Analytical investigations in a death case by suffocation in an argon atmosphere.

A 31-year-old engineer was found dead in a reaction vessel (diameter 0.8 m, height 1.8 m) of a bulb factory some minutes after he had entered it for repair work. Resuscitation attempts with artificial respiration were unsuccessful. Despite autopsy and usual toxicological analyses, no cause of death could be found. Since in the normal production process, argon was used as a protecting gas, the possibility of suffocation in an argon atmosphere was investigated. This was rendered more difficult because of the natural content of 0.93 vol.% argon in air and since the excessive argon could have been removed by the resuscitation attempts. Gas samples from larynx, esophagus, bronchi, and stomach, separated blood samples from both ventricles of the heart and from the vena iliaca externa as well as tissue samples from lung and liver were collected during autopsy into headspace vials in such a way that the loss of gas and a dilution by surrounding air was avoided as far as possible. The samples were analyzed by headspace GC-MS. The abundance of Ar+ (m/z = 40) was used for quantification with N2(2+) (m/z = 14) as internal standard. The following argon concentrations were measured (mean values, case under investigation/comparison cases): gas from larynx 1.79/0.96 vol.%, stomach gas 1.58/0.89 vol.%, heart blood (left ventricle) 7.2/2.7 microg/mL, heart blood (right ventricle) 5.8/2.7 microg/mL, blood from vena iliaca externa 3.6/2.7 microg/mL. A clearly increased concentration was also found in lung tissue, whereas in liver tissue no significant difference in comparison to other cases was measured. From the results, it follows that the deceased inhaled an increased amount of argon a short time before death. The concentrations are consistent with asphyxia and subsequent resuscitation attempts. They cannot be explained by a long-term inhalation of an atmosphere enriched with argon before the incident as it is likely to have occurred in this factory hall.