Rapid analysis of Δ8-tetrahydrocannabinol, Δ9-tetrahydrocannabinol, and cannabidiol in Δ8-tetrahydrocannabinol edibles by Ag(I) paper spray mass spectrometry after simple extraction

Δ8-Tetrahydrocannabinol (THC) products are increasingly popular despite uncertainties regarding their legality and safety. Based on the hypothesis that unique double-stage tandem mass spectrometry (MS²) and triple-stage tandem mass spectrometry (MS³) fragments would allow unambiguous identification of cannabinoids, a simple and rapid method was developed for the differentiation of Δ8-THC, Δ9-THC, and cannabidiol (CBD) within 1 min. This approach combines methanol extraction and silver(I)-impregnated paper spray mass spectrometry (AgPS-MS) for the analysis of Δ8-THC products. Extraction recovery exceeded 85 % for all three cannabinoids from Δ8-THC edibles, with acceptable matrix effects observed in both brownie and vape oil samples. The Δ9-THC:Δ8-THC ratios in acid-treated cannabidiol mixtures were quantified with results comparable to GC-FID method (0 to -11 % deviation). Analysis of commercial Δ8-THC products revealed four contained illegal Δ9-THC levels (> 0.3 %) and all contained various other THC isomers, e.g., Δ8-iso-THC, Δ(4)8-iso-THC, or Δ3-THC. This method offers a reliable solution for Δ8-THC product screening.