, 4,794,260, and 4,708,882.

Various acrylate constructions containing fluorescent agents have been described. U.S. Patent 3,322,680 relates to polymeric compositions containing a bis(benzoxazolyl) fluorescent agent. These compositions can be in the form of films, fibers, filaments, sheets, and other shaped objects. There are no specific references to cyanoacrylates, however acrylates are generally covered.

U.S. Patent 4,751,020 disclose UV-fluorescent cyanoacrylate adhesive compositions exhibiting improved whiteness/brightness properties. The fluorescent agent is selected from either specific bis(benzoxazolyl) derivatives or specific coumarin derivatives. The composition may contain standard additives, such as polymerization inhibitors, thickeners, plastizers, perfumes, dyes, pigments, polymerization catalyst.

SUMMARY OF INVENTION

Volatilization, by the application of heat, of an either a monomeric cyanoacrylate ester or, a polymeric cyanoacrylate ester produces a chemical vapor that can be used to visualize latent fingerprints. A presently preferred form of the invention is the formation of a solid cyanoacrylate into a solid disc or torus contained in a cartridge or impregnation of an inert thermally resistant fibrous substrate by liquid cyanoacrylate contained in a cartridge. Another presently preferred form of the invention is has an intimate mixture of a fluorescent compound, a polymeric cyanoacrylate ester, and the inert fibrous substrate contained in a cartridge which can be attached to a heating device. A preferred heating device is a butane-powered torch. Another aspect to our invention has been the discovery of classes of fluorescent dyes, that can be used in the above system. Yet another aspect to our invention, is the discovery that 4-dicyanovinyl-N,N-disubstituted anilines and 4- tricyanovinyl-N,N-disubstituted anilines appear to be especially selective, in terms of co-depositing with the cyanoacrylate vapors on the fingerprinted residue. This results in excellent contrast between the fingerprinted residue and the background areas. A presently preferred material is 4-tricyanovinyl-N,N- diethylaniline.

Brief Description of the Drawings Figure 1 is a cross-sectional view of the housing with a load of cyanoacrylate ready for use;

Figure 2 is a cross-sectional view of the housing loaded with steel wool impregnated with cyanoacrylate, ready for use;

Figure 3 is a side view of the housing as placed on the small torch; and

Figure 4 is a detailed view of the device in use.

Detailed Description of the Invention Referring now to the drawings, the device has a cylindrical housing 1. The housing is open at the top 2. The bottom of the housing 3 can be tapered as shown. In a presently preferred embodiment, the taper is used. This allows the housing 1 to be placed onto the exhaust port of a small commercially available propane torch, as discussed below. A connecting tube 4 is attached to the tapered base 3. This assembly can be constructed from one piece of metal.

In the preferred embodiment, the entire housing 1 is hollow. This permits a quantity of a thermally stable, preferably thermally conductive, fibrous or porous support material 5 to be located within the housing. Examples of such support materials include steel wool, woven wire, porous ceramic, fiberglass and the like. A quantity of a liquid cyanoacrylate 6, selected from the group consisting of monomeric cyanoacrylate esters, and polycyanoacrylate esters is then poured over the support material 5, and allowed to impregnate the support material and dry, or polymerize. The support material is preferably formed such that a central cylindrical opening 7 is formed. This opening conforms to the diameter of the torch ejector 11, (see Figs. 2 and 3) . Typically, the housing can be sized to match different sized torches.

In the preferred embodiment, a small propane torch 10, as shown in Fig. 3, is used to vaporize the cyanoacrylate 6 stored within the housing. Commercially available torches include ULTRATORCH™ MODEL UT-50 and UTIOOSi. These torches are available from the Master Appliance Corporation, Racine, Wisconsin. These torches provide sufficient heat to vaporize the cyanoacrylate. This size torch can be used indoors or outdoors.

In use, the torch 10 is lit. Then the housing 1 is placed over the lit torch ejector 11 at the connecting tube 4. The exhaust is then directed toward the object to be tested. Fig. 4 shows the device in use. As the cyanoacrylate 6 is vaporized, it is propelled forward toward the object being tested 20, developing any latent fingerprints thereon. This forward motion of the exhaust gas 15 focuses the cyanoacrylate stream on the object and produces much faster developing times. This compares to the evaporative type developers, discussed above, that must operate in a closed environment and over long periods of time.

