General unknown screening in postmortem tissue and blood samples: a semi-automatic solid-phase extraction using...

Area of Science:

• Forensic Toxicology
• Analytical Chemistry

Background:

• Identifying unknown poisons in postmortem samples presents significant challenges for forensic toxicologists.
• Existing methods may lead to loss of crucial compounds due to protein denaturation and adsorption.

Purpose of the Study:

• To develop a semi-automatic screening procedure for the identification of general unknown poisons in complex biological matrices.
• To improve the efficiency and accuracy of toxicological analysis in forensic investigations.

Main Methods:

• Utilized a semi-automatic work-up with an Automated Sample Preparation with Extraction (ASPEC) system.
• Employed non-selective polymeric sorbents (OASIS HLB, Isolute 101) for compound isolation.
• Applied colloidal solutions to sorbents to prevent protein denaturation and subsequent compound loss.
• Incorporated micellar chromatography and liquid-liquid extraction for clean fraction isolation from postmortem samples.

Main Results:

• Achieved high recoveries (72-100%) for a broad range of compounds from complex matrices including blood, liver, and brain.
• Obtained very clean sample fractions, minimizing interference from biological components.
• Demonstrated good day-to-day reproducibility with relative standard deviations ranging from 1-17%.

Conclusions:

• The developed procedure is an effective tool for forensic toxicologists to identify general unknown poisons.
• This method enhances the analysis of complex biological samples, aiding in postmortem investigations.
• The technique offers a reliable and efficient approach to toxicological screening.