Estimation of chlorpyrifos distribution in forensic visceral samples and body fluids using LCMS method

The ingestion of the insecticide chlorpyrifos leads to fatal intoxication in suicidal cases, and its distribution can be assessed only after post-mortem. This study attempted to investigate the distribution of chlorpyrifos in forensic visceral tissue samples like stomach, liver, kidney, heart, brain, lung, spleen, muscle and body fluids like blood and urine by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with the liquid-liquid extraction method. An analysis time of 8.77 min with 1 μl as an injection volume was chosen. The results obtained are analysed using Labsolutions insight LCMS software, considering Multiple Reaction Monitoring (MRM) and Retention Time (RT). Our findings depict that the stomach tissue has very high concentrations of chlorpyrifos, which suggests the possibility of high distribution and aspiration in the stomach tissue. The concentration of chlorpyrifos in stomach tissue ranged from 816 to 901 μg/g in male cadavers and from 443 to 612 μg/g in female cadavers. Among all the tissues, the stomach tissue showed the highest concentration, while the lowest concentration was found in muscle. Metabolic distribution of chlorpyrifos from the stomach contents to the other surrounding organs may occur and hence the concentrations of CPF were also seen in other organs like the liver, lung, kidney, brain, and muscle. These toxicological results from autopsy findings, together with LC-MS/MS indicate that stomach tissue examination gives an accurate profile of insecticide poisoning in forensic samples with acute poisoning.