title: Chemical changes exhibited by latent fingerprints after exposure to vacuum conditions.
abstract: The effect of vacuum exposure on latent fingerprint chemistry has been evaluated. Fingerprints were analysed using a quartz crystal microbalance to measure changes in mass, gas chromatography mass spectrometry to measure changes in lipid composition and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine changes in the content of water, fatty acids and their esters after exposure to vacuum. The results are compared with samples aged under ambient conditions. It was found that fingerprints lose around 26% of their mass when exposed to vacuum conditions, equivalent to around 5 weeks ageing under ambient conditions. Further exposure to vacuum causes a significant reduction in the lipid composition of a fingerprint, in particular with the loss of tetradecanoic and pentadecanoic acid, that was not observed in ambient aged samples. There are therefore implications for sequence in which fingerprint development procedures (for example vacuum metal deposition) are carried out, as well as the use of vacuum based methods such as secondary ion mass spectrometry (SIMS) and matrix-assisted laser desorption ionisation (MALDI) in the study of fingerprint chemistry.
authors.affiliation: Surrey Ion Beam Centre, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Bright
authors.forename: Terry R
authors.initials: TR
authors.lastname: Willson
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Driscoll
authors.forename: Subrayal M
authors.initials: SM
authors.lastname: Reddy
authors.forename: Roger P
authors.initials: RP
authors.lastname: Webb
authors.forename: Stephen
authors.initials: S
authors.lastname: Bleay
authors.forename: Neil I
authors.initials: NI
authors.lastname: Ward
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Kirkby
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Bailey
mesh_terms: D001834:Body Water; D003878:Dermatoglyphics; D004952:Esters; D005227:Fatty Acids / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D058525:Quartz Crystal Microbalance Techniques; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014618:Vacuum
chemical_list: D004952:Esters; D005227:Fatty Acids