Chemical formulation used as luminescent chemical markers in firearm ammunition, method of ammunition preparation, and uses for commercial identification of ammunition and manufacturers.

Description

1 / 23 Chemical formulation used as luminescent chemical markers in firearm ammunition, method of ammunition preparation and uses for commercial identification of ammunition. AND MANUFACTURERS Field of invention

[01] The present invention falls within the field of forensic chemical analysis, more specifically in the area of ​​investigation or analysis of chemical substances by the use of luminescent means, since it refers to an optical process for detecting luminescent organic chemical substances, of a chemical class different from those already existing in the literature, which have the potential to be inserted into firearm ammunition, aiming both at their visual detection in targets of forensic interest, and the possible use of the same as identifiers of manufacturers of these ammunitions. Fundamentals of the invention

[02] Forensic Chemistry is a branch of Chemistry that uses its knowledge both in forensic investigation and in the analysis, classification, identification, and detection of a set of material (elements, substances, or compounds) collected at crime scenes (Bruni, AT, Velho, JA, de Oliveira, MF, 2012; Velho, JA, et al., 2012).

[03] And gunshot residues (GSRs) are considered important evidence at the crime scene. They consist of microtraces resulting from the combustion of gunpowder contained in ammunition, which are deposited on surfaces near the firing location, such as the shooter's hands and clothing, as well as objects and surfaces in the vicinity (Bruni, AT, Velho, JA, de Oliveira, MF, 2012; Destefani, CA, et al., 2016; Castro, SVF, et al., 2020).

[04] Chemical analysis of these residues allows the determination of the recent presence of a person in contact with a firearm, as well as the identification of the type of ammunition. Petition 870250001217, dated 07 / 01 / 2025, page 18 / 54 2 / 23 employed, thus becoming important evidence in the elucidation of crimes. Such results are useful for identifying the perpetrator of the criminal offense and providing information to the judicial system (Menking-Hoggatt, K., et al., 2022; Charles, S. and Jonckheere, A., 2022).

[05] Regarding firearms, these are devices designed for the propulsion of projectiles through the use of explosive charges. They have a basic structure consisting of a combustion chamber, where the explosive charge is housed, and a barrel, responsible for directing and guiding the projectile. Firearms can be classified into different categories, such as pistols, revolvers, rifles, shotguns, carbines, machine guns, carbines, muskets, among others. They are used for various purposes, such as hunting, sports, self-defense and military use (O'Mahony, AM and J. Wang, 2013; Salles, MO, Bertotti, M., and Paixao, TRLC 2012).

[06] Ammunition, in turn, is a set of elements that, when joined together, form a cartridge that can be inserted into a firearm to be fired. Ammunition is composed of three main parts: (1) projectile, (2) propellant charge (gunpowder) and (3) cartridge case. In addition, there may also be a fourth part, the (4) primer, which is responsible for initiating the combustion of the propellant charge. Figure 1A shows a firearm during firing and Figure 1B shows a diagram of a firearm cartridge (Charles, S. and Jonckheere, A. 2022).

[07] The components of conventional ammunition are described below:

[08] The projectile (1) is the part of the ammunition that is fired from the firearm and may consist of various materials, such as lead, steel or copper. Its shape and weight vary according to the purpose of the ammunition, such as target shooting, hunting or personal defense. Particles derived from the composition of the projectile alloy may be identified, for example, Pb, Ba and Sb (Bruni, AT, Velho, Petition 870250001217, dated 07 / 01 / 2025, p. 19 / 54 3 / 23 JA, de Oliveira, MF, 2012; O'Mahony, AM and Wang, J., 2013).

[09] The propellant charge (2), also known as gunpowder, is responsible for generating the pressure and energy needed to propel the projectile through the gun barrel. It can be composed of different types of gunpowder, such as black powder or smokeless powder, depending on the type of ammunition. The propellant composition accounts for the main organic residues. In older firearms, black powder is used, consisting of the oxidant potassium nitrate which, together with carbon and sulfur, produces nitrogen and carbon dioxide gases. Smokeless gunpowder can consist of nitrocellulose, a double base (nitrocellulose and nitroglycerin) or a triple base (nitrocellulose, nitroglycerin and nitroguanidine), as well as other compounds such as diphenylamine (DPA) and derivatives, 2,4-dinitrotoluene (2,4-DNT), ethyl centrilite (EC) which act as stabilizers, plasticizers, sensitizers and flash suppressants (Bruni, AT, Velho, JA, de Oliveira, MF, 2012; Dalzell, KA)., 2022).

