A new clean-up approach for stomach content toxicological analysis

Area of Science:

• Forensic Toxicology
• Analytical Chemistry

Background:

• Stomach content is a crucial matrix in post-mortem analysis, especially for oral intoxication cases.
• High analyte concentrations and lack of biotransformation are advantages, but sample preparation can be challenging due to lipid content.

Purpose of the Study:

• To develop and validate an alternative QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method for extracting drugs and pesticides from post-mortem stomach content.
• To improve sample clean-up for high-lipid matrices encountered in forensic toxicology.

Main Methods:

• Utilized QuEChERS extraction with acetonitrile and acetic acid, followed by EMR-Lipid sorbent clean-up.
• Incorporated MgSO4/NaCl and MgSO4 for water removal and final clean-up.
• Analyzed extracts using Gas Chromatography-Mass Spectrometry (GC-MS) in full scan mode.

Main Results:

• The method successfully produced clean extracts with low lipid levels from stomach content samples.
• Achieved a limit of detection of 0.1 mg/g or 0.1 mg/L for target drugs and pesticides.
• Demonstrated recovery rates over 70% for most analytes, with acceptable precision and accuracy.
• Successfully applied to real forensic cases, detecting additional compounds like carbofuran, terbuphos, and fluoxetine.

Conclusions:

• The developed QuEChERS method provides an effective clean-up strategy for lipid-rich stomach content samples.
• This approach is suitable for the reliable analysis of drugs and pesticides in forensic toxicology cases.
• The method enhances the analysis of challenging post-mortem samples, aiding in intoxication investigations.