In a recent paper titled “Soft and Robust Identification of Body Fluid Using Fourier Transform Infrared Spectroscopy and Chemometric Strategies for Forensic Analysis,” a team of researchers described the use of Fourier transform infrared spectroscopy (FT-IR) for the forensic analysis and identification of body fluids (1). In their paper, the team indicated that contrasting with current methods that use serological and biochemical techniques, vibrational spectroscopic approaches such as FT-IR provide alternative advantages for forensic body fluid identification, such as non-destructivity and versatility for various body fluid types and analytical interests.

The researchers collected attenuated total reflection (ATR) FT-IR spectra of five types of body fluids, peripheral blood, saliva, semen, urine, and sweat from ten to twenty volunteers. Because body fluid body fluid spectra have spatially dependent variations as well as donor-dependent variations, the ATR FT-IR spectra were collected from different areas in the BF samples dried overnight, resulting in a total of 100 spectra for peripheral blood, semen, and urine, 90 spectra for saliva, and 75 spectra for sweat.

The spectra from each body fluid type were shown with characteristic contributions from each principle component and different spreads of the distribution. The researchers found that the results indicated that the spectral characteristics of a body fluid type cannot be represented by a single or average spectrum. They determined that multivariate statistical analysis of the spectral variations is essential to characterize and objectively distinguish the body fluid spectra.

Reference

(1)  DOI:10:1038/s41598-26873-9