Doseamento do mercúrio total e de derivados orgânicos de mercúrio em amostras de cadáveres - Estudo de dois casos

• Author(s): Martins, Paula Alexandra Aguieiras Triunfante
• Date: 2011
• Persistent ID: http://hdl.handle.net/10216/21986
• Origin: Repositório Aberto da Universidade do Porto
• Subject(s): Estatística; Statistics; Porto
• Document Type: Master thesis
• Language: Portuguese

Description

The research carried out in the present study aimed at determining the total mercury concentration in post-mortem human tissues in order to determine the death cause. The tissues were collected from two corpses of individuals that presumably died from inorganic mercury intoxication. Given the time gap between the intoxication moment and death, further research was carried on the biotransformation of inorganic mercury into organomercurials in resemblance to the environmental behaviour. The corpses in this study belonged to two individuals aged 39 and 77, respectively male and female. In the first individual, the intoxication was due to inorganic mercury ingestion and on the second due to dermal exposition to inorganic mercury. Total mercury quantification was determined through Cold Vapour Generation Atomic Absorption Spectrometry (CVAAS). A High Resolution Liquid Chromatographic method with UV detection (HPLCUV) was developed for methilmercury dosing. Method validation was performed taking into account analytical parameters such as linearity, precision and accuracy. For the CVAAS technique linearity was achieved through the calibration curve method. Precision was tested using a variation coefficient. Accuracy was tested using standards addition method. Accuracy was further tested using certified material, namely certified Tuna Fish standard (CRM 463) and certified Pig Kidney standard (BCR 186). The linearization study for the HPLC-UV was performed using the calibration curve method. The precision of this method was evaluated in kidney and liver digests, regarding variation coefficient. Accuracy was evaluated using standards addition method. Accuracy was also studied using certified Tuna Fish standards (CRM 463). In terms of total mercury, the results obtained for the first case samples were: liver 49,9 g/g, brain 0,33 g/g and blood 11,7 g/g. For the second case samples the following results were achieved: kidney 77,7 g/g, liver 46,6 g/g, lungs 14,6 g/g, stomach 7,12 g/g, spleen 6,40 g/g, blood 2,95 g/mL, hart 2,34 g/g, urine 1,40 g/mL and encephalon 0,21 g/g. In the first case samples the values obtained for the methilmercury were: liver 1,70 g/g, blood 0,15 g/mL. In lungs and brain the results were less than the detection limit of the method. In the second case all the results were less than the detection limit of the method. Given the obtained results it can be concluded that, for both cases, obtained total mercury values from post-morten samples were consistent with mercury intoxication dead. The results corresponding to methilmercury dosing suggest that biotransformation on the human body occurs from inorganic mercury into methilmercury.