[010] The cartridge case (3) is the outer part of the ammunition and is usually made of metal. It is responsible for containing all the other elements of the ammunition and for protecting them from the external environment (Tobin, JJ, Jr., 2012). The cartridge case can be reloadable or disposable, depending on the type of ammunition. It is made of a metal alloy in a 70:30 ratio, that is, 70% copper and 30% zinc (Bruni, AT, Velho, JA, de Oliveira, MF, 2012, 2012).

[011] The primer (4) (primer or initiating mixture) is a small device that initiates the combustion of the propellant charge in a firearm cartridge. It is usually placed at the base of the cartridge case and is activated when the firing pin or hammer of the firing mechanism is struck. This shock-sensitive mixture is essential for Petition 870250001217, dated 07 / 01 / 2025, p. 20 / 54 4 / 23 combustion of gunpowder occurs and its composition may vary depending on the type of ammunition (Bruni, AT, Velho, JA, de Oliveira, MF, 2012; Dalzell, KA, 2022).

[012] However, in conventional ammunition, the primer basically comprises an explosive compound (lead styphnate, C6HN3O8Pb), an oxidizer (barium nitrate, Ba(NO3)2), the fuel (antimony sulfide, Sb2S3), and the stabilizers 2,4,6-trinitrotoluene (TNT) and tetracene. After firing, the heat produced in the explosion allows these ions to be reduced to their forms, originating particles called fusion microspheres, which generally contain in their chemical composition the species lead (Pb), barium (Ba), and antimony (Sb) (Dalzell, KA, 2022), as can be seen in Figure 2B.

[013] Although these three metals constitute the main traceable source of GSRs, there are other organic and inorganic substances that can also contribute residual elements, such as copper (Cu), aluminum (Al), calcium (Ca), silicon (Si), depending on the manufacturer's composition (Bruni, AT, Velho, JA, de Oliveira, MF, 2012).

[014] Firearm residue detection methods (IGSRs) are based on the analysis of chemical residues produced by firing a firearm, in which microtraces of metallic and organic species can be deposited on the shooter's hands, arms, face, hair, and clothing.

[015] Different types of physicochemical analysis techniques can be employed for the analysis of so-called inorganic GSRs, such as, for example: atomic absorption spectroscopy (AAS), inductively coupled plasma (ICP) and scanning electron microscopy combined with energy-dispersive X-rays (SEM / EDX). For organic GSRs, chromatographic techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC) can be regularly used. Petition 870250001217, dated 07 / 01 / 2025, page 21 / 54 5 / 23 coupled or not with mass spectrometry (MS) and capillary electrophoresis (CE) (Bruni, AT, Velho, JA, de Oliveira, MF, 2012; Tobin, JJ, Jr., 2012; Ferreira, BC, 2017; Santos, A., et al., 2015; Gagliano-Candela, R., Colucci, AP and Napoli, S., 2008; Zuy, Y., et al., 2020).

[016] However, this equipment requires professional training to conduct the analyses, and it is impossible to perform chemical analyses in the field, directly at the crime scene.

[017] Currently, forensic analysis of GSRs faces a serious problem in its execution. With the development of so-called ecological ammunition (which does not contain conventional metals in its composition, such as Pb, Sb, and Ba), conventional traces are not found, since the objective of this ammunition is to be considered a cleaner alternative to conventional ammunition, as it does not generate toxic gases and residues for the shooter after firing (CBC - Companhia Brasileira de Cartuchos. NTA ammunition - non-toxic ammunition. Technical bulletin no. 61, 2013). Therefore, the techniques used for the recognition of conventional ammunition end up losing their value when used for ecological ammunition.

[018] One way to circumvent this lack of traces produced by so-called ecological ammunition consists of the purposeful addition of an organic or inorganic chemical substance to the ammunition itself, usually mixed with the propellant, and that, after the firearm is discharged, this substance shows resistance to the combustion process and is readily detected at the crime scene.

[019] In this context, an example of successful inorganic chemical markers is the use of lanthanide metals. These markers are luminescent, meaning they make GSR particles visible, allowing for in situ visualization using a portable ultraviolet lamp. This Petition 870250001217, dated 07 / 01 / 2025, page 22 / 54 6 / 23 feature facilitates crime scene investigation, as well as the collection of luminescent firearm discharge residue (LGSR) and laboratory analysis (Chedid, AA, Azevedo, LS, da Silva Galaço, ARB, Casagrande, TR, Serra, OA, de Oliveira, MF, 2023; Serra, ARB, Casagrande, TR, de Lima, JF, de Oliveira, MF, Júnior, SA, de Oliveira, JM, et al., 2022).

