Evaluation of alizarin and purpurin dyes for their ability to visualize latent fingermark on porous surfaces

Author(s):  
Kıymet Berkil Akar
2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis

<div> <div> <div> <p>The quantitative variation in latent fingermark deposits sampled from the same donor (intra-donor) poses considerable challenges to studies into the chemical composition of latent fingermarks. The work presented here investigates approaches to the sampling of latent fingermark residues within this context. The amount of squalene in fingermarks deposited on non-porous surfaces, determined by GC-MS, was used as an indicator of the amount of non-polar material present. It was found that the percentage difference of squalene between deposits from two hands at a given time, without controlling the deposition pressure, was in the range of 4-100 %. This was reduced to 0-44 % in alternative sampling approaches where deposition pressure was controlled. These results demonstrate the significant influence of sampling on subsequent chemical analysis of fingermark residues, and offer possible sampling strategies to overcome issues associated with intra-donor variation. </p> </div> </div> </div>


2019 ◽  
Author(s):  
Jason Wells ◽  
Zachary Parsons ◽  
Renee Jelly ◽  
Alan Payne ◽  
Simon Lewis

<div><div><div><p>The ability to detect latent fingermarks on porous surfaces, such as paper-based documents, is extremely important in resolving criminal cases. Detection methods that target amino acids present in latent fingermark deposits have achieved widespread use due to the binding of these acids to paper fibres resulting in a good representation of the fingermark. This communication is the first report of 6-(N,N-dimethylamino)fulvene (DMAF) as a novel reagent for the detection of latent fingermarks on porous surfaces. Through observation of undergraduate students showing poor laboratory hygiene, we noted that exposure to DMAF leads to brown staining on the students’ skin. We discovered that indeed it can develop latent fingermarks on paper surfaces as pale pink impressions, which are luminescent when illuminated at 505 nm and viewed through orange goggles. The procedure is simple, requiring treatment of the specimen with a solution of DMAF in hexane with subsequent heat treatment. Preliminary experiments indicate that DMAF is reacting with the amino acids present in the latent fingermark.</p></div></div></div>


2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis

Compositional variation of latent fingermark deposits sampled from the same donor (intra-donor) poses considerable challenges for the investigation of the degradation of chemical composition. The work presented here investigates the best approach of sampling of latent fingermark residues within this context. Gas chromatography-mass spectrometry (GC-MS) was used to quantify the amount of squalene in fingermarks deposited on non-porous surfaces and used it as an indicator of the amount of non-polar material successfully extracted. It was found that the percentage difference of squalene between two deposits (from two hands) obtained at a given time without controlling the deposition pressure was in the range of 4-100%. This was reduced to 0-44% in the other three sampling approaches, where deposition pressure was controlled. Under controlled deposition pressure, the averages of percentage difference (n=9) for sebum-rich and natural deposits were 13% and 20% respectively. These results demonstrate the significant influence of fingermark sampling approach over data and offer possible sampling strategies that can be undertaken to overcome issues associated with intra-donor variation.


2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis

<div> <div> <div> <p>The quantitative variation in latent fingermark deposits sampled from the same donor (intra-donor) poses considerable challenges to studies into the chemical composition of latent fingermarks. The work presented here investigates approaches to the sampling of latent fingermark residues within this context. The amount of squalene in fingermarks deposited on non-porous surfaces, determined by GC-MS, was used as an indicator of the amount of non-polar material present. It was found that the percentage difference of squalene between deposits from two hands at a given time, without controlling the deposition pressure, was in the range of 4-100 %. This was reduced to 0-44 % in alternative sampling approaches where deposition pressure was controlled. These results demonstrate the significant influence of sampling on subsequent chemical analysis of fingermark residues, and offer possible sampling strategies to overcome issues associated with intra-donor variation. </p> </div> </div> </div>


2019 ◽  
Author(s):  
Jason Wells ◽  
Zachary Parsons ◽  
Renee Jelly ◽  
Alan Payne ◽  
Simon Lewis

