A case of fatal methemoglobinemia of unknown origin but presumably due to ingestion of nitrate.

A case of fatal methemoglobinemia (MetHb-emia) which was presumably due to ingestion of nitrate is presented. An unidentified man was taken to a local emergency hospital suffering from deep cyanosis and 7 h later he was found dead in the hospital bed. The post-mortem examination of the blood revealed a methemoglobin (MetHb) concentration of 78% and the concentrations of nitrate and nitrite were 1.50 and 0.76 μg/mL, respectively. Capillary gas chromatography coupled to mass spectrometry (GC-MS) and capillary gas chromatography with a nitrogen-phosphorus detector (NPD) were used to detect nitrates and nitrites in the blood.