[020] In addition to inorganic markers, it is also possible to use organic substances with luminescent properties, such as anthracenes, which necessarily have three linear benzene rings in their main structure. Such substances have been synthesized and tested as luminescent chemical markers, showing good results, but at a very high cost.

[021] Thus, the present invention aims to study and propose alternative luminescent organic chemical markers for application both in the analysis of firearm discharge residue and in the commercial identification of ammunition and manufacturers. State of the art

[022] Some prior art documents already describe chemical substances used as markers in firearm ammunition. For example, document BR 102012033810-6 from UFRJ describes the synthesis and use of anthracene-based luminescent chemical substances for application as chemical markers in firearm ammunition, as mentioned above. Anthracene is a molecule formed by 3 benzene rings, which, according to its MSDS (Material Safety Data Sheet), has high toxicity in aquatic environments, with a long-lasting effect, and is also considered bioresistant to degradation. Anthracenes are organic substances, but belong to a class of organic luminescent marker compounds different from those studied in Petition 870250001217, dated 07 / 01 / 2025, page 23 / 54 7 / 23 present patent application. Furthermore, these anthracene-based compounds cost 10 times more than the chemical markers listed in the patent application now claimed, not to mention that the markers proposed for use in the present patent application have lower toxicity. The combination of these characteristics makes the use of the luminescent organic chemical markers proposed in the present invention quite advantageous when compared to anthracene-based luminescent markers already on the market.

[023] The article entitled “Investigation of the use of luminescent markers as indicators of weapons residue” describes the use of rare earth or lanthanide metals such as yttrium (Y), terbium (Tb) and ytterbium (Yb) as ammunition marker metals.

[024] Other lanthanide metallic markers such as europium and terbium can also be used for this purpose, as described in patent application PI 0901063-7 from UFPE (international publication WO 2010 / 105326). However, these markers are inorganic, cost 10 times more than the chemical markers listed in the patent application in question, and are also more toxic than the organic markers proposed in this patent application. The combination of these characteristics also makes the use of the luminescent organic chemical markers proposed in the present invention quite advantageous when compared to the lanthanide metallic markers already on the market.

[025] US patent 10,001,437 from the Research Foundation of the State University of New York describes a method for analyzing chemical markers present in gunshot residue, but does not focus on the chemical markers themselves. As an example, in the present invention, as well as in documents BR 102012033810-6 from UFRJ and PI 0901063-7 from UFPE, the detection of said chemical markers is done by applying ultraviolet radiation, using a flashlight containing UV lamps. In the patent... Petition 870250001217, dated 07 / 01 / 2025, p. 24 / 54 8 / 23 US patent 10,001,437 describes a method that utilizes a Raman spectrophotometer, which operates in the infrared region, not the ultraviolet region. These are distinct regions of the electromagnetic radiation spectrum, resulting in different sets of results. For example, an ultraviolet flashlight costs R$120.00, while a Raman spectrophotometer costs R$120,000.00. US patent 10,001,437 mandates the use of a Raman spectrophotometer, whereas in the present invention, the proposed markers can be instrumentally analyzed using a wide range of analytical techniques, such as chromatographic methods (HPLC, GC, TLC, etc.), spectroscopic methods (UV-Vis, Raman, FTIR, etc.), and electrochemical methods (potentiometry, voltammetry, amperometry, etc.). Therefore, the high cost of the Raman technique is unfavorable compared to the simpler and cheaper analysis techniques of the markers proposed in the present invention.

[026] Document WO 2022 / 020379 from Veriteque USA, INC. describes a colorimetric chemical analysis kit for the detection of firearm discharge residue and explosive residue. Colorimetric chemical analysis is a method of chemical analysis where a liquid reagent is applied to the sample under study, producing a chemical reaction which results in a color change in the sample. The color produced can provide confirmatory or exclusionary information regarding a given analyte under investigation.

[027] Thus, the aforementioned document consists of the protection of an analytical method for conventional firearm residues (those produced from the combustion of conventional propellant material, which do not include chemical markers intentionally added to the cartridge case), while the present invention claims the use of new chemical marker substances, aimed at ecological ammunition, which Petition 870250001217, dated 07 / 01 / 2025, page 25 / 54 9 / 23 are free of conventional residues. The proposed kit requires the use of a swab (a stick with cotton at the end), which is previously treated with solvent and a drying agent. The swab is pressed against a surface supposedly containing gunshot or explosive residue, physically collecting it. Subsequently, a specific solution containing a chemical reagent for detecting a particular type of gunshot residue, which can be organic or inorganic, present in gunshot residue from conventional ammunition, is added to this cotton head.

