Abstract: Objective To establish a gas chromatography-mass spectrometry （GC-MS） method for the determination of sulfide ion in blood and apply it to the practical cases. Methods The 1, 3, 5-tribromobenzene was selected as an internal standard, and 0.2 mL blood sample was collected and analyzed using GC-MS after α-Bromo-2, 3, 4, 5, 6-pentafluorobenzyl bromide derivatization. Results The mass concentration of sulfide ion in blood had good linearity in the range of 0.2-40 μg/mL with a limit of detection （LOD） of 0.05 μg/mL. The mass concentration of sulfide ion was less than 0.05 μg/mL in blank blood from different sources such as healthy subjects and dead cases. In 3 sulfide poisoning cases, sulfide ion was detected in the blood samples of 6 victims, and the mass concentration range was 1.02-3.13 μg/mL. Conclusion This study establishes a method for investigation of sulfide ion in blood which has been applied successfully to the cases of fatal sulfide poisonings.

Key words: forensic toxicology, poisoning, hydrogen sulfide, derivatization, gas chromatography-mass spectrometry