Developing Spectroscopic and Mass Spectrometry Based Database of Tattoo Ink for Forensic Investigation
Disciplines
Analytical Chemistry
Abstract (300 words maximum)
About 20% of the global population has some form of tattoos on some parts of their body. About 32% of the US population has at least one tattoo, meaning almost one third of the entire national population has a tattoo. Moreover, 75-85% of criminals also have tattoos. Though many departments around the nation have used tattoo markings and inks, found in many places such as ink on the floor or on an object, part of a victim or under a victim’s nails, and identification of a suspect or offender, as key evidence in cases. The identification of the compound present in tattoo inks and how these compounds would degrade with buried skin are not known. This research has two goals: i) to build spectroscopic and mass spectrometry-based database for tattoo ink compounds with and without skin; ii) how ink compounds are decomposed when skin is buried. For a pilot project, IR spectroscopy was used to analyze the functional groups contained in various ink samples. In addition, Direct analysis in real time mass spectroscopy (DART-MS) was used to determine the compounds present in ink samples. It is found that all samples showed strong and broad peaks at around 3300 cm-1 for O-H stretching and a strong and sharp peak at around 1650 cm-1 for C=C stretching. The data obtained from the IR were used to run a Principal Components Analysis (PCA). Based on the PCA, Light Purple and Fuchsia are surprisingly not similar to Baby Blue and Mario’s Blue, as one would think they would be since their colors are very similar. Expectedly, Orange, Lime Green, and Yellow are all extremely similar according to the PCA. These ink samples were also investigated by DART-MS, however, identification of the mass of the related compounds is still in progress.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Developing Spectroscopic and Mass Spectrometry Based Database of Tattoo Ink for Forensic Investigation
About 20% of the global population has some form of tattoos on some parts of their body. About 32% of the US population has at least one tattoo, meaning almost one third of the entire national population has a tattoo. Moreover, 75-85% of criminals also have tattoos. Though many departments around the nation have used tattoo markings and inks, found in many places such as ink on the floor or on an object, part of a victim or under a victim’s nails, and identification of a suspect or offender, as key evidence in cases. The identification of the compound present in tattoo inks and how these compounds would degrade with buried skin are not known. This research has two goals: i) to build spectroscopic and mass spectrometry-based database for tattoo ink compounds with and without skin; ii) how ink compounds are decomposed when skin is buried. For a pilot project, IR spectroscopy was used to analyze the functional groups contained in various ink samples. In addition, Direct analysis in real time mass spectroscopy (DART-MS) was used to determine the compounds present in ink samples. It is found that all samples showed strong and broad peaks at around 3300 cm-1 for O-H stretching and a strong and sharp peak at around 1650 cm-1 for C=C stretching. The data obtained from the IR were used to run a Principal Components Analysis (PCA). Based on the PCA, Light Purple and Fuchsia are surprisingly not similar to Baby Blue and Mario’s Blue, as one would think they would be since their colors are very similar. Expectedly, Orange, Lime Green, and Yellow are all extremely similar according to the PCA. These ink samples were also investigated by DART-MS, however, identification of the mass of the related compounds is still in progress.