An alternative embodiment uses cured granulated cyanoacrylate 8 that is packed around the inner wall of the housing. When the granulated cyanoacrylate 8 is used up, the housing 1 can be discarded, and a new housing can be substituted, and the process can continue. It is possible to change housings by using pliers without shutting off the torch although this is not recommended.

In another embodiment, the article of the invention comprises a cartridge of a porous or fibrous support impregnated with a cyanoacrylate ester or a polycyanoacrylate ester, and a volatile fluorescent dye.

Any ester of cyanoacrylate or polycyanoacrylate can be used. Preferred esters of cyanoacrylate are small alkyl esters, especially preferred are the methyl and ethyl esters.

The volatile fluorescent dye, also referred to as a fluorophore, should have a molecular weight between 100 to 500 Daltons, preferably between about 100 to 350 Daltons (most preferably with the dye solid at room temperature although a liquid dye would be far less useful) . In addition, the fluorescent compound should not significantly react with the cyanoacrylate monomer under the conditions of storage or use. A significant reaction would be one that reduced the strength of the dye fluorescence by at least 50%. The fluorophore should absorb between 250 nm and 900 nm with an extinction coefficient greater than 3000 liters/ (moles x cm) at least at some wavelength in this range, and have a quantum yield of emission of at least 10"⁴ in benzene solution at ambient temperature. A preferred embodiment of this invention is when the fluorophore is non-ionic, i.e. not a salt, and possesses a molecular weight between 100 to 300 Daltons, an absorption between 250 nm and 650 nm with a extinction coefficient greater than 10,000 liters/ (moles x cm) somewhere in this absorption region and has a quantum yield of emission greater than 10^"4 in benzene solution at ambient temperatures. Although the fluorophores that are useful in this invention are not limited to any class of organic molecules, preferred fluorophores are derived from one of the following classes: stilbenes, coumarins, 1, 2-ethylene derivatives where at least one of the substituents is a heteroaromatic moiety and the other substituent is either an aromatic moiety or a heteroaromatic moiety, 1, 3-diphenyl-2pyrazolines, naphthalimides, polycyclic hetereocyclics, and anthraquinones, aminostyryl, benzothiazoles. By volatile it is meant that the dye produces a significant vapor pressure (at least 0.05 to 0.1 Torr) at 100 to 200°C and ambient pressure. Although it is preferred that neutral organic molecules be used in this invention, it is possible that some acid adducts (e.g., hydrogen chloride, hydrogen bromide adducts) of the fluorophore may also be used, provided that upon heating to between 100-300°C, a significant vapor pressure of the fluorescent compound is generated.

TABLE 1. VAPOR PRESSURES OF DYES AT 200°C

COMPOUND PRESSURE @ 200 °C MOLECULAR WEI

Mbar Torr

4-Tricyanoviιιyl-n,n-diethylaniline 0.91 0.68 250.30

4-Dicyanovinyl-n,n-diethylaniline 0.29 0.22 225.29

1 - Aminoanthraquinone 0.29 0.21 223.23

1 - Amino-2-methylanthraquinone 0.62 0.47 237.26 l-Arnino-2-bromo-4-p-toluidino-anthraquinone 0.0057 0.0043 407.27 l-A ino-2-methyl-4-toluidirιo-anthraquinone 0.0013 0.0010 342.40

Anisol-2-azo-l,2-naphthol 0.77 0.58 278.31 p-Diethylaminoazobenzene 1.68 1.26 253.35

1 ,4-Diaminoanthraquinone 0.034 0.025 238.25

1 ,5-Diaminoanthraquinone 0.01 0.0074 238.25

1 ,4-Diisobutylaminoanthraquinone 0.013 0.010 350.47

1 ,4-Di-n-butylaminoanthraquinone 0.037 0.028 350.47

1 ,4-Dimethylaminoanthraquinone 0.12 0.090 266.30

1 ,4-Dihydroxyaminoanthraquinone 1.02 0.77 240.22

2-Hydroxy- 1 -pheny lazonaphthlene 4.46 3.35 248.30

2-Hydroxy-4-p-toluidino-anthraquinone 1.31 0.99 329.35

1 -Methylaminoanthraquinone 1.15 0.86 237.26

1 -Methylamino-4-m-toluidino- 0.015 0.11 342.40 l-Methylamino-4-p-toluidino-arithraquinone 0.016 0.012 342.40

