Lee Miyeon, Lee Doyeon, Jo Young-Hoon, Kim Hyun Jee, Park Wooyoung
Daejeon District Office, National Forensic Service, Daejeon, 34054, Republic of Korea.
Forensic Chemical Division, National Forensic Service, Wonju, 26460, Republic of Korea.
Sci Rep. 2025 Jul 22;15(1):26564. doi: 10.1038/s41598-025-12183-4.
Analyzing carbon monoxide concentration within an individual is crucial. The analysis of CO content in a tissue sample is performed using gas chromatography. The concentration is calculated based on a linear equation derived from the calibration curve created with the CO-fortified sample. However, when methemoglobin (MetHb) is formed from putrefaction, it inhibits CO binding to the sample and may lead to inaccurate results. MetHb results from the iron oxidation of normal heme hemoglobin (HHb), and by treating the sample with a reducing agent, it can be converted back to HHb. To investigate the effect of the reducing agent on spleen CO analysis, each sample was divided into two parts. One was treated with a 0.574 M sodium dithionite solution (NaSO), a reduced sample, and the other was treated with a rinse solution, serving as the control sample, with both undergoing the same preparation process and analyzed using Gas Chromatography with a Thermal Conductivity Detector (GC-TCD). Spleen samples from 60 autopsy cases were analyzed. The results indicated that 48 cases showed lower CO levels when the sample was reduced compared to the control sample, where the difference of the control and reduced samples ranged from 2.21 to 93.24%, with a median value of 13.83%. 12 cases exhibited no difference, where the difference between control and reduced sample ranged from 0.05 to 1.57%, with a median value of 0.67%. Our findings demonstrate that MetHb formed during decomposition can significantly inhibit CO binding in spleen tissue, leading to overestimation of CO levels when no reducing agent is used. Therefore, incorporating sodium dithionite treatment into GC-TCD methods improves the accuracy of postmortem CO quantification, particularly in putrefied samples.
分析个体内的一氧化碳浓度至关重要。组织样本中一氧化碳含量的分析是使用气相色谱法进行的。浓度是根据由用一氧化碳强化样本创建的校准曲线得出的线性方程来计算的。然而，当因腐败形成高铁血红蛋白（MetHb）时，它会抑制一氧化碳与样本的结合，并可能导致结果不准确。高铁血红蛋白是由正常血红素血红蛋白（HHb）的铁氧化形成的，通过用还原剂处理样本，它可以转化回HHb。为了研究还原剂对脾脏一氧化碳分析的影响，将每个样本分成两部分。一部分用0.574 M连二亚硫酸钠溶液（NaSO）处理，即还原样本，另一部分用冲洗液处理，作为对照样本，两者都经过相同的制备过程，并使用热导检测器气相色谱法（GC-TCD）进行分析。对60例尸检病例的脾脏样本进行了分析。结果表明，与对照样本相比，48例样本在还原后一氧化碳水平较低，对照样本与还原样本的差异范围为2.21%至93.24%，中位数为13.83%。12例样本无差异，对照样本与还原样本的差异范围为0.05%至1.57%，中位数为0.67%。我们的研究结果表明，分解过程中形成的高铁血红蛋白可显著抑制脾脏组织中一氧化碳的结合，导致在不使用还原剂时一氧化碳水平被高估。因此，在GC-TCD方法中加入连二亚硫酸钠处理可提高死后一氧化碳定量的准确性，特别是在腐败样本中。
