Innovative Approaches to the Preparation of Complex Biological Samples in the Forensic Detection of Carfentanil

This study compares two sample preparation procedures—liquid–liquid extraction using a nonpolar solvent and solid-phase extraction—for analyzing decomposed biological tissues from cadavers changed due to decomposition. The research aimed to develop a rapid and a straightforward method for sample preparation to determine carfentanil in decomposed tissue samples. A gas chromatography–mass spectrometry (GC–MS) analysis was performed using an Agilent 7820/5975 Maestro chromatograph with a Rxi-5ms mass-selective detector (Restek). For a liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis, a Shimadzu 8050 triple quadrupole mass spectrometer detector was employed. Chromatographic separation was conducted in a reversed-phase adsorbent column (Phenomenex Kinetex C18). Liver homogenates were selected as the primary research material, with lysis products derived from freezing and thawing liver tissue samples used as an alternative. Sample preparation of the homogenates was conducted by liquid–liquid extraction with heptane and solid-phase extraction. The results indicate that fluids containing lysis products offer the optimal choice for rapid and efficient sample preparation. The analytical signal of the target substances was 1.5–2 times higher in the lysis-derived samples compared to the tissue homogenates, regardless of whether solid-phase or liquid–liquid extraction methods were employed.