RESUMO
Presence of diatoms in tissues has been considered as a significant sign of drowning. However, there are limitations in the present extraction methods. We developed a new digestion method using the Lefort aqua regia solution (3:1 nitric acid to hydrochloric acid) for diatom extraction and evaluated the digestive capability, diatom destruction, and diatoms' recovery of this new method. The kidney tissues from rabbit mixed with water rich in diatoms were treated by the Lefort aqua regia digestion method (n = 10) and the conventional acid digestion method (n = 10). The results showed that the digestive capability of Lefort aqua regia digestion method was superior to conventional acid digestion method (p < 0.01); the structure of diatom remained almost intact; and the recovery of diatom was comparable to the conventional acid digestion method (p > 0.05). The Lefort aqua regia reagent is an improvement over the conventional acid digestion for recovery of diatoms from tissue samples.
Assuntos
Diatomáceas/isolamento & purificação , Ácido Clorídrico/química , Peróxido de Hidrogênio/química , Rim/ultraestrutura , Ácido Nítrico/química , Animais , Patologia Legal/métodos , Microscopia Eletrônica de Varredura , CoelhosRESUMO
Objective The forensic application of Lefort aqua regia digestion method detecting diatom in rabbits’s organs. Methods Using the Lefort aqua regia digestion-membrane ifltrition-SEM observation method and the traditional acid digestion-centrifugation-light microscopy observation method to detect diatom of drowning or postmortem immersion rabbits’s organs(lung,liver,kidney), and make statistical analysis of diatom number, consuming time, digestive capability and ifne structure of diatoms. Results The diatom number of Lefort aqua regia digestion method was superior to conventional acid digestion method, with the difference being statistically signiifcant (P0.05), and have a better observation effect. Conclusion The Lefort aqua regia digestion method for diatom extraction was helpful for diatom identiifcation., and useful in drowning test by conventional and economicly.