Trimethylamine in postmortem tissues as a predictor of postmortem interval estimation using the GC method.

Trimethylamine (TMA), a simple amine in volatile compounds, indicating the spoilage degree of meat, related with the late postmortem interval (PMI) during the cadaver decomposition process. In this paper, a headspace gas chromatography (HS-GC) method has been successfully built to analyze the content of TMA in postmortem rat tissues (liver, myocardial and skeletal muscle tissues), which is used for PMI estimation with the wide range of PMI (0-720 h postmortem) at 16 °C ± 1 °C. Correspondingly, three equations about the relationship between the PMI and TMA content were established, in which they showed that the TMA content in all three tissues increased from the firstly detected time to 192 h and gradually decreased after 384 h. Furthermore, the TMA measurement in five human samples was carried out and the results (<35 h PMI) showed a good agreement about the change trend of TMA content between human and rat, which elucidated that this research might provide a new insight for the forensic scientist to band HS-GC technology together with TMA determination in the PMI estimation.