[028] As an operational difference, the detection method used in the present invention is visual, by applying ultraviolet light to the residues, revealing their presence. It does not involve sample destruction by mandatory addition of colorimetric chemical reagents, as proposed in document WO 2022 / 020379.

[029] Given the high cost and complexity of analytical techniques and the toxicity of known chemical markers, the present invention aims to study and propose alternative luminescent organic chemical markers for application in both firearm discharge residue analysis and commercial identification of ammunition and manufacturers, investigating six commercial organic dye substances (Rhodamine B, Blue 1, Orange 5, Yellow 10, Green S and Eosin Y), previously available on the market and possessing specific chemical structures not yet used for these proposed purposes. Brief description of the invention

[030] The present invention describes a chemical formulation and its preparation for firearm ammunition comprising solid, powdered or solvent-soluble organic chemical substances, which are free of anthracenes and exhibit luminescent properties, i.e., emit colors visible to Petition 870250001217, dated 07 / 01 / 2025, page 26 / 54 10 / 23 can be irradiated with ultraviolet light. These substances (Rhodamine B, Blue 1, Orange 5, Yellow 10, Green S, and Eosin Y) can be mechanically inserted into the cartridge case chamber or mixed into the propellant material or any other component of the ammunition. After firing, the residue produced is visually identified by applying ultraviolet light, through the luminescence of these substances, which can be detected on the target, the weapon, the shooter's hands, arms, face, body, and clothing, constituting an alternative method of identification and classification of these munitions, both for forensic and industrial or commercial purposes. Brief description of the figures

[031] To obtain a full and complete visualization of the object of this invention, the figures to which reference is made are presented, as follows.

[032] Figure 1A shows a firearm at the moment of firing.

[033] Figure 1B shows a diagram of a firearm cartridge with the components projectile, propellant (gunpowder), case and primer.

[034] Figure 2A shows a typical fusion microsphere formed by lead (Pb), barium (Ba) and antimony (Sb), produced in a firearm discharge using conventional ammunition.

[035] Figure 2B shows a typical fusion microsphere formed by lead (Pb), barium (Ba) and antimony (Sb), produced in a firearm discharge using conventional ammunition, with close-up view.

[036] Figure 2C is a graph showing the elemental analysis produced by the Energy Dispersive X-ray Spectroscopy (EDS) technique regarding the chemical composition of the microsphere.

[037] Figures 3A and 3B represent the inertia hammer. Petition 870250001217, dated 07 / 01 / 2025, page 27 / 54 11 / 23 used for projectile extraction and to assist in the disassembly and modification of ammunition that uses metal casings in its composition.

[038] Figure 4A represents the luminescent powder dyes in blue, red, yellow, green and orange colors in natural light.

[039] Figure 4B represents the same dyes under the incidence of ultraviolet light at a wavelength of λ= 360 nm.

[040] Figure 5A represents a typical firearm ammunition, of the pistol type, opened to receive the insertion of dyes.

[041] Figure 5B represents ammunition typically modified with blue, red, yellow, green and orange dyes in natural light (5B1 5B2) and in UV light λ= 360 nm (5B3).

[042] Figure 6A represents a typical 12-gauge rifle cartridge, opened to receive the insertion of dyes.

[043] Figure 6B represents some of the dyes diluted in water and in powder form under the incidence of ultraviolet light at a wavelength of λ= 360 nm.

[044] Figure 7A represents the weapon used in shooting range tests, a 380 Taurus® pistol along with ammunition modified with dyes before firing at the indoor shooting range.

[045] Figure 7B represents the shooter's grip before the target is fired.

[046] Figures 8A, 8B, 8C and 8D represent targets hit with the modified ammunition in red, orange and yellow colors under the incidence of ultraviolet light.

[047] Figure 9A represents the target hit by ammunition modified with Rhodamine B dye, showing a purple hue visible to the naked eye under natural light. Petition 870250001217, dated 07 / 01 / 2025, page 28 / 54 12 / 23

[048] Figure 9B illustrates the same target after the application of water to the impacted area, still under natural light and visible to the naked eye.

