Relationship between the Change Rules of Volatile Organic Compounds in Rat Muscle and Postmortem Interval / 法医学杂志

Objective T o explore the relationship betw een the change rules of volatile organic com pounds (V O C s) in rat m uscle and postm ortem interval (PM I). Methods A total of 120 healthy rats w ere divided random ly into 12 groups (10 for each group). A fter the rats w ere sacrificed by cervical dislocation, the bodies w ere kept at (25±1)℃. R at m uscle sam ples w ere separately obtained at 12 PM I points, including 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 d. T he V O C s in rat m uscles w ere collected, detected and ana-lyzed by headspace solid-phase m icroextraction (H S-SPM E ) coupled to gas chrom atography-m ass spec-trom eter (G C-M S ). Results In total, 15 species of V O C s w ere identified, including 9 arom atic com-pounds, 3 sulfur com pounds, 2 aliphatic acids and 1 heterocyclic com pound. T he species of V O C s in-creased w ith PM I: no species w ere detected w ithin 1 day, 3 species w ere detected on day 2, 9 on day 3, 11 on day 4, 14 from day 5 to 7, and 15 from day 8 to 10. T otal peak area of 15 species of V O C s w as significantly correlated to PM I (adjusted R2=0.15-0.96): the regression function w as y=-17.05 x2+164.36 x-246.36 (adjusted R2=0.96) from day 2 to 5, and y=2.24 x+101.13 (adjusted R2=0.97) from day 6 to 10. Conclusion T he change rules of V O C s in rat m uscle are helpful for PM I estim ation.

Determination of Sulfide Ion in Blood from Hydrogen Sulfide Poisoning Cases / 法医学杂志

Objective T o establish a gas chrom atography-m ass spectrom etry (G C-M S ) m ethod for the determ ination of sulfide ion in blood and apply it to the practical cases. Methods T he 1, 3, 5-tribro-m obenzene w as selected as an internal standard, and 0.2 m L blood sam ple w as collected and analyzed using G C-M S after α-B rom o-2, 3, 4, 5, 6-pentafluorobenzyl brom ide derivatization. Results T he m ass concentration of sulfide ion in blood had good linearity in the range of 0.2-40μg/m L w ith a lim it of detection (L O D ) of 0.05μg/m L . T he m ass concentration of sulfide ion w as less than 0.05μg/m L in blank blood from different sources such as healthy subjects and dead cases. In 3 sulfide poisoning cases, sul-fide ion w as detected in the blood sam ples of 6 victim s, and the m ass concentration range w as 1.02-3.13μg/m L . Conclusion T his study establishes a m ethod for investigation of sulfide ion in blood w hich has been applied successfully to the cases of fatal sulfide poisonings.

Analysis of Pesticides in Blood Specimen by GC/MS with Accelerated Solvent Ex-traction / 法医学杂志

Objective To develop the accelerated solvent extraction (ASE ) for determ ining pesticides pre-sent in blood sam ples. Methods Pesticides were extracted by ASE with optimized param eters to study recovery rate affected by extraction tem perature, time and agent. GC/MS was used to perform quantita-tive analysis.Results The recovery rates of eight pesticides were 70.6%-92.4%. The coefficient of variation was less than 5.0%. Agood linear relationship was obtained at the concentration range of 0.5-5.0μg/m L . Conclusion The m ethod was fast and sim ple with high recovery rate and good repeatability. It can be applied to analyze pesticides present in the blood specimen.