UCT’s Clean Screen® DAU columns were used in a recently published method extracting fentanyl analogs from brain tissue
Fentanyl and its analogues have become of increasing interest to forensic toxicologists with the rise in prevalence of the compounds on the illicit drug market. They are often implicated in overdose deaths, so they have become part of routine postmortem analysis in many forensic laboratories. Brain tissue is a useful matrix for postmortem analysis as it is less prone to degradation and redistribution, however, it is a very dirty matrix and hard to source, so methods analyzing brain homogenate are lacking. The Harris County Institute of Forensic Sciences in Houston, Texas recently validated their fentanyl analogue method in brain homogenate for postmortem casework.
The method was validated for 17 synthetic opioids including 14 fentanyl analogues and 3 U-series compounds. Brain homogenate, prepared at a 1:4 dilution, was vortexed with 3 mL of phosphate buffer before centrifugation. Solid phase extraction was utilized for sample clean up. Clean Screen DAU (6 mL, 200 mg) columns were conditioned with methanol, water, and phosphate buffer before applying the buffered brain homogenate. Matrix components were then removed by washing with water, 100 mM acetic acid, and methanol. Analytes were eluted with 5% ammonium hydroxide in ethyl acetate before evaporation and reconstitution for analysis by LC-MS/MS. Using this extraction, a limit of detection of 0.5 ng/g was achieved in brain. This extraction was also used to assess stability of fentanyl analogues in stored brain homogenate. Freezing was found to preserve the integrity of several analytes for up to 90 days. Validation data and further stability data are covered in detail in the publication.
Solid phase extraction is a great sample clean-up option for toxicology samples to properly remove matrix components from even the most difficult matrices such as postmortem tissue. Proper sample clean-up is vital in postmortem analysis to remove compounds that could damage analytical columns and instruments. Clean Screen DAU is a versatile column that can extract a variety of analytes, including novel compounds such as fentanyl analogues.
Reference:
Behnke G, Skillman B, Palmquist-Orlando K, Arndt C, Gray TR. Expanding fentanyl analog testing to include brain specimens: method validation and homogenate stability assessment, Journal of Analytical Toxicology, 2025;, bkaf082, https://doi.org/10.1093/jat/bkaf082
