Foi encontrado um recente artigo: “Another case of diethyl ether intoxication? A case report focusing on toxicological analysis” publicado em 2011 cujo tema aborda a utilização de álcool etílico em suicídios com saco plástico e a maneira de se detectar esse tipo de substância volátil na autópsia. Mostra a utilização de métodos de escolha em detecção de substâncias.
Abaixo estão alguns trechos importantes do artigo e que remetem ao tema de toxicologia analítica.
“Diethyl ether was widely used as an anesthetic agent in many countries in the second half of the 19th century and the first half of the 20th century. For this reason the majority of lethal cases involving diethyl ether reported during this period were associated with anesthesia. We present a case of asphyxial death by plastic-bag suffocation with additional detection of diethyl ether in autopsy specimens. Autopsy initially failed to reveal the cause of death. Macroscopic and microscopic findings as well as subsequent toxicological examination procedures and results are pointed out in the present case report. Headspace gas chromatography with flame ionization detection (HS-GC–FID) coupled with gas chromatography/mass spectrometry (GC–MS) proved to be the method of choice for fast and reliable analysis of unknown highly volatile substances (other than blood alcohol). In this case the detection of diethyl ether in autopsy specimens led to further investigations by the police at the death scene. During these investigations a bottle bearing a diethyl ether label was found and confiscated, which proved the insufficiency of prior death scene investigation.
In order to evaluate the case from every possible angle, in such cases, especially when plastic-bag suffocation is suspected, we strongly recommend the collection of postmortem specimens in gas-tight vessels as well as the presence of a forensic expert at the death scene.” (…)
Case history - A middle aged man was found dead in his bed. A plastic-bag had been pulled over his head and was loose around his neck. Body temperature was 36.5 ºC and room temperature was 29 ºC. The body was placed on the floor by the emergency personnel, as shown in Fig. 1. You will also notice a gas mask, located on the office chair, as well as a green plastic-bag (white arrows in Fig. 1) being removed from the victim’s head during resuscitation attempts. No forensic expert was present at the death scene. (…)
Screening of volatile substances in peripheral blood and urine by headspace GC–MS - Toxicological analyzes were performed with an Agilent G 1888 headspace sampler and an Agilent 6890 gas chromatograph coupled with an Agilent 5973 mass spectrometer and a flame ionization detector in parallel detection mode. (…)
Quantitative diethyl ether analysis by headspace GC–FID - Sample preparation: All the samples were defrosted, rapidly pipetted and analyzed twice: pure and spiked with diethyl ether by the standard addition procedure. In the case of pure samples, 200 µL of blood, urine, cerebrospinal fluid, stomach contents and bile samples was placed in a headspace vial and 200 µL of the internal standard tert-butanol as well as 20 µL of water were added and immediately sealed with butyl septa. An amount of 50–300 mg of solid tissue samples (lung, brain and fat) of each was rapidly weighed and transferred to the headspace vial. Internal standard as well as water were added before sealing. Sample preparation for spiked samples took place in the same way. Instead of 20 µL water, 20 µL of the standard stock solution with diethyl ether (1000 µg/mL) was used. Because of the high vapor pressure of diethyl ether, no addition of salt or further enrichment steps were necessary. Sample preparation at liquid nitrogen temperature seemed unnecessary. (…)
In the present case, autopsy only revealed uncharacteristic findings such as brain and hemorrhagic lung edema, which are often encountered as a consequence of a protracted agony phase. Neither signs of aspiration nor typical findings indicating an asphyxiation process could be seen. Finally, diethyl ether was detected in body fluids. The selected method documented above to analyze diethyl ether was adopted from Schulz et al. who validated the static headspace methodology for the analysis of low molecular substances like alcohols and congener substances.(…)
The relatively low concentrations of diethyl ether in the lung can be explained by the additional asphyxiation due to the plastic- bag as well as the resuscitation attempts. The concentration of diethyl ether in cardiac blood (237.6 mg/L) was below the concentration range published for surgical anesthesia (approx. 500– 1500 mg/L). Although the relatively low concentrations of diethyl ether in blood samples can be explained by the additional use of the plastic-bag and the resuscitation efforts made, we assumed that death was due to asphyxiation rather than intoxication. The manner of death was determined as unnatural.
After toxicological examination a diethyl ether bottle was found at the death scene, but it was not possible to state where it has been purchased by the victim. Because of the relatively high concentration of diethyl ether in the gastric contents the manner of administration was probably inhalation, followed by involuntary air deglutition. Nevertheless, oral ingestion may also be considered. Neither the plastic-bag nor the gas mask found at the death scene were examined toxicologically. The forensic relevance of the gas mask to this case still remains unclear.
Finally it can be stated that in cases where plastic-bag suffocation or the presence of volatile organic substances is suspected, we strongly recommend the collection of postmortem specimens in gas-tight vessels. The applied GC headspace MS analysis technique proved to be the method of choice for fast and reliable detection of unknown highly volatile substances (other than blood alcohol) in forensically relevant material. In such cases we strongly recommend the presence of a forensic expert at the death scene in order to evaluate the case from every possible angle.
Para visualizar o artigo complete, acesse o link a seguir: http://www.sciencedirect.com/science/article/pii/S1344622311000794
Bibliografia:
MONTICELLI, FABIO; et.al. Another case of diethyl ether intoxication? A case report focusing on toxicological analysis. Legal medicine, 2011.
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