[049] Figure 10A represents the shooter's left hand after firing, showing the gunshot residue modified with the dye, deposited with less intensity under UV light.

[050] Figure 10B represents the shooter's right hand after firing, showing the gunshot residue modified with the dye, deposited with greater intensity under UV light.

[051] Figure 11 represents the gunshot residue typically distributed on the shooter's face after firing a firearm under UV light.

[052] Figure 12 is a typical voltammogram obtained from the Rhodamine B dye collected from the shooter's hands.

[053] Figure 13 is the voltammogram obtained from the Rhodamine B dye.

[054] Figure 14 is the voltammogram obtained from Orange 5 dye.

[055] Figure 15 is the voltammogram obtained from the Yellow 10 dye.

[056] Figure 16 shows the three voltammograms together, obtained for the three dyes (Rhodamine B, Orange 5 and Yellow 10), using the cyclic voltammetry technique. Detailed description of the invention

[057] The present invention relates to a chemical formulation comprising luminescent organic substances, in their pure form or accompanied by adjunct substances that perform functions such as stabilizers, diluents, preservatives, protectors, etc., and their use as chemical markers in firearm ammunition.

[058] Firearm ammunition is prepared following Petition 870250001217, dated 07 / 01 / 2025, page 29 / 54 13 / 23 the following steps: a) Weighing the appropriate mass of the luminescent organic chemical substance (luminescent marker), the quantity of which must be between 0.01% and 25% of the total mass of gunpowder present in each type of ammunition. b) Mechanical mixing of the aforementioned mass with the propellant to obtain the chemical formulation; c) Insertion of the aforementioned chemical formulation containing the luminescent organic marker inside the previously opened ammunition; d) Sealing of the ammunition containing the aforementioned luminescent marker, ready for firing.

[059] The chemical formulation can also be added to the surface of the ammunition or added to the body of the projectiles in the form of thin adsorbed films, by mechanical mixing with them or by deposition in any way, such as spraying with aerosol, liquid solutions to soak the projectiles, primers, cartridges and cases.

[060] The chemical formulation of said luminescent markers may contain only one isolated chemical marker or may consist of a mixture of markers.

[061] The luminescent organic chemical substances used in this patent application can be incorporated into ammunition for revolvers, pistols, rifles, shotguns, carbines, rifles, machine guns or carbines, and can be conventional ammunition as well as ecological or marker-free ammunition.

[062] In addition, markers may be incorporated inside ammunition cartridges either in their solid powder form or diluted in solid, liquid or gaseous solutions. Structure of luminescent organic chemical substances (luminescent markers)

[063] Luminescent organic chemicals Petition 870250001217, dated 07 / 01 / 2025, page 30 / 54 14 / 23 used as luminescent markers in firearm ammunition comprise the following structures: a) Blue No. 1 dye (CAS: 3844-45-9, CI 42090), as well as other derivatives of this structure, containing any additional or substituted atoms, ions, or chemical groups at any atom in its molecular structure. Molecular formula: C37H34N2Na2O9S3 b) Orange 5 dye (CAS: 4372-02-5 / 596-03-2, CI 45370), as well as other derivatives of this structure, containing any additional or substitute atoms, ions, or chemical groups, at any atom in its molecular structure. Molecular formula: C2OHiOBr2O5 c) Yellow 10 dye (CAS: 8004-92-0 / 94891-32-4 / 9519383-2 / 68814-04-0, Cl 47005), as well as other derivatives of this structure, containing any additional or substitute atoms or ions or chemical groups, in any atom of its molecular structure. Molecular formula: Ci8Hi3NO5 / 8 / nSi / 2 / 3Nai / 2 / 3 Petition 870250001217, dated 07 / 01 / 2025, p. 31 / 54 15 / 23 d) Eosin Y dye (CAS: 17372-87-1; CI 45380), as well as other derivatives of this structure, containing any additional or substitute atoms, ions, or chemical groups, at any atom in its molecular structure. Molecular formula: C2OH6OsBr4Na2 e) Rhodamine B dye (CAS: 81-88-9; CI 45170), as well as other derivatives of this structure, containing any additional or substitute atoms, ions, or chemical groups, at any atom in its molecular structure. Molecular formula: C28H31ClN2O3 f) Green S dye (CAS: 3087-16-9; CI 44090) as well as other derivatives of this structure, containing any additional or substituted atoms, ions, or chemical groups, in Petition 870250001217, dated 07 / 01 / 2025, page 32 / 54 16 / 23 any atom in its molecular structure. Molecular formula: C27H25N2O7S2Na Methodology for identifying luminescent organic chemical residues.

