title: Spectrophotometric determination of trimethylamine-nitrogen in cadaver tissues for the estimation of late postmortem interval: a pilot study.
abstract: 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.
authors.affiliation: Faculty of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. caixe_liu0222@tom.com
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Cai
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Lan
authors.initials: L
authors.lastname: Zhou
authors.forename: Shaohua
authors.initials: S
authors.lastname: Yi
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
mesh_terms: D000818:Animals; D002102:Cadaver; D005260:Female; D049429:Forensic Pathology; D008297:Male; D008744:Methylamines / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D010865:Pilot Projects; D011180:Postmortem Changes; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013053:Spectrophotometry; D013997:Time Factors
chemical_list: D008744:Methylamines; C023336:trimethylamine; D009584:Nitrogen