Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to obtain molecular images and data for principal component analysis (PCA). The results showed that the peaks at m/z 1511, 1543, 1564, 1586 clearly decreased in intensity from 0 to 144 h postmortem and that the time groups were separated from each other on the PCA score plot. The prediction model showed high recognition capability (95.93%) and cross-validation (83.72%). Our work suggests that MALDI-TOF MS can be used to determine the PMI.
Keywords: forensic pathology; forensic science; matrix-assisted laser desorption/ionization imaging mass spectrometry; postmortem interval; prediction model; principal component analysis.
© 2017 American Academy of Forensic Sciences.