Abstract: Objective To study postmortem degradation in rat's skeletal muscle with fourier transform infrared spectroscopy (FTIR) and explore a new method to estimate postmortem interval (PMI). Methods Rats were sacrificed by cervical dislocation and the bodies were kept in a chamber set at (20±2) ℃. FTIR spectra of rat's skeletal muscle were measured at the different postmortem time points from 0 to 144 h. Results The FTIR absorbance bands at different FTIR wave length (cm-1) showed the four different type changes: increase, decrease, stable, and fluctuation. The various bands intensity ratio also demonstrated the similar changes to the relative bands intensity. Conclusion FTIR spectroscopy may be a new effective method to estimate the PMI in forensic practice.

Key words: fourier transform infrared (FTIR), postmortem interval, skeletal muscle, chemical group