2-Phthaloquinone 0.085 0.063 291.30

Phenyl-l-azo-4,3-methyl-l-phenyl-hydroxypyrazole 0.17 0.13 278.32 p,p'-Tetramethyldiaminophenyl-ketonimino-HCL 0.045 0.34 303.84 One particularly important sub-class of compounds useful as fluorophore in our invention are referred to as optical brighteners. A discussion on optical brighteners can be found in Chapter 10 of "Color Chemistry", Heinrich Zollinger, Verlagsgesellschaft mbH, D-6940 Weinheim (Federal Republic of Germany) 1987. Optical brighteners free of water solubilizing groups are preferred materials. Some common names of these materials are Tinopal E (C. I. Fluorescent Brightener 72), Palanil Brilliant White R (C. I. Fluorescent Brightener 199), Uvitex ERN (C. I. Fluorescent Brightener 135, Uvitex A (Fluorescent Brightener 133), Tinopal SWN (C. I. Fluorescent Brightener 236), Leukopur EGM (C. I. Fluorescent Brightener 133). Mikawhite AT, C. I. Fluorescent Brightener 162, Fluolite XMF C. I. Fluorescent Brightener 179) .

Optical brighteners are appropriate fluorophores for the detection of fingerprints on many important substrates (e.g. , glass, human tissue) . However, some substrates contain optical brightener (e.g., some papers, clothing, and plastics) . In these cases, the use of optical brighteners as the volatile fluorophore could severely limit the contrast of the fingerprinted region and the substrate. Therefore, for substrates containing optical brighteners, other volatile fluorophores are required to maximize the visualization of the fingerprint. Since it is still desirable in many cases to use a portable UV light source, volatile fluorophores that absorb in the UV region but emit a color other than blue are preferred. One class of fluorophores, that is useful in this regard, are dyes that undergo excited state intramolecular proton transfer (ESIPT) reactions. Fluorophores that undergo ESIPT are typically characterized by a large energy difference between the absorption maximum and the fluorescence maximum. The difference between the absorption maximum and the fluorescence maximum is commonly referred to as the Stokes shift. Stokes shifts are typically represented in cm^"1 units. Stokes shift values above 3500 cm^"1, generally, are considered large and are associated with significant geometric distortions or rearrangements (e.g., ESIPT reactions) in the excited state. Some ESIPT materials have Stokes shifts which are in excess of 7500 cm^'1. Examples of fluorescent materials that undergo ESIPT are 2-(o-hydroxyphenyl)benzothiazole,

2-(o-hydroxyphenyl)benzoxazole, 1-hydroxyanthraquinone. An especially preferred material from this class is 2-(o-hydroxyphenyl)benzothiazole.

Other fluorescent materials that exhibit large Stokes shifts, and which therefore could be useful on substrates containing optical brighteners, are twisted internal charge transfer (TICT) compounds. A review article of these materials is W. Rettig, Angew . Chem . Int . Ed . Engl . 25, 1986, 971-988. A list of such compounds is given in Fig. 8 of this paper.

Some of the Coumarin laser dyes (e.g., Coumarin 1) are TICT compounds. ESIPT and TICT complexes often exhibit a phenomenon referred to as dual emission. Dual fluorescence refers to the observation of two emission bands derived from two singlet excited states upon excitation of a fluorophore at a single wavelength.

For some situations, it is preferred to use a laser as the light source for the visualization or detection of fingerprints. Preferred lasers are argon ion, copper vapor, and frequency doubled neodynium YAG lasers. (See for example, B. J. Delmas, Journal of Forensic Identification 38, 1988, 49-56 and, M. McCarthy, Journal of Forensic Identification 40, 1990, 75-80. These lasers output light in the visible spectrum (400-700 nm) and therefore require the use of a colored fluorophore. In addition to the 4-tricyanovinyl-anilines mentioned above acridine orange (3,6-bis(dimethylamino)acridine) and acridine red can.be used.

Other materials that could be used in our invention are colorants used in pyrotechnic displays. A list of these materials can be found in G. Krein, Thermochimica Acta , 81 1984 29-43. Many of these fluorescing dyes are anthraquinones.

