Spectrophotometric determination of trimethylamine-nitrogen in cadaver tissues for the estimation of late postmortem interval: A pilot study

• Published in: Journal of Huazhong University of Science and Technology. Medical sciences Vol. 28; no. 6; pp. 630 - 633
• Main Authors: Liu, Qian, Cai, Xiangyang, Liu, Yan, Zhou, Lan, Yi, Shaohua, Liu, Liang
• Format: Journal Article
• Language: English
• Published: Heidelberg Huazhong University of Science and Technology 01.12.2008; Faculty of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology,Wuhan 430030,China%Faculty of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology,Wuhan 430030,China; Key Laboratory of Evidence Science China University of Political Science and Law, Ministry of Education, Beijng 100040, China
• Subjects: Animals; Cadaver; Female; Forensic Pathology; Male; Medicine; Medicine & Public Health; Methylamines - analysis; Nitrogen - analysis; Pilot Projects; Postmortem Changes; Random Allocation; Rats; Rats, Sprague-Dawley; Spectrophotometry; Time Factors; forensic medicine; spectrophotometry; trimethylamine-nitrogen; postmortem interval; spoilage product
• ISSN: 1672-0733; 1993-1352
• DOI: 10.1007/s11596-008-0603-x

Summary To study the relationship between the late postmortem interval (PMI) and trimethylamine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMI) by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance ( A value) and TMA-N at the concentration of 1–10 mg/L ( R 2 = 0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7 d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y= −0.457x 3 +6.519x 2 −24.574x+27.207 ( R 2 =0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x 3 −9.153x 2 +55.727x−95.819 ( R 2 =0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.