HNO3-PCF: A new lossless light microscopy method for forensic diatom drowning analysis

IF 2.2 3区医学 Q1 MEDICINE, LEGAL

Forensic science international Pub Date : 2025-03-22 DOI:10.1016/j.forsciint.2025.112449

Tomáš Bešta , Hana Hamrová , Petr Tomášek , Petra Dohnalová , Jana Markvartová , Tomáš Hauer , Tereza Švejdová , Kateřina Zubíčková , Iva Zagatová , Radek Lefnar , Eva Tomášková , Kateřina Čapková , Jan Kaštovský

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引用次数: 0

Abstract

Five simple methods for diatom drowning analysis, including three newly developed ones, were compared for diatom yield and species composition consistency. Saponification of fats using sodium hydroxide solution significantly improved the yield of the extraction step, as well as the use of filtration instead of centrifugation. The combination of nitric acid digestion, vacuum filtration, and polycarbonate filter melting led to the development of the lossless light microscopy diatom forensic method (HNO3-PCF), with no detectable alteration in diatom community composition. When applied to 4-week submerged pig cadavers and six confirmed drowned human cases, the method exhibited unprecedented sensitivity. Among eight tissue types, lung diatom concentration was found to be the only reliable indicator for distinguishing between non-drowned and drowned cases. To minimize false positives from systematic contamination of the thoracic cavity, subtraction of heart diatom concentration from lung values was recommended. Provisional diatom concentration thresholds for drowning determination were set. The method’s low equipment requirements (simple vacuum filtration, light microscope, hot plate) and high efficiency make it a promising tool for widespread use in forensic practice.

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来源期刊

Forensic science international 医学-医学：法

CiteScore

5.00

自引率

9.10%

发文量

285

审稿时长

49 days

期刊介绍： Forensic Science International is the flagship journal in the prestigious Forensic Science International family, publishing the most innovative, cutting-edge, and influential contributions across the forensic sciences. Fields include: forensic pathology and histochemistry, chemistry, biochemistry and toxicology, biology, serology, odontology, psychiatry, anthropology, digital forensics, the physical sciences, firearms, and document examination, as well as investigations of value to public health in its broadest sense, and the important marginal area where science and medicine interact with the law. The journal publishes: Case Reports Commentaries Letters to the Editor Original Research Papers (Regular Papers) Rapid Communications Review Articles Technical Notes.