中文摘要：

目的应用傅里叶变换红外（Fourier transform infrared,FTIR）光谱技术分析大鼠死后心肌及骨骼肌随死亡时间推移的化学降解过程,为死亡时间推断提供新的途径与方法。方法大鼠机械性窒息处死后,在不同死亡时间点提取左心室心肌及骨骼肌,用FTIR光谱仪测定不同化学基团的变化,计算不同吸收峰吸光度（A）的比值,将吸光度比值（x）和死亡时间（y）进行曲线拟合建立6种数学模型。结果大鼠肌肉组织FTIR光谱的主要吸收峰随着死亡时间延长表现为增强、下降和稳定3种变化方式。三次方曲线有最佳的拟合相关系数,骨骼肌A1 080/A1 396相关系数最高（r=0.832）,推断PMI更准确。结论应用FTIR光谱技术检测死后心肌和骨骼肌组织的光谱学改变在法医病理学死亡时间推断中具有一定的应用价值。

英文摘要：

Objective To observe the postmortem degradation process in rat myocardium and skeletal mus- cle using Fourier transform infrared （FTIR） spectroscopy and to provide a new method for estimating post- mortem interval（PMI）. Methods Left ventricle and skeletal muscles of rats dying of mechanical asphyxiat- ed were sampled at different PMIs. The changes of different chemical functional group in the myocardium and skeletal muscle samples were measured by FTIR spectroscopy. The different absorbance （A） ratios of peaks were calculated and the curve estimation analysis between absorbance ratios （x） and PMI （y） were performed to establish six mathematical models. Results FTIR spectral absorption peak of rat myocardium and skeletal muscle showed three changes： increase, decrease and stable. The cubic model function showed the strongest correlation coefficient. The A1080/A1396 ratio of skeletal muscle showed the strongest correlation co- efficient （r=0.832） with more accurate determination of PMI. Conclusion FTIR spectroscopy can be potentially used as an effective method for estimating PMI in forensic practice using myocardium and skeletal muscle.