[064] After the firearm is discharged, luminescent organic chemical residues can be visually identified on the target, the weapon, the shooter’s hands, arms, face, body and clothing in general, by means of ultraviolet light.

[065] The visual identification of said residues by means of ultraviolet radiation constitutes in itself an important method of forensic or industrial or commercial analysis. However, said residues may, at the analyst's discretion, be collected mechanically, using various instruments (tweezers, adhesive tape, spatulas or swabs soaked with solutions, etc.), for subsequent confirmatory instrumental chemical analysis.

[066] Additional confirmatory chemical tests performed on these luminescent residues may be provided by instrumental techniques such as chromatography (HPLC, GC), combined with mass spectrometry (GC-MS), spectrophotometry (UV-Vis, Raman, Infrared) or electrochemistry (voltammetry, potentiometry, amperometry, conductometry, coulometry). Examples Petition 870250001217, dated 07 / 01 / 2025, page 33 / 54 17 / 23 Preparation of luminescent organic markers

[067] The appropriate masses of organic chemical markers, in their pure form or accompanied by stabilizing adjuncts, were used in this process, without any prior chemical treatment being necessary. - Insertion of markers into commercial ammunition

[068] The appropriate masses of the aforementioned markers (Rhodamine B, Blue 1, Orange 5, Yellow 10, Green S and Eosin Y) were added inside the opened commercial ammunition cases (3). The opening of the cases was carried out using a device commonly known as an “inertia hammer” (Figures 3A and 3B). In this device, the intact ammunition is attached to the end of the hammer, and the assembly is struck on a wooden surface to open the ammunition cartridge and subsequently expose its interior. Subsequently, the chemical marker is inserted inside, along with the propellant material (2) specific to this cartridge, and the ammunition is then closed in a press suitable for this purpose. - Visualization of the waste produced

[069] Using a weapon suitable for the calibers of ammunition modified with the aforementioned markers, these munitions were fired at an appropriate shooting range, using cardboard targets positioned 1 meter from the muzzle of the weapon.

[070] After each shot, a commercial ultraviolet flashlight was used, equipped with two ultraviolet lamps, one emitting at 254 nanometers and the other emitting at 360 nanometers. Activating the flashlight allows visualization of the luminescent organic markers present in the gunshot residue, located both on the target and on the weapon, hands, face, and clothing of the shooter. Instrumental analysis of the residues Petition 870250001217, dated 07 / 01 / 2025, page 34 / 54 18 / 23

[071] For confirmatory purposes of the chemical identification of such luminescent organic substances present in the gunshot residue, they may optionally be investigated by instrumental chemical analysis equipment, either by chromatographic techniques such as HPLC or gas chromatography coupled to mass spectrometry (GC-MS), as well as spectroscopic techniques such as Fourier Transform Infrared (FTIR), as well as electrochemical techniques such as voltammetry. Tests performed

[072] Initial tests were carried out using 5% mass of each organic luminescent modifier (Rhodamine B, Blue 1, Orange 5, Yellow 10, Green S and Eosin Y), previously incorporated inside commercial ammunition for both .380 caliber pistols and 12 gauge shotguns.

[073] After the ammunition cartridges were sealed, they were fired at a shooting range, in front of a cardboard target suitable for this purpose (Figures 7A and 7B).

[074] Visual analysis of the residue was provided by using a commercial ultraviolet flashlight, and it was possible to detect such luminescent residue on the target as well as on the weapon, hands, arms, face and clothing of the shooter (Figures 8A, 8B, 8C, 8D, 9A, 9B, 10A, 10B and 11).

[075] For subsequent instrumental chemical analyses of these luminescent residues, voltammetric analyses were chosen.

[076] Cyclic voltammetry, square wave voltammetry, and differential pulse voltammetry measurements were performed using the PGSTAT128N Potentiostat and NOVA software, version 1.8.17. A conventional 5.0 mL electrochemical cell was employed with a 3.00 mm diameter, 0.071 cm² area carbon paste working electrode with silver contact, a platinum spiral auxiliary electrode, and a saturated Ag / AgCl reference electrode. For these analyses, Petition 870250001217, dated 07 / 01 / 2025, page 35 / 54 19 / 23 A 0.1 mol L⁻¹ Britton-Robinson buffer electrolyte solution was prepared by pipetting 1.44 mL of acetic acid, 1.55 mL of boric acid, and 1.55 mL of phosphoric acid into a final volume of 250 mL of aqueous solution. The pH was adjusted by adding 2.0 mol L⁻¹ sodium hydroxide, resulting in a pH of 7 using a pH meter. Standard solutions of each luminescent organic marker were obtained by dissolving appropriate aliquots in supporting electrolyte solutions. The collection of luminescent residues from the targets was carried out using a conventional carbon paste electrode, which is pressed onto the luminescent residue, thus removing it from the sample. Subsequently, this electrode containing the luminescent residue is added to the conventional electrochemical cell, and voltammetric analysis is performed.The voltammogram obtained for the gunshot residue sample is compared with the voltammogram of a standard solution of the marker, allowing for chemical confirmation of its presence.