Other preferred fluorescent dyes that can be used in this invention are various non-ionic laser dyes which are free of water-solubilizing groups such as carboxy, sulfo. Examples include the following: Coumarin 1, Coumarin 2, Coumarin 4, Coumarin 6, Coumarin 7, Coumarin 30, Coumarin 102, Coumarin 106, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin 307, Coumarin 314, Coumarin 314T, Coumarin 334, Coumarin 338, Coumarin 500. Other useful laser dyes are l,4-Bis(5-phenyloxazol-2yl)benzene (POPOP) 1,4-Bis (4-methyl-5-phenyloxazol-2yl)benzene (Dimethyl-POPOP) , rubicene, tetracene, chrysene, triphenylene,

O-phenylene-pyrene, anthanthrene, azulene, fluoranthrenene, decacyclene, benz (e) acephenanthrylene, benzo(ghi) fluoranthene, 3,4-benzophenanthrene, p-terphenyl, p-quaterphenyl, phenanthrene, perylene, or substituted derivatives thereof.

A presently preferred class of fluorescent material which is useful in our invention are aminostyryl dyes. These dyes have the general structure shown in Figure 1:

Figure 1. wherein R, and R₂ can independently be a hydrogen, an alkyl groups, an alkaryl groups, an aryl groups, an aralkyl. groups, having up to 18 carbon atoms; R₃, R₄, R₅, and R_ή can be independently be a hydrogen atom, an alkyl group, an aryl group, a halogen atom, a cyano group, an alkoxy group, an aryloxy group, dialkylamino group, carboxy group (C00-) , wherein the pairs Rj and R₃, and R, and R₄, may be covalently linked to on another to form a cyclic structure; X can be a hydrogen atom, cyano group, or if included in a ring, an alkoxide, a divalent oxygen, a divalent sulfur, divalent alkylene with four or fewer carbons (e.g., methylene, ethylene, propylene) ; the pair, R₅ and X may be covalently linked to one another to form a cyclic structure; Y and Z can independently be a hydrogen, a cyano group (CN) , a ester group (COOR) , an amide group (CONHR) , a sulfonyl group (S02R) , the pair X and Y may be covalently linked to one another to form a cyclic structure.

Preferred structures are when Y and Z are cyano groups, and X is selected from a hydrogen atom, a cyano group, an alkyl group; R_{ and R₂ are independently alkyl or alkaryl groups; R₃, R,, R₅, and P^ are independently hydrogen atoms, alkyl groups, alkoxy groups and wherein the pairs X and R₅, and R, and R₃, and R₂ and R₄ may form a ring systems.

Especially preferred structures are when Y and Z are cyano groups, and X is either a hydrogen atom a cyano group; R_! and R, are independently alkyl or alkaryl groups with less than 12 atoms; R₃, R₄, R₅, R,- are hydrogen atoms.

It is remarkable that the preferred aminostyryl dye structures are effective in a fluorescent detection system because of their relatively low quantum efficiencies. The quantum yields for emission for 4- dicyanovinyl-N,N-diethylaniline (DCVA) , and 4-tricyano- N,N-diethylaniline (TCVA) have been measured in a variety of media. (See for example: A. V. Deshpande, A. Beidoun, and A. Penzkofer, Chemical Physics 142, 1990, 123-131 and A. V. Deshpande, ibid. 148, 1990, 141-154. In the gas phase the quantum efficiency for DCVA and TCVA are reported to be about 1.5 x 10-4. In fluid media, the quantum yields are higher in benzene solution the quantum yields are 7.3 x 10-4 (DCVA) and 1.8 x 10-3 (TCVA). In more viscous media, the quantum yields are somewhat higher. In general, most fluorescent compounds used to develop prints have much higher quantum yields of fluorescence. Apparently, the unique high efficiency utility of these preferred aminostyryl compounds is the result of 1) their ability to selectively codeposit with the cyanoacrylate, 2) their relatively high extinction coefficients, and 3) the volatility of these compounds.

The preparation of the cartridge can be accomplished by a number of methods.

When granulated cyanoacrylate is used, the cyanoacrylate may be formed by any conventional technique such a pressure forming into a cylinder or torus which is then loaded into the cartridge around the inner wall of the housing.

Alternatively, the granulated cyanoacrylate may be simply poured directly into the housing and tamped until firm.

When liquid cyanoacrylate is used, the important feature is that the cyanoacrylate (and the fluorescent compound, if used) are placed on the inert substrate in close enough proximity, such that upon heating, the materials effectively volatilize.

