Li Shi-ying, Shao Yu, Li Zheng-dong, Zou Dong-hua, Qin Zhi-qiang, Chen Yi-jiu, Huang Ping
Department of Forensic Medicine, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Fa Yi Xue Za Zhi. 2012 Oct;28(5):321-6.
Fourier transform infrared (FTIR) spectroscopy was applied to observe the postmortem degradation process in mechanical asphyxiated rat's liver and spleen for providing a new method of estimating PMI.
Rats were sacrificed by mechanical asphyxia and cadavers were kept at (20 +/- 2) degrees C in a control chamber. The liver and spleen were sub-sampled from the same rat at intervals of 0-15 days postmortem and the data were measured by FTIR spectrometer. 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 mathematical models by the statistical software.
The band absorbance ratios showed increase, decrease and stable with PMI. The cubic model functions showed the strongest correlation coefficient. Compared with the spleen, the liver showed a higher correlation coefficient. The A1541/A1396 of liver showed the highest correlation coefficient (r=0.966). After 6-7 days postmortem, band absorbance ratios showed a steady period.
FTIR spectroscopy can be a new and efficient method to estimate PMI within 7 days.
应用傅里叶变换红外（FTIR）光谱法观察机械性窒息大鼠肝脏和脾脏的死后降解过程，为推断死亡时间提供新方法。
采用机械性窒息法处死大鼠，尸体置于（20±2）℃的控制箱中。于死后0 - 15天每隔一定时间从同一大鼠取肝脏和脾脏样本，用FTIR光谱仪测量数据。计算不同峰的吸光度（A）比值，利用统计软件对吸光度比值（x）和死亡时间（y）进行曲线估计分析，建立数学模型。
谱带吸光度比值随死亡时间呈现升高、降低和稳定的变化。三次模型函数的相关系数最强。与脾脏相比，肝脏的相关系数更高。肝脏的A1541/A1396相关系数最高（r = 0.966）。死后6 - 7天，谱带吸光度比值呈现稳定期。
FTIR光谱法可成为7天内推断死亡时间的一种新的有效方法。