[077] New voltammetric tests were performed using the same methodology described previously. In a larger volume electrochemical cell, 10 mL of supporting electrolyte (Britton-Robinson buffer pH 5) and 1 mg of each dye synthesized in the laboratory were added separately: Rhodamine B (neon pink), Orange 5 (neon orange), and Yellow 10 (neon yellow). Three voltammograms were obtained (Figures 13, 14, and 15), one for each dye, and each showed a distinct peak.

[078] For the Rhodamine B. dye, the electrochemical technique employed was cyclic voltammetry. A peak dye intensity is observed at +1.04 V using the supporting electrolyte (Britton-Robinson buffer with pH 5). This electrical signal (peak current) is proportional to the concentration of the chemical species studied, and can also be used for the Petition 870250001217, dated 07 / 01 / 2025, page 36 / 54 20 / 23 Mass quantification of the aforementioned residue.

[079] For the Orange 5 dye, the electrochemical technique employed was cyclic voltammetry. A peak dye intensity is observed at +1.19 V using the supporting electrolyte (Britton-Robinson buffer with pH 5). This electrical signal (peak current) is proportional to the concentration of the chemical species studied, and can also be used for the mass quantification of the residue.

[080] For the Yellow 10 dye, the electrochemical technique employed was cyclic voltammetry. A peak dye intensity is observed at +1.28 V using the supporting electrolyte (Britton-Robinson buffer with pH 5). This electrical signal (peak current) is proportional to the concentration of the chemical species studied, and can also be used for the mass quantification of the residue.

[081] The blue (Blue 1) and green (Green S and Eosin Y) dyes did not show electrochemical activity under the tested conditions. Changes will be made to the electroanalytical parameters to try to obtain an electrochemical signal that characterizes these dyes.

[082] To obtain the electroanalytical response of the pink, orange, and yellow dyes, specific electrochemical parameters were used, employing a commercial glassy carbon (GC) electrode from Metrohm® (Figure 16). The parameters used are shown below in Table 1: Table 1 - Electroanalytical parameters Electroanalytical parameters: Electrolyte: Britton-Robinson buffer, pH 5.0; Scanning window: 0 to 1.5 V; Scanning speed: 100 mV / s; Deposition time: 60 seconds; Cell volume: 1 x 10⁻² L; Dye solution volume: 5 x 10⁻⁴ L Petition 870250001217, dated 07 / 01 / 2025, page 37 / 54 21 / 23 added

[083] The dyes Blue 1 and Green S showed positive results when inserted into the ammunition and fired, being visible with the aid of a UV lamp. However, in the electrochemical analyses performed with the same parameters used for the other dyes, these two did not show significant voltammetric results. Therefore, other parameters, such as pH variation and the use of different electrodes, will be tested in the search for results that can qualify these dyes electrochemically. It is worth noting that they can be detected by other conventional analytical techniques such as chromatography and spectroscopy. Bibliographic References:

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[093] Dalzell, KA, Electrochemical and mass spectrometry methods for identifying gunshot residue (GSR) in forensic investigations at the Department of Forensic and Investigative Science. Morgantown, West Virginia

[094] Tobin, JJ, Jr. Method for the Separation and Identification of Components of Organic Gunshot Residue and Its Use as a Forensic Tool for Association of Firearms Related Evidence. 2012.

[095] Ferreira, BC, Determination of Pb, Ba and Sb in gunshot residue by ET AAS and SEM-EDS, aiming at false-positive diagnosis. 2017, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto FFCLRP-USP.

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[097] Gagliano-Candela, R., Colucci, AP and Napoli, S. Determination of the shutdown distance. Analysis of lead in the target by atomic absorption spectroscopy (AAS). Journal of Forensic Petition 870250001217, dated 07 / 01 / 2025, p. 39 / 54 23 / 23 Sciences, 2008. 53(2): p. 321-324.