<div><div><div><p>The ability to detect latent fingermarks on porous surfaces, such as paper-based documents, is extremely important in resolving criminal cases. Detection methods that target amino acids present in latent fingermark deposits have achieved widespread use due to the binding of these acids to paper fibres resulting in a good representation of the fingermark. This communication is the first report of 6-(N,N-dimethylamino)fulvene (DMAF) as a novel reagent for the detection of latent fingermarks on porous surfaces. Through observation of undergraduate students showing poor laboratory hygiene, we noted that exposure to DMAF leads to brown staining on the students’ skin. We discovered that indeed it can develop latent fingermarks on paper surfaces as pale pink impressions, which are luminescent when illuminated at 505 nm and viewed through orange goggles. The procedure is simple, requiring treatment of the specimen with a solution of DMAF in hexane with subsequent heat treatment. Preliminary experiments indicate that DMAF is reacting with the amino acids present in the latent fingermark.</p></div></div></div>


2018 ◽  
Author(s):  
Jason Wells ◽  
Zachary Parsons ◽  
Renee Jelly ◽  
Alan Payne ◽  
Simon Lewis

<div><div><div><p>The ability to detect latent fingermarks on porous surfaces, such as paper-based documents, is extremely important in resolving criminal cases. Detection methods that target amino acids present in latent fingermark deposits have achieved widespread use due to the binding of these acids to paper fibres resulting in a good representation of the fingermark. This communication is the first report of 6-(N,N-dimethylamino)fulvene (DMAF) as a novel reagent for the detection of latent fingermarks on porous surfaces. Through observation of undergraduate students showing poor laboratory hygiene, we noted that exposure to DMAF leads to brown staining on the students’ skin. We discovered that indeed it can develop latent fingermarks on paper surfaces as pale pink impressions, which are luminescent when illuminated at 505 nm and viewed through orange goggles. The procedure is simple, requiring treatment of the specimen with a solution of DMAF in hexane with subsequent heat treatment. Preliminary experiments indicate that DMAF is reacting with the amino acids present in the latent fingermark.</p></div></div></div>


2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis

<div> <div> <div> <p>The quantitative variation in latent fingermark deposits sampled from the same donor (intra-donor) poses considerable challenges to studies into the chemical composition of latent fingermarks. The work presented here investigates approaches to the sampling of latent fingermark residues within this context. The amount of squalene in fingermarks deposited on non-porous surfaces, determined by GC-MS, was used as an indicator of the amount of non-polar material present. It was found that the percentage difference of squalene between deposits from two hands at a given time, without controlling the deposition pressure, was in the range of 4-100 %. This was reduced to 0-44 % in alternative sampling approaches where deposition pressure was controlled. These results demonstrate the significant influence of sampling on subsequent chemical analysis of fingermark residues, and offer possible sampling strategies to overcome issues associated with intra-donor variation. </p> </div> </div> </div>


2019 ◽  
Author(s):  
Jason Wells ◽  
Zachary Parsons ◽  
Renee Jelly ◽  
Alan Payne ◽  
Simon Lewis

<div><div><div><p>The ability to detect latent fingermarks on porous surfaces, such as paper-based documents, is extremely important in resolving criminal cases. Detection methods that target amino acids present in latent fingermark deposits have achieved widespread use due to the binding of these acids to paper fibres resulting in a good representation of the fingermark. This communication is the first report of 6-(N,N-dimethylamino)fulvene (DMAF) as a novel reagent for the detection of latent fingermarks on porous surfaces. Through observation of undergraduate students showing poor laboratory hygiene, we noted that exposure to DMAF leads to brown staining on the students’ skin. We discovered that indeed it can develop latent fingermarks on paper surfaces as pale pink impressions, which are luminescent when illuminated at 505 nm and viewed through orange goggles. The procedure is simple, requiring treatment of the specimen with a solution of DMAF in hexane with subsequent heat treatment. Preliminary experiments indicate that DMAF is reacting with the amino acids present in the latent fingermark.</p></div></div></div>


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


2019 ◽  
Author(s):  
Clara M. Agapie ◽  
Melissa Sampson ◽  
William Gee

The work describes a new chemical means of visualising latent fingerprints (fingermarks) using tropolone. Tropolone reacts with amino acids within the fingermark residue to form adducts that absorb UV radiation. These adducts provide useful contrast on highly-fluorescent prous surfaces will illuminated with UV radiation. The conjugated seven-membered ring of the tropolone adduct can be reacted further diazonium salts, which is demonstrated here with formation of two dyes. The methodology is extremely rapid, occurring in minutes with mild heating, and can be applied before ninhydrin in a chemical detection sequence. <br>


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