One method includes taking a hollow metal housing having a forward end and a bottom end, inserting a quantity of a thermally stable porous material into said housing, pouring a quantity of liquid cyanoacrylate into the housing to impregnate the thermally stable porous material, and allowing the liquid cyanoacrylate to polymerize. When the fluorescent dye is used, it is preferred that the polycyanoacrylate and the fluorescent compound are either in intimate contact or co-dissolved for effective co-volatilization. Some methods for loading the cartridge when liquid cyanoacrylate and fluorescent dye are used are as follows:

1) adding the monomeric cyanoacrylate to the inert fibrous substrate, a polymerization catalyst, and then a fluorophore-containing solution and then allowing the solvent to evaporate;

2) co-dissolving the polycyanoacrylate and the fluorescent compound and adding the resultant solution to the inert fibrous substrate and allowing the solvent to evaporate.

The above procedures represent simple methods for loading the cartridges but are not intended as being unduly limiting.

It is preferred that the fluorescent compound have a Stokes shift greater than 3500/cm^"1. It is also preferred that the fluorescent compound exhibit dual emission and/or undergoes excited state proton transfer. Some also exhibit a twisted internal transfer excited state.

Examples Materials

The following compounds were obtained from Aldrich Chemical Company: 7-diethylamino-4-methylcoumarin (cat. no. D8,775-9), Fluorene (cat. no. 12,833-3). These and other aminostyryl derivatives, 4-diethylaminobenzalmalononitrile and 4-tricyanovinyl- N,N-diethylaminoaniline were and can be prepared by the methods listed in B. C. Mckusick, et. al. J . Am . Chem . Soc . 80, 1958, 2806.

2-(o-Hydroxyphenyl)benzothiazole (cat. no. 00730 and Acridine Orange (cat. no. 01757) were purchased from the Eastman Fine Chemicals, Eastman Kodak Company. The Acridine Orange was used as the hydrogen chloride adduct, as obtained from Eastman Fine Chemical, and also as the free-based form. Loctite Hard Evidence™, obtained from Lightning Powder Co., Inc., 1230 Hoyt St., S. E. , Salem, Oregon 97302, was the cyanoacrylate employed. Zip-Kicker™, is a cyanoacrylate curing agent, available from Pacer, Ranch Cucamonga, California 91730. All other materials were obtained from standard sources.

Equipment

A model UT-lOOSi (self igniting) or UT-50 butane powered heat tool was used as the heating source. Where fluorescent dyes are used, the UV source was a Model UVG-11 Mineralight Lamp (Short Wavelength UV-254 nm) handheld unit from UVP. Inc., San Gabriel, CA.

Preparation of Cartridges. Dichloromethane solutions, 1% - 5% by weight, of each of the dyes were prepared.

Brass cartridges were packed with steel wool. (These cartridges were packed with the steel wool such that the steel wool formed a torus in the cartridge; this design allows the hot vapors to escape through the central channel.) For one cartridge, the steel wool was impregnated with the cyanoacrylate (Loctite) , sprayed with the curing agent and the solvent was allowed to evaporate. For another cartridge, the steel wool was impregnated with the cyanoacrylate and sprayed with the curing agent. A few drops of the dye solution was added to the cyanoacrylate impregnated steel wool and the solvent allowed to evaporate. For the alternative embodiment using cured granulated cyanoacrylate, the granulated cyanoacrylate may be preformed into a cylinder which is packed around the inner wall of the housing or simply packed directly into the housing and tamped until firm.

Development of Fingerprints. The butane heater was started, when the ceramic element started to glow red, the cartridge was placed onto the top of the burner. Within seconds, fumes began to develop. In the case of the aminostyryl dyes the fumes were colored. The fumes were allowed to come into contact with a glass slide which had been touched so as to provide a fingerprint. Within seconds an enhanced fingerprint was observed. Samples containing dyes except for the 4-tricyanovinyl-N,N-diethylaniline exhibited bright emission when viewed obliquely with the UV light. The tricyanovinyl-N,N-diethylaniline could be visualized with an argon ion laser.

Claims

Claims :

1.. A cartridge for developing latent fingerprints on objects using cyanoacrylate comprising: a cylindrical housing having an open top and an open bottom and a solid wall, said housing containing a quantity of cyanoacrylate cured to a solid form having an open area in its center.

2. A cartridge for developing latent fingerprints on objects using cyanoacrylate comprising: a cylindrical housing having an open top and an open bottom and a solid wall, said housing containing a quantity of thermally stable, thermally conductive, porous support material, said support material being impregnated with liquid cyanoacrylate cured to a solid form in said support material, said support material having a open area in its center.