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Claims

1 / 5 CLAIMS 1. A chemical formulation used as chemical markers in firearm ammunition, characterized by comprising luminescent organic chemical substances and a propellant; wherein the luminescent organic chemical substances are in an amount between 0.01% and 25% of the total mass of propellant present in each type of ammunition; and wherein the luminescent organic chemical substances are organic chemical markers comprising the following structures: a) Blue Dye 1, whose molecular formula is C37H34N2Na2OgS3, as well as other derivatives of this structure, containing any additional or substitute atoms or ions or chemical groups, in any atom of its molecular structure; b) Orange Dye 5, whose molecular formula is C2OHiOBr2O5, as well as other derivatives of this structure, containing any additional or substitute atoms or ions or chemical groups,in any atom of its molecular structure c) Yellow 10 dye whose molecular formula is Ci8Hi3NO5 / 8 / iiSi / 2 / 3Nai / 2 / 3, as well as the other derivatives of this Petition 870250001217, dated 07 / 01 / 2025, page. 41 / 54 2 / 5 structure, containing any additional or substitute atoms or ions or chemical groups, at any atom of its molecular structure d) Eosin Y dye whose molecular formula is C2OHeO5Br4Na2, as well as other derivatives of this structure, containing any additional or substitute atoms or ions or chemical groups, at any atom of its molecular structure e) Rhodamine B dye whose molecular formula is C28H31ClN2O3, as well as other derivatives of this structure, containing any additional or substitute atoms or ions or chemical groups, at any atom of its molecular structure or f) Green S dye whose molecular formula is C27H25N2O?S2Na as well as other derivatives of this structure,containing any additional or substitute atoms or ions or chemical groups, in any atom of its molecular structure. Petition 870250001217, dated 07 / 01 / 2025, page 42 / 54 3 / 5, 2. Chemical formulation used as chemical markers in firearm ammunition, according to claim 1, characterized by containing only one isolated chemical marker or a mixture of markers.

3. Chemical formulation used as chemical markers in firearm ammunition, according to claim 1 or 2, characterized by the luminescent organic chemical substances being in their pure form, in a mixture or accompanied by adjunct substances whose functions are stabilizers, diluents, preservatives or protectors.

4. Chemical formulation used as chemical markers in firearm ammunition, according to claim 1, characterized by the luminescent organic chemical substances being incorporated into firearm ammunition of the revolver, pistol, rifle, shotgun, carbine, machine gun, or carbine type, being both conventional and ecological type ammunition.

5. Chemical formulation used as chemical markers in firearm ammunition, according to claim 1, characterized in that the chemical markers are incorporated inside the ammunition cartridges either in their solid powder form or diluted in solid, liquid or gaseous solutions.

6. Method of preparing firearm ammunition characterized by comprising the steps of: a) weighing the appropriate mass of the luminescent organic chemical substance (luminescent marker), the quantity of which must be between 0.01% and 25% of the total mass of gunpowder present in each type of ammunition; b) mechanical mixing of said mass with the propellant to obtain the chemical formulation of claim 1; c) insertion of said chemical formulation containing the luminescent organic marker inside the previously opened ammunition; d) closing the ammunition containing said luminescent organic marker, which is then ready for firing.

7. Use of the chemical formulation defined in claim 1 containing chemical markers in firearm ammunition, characterized by being for analysis of firearm discharge residue and commercial identification of ammunition and manufacturers.

8. Use, according to claim 7, characterized in that after the firearm is discharged, the luminescent organic chemical residues are visually identified on the target, the weapon, the shooter's hands, arms, face, body and clothing, by means of ultraviolet light.

9. Use, according to claim 8, characterized by the luminescent organic chemical residues also being, at the analyst's discretion, collected mechanically, using various instruments such as tweezers, adhesive tape, spatulas or swabs soaked with solutions for subsequent confirmatory instrumental chemical analysis thereof.

10. Use, according to claim 9, characterized in that confirmatory instrumental chemical analysis is performed by instrumental techniques such as chromatography (HPLC, GC, TLC), combined with mass spectrometry (GC-MS), spectrophotometry (UV-Vis, Raman, Infrared) or electrochemical techniques (voltammetry, potentiometry, amperometry, conductometry, coulometry).

11. Use, according to claim 10, characterized by confirmatory instrumental chemical analysis being performed via voltammetry. Petition 870250001217, dated 07 / 01 / 2025, p. 44 / 54 5 / 5.

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