Stability of carbon monoxide, methemoglobin and cyanide in blood samples from fire episode

FERRARI L., GIANNUZZI L.

Madeiras

Congreso; 51th Annual Meeting International Association of Forensic Toxicologis (TIAFT); 2013

The International Association of Forense Toxicolgy (TIAFT)

Introduction: The stability of drugs in blood is an important issue in forensic toxicology. Generally data for common drugs have already been reviewed. However, some toxic agents involved in fire, have been no enough studied and it does avoid the correct interpretation of toxicological finding. There are several issues to be taking into account in these episodes as physics-chemical property of moiety, biological samples; time elapsed between intoxication and death, death and analysis, preservation of samples, isolation methods, between others. Aim: Study the stability of carboxihemoglobin (COHb) and methemoglobin (MetHb) in blood?s victims samples of 10 cases of tragic polyurethane mattress fire which caused the deaths of 32 inmates in a prison. The stability of blood samples were analyzed at 1, 2 and 4 weeks of storage at 2ºC without preservation. In addition, hydrogen cyanide (HCN) in blood?s victims was determined at the initial storage time. Methods: The cadaveric blood samples from 10 fatal victims were gently drawn by puncturing the femoral vein and analyzed by CO-oximeter system IL80 (for tHb, MetHb, CO), microdifusion by Feldstein & Klendshoj technique reviewed by Ballantyne (for HCN) (1). Blood alcohol (ethanol) and drugs were examined by HS-GC-FID and GC-MS respectively. We have taken 1 mL of blood at one, three and four week for each victim and immediately analyzed. Results: In all cases, drug and alcohol were negatives. HCN initial levels varied between 0.36 and 15 mg/L presenting the most cases values between 8.6 mg/L. COHb initial content in the samples varied from 30-42% COHb. At the end of storage 8 cases out of 10 were stable (variation less than 10% of the original value. Only 2 out of 10 was observed a variation of the content of COHb gave an error probably upper 10% due NOx and methemoglobin generated by combustion. Methemoglobin Seems to follow and erratic behaviour. The initial value varied between 1.8-35% MetHb. During storage 8 cases out of 10 MetHb content increased from 1 to 5 times the initial value. Conclusion: These results show the stability of COHb in blood samples maintained only at 2°C and without preservation. We think that the position of body in the place of fie could explain different concentration found. Others considerations have been taking into account and it will discuss with more details.