3. The cartridge of claim 2 wherein said thermally stable support material is selected from steel wool, wire, fiberglass and ceramic.

4. A cartridge according to claim 2 wherein said chamber contains a thermally stable porous or fibrous support impregnated with both:

1) a polycyanoacrylate ester, and

2) a volatile fluorescent dye with a molecular weight between 100 to 500 Daltons and a quantum efficiency in fluid benzene solution at ambient temperature of greater than 10^"4.

5. A device for developing latent fingerprints on objects using liquid cyanoacrylate comprising: a) a removable cylindrical cartridge according to claim 1 having an open top and an open bottom and a solid wall, said housing containing cyanoacrylate, and b) heating means for producing sufficient temperature to sublimate the cyanoacrylate and having an exhaust gas with sufficient velocity that projects the sublimated cyanoacrylate from said housing in an outward direction, said heating means being removably connected to the open bottom of said cartridge such that said exhaust gases pass through said housing and exit therefrom through said open top.

6. The device for developing latent fingerprints of claim 3 wherein said housing comprises a quantity of thermally stable support material selected from the group consisting of porous and fibrous support material, said support material being impregnated with a liquid cyanoacrylate, and said heating means comprises a portable blowtorch.

7. The method for making a cartridge according to claim 2 containing a quantity of cyanoacrylate adapted to be vaporized for developing latent fingerprints comprising the steps of taking a hollow metal housing having a forward end and a bottom end, inserting a quantity of a thermally stable porous material into said housing, pouring a quantity of liquid cyanoacrylate into the housing to impregnate the thermally stable porous material, and allowing the liquid cyanoacrylate to polymerize.

8. A method of developing latent fingerprints on an object, using liquid cyanoacrylate comprising the steps of: a) providing a cartridge according to claim 1 or 2, having a forward end, a bottom end and a solid wall, and a quantity of cyanoacrylate within said housing b) . attaching the bottom end of said housing to the exhaust port of a propane torch, c) lighting said torch, thereby producing a relatively high temperature exhaust gas having a forward velocity, d) projecting said exhaust gas through said housing and cyanoacrylate, causing said cyanoacrylate to sublimate into a vapor, e) positioning said exhaust gas and said cyanoacrylate vapor being discharged from said forward end onto a said object for testing whereby the cyanoacrylate deposits onto said object to develop any said latent fingerprints.

9. The method of developing latent fingerprints of claim 8 wherein said housing has a porous support material selected from steel wool, wire, ceramic or fiberglass, positioned within said housing against said wall, which support material is impregnated initially by liquid cyanoacrylate which is allowed to cure.

10. A fingerprint development composition for use in a cartridge according to claim 1 or 2 comprising a monomeric or polymeric cyanoacrylate and a fluorescent dye of the following structure,

Rj and R₂ can independently be alkyl group, an aryl groups, an aralkyl groups, each having up to 18 carbon atoms; R₃, R₄, R₅, P^ can be independently be a hydrogen atom, an alkyl group, an aryl group, a halogen atom, a cyano group, an alkoxy group, an aryloxy group, dialkyla ino group, carboxy group (C00-) wherein R is an alkyl or aryl group, wherein the pairs R_j and R₃, and R_j and R_4/ may be covalently linked to on another to form a cyclic structure;

X can be a hydrogen atom, cyano group, an alkoxide, a divalent oxygen, a divalent sulfur, divalent alkylene with four or fewer carbons (e.g., ethylene, ethylene, propylene) ; the pair, R₅ and X may be covalently linked to one another to form a cyclic structure; Y and Z can independently be a hydrogen, a cyano group (CN) , a ester group (COOR) , an amide group (CONHR) , a sulfonyl group (S02R) , the pair X and Y may be covalently linked to on another to form a cyclic structure.

11. The composition of claim 10 wherein said compound contains a ring nuclei selected from the group consisting of carbazole, indole, imidazole, furan, thiophene, oxazole, oxadiazole, acridine, acridone, quinoline, flavone, pyridine, quinoxaline, and quinazoline.

12. The composition of claim 11, wherein the fluorescent compound exhibits dual emission.

13. The cartridge of claim 4, wherein the fluorescent compound undergoes excited state proton transfer and has a Stokes shift greater than 3500 cm"¹.