Comparison of spectroscopic methods in the detection of silicone-based condom lubricant evidence

Abstract

Different spectroscopic techniques are compared and discussed for the analysis of silicone-based condom lubricants for forensic purposes.

Combined Statistical Analyses of Forensic Evidence in Sexual Assault: A Case Report and Brief Review of the Literature

“…If the victim did not use condoms or external lubricants nor had medical vaginal treatment, it is unlikely that those lubricants would ordinarily be present in the genital zones. In this case, especially, the identification of PDMS lubricant in the vagina turned out to be very significant, since the victim did not refer any use of condoms in the weeks preceding the assaults, and the probability that those traces would originate from cosmetics is very low, as it is not likely that PDMS be used inside the vagina (28).…”

“…Massonnet et al (28) showed that DRIFTS is the ideal technique for performing IR on condom residues. However, we decided to apply ATR, which is a routine technique in most forensic laboratories, with the further advantage that the analysis could be executed directly on the swab, without previous extraction steps.…”

Innovative Vibrational Spectroscopy Research for Forensic Application

“…Burnier et al have also conducted work comparing spectroscopic methods to analyze silicone-based condom lubricants. 107 Raman spectroscopy using four different wavelengths and five FTIR sampling techniques was analyzed for sensitivity, analysis time, and sample preparation time and difficulty. Based on spectral quality, they determined that diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was the best method, followed closely by ATR-FTIR spectroscopy.…”

“…This is important for forensic scientists to understand so that they can properly identify the probative value of the results. Burnier et al have also conducted work comparing spectroscopic methods to analyze silicone-based condom lubricants . Raman spectroscopy using four different wavelengths and five FTIR sampling techniques was analyzed for sensitivity, analysis time, and sample preparation time and difficulty.…”

Negative results: Investigations into the quantification of silicone-based condom lubricants in solution by DRIFTS-FTIR

“…In forensic casework, analysis of condom evidence is usually focused on detecting silicone lubricants such as polydimethylsiloxane (PDMS), as they are most commonly known to transfer into the vaginal matrix [1][2][3][4]. These analyses are routinely carried out using Fourier transform infrared spectroscopy (FTIR) [5][6][7][8][9] and pyrolysis gas chromatography-mass spectrometry (py-GC/MS) [3,4,10] although other methods such as matrix-assisted laser desorption/ionisation-mass spectrometry (MALDI-MS) or direct analysis in real time/time-of-flight (DART-TOF)-MS have also been reported [7,[11][12][13][14][15].…”