Chemical Composition of Fingerprints for Gender Determination

Abstract

This work investigates the chemical nature of fingerprints to ascertain whether differences in chemical composition or the existence of chemical markers can be used to determine personal traits, such as age, gender, and personal habits. This type of information could be useful for reducing the pool of potential suspects in criminal investigations when latent fingerprints are unsuitable for comparison by traditional methods. Fin-gertip residue that has been deposited onto a bead was extracted with a solvent such as chloroform. Samples were analyzed by gas chromatogra-phy/ mass spectrometry (GC/MS). The chemical components identified include fatty acids, long chain fatty acid esters, cholesterol and squalene. The area ratios of ten selected components relative to squalene were calculated for a small preliminary experiment that showed a slight gender dif-ference for three of these components. However, when the experiment was repeated with a larger, statistically designed experiment no significant differences between genders were detected for any of the component ratios. The multivariate Hotelling's T2 test that tested all ten-component ratios simultaneously also showed no gender differences at the 5% significance level.

Fatty Acid Structure and Degradation Analysis in Fingerprint Residues

“…GC-MS was used in 1999 to identify components of fingerprint residues, including free fatty acids, triglycerides, wax ester, amino acids, glycerol, cholesterol, and squalene [17], followed by several studies combining chromatography, mass spectrometry, and spectroscopic techniques [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Gender determination [21], donor classification [21][22][23][24][25], and aging studies [26][27][28][29][30][31][32] were among the major targets of fingerprint research recently.…”

“…Gender determination [21], donor classification [21][22][23][24][25], and aging studies [26][27][28][29][30][31][32] were among the major targets of fingerprint research recently. Francese et al show in their review article the power of MALDI mass spectrometry for the manifold analyses of fingerprints, even after aging [33].…”

Variation in amino acid and lipid composition of latent fingerprints

“…The lipid composition of latent fingerprints has been found to vary between individuals with age and gender [12,13,14]. Chemical changes that occur following deposition and environmental conditions are an important factor [15].…”

The analytical determination of the uniqueness and persistence of the volatile components of human scent using optimized collection methods

“…These studies show that adult fingerprints differ from child fingerprints in both composition and duration of presence after contact. Compositions of the fingerprint residues of adults have been determined through gas chromatographic analysis (Appendix A) and fatty acids [23,47], cholesterol [47], and squalene [48] were determined to be components of fingerprint residue. It has been shown that fingerprint residue components can be separated by thin-layer chromatography (TLC) [49] and visibly-excited fluorescent components are also present that can also be separated by TLC [50].…”