title: Characterization of postmortem biochemical changes in rabbit plasma using ATR-FTIR combined with chemometrics: A preliminary study.
abstract: Postmortem interval (PMI) determination is one of the most challenging tasks in forensic medicine due to a lack of accurate and reliable methods. It is especially difficult for late PMI determination. Although many attempts with various types of body fluids based on chemical methods have been made to solve this problem, few investigations are focused on blood samples. In this study, we employed an attenuated total reflection (ATR)-Fourier transform infrared (FTIR) technique coupled with principle component analysis (PCA) to monitor biochemical changes in rabbit plasma with increasing PMI. Partial least square (PLS) model was used based on the spectral data for PMI prediction in an independent sample set. Our results revealed that postmortem chemical changes in compositions of the plasma were time-dependent, and various components including proteins, lipids and nucleic acids contributed to the discrimination of the samples at different time points. A satisfactory prediction within 48h postmortem was performed by the combined PLS model with a good fitting between actual and predicted PMI of 0.984 and with an error of ±1.92h. In consideration of the simplicity and portability of ATR-FTIR, our preliminary study provides an experimental and theoretical basis for application of this technique in forensic practice.
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Ji
authors: J
authors: Zhang
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Bing
authors: B
authors: Li
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Qi
authors: Q
authors: Wang
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Chengzhi
authors: C
authors: Li
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Yinming
authors: Y
authors: Zhang
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China.
authors: Hancheng
authors: H
authors: Lin
authors: Department of Forensic Pathology, College of Forensic Medicine, Xian Jiaotong University, Xi'an, Shaanxi, China. Electronic address: wzy218@xjtu.edu.cn.
authors: Zhenyuan
authors: Z
authors: Wang
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D008055:Lipids / Q000097:blood*; D009696:Nucleic Acids / Q000097:blood*; D011180:Postmortem Changes; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013997:Time Factors
chemical_list: D001798:Blood Proteins; D008055:Lipids; D009696:Nucleic Acids
keywords: Fourier transform infrared spectroscopy; Partial least square; Plasma; Postmortem interval; Principle component analysis