The effects of storage conditions on the stability of carbon monoxide in postmortem blood.

The stability of carbon monoxide (CO) in blood was studied under various conditions of storage using both spectrophotometric and gas chromatographic-flame ionization detector (GC-FID) methods of analysis. Changes (losses) in percent carbon monoxide saturation occurred under some conditions but not under others. Various mechanisms for CO losses are considered and one (passive diffusion of CO gas) best explains these observations. Losses of up to 60% of the original saturation occurred when blood was kept in uncapped containers at room temperature for 2 1/2 weeks or at 4 degrees C for 3 weeks. However, no changes occurred when blood was kept in tightly sealed containers for at least 4 months at either temperature.