Gruszczyńska Emilia, Lewkowicz Aneta, Czarnomska Martyna, Koczur Joanna, Walczewska-Szewc Katarzyna, Kaliszan Michał, Balwicki Łukasz, Bojarski Piotr
Institute of Experimental Physics, Faculty of Mathematics, Physics and Informatics, University of Gdansk, ul. Wita Stwosza 57, 80-308 Gdańsk, Poland.
Institute of Law Sciences, Faculty of Law and Administration, University of Silesia in Katowice, ul. Bankowa 11 B, 40-007 Katowice, Poland.
Int J Mol Sci. 2024 Nov 30;25(23):12915. doi: 10.3390/ijms252312915.
The estimation of the time of death represents a highly complex and challenging task within the field of forensic medicine and science. It is essential to approach this matter with the utmost respect for human rights while acknowledging the inherent limitations of the current methods, which require continuous refinement and expansion. Forensic science recognizes the necessity to improve existing techniques and develop new, more accurate, and non-invasive procedures, such as physicochemical approaches, to enhance the precision and reliability of time of death determinations. This article proposes a novel, non-invasive method for estimating the time of death using a spectroscopic analysis of tryptophan. The initial phase of the study concerns the presentation of the spectroscopic properties of tryptophan at varying pH levels, with consideration given to the pH fluctuations that occur during the decomposition of cadavers. The findings confirm the stability of the spectroscopic properties at different environmental pH levels. Subsequently, preliminary trials were conducted on 15 healthy human volunteers, which demonstrated that tryptophan concentrations in fingerprint samples were within the detection limits using molecular spectroscopy techniques. The final objective was to ascertain whether the composition of the substance present on the skin surface of a deceased individual up to 48 h postmortem is comparable to that of the sweat-fatty substance in living individuals. This was confirmed by the absorption and emission spectral profiles, which showed overlapping patterns with those obtained from living volunteers. The most significant outcome at this stage was the demonstration of a considerable increase in emission intensity in the spectra for samples obtained approximately 48 h after death in comparison to that obtained from a sample taken approximately 24 h after death. This indicates a rise in the concentration of tryptophan on the skin surface as the postmortem interval (PMI) increases, which could serve as a basis for developing a tool to estimate the time of death.
死亡时间的估算在法医学和科学领域是一项极其复杂且具有挑战性的任务。在承认当前方法存在固有局限性（需要不断完善和扩展）的同时，以对人权的最大尊重来处理这个问题至关重要。法医学认识到改进现有技术并开发新的、更准确且非侵入性的程序（如物理化学方法）以提高死亡时间判定的准确性和可靠性的必要性。本文提出了一种使用色氨酸光谱分析来估算死亡时间的新型非侵入性方法。研究的初始阶段涉及呈现不同pH水平下色氨酸的光谱特性，并考虑尸体分解过程中发生的pH波动。研究结果证实了光谱特性在不同环境pH水平下的稳定性。随后，对15名健康人类志愿者进行了初步试验，结果表明使用分子光谱技术可检测到指纹样本中的色氨酸浓度。最终目标是确定在死后长达48小时的死者皮肤表面存在的物质组成是否与活体中的汗液 - 脂肪物质组成相当。吸收和发射光谱图证实了这一点，其显示出与从活体志愿者获得的光谱图有重叠模式。此阶段最重要的结果是，与死后约24小时采集的样本相比，死后约48小时获得的样本光谱发射强度显著增加。这表明随着死后间隔（PMI）增加，皮肤表面色氨酸浓度上升，这可为开发一种估算死亡时间的